diff --git a/googletest/include/gtest/gtest-matchers.h b/googletest/include/gtest/gtest-matchers.h
index 7711178b..5eb0a4ef 100644
--- a/googletest/include/gtest/gtest-matchers.h
+++ b/googletest/include/gtest/gtest-matchers.h
@@ -1,748 +1,750 @@
 // Copyright 2007, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // The Google C++ Testing and Mocking Framework (Google Test)
 //
 // This file implements just enough of the matcher interface to allow
 // EXPECT_DEATH and friends to accept a matcher argument.
 
 // IWYU pragma: private, include "testing/base/public/gunit.h"
 // IWYU pragma: friend third_party/googletest/googlemock/.*
 // IWYU pragma: friend third_party/googletest/googletest/.*
 
 #ifndef GTEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
 #define GTEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
 
 #include <memory>
 #include <ostream>
 #include <string>
+#include <type_traits>
 
 #include "gtest/gtest-printers.h"
 #include "gtest/internal/gtest-internal.h"
 #include "gtest/internal/gtest-port.h"
 
 // MSVC warning C5046 is new as of VS2017 version 15.8.
 #if defined(_MSC_VER) && _MSC_VER >= 1915
 #define GTEST_MAYBE_5046_ 5046
 #else
 #define GTEST_MAYBE_5046_
 #endif
 
 GTEST_DISABLE_MSC_WARNINGS_PUSH_(
     4251 GTEST_MAYBE_5046_ /* class A needs to have dll-interface to be used by
                               clients of class B */
     /* Symbol involving type with internal linkage not defined */)
 
 namespace testing {
 
 // To implement a matcher Foo for type T, define:
 //   1. a class FooMatcherImpl that implements the
 //      MatcherInterface<T> interface, and
 //   2. a factory function that creates a Matcher<T> object from a
 //      FooMatcherImpl*.
 //
 // The two-level delegation design makes it possible to allow a user
 // to write "v" instead of "Eq(v)" where a Matcher is expected, which
 // is impossible if we pass matchers by pointers.  It also eases
 // ownership management as Matcher objects can now be copied like
 // plain values.
 
 // MatchResultListener is an abstract class.  Its << operator can be
 // used by a matcher to explain why a value matches or doesn't match.
 //
 class MatchResultListener {
  public:
   // Creates a listener object with the given underlying ostream.  The
   // listener does not own the ostream, and does not dereference it
   // in the constructor or destructor.
   explicit MatchResultListener(::std::ostream* os) : stream_(os) {}
   virtual ~MatchResultListener() = 0;  // Makes this class abstract.
 
   // Streams x to the underlying ostream; does nothing if the ostream
   // is NULL.
   template <typename T>
   MatchResultListener& operator<<(const T& x) {
     if (stream_ != nullptr) *stream_ << x;
     return *this;
   }
 
   // Returns the underlying ostream.
   ::std::ostream* stream() { return stream_; }
 
   // Returns true if the listener is interested in an explanation of
   // the match result.  A matcher's MatchAndExplain() method can use
   // this information to avoid generating the explanation when no one
   // intends to hear it.
   bool IsInterested() const { return stream_ != nullptr; }
 
  private:
   ::std::ostream* const stream_;
 
   GTEST_DISALLOW_COPY_AND_ASSIGN_(MatchResultListener);
 };
 
 inline MatchResultListener::~MatchResultListener() {
 }
 
 // An instance of a subclass of this knows how to describe itself as a
 // matcher.
 class MatcherDescriberInterface {
  public:
   virtual ~MatcherDescriberInterface() {}
 
   // Describes this matcher to an ostream.  The function should print
   // a verb phrase that describes the property a value matching this
   // matcher should have.  The subject of the verb phrase is the value
   // being matched.  For example, the DescribeTo() method of the Gt(7)
   // matcher prints "is greater than 7".
   virtual void DescribeTo(::std::ostream* os) const = 0;
 
   // Describes the negation of this matcher to an ostream.  For
   // example, if the description of this matcher is "is greater than
   // 7", the negated description could be "is not greater than 7".
   // You are not required to override this when implementing
   // MatcherInterface, but it is highly advised so that your matcher
   // can produce good error messages.
   virtual void DescribeNegationTo(::std::ostream* os) const {
     *os << "not (";
     DescribeTo(os);
     *os << ")";
   }
 };
 
 // The implementation of a matcher.
 template <typename T>
 class MatcherInterface : public MatcherDescriberInterface {
  public:
   // Returns true if the matcher matches x; also explains the match
   // result to 'listener' if necessary (see the next paragraph), in
   // the form of a non-restrictive relative clause ("which ...",
   // "whose ...", etc) that describes x.  For example, the
   // MatchAndExplain() method of the Pointee(...) matcher should
   // generate an explanation like "which points to ...".
   //
   // Implementations of MatchAndExplain() should add an explanation of
   // the match result *if and only if* they can provide additional
   // information that's not already present (or not obvious) in the
   // print-out of x and the matcher's description.  Whether the match
   // succeeds is not a factor in deciding whether an explanation is
   // needed, as sometimes the caller needs to print a failure message
   // when the match succeeds (e.g. when the matcher is used inside
   // Not()).
   //
   // For example, a "has at least 10 elements" matcher should explain
   // what the actual element count is, regardless of the match result,
   // as it is useful information to the reader; on the other hand, an
   // "is empty" matcher probably only needs to explain what the actual
   // size is when the match fails, as it's redundant to say that the
   // size is 0 when the value is already known to be empty.
   //
   // You should override this method when defining a new matcher.
   //
   // It's the responsibility of the caller (Google Test) to guarantee
   // that 'listener' is not NULL.  This helps to simplify a matcher's
   // implementation when it doesn't care about the performance, as it
   // can talk to 'listener' without checking its validity first.
   // However, in order to implement dummy listeners efficiently,
   // listener->stream() may be NULL.
   virtual bool MatchAndExplain(T x, MatchResultListener* listener) const = 0;
 
   // Inherits these methods from MatcherDescriberInterface:
   //   virtual void DescribeTo(::std::ostream* os) const = 0;
   //   virtual void DescribeNegationTo(::std::ostream* os) const;
 };
 
 namespace internal {
 
 // Converts a MatcherInterface<T> to a MatcherInterface<const T&>.
 template <typename T>
 class MatcherInterfaceAdapter : public MatcherInterface<const T&> {
  public:
   explicit MatcherInterfaceAdapter(const MatcherInterface<T>* impl)
       : impl_(impl) {}
   ~MatcherInterfaceAdapter() override { delete impl_; }
 
   void DescribeTo(::std::ostream* os) const override { impl_->DescribeTo(os); }
 
   void DescribeNegationTo(::std::ostream* os) const override {
     impl_->DescribeNegationTo(os);
   }
 
   bool MatchAndExplain(const T& x,
                        MatchResultListener* listener) const override {
     return impl_->MatchAndExplain(x, listener);
   }
 
  private:
   const MatcherInterface<T>* const impl_;
 
   GTEST_DISALLOW_COPY_AND_ASSIGN_(MatcherInterfaceAdapter);
 };
 
 struct AnyEq {
   template <typename A, typename B>
   bool operator()(const A& a, const B& b) const { return a == b; }
 };
 struct AnyNe {
   template <typename A, typename B>
   bool operator()(const A& a, const B& b) const { return a != b; }
 };
 struct AnyLt {
   template <typename A, typename B>
   bool operator()(const A& a, const B& b) const { return a < b; }
 };
 struct AnyGt {
   template <typename A, typename B>
   bool operator()(const A& a, const B& b) const { return a > b; }
 };
 struct AnyLe {
   template <typename A, typename B>
   bool operator()(const A& a, const B& b) const { return a <= b; }
 };
 struct AnyGe {
   template <typename A, typename B>
   bool operator()(const A& a, const B& b) const { return a >= b; }
 };
 
 // A match result listener that ignores the explanation.
 class DummyMatchResultListener : public MatchResultListener {
  public:
   DummyMatchResultListener() : MatchResultListener(nullptr) {}
 
  private:
   GTEST_DISALLOW_COPY_AND_ASSIGN_(DummyMatchResultListener);
 };
 
 // A match result listener that forwards the explanation to a given
 // ostream.  The difference between this and MatchResultListener is
 // that the former is concrete.
 class StreamMatchResultListener : public MatchResultListener {
  public:
   explicit StreamMatchResultListener(::std::ostream* os)
       : MatchResultListener(os) {}
 
  private:
   GTEST_DISALLOW_COPY_AND_ASSIGN_(StreamMatchResultListener);
 };
 
 // An internal class for implementing Matcher<T>, which will derive
 // from it.  We put functionalities common to all Matcher<T>
 // specializations here to avoid code duplication.
 template <typename T>
 class MatcherBase {
  public:
   // Returns true if the matcher matches x; also explains the match
   // result to 'listener'.
   bool MatchAndExplain(const T& x, MatchResultListener* listener) const {
     return impl_->MatchAndExplain(x, listener);
   }
 
   // Returns true if this matcher matches x.
   bool Matches(const T& x) const {
     DummyMatchResultListener dummy;
     return MatchAndExplain(x, &dummy);
   }
 
   // Describes this matcher to an ostream.
   void DescribeTo(::std::ostream* os) const { impl_->DescribeTo(os); }
 
   // Describes the negation of this matcher to an ostream.
   void DescribeNegationTo(::std::ostream* os) const {
     impl_->DescribeNegationTo(os);
   }
 
   // Explains why x matches, or doesn't match, the matcher.
   void ExplainMatchResultTo(const T& x, ::std::ostream* os) const {
     StreamMatchResultListener listener(os);
     MatchAndExplain(x, &listener);
   }
 
   // Returns the describer for this matcher object; retains ownership
   // of the describer, which is only guaranteed to be alive when
   // this matcher object is alive.
   const MatcherDescriberInterface* GetDescriber() const {
     return impl_.get();
   }
 
  protected:
   MatcherBase() {}
 
   // Constructs a matcher from its implementation.
   explicit MatcherBase(const MatcherInterface<const T&>* impl) : impl_(impl) {}
 
   template <typename U>
   explicit MatcherBase(
       const MatcherInterface<U>* impl,
-      typename internal::EnableIf<
-          !internal::IsSame<U, const U&>::value>::type* = nullptr)
+      typename std::enable_if<!internal::IsSame<U, const U&>::value>::type* =
+          nullptr)
       : impl_(new internal::MatcherInterfaceAdapter<U>(impl)) {}
 
   MatcherBase(const MatcherBase&) = default;
   MatcherBase& operator=(const MatcherBase&) = default;
   MatcherBase(MatcherBase&&) = default;
   MatcherBase& operator=(MatcherBase&&) = default;
 
   virtual ~MatcherBase() {}
 
  private:
   std::shared_ptr<const MatcherInterface<const T&>> impl_;
 };
 
 }  // namespace internal
 
 // A Matcher<T> is a copyable and IMMUTABLE (except by assignment)
 // object that can check whether a value of type T matches.  The
 // implementation of Matcher<T> is just a std::shared_ptr to const
 // MatcherInterface<T>.  Don't inherit from Matcher!
 template <typename T>
 class Matcher : public internal::MatcherBase<T> {
  public:
   // Constructs a null matcher.  Needed for storing Matcher objects in STL
   // containers.  A default-constructed matcher is not yet initialized.  You
   // cannot use it until a valid value has been assigned to it.
   explicit Matcher() {}  // NOLINT
 
   // Constructs a matcher from its implementation.
   explicit Matcher(const MatcherInterface<const T&>* impl)
       : internal::MatcherBase<T>(impl) {}
 
   template <typename U>
-  explicit Matcher(const MatcherInterface<U>* impl,
-                   typename internal::EnableIf<
-                       !internal::IsSame<U, const U&>::value>::type* = nullptr)
+  explicit Matcher(
+      const MatcherInterface<U>* impl,
+      typename std::enable_if<!internal::IsSame<U, const U&>::value>::type* =
+          nullptr)
       : internal::MatcherBase<T>(impl) {}
 
   // Implicit constructor here allows people to write
   // EXPECT_CALL(foo, Bar(5)) instead of EXPECT_CALL(foo, Bar(Eq(5))) sometimes
   Matcher(T value);  // NOLINT
 };
 
 // The following two specializations allow the user to write str
 // instead of Eq(str) and "foo" instead of Eq("foo") when a std::string
 // matcher is expected.
 template <>
 class GTEST_API_ Matcher<const std::string&>
     : public internal::MatcherBase<const std::string&> {
  public:
   Matcher() {}
 
   explicit Matcher(const MatcherInterface<const std::string&>* impl)
       : internal::MatcherBase<const std::string&>(impl) {}
 
   // Allows the user to write str instead of Eq(str) sometimes, where
   // str is a std::string object.
   Matcher(const std::string& s);  // NOLINT
 
   // Allows the user to write "foo" instead of Eq("foo") sometimes.
   Matcher(const char* s);  // NOLINT
 };
 
 template <>
 class GTEST_API_ Matcher<std::string>
     : public internal::MatcherBase<std::string> {
  public:
   Matcher() {}
 
   explicit Matcher(const MatcherInterface<const std::string&>* impl)
       : internal::MatcherBase<std::string>(impl) {}
   explicit Matcher(const MatcherInterface<std::string>* impl)
       : internal::MatcherBase<std::string>(impl) {}
 
   // Allows the user to write str instead of Eq(str) sometimes, where
   // str is a string object.
   Matcher(const std::string& s);  // NOLINT
 
   // Allows the user to write "foo" instead of Eq("foo") sometimes.
   Matcher(const char* s);  // NOLINT
 };
 
 #if GTEST_HAS_ABSL
 // The following two specializations allow the user to write str
 // instead of Eq(str) and "foo" instead of Eq("foo") when a absl::string_view
 // matcher is expected.
 template <>
 class GTEST_API_ Matcher<const absl::string_view&>
     : public internal::MatcherBase<const absl::string_view&> {
  public:
   Matcher() {}
 
   explicit Matcher(const MatcherInterface<const absl::string_view&>* impl)
       : internal::MatcherBase<const absl::string_view&>(impl) {}
 
   // Allows the user to write str instead of Eq(str) sometimes, where
   // str is a std::string object.
   Matcher(const std::string& s);  // NOLINT
 
   // Allows the user to write "foo" instead of Eq("foo") sometimes.
   Matcher(const char* s);  // NOLINT
 
   // Allows the user to pass absl::string_views directly.
   Matcher(absl::string_view s);  // NOLINT
 };
 
 template <>
 class GTEST_API_ Matcher<absl::string_view>
     : public internal::MatcherBase<absl::string_view> {
  public:
   Matcher() {}
 
   explicit Matcher(const MatcherInterface<const absl::string_view&>* impl)
       : internal::MatcherBase<absl::string_view>(impl) {}
   explicit Matcher(const MatcherInterface<absl::string_view>* impl)
       : internal::MatcherBase<absl::string_view>(impl) {}
 
   // Allows the user to write str instead of Eq(str) sometimes, where
   // str is a std::string object.
   Matcher(const std::string& s);  // NOLINT
 
   // Allows the user to write "foo" instead of Eq("foo") sometimes.
   Matcher(const char* s);  // NOLINT
 
   // Allows the user to pass absl::string_views directly.
   Matcher(absl::string_view s);  // NOLINT
 };
 #endif  // GTEST_HAS_ABSL
 
 // Prints a matcher in a human-readable format.
 template <typename T>
 std::ostream& operator<<(std::ostream& os, const Matcher<T>& matcher) {
   matcher.DescribeTo(&os);
   return os;
 }
 
 // The PolymorphicMatcher class template makes it easy to implement a
 // polymorphic matcher (i.e. a matcher that can match values of more
 // than one type, e.g. Eq(n) and NotNull()).
 //
 // To define a polymorphic matcher, a user should provide an Impl
 // class that has a DescribeTo() method and a DescribeNegationTo()
 // method, and define a member function (or member function template)
 //
 //   bool MatchAndExplain(const Value& value,
 //                        MatchResultListener* listener) const;
 //
 // See the definition of NotNull() for a complete example.
 template <class Impl>
 class PolymorphicMatcher {
  public:
   explicit PolymorphicMatcher(const Impl& an_impl) : impl_(an_impl) {}
 
   // Returns a mutable reference to the underlying matcher
   // implementation object.
   Impl& mutable_impl() { return impl_; }
 
   // Returns an immutable reference to the underlying matcher
   // implementation object.
   const Impl& impl() const { return impl_; }
 
   template <typename T>
   operator Matcher<T>() const {
     return Matcher<T>(new MonomorphicImpl<const T&>(impl_));
   }
 
  private:
   template <typename T>
   class MonomorphicImpl : public MatcherInterface<T> {
    public:
     explicit MonomorphicImpl(const Impl& impl) : impl_(impl) {}
 
     virtual void DescribeTo(::std::ostream* os) const { impl_.DescribeTo(os); }
 
     virtual void DescribeNegationTo(::std::ostream* os) const {
       impl_.DescribeNegationTo(os);
     }
 
     virtual bool MatchAndExplain(T x, MatchResultListener* listener) const {
       return impl_.MatchAndExplain(x, listener);
     }
 
    private:
     const Impl impl_;
   };
 
   Impl impl_;
 };
 
 // Creates a matcher from its implementation.
 // DEPRECATED: Especially in the generic code, prefer:
 //   Matcher<T>(new MyMatcherImpl<const T&>(...));
 //
 // MakeMatcher may create a Matcher that accepts its argument by value, which
 // leads to unnecessary copies & lack of support for non-copyable types.
 template <typename T>
 inline Matcher<T> MakeMatcher(const MatcherInterface<T>* impl) {
   return Matcher<T>(impl);
 }
 
 // Creates a polymorphic matcher from its implementation.  This is
 // easier to use than the PolymorphicMatcher<Impl> constructor as it
 // doesn't require you to explicitly write the template argument, e.g.
 //
 //   MakePolymorphicMatcher(foo);
 // vs
 //   PolymorphicMatcher<TypeOfFoo>(foo);
 template <class Impl>
 inline PolymorphicMatcher<Impl> MakePolymorphicMatcher(const Impl& impl) {
   return PolymorphicMatcher<Impl>(impl);
 }
 
 namespace internal {
 // Implements a matcher that compares a given value with a
 // pre-supplied value using one of the ==, <=, <, etc, operators.  The
 // two values being compared don't have to have the same type.
 //
 // The matcher defined here is polymorphic (for example, Eq(5) can be
 // used to match an int, a short, a double, etc).  Therefore we use
 // a template type conversion operator in the implementation.
 //
 // The following template definition assumes that the Rhs parameter is
 // a "bare" type (i.e. neither 'const T' nor 'T&').
 template <typename D, typename Rhs, typename Op>
 class ComparisonBase {
  public:
   explicit ComparisonBase(const Rhs& rhs) : rhs_(rhs) {}
   template <typename Lhs>
   operator Matcher<Lhs>() const {
     return Matcher<Lhs>(new Impl<const Lhs&>(rhs_));
   }
 
  private:
   template <typename T>
   static const T& Unwrap(const T& v) { return v; }
   template <typename T>
   static const T& Unwrap(std::reference_wrapper<T> v) { return v; }
 
   template <typename Lhs, typename = Rhs>
   class Impl : public MatcherInterface<Lhs> {
    public:
     explicit Impl(const Rhs& rhs) : rhs_(rhs) {}
     bool MatchAndExplain(Lhs lhs,
                          MatchResultListener* /* listener */) const override {
       return Op()(lhs, Unwrap(rhs_));
     }
     void DescribeTo(::std::ostream* os) const override {
       *os << D::Desc() << " ";
       UniversalPrint(Unwrap(rhs_), os);
     }
     void DescribeNegationTo(::std::ostream* os) const override {
       *os << D::NegatedDesc() <<  " ";
       UniversalPrint(Unwrap(rhs_), os);
     }
 
    private:
     Rhs rhs_;
   };
   Rhs rhs_;
 };
 
 template <typename Rhs>
 class EqMatcher : public ComparisonBase<EqMatcher<Rhs>, Rhs, AnyEq> {
  public:
   explicit EqMatcher(const Rhs& rhs)
       : ComparisonBase<EqMatcher<Rhs>, Rhs, AnyEq>(rhs) { }
   static const char* Desc() { return "is equal to"; }
   static const char* NegatedDesc() { return "isn't equal to"; }
 };
 template <typename Rhs>
 class NeMatcher : public ComparisonBase<NeMatcher<Rhs>, Rhs, AnyNe> {
  public:
   explicit NeMatcher(const Rhs& rhs)
       : ComparisonBase<NeMatcher<Rhs>, Rhs, AnyNe>(rhs) { }
   static const char* Desc() { return "isn't equal to"; }
   static const char* NegatedDesc() { return "is equal to"; }
 };
 template <typename Rhs>
 class LtMatcher : public ComparisonBase<LtMatcher<Rhs>, Rhs, AnyLt> {
  public:
   explicit LtMatcher(const Rhs& rhs)
       : ComparisonBase<LtMatcher<Rhs>, Rhs, AnyLt>(rhs) { }
   static const char* Desc() { return "is <"; }
   static const char* NegatedDesc() { return "isn't <"; }
 };
 template <typename Rhs>
 class GtMatcher : public ComparisonBase<GtMatcher<Rhs>, Rhs, AnyGt> {
  public:
   explicit GtMatcher(const Rhs& rhs)
       : ComparisonBase<GtMatcher<Rhs>, Rhs, AnyGt>(rhs) { }
   static const char* Desc() { return "is >"; }
   static const char* NegatedDesc() { return "isn't >"; }
 };
 template <typename Rhs>
 class LeMatcher : public ComparisonBase<LeMatcher<Rhs>, Rhs, AnyLe> {
  public:
   explicit LeMatcher(const Rhs& rhs)
       : ComparisonBase<LeMatcher<Rhs>, Rhs, AnyLe>(rhs) { }
   static const char* Desc() { return "is <="; }
   static const char* NegatedDesc() { return "isn't <="; }
 };
 template <typename Rhs>
 class GeMatcher : public ComparisonBase<GeMatcher<Rhs>, Rhs, AnyGe> {
  public:
   explicit GeMatcher(const Rhs& rhs)
       : ComparisonBase<GeMatcher<Rhs>, Rhs, AnyGe>(rhs) { }
   static const char* Desc() { return "is >="; }
   static const char* NegatedDesc() { return "isn't >="; }
 };
 
 // Implements polymorphic matchers MatchesRegex(regex) and
 // ContainsRegex(regex), which can be used as a Matcher<T> as long as
 // T can be converted to a string.
 class MatchesRegexMatcher {
  public:
   MatchesRegexMatcher(const RE* regex, bool full_match)
       : regex_(regex), full_match_(full_match) {}
 
 #if GTEST_HAS_ABSL
   bool MatchAndExplain(const absl::string_view& s,
                        MatchResultListener* listener) const {
     return MatchAndExplain(std::string(s), listener);
   }
 #endif  // GTEST_HAS_ABSL
 
   // Accepts pointer types, particularly:
   //   const char*
   //   char*
   //   const wchar_t*
   //   wchar_t*
   template <typename CharType>
   bool MatchAndExplain(CharType* s, MatchResultListener* listener) const {
     return s != nullptr && MatchAndExplain(std::string(s), listener);
   }
 
   // Matches anything that can convert to std::string.
   //
   // This is a template, not just a plain function with const std::string&,
   // because absl::string_view has some interfering non-explicit constructors.
   template <class MatcheeStringType>
   bool MatchAndExplain(const MatcheeStringType& s,
                        MatchResultListener* /* listener */) const {
     const std::string& s2(s);
     return full_match_ ? RE::FullMatch(s2, *regex_)
                        : RE::PartialMatch(s2, *regex_);
   }
 
   void DescribeTo(::std::ostream* os) const {
     *os << (full_match_ ? "matches" : "contains") << " regular expression ";
     UniversalPrinter<std::string>::Print(regex_->pattern(), os);
   }
 
   void DescribeNegationTo(::std::ostream* os) const {
     *os << "doesn't " << (full_match_ ? "match" : "contain")
         << " regular expression ";
     UniversalPrinter<std::string>::Print(regex_->pattern(), os);
   }
 
  private:
   const std::shared_ptr<const RE> regex_;
   const bool full_match_;
 };
 }  // namespace internal
 
 // Matches a string that fully matches regular expression 'regex'.
 // The matcher takes ownership of 'regex'.
 inline PolymorphicMatcher<internal::MatchesRegexMatcher> MatchesRegex(
     const internal::RE* regex) {
   return MakePolymorphicMatcher(internal::MatchesRegexMatcher(regex, true));
 }
 inline PolymorphicMatcher<internal::MatchesRegexMatcher> MatchesRegex(
     const std::string& regex) {
   return MatchesRegex(new internal::RE(regex));
 }
 
 // Matches a string that contains regular expression 'regex'.
 // The matcher takes ownership of 'regex'.
 inline PolymorphicMatcher<internal::MatchesRegexMatcher> ContainsRegex(
     const internal::RE* regex) {
   return MakePolymorphicMatcher(internal::MatchesRegexMatcher(regex, false));
 }
 inline PolymorphicMatcher<internal::MatchesRegexMatcher> ContainsRegex(
     const std::string& regex) {
   return ContainsRegex(new internal::RE(regex));
 }
 
 // Creates a polymorphic matcher that matches anything equal to x.
 // Note: if the parameter of Eq() were declared as const T&, Eq("foo")
 // wouldn't compile.
 template <typename T>
 inline internal::EqMatcher<T> Eq(T x) { return internal::EqMatcher<T>(x); }
 
 // Constructs a Matcher<T> from a 'value' of type T.  The constructed
 // matcher matches any value that's equal to 'value'.
 template <typename T>
 Matcher<T>::Matcher(T value) { *this = Eq(value); }
 
 // Creates a monomorphic matcher that matches anything with type Lhs
 // and equal to rhs.  A user may need to use this instead of Eq(...)
 // in order to resolve an overloading ambiguity.
 //
 // TypedEq<T>(x) is just a convenient short-hand for Matcher<T>(Eq(x))
 // or Matcher<T>(x), but more readable than the latter.
 //
 // We could define similar monomorphic matchers for other comparison
 // operations (e.g. TypedLt, TypedGe, and etc), but decided not to do
 // it yet as those are used much less than Eq() in practice.  A user
 // can always write Matcher<T>(Lt(5)) to be explicit about the type,
 // for example.
 template <typename Lhs, typename Rhs>
 inline Matcher<Lhs> TypedEq(const Rhs& rhs) { return Eq(rhs); }
 
 // Creates a polymorphic matcher that matches anything >= x.
 template <typename Rhs>
 inline internal::GeMatcher<Rhs> Ge(Rhs x) {
   return internal::GeMatcher<Rhs>(x);
 }
 
 // Creates a polymorphic matcher that matches anything > x.
 template <typename Rhs>
 inline internal::GtMatcher<Rhs> Gt(Rhs x) {
   return internal::GtMatcher<Rhs>(x);
 }
 
 // Creates a polymorphic matcher that matches anything <= x.
 template <typename Rhs>
 inline internal::LeMatcher<Rhs> Le(Rhs x) {
   return internal::LeMatcher<Rhs>(x);
 }
 
 // Creates a polymorphic matcher that matches anything < x.
 template <typename Rhs>
 inline internal::LtMatcher<Rhs> Lt(Rhs x) {
   return internal::LtMatcher<Rhs>(x);
 }
 
 // Creates a polymorphic matcher that matches anything != x.
 template <typename Rhs>
 inline internal::NeMatcher<Rhs> Ne(Rhs x) {
   return internal::NeMatcher<Rhs>(x);
 }
 }  // namespace testing
 
 GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251 5046
 
 #endif  // GTEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
diff --git a/googletest/include/gtest/gtest.h b/googletest/include/gtest/gtest.h
index db81359d..dfe7c786 100644
--- a/googletest/include/gtest/gtest.h
+++ b/googletest/include/gtest/gtest.h
@@ -1,2477 +1,2477 @@
 // Copyright 2005, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 //
 // The Google C++ Testing and Mocking Framework (Google Test)
 //
 // This header file defines the public API for Google Test.  It should be
 // included by any test program that uses Google Test.
 //
 // IMPORTANT NOTE: Due to limitation of the C++ language, we have to
 // leave some internal implementation details in this header file.
 // They are clearly marked by comments like this:
 //
 //   // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
 //
 // Such code is NOT meant to be used by a user directly, and is subject
 // to CHANGE WITHOUT NOTICE.  Therefore DO NOT DEPEND ON IT in a user
 // program!
 //
 // Acknowledgment: Google Test borrowed the idea of automatic test
 // registration from Barthelemy Dagenais' (barthelemy@prologique.com)
 // easyUnit framework.
 
 // GOOGLETEST_CM0001 DO NOT DELETE
 
 #ifndef GTEST_INCLUDE_GTEST_GTEST_H_
 #define GTEST_INCLUDE_GTEST_GTEST_H_
 
 #include <cstddef>
 #include <limits>
 #include <memory>
 #include <ostream>
 #include <type_traits>
 #include <vector>
 
 #include "gtest/internal/gtest-internal.h"
 #include "gtest/internal/gtest-string.h"
 #include "gtest/gtest-death-test.h"
 #include "gtest/gtest-matchers.h"
 #include "gtest/gtest-message.h"
 #include "gtest/gtest-param-test.h"
 #include "gtest/gtest-printers.h"
 #include "gtest/gtest_prod.h"
 #include "gtest/gtest-test-part.h"
 #include "gtest/gtest-typed-test.h"
 
 GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
 /* class A needs to have dll-interface to be used by clients of class B */)
 
 namespace testing {
 
 // Silence C4100 (unreferenced formal parameter) and 4805
 // unsafe mix of type 'const int' and type 'const bool'
 #ifdef _MSC_VER
 # pragma warning(push)
 # pragma warning(disable:4805)
 # pragma warning(disable:4100)
 #endif
 
 
 // Declares the flags.
 
 // This flag temporary enables the disabled tests.
 GTEST_DECLARE_bool_(also_run_disabled_tests);
 
 // This flag brings the debugger on an assertion failure.
 GTEST_DECLARE_bool_(break_on_failure);
 
 // This flag controls whether Google Test catches all test-thrown exceptions
 // and logs them as failures.
 GTEST_DECLARE_bool_(catch_exceptions);
 
 // This flag enables using colors in terminal output. Available values are
 // "yes" to enable colors, "no" (disable colors), or "auto" (the default)
 // to let Google Test decide.
 GTEST_DECLARE_string_(color);
 
 // This flag sets up the filter to select by name using a glob pattern
 // the tests to run. If the filter is not given all tests are executed.
 GTEST_DECLARE_string_(filter);
 
 // This flag controls whether Google Test installs a signal handler that dumps
 // debugging information when fatal signals are raised.
 GTEST_DECLARE_bool_(install_failure_signal_handler);
 
 // This flag causes the Google Test to list tests. None of the tests listed
 // are actually run if the flag is provided.
 GTEST_DECLARE_bool_(list_tests);
 
 // This flag controls whether Google Test emits a detailed XML report to a file
 // in addition to its normal textual output.
 GTEST_DECLARE_string_(output);
 
 // This flags control whether Google Test prints the elapsed time for each
 // test.
 GTEST_DECLARE_bool_(print_time);
 
 // This flags control whether Google Test prints UTF8 characters as text.
 GTEST_DECLARE_bool_(print_utf8);
 
 // This flag specifies the random number seed.
 GTEST_DECLARE_int32_(random_seed);
 
 // This flag sets how many times the tests are repeated. The default value
 // is 1. If the value is -1 the tests are repeating forever.
 GTEST_DECLARE_int32_(repeat);
 
 // This flag controls whether Google Test includes Google Test internal
 // stack frames in failure stack traces.
 GTEST_DECLARE_bool_(show_internal_stack_frames);
 
 // When this flag is specified, tests' order is randomized on every iteration.
 GTEST_DECLARE_bool_(shuffle);
 
 // This flag specifies the maximum number of stack frames to be
 // printed in a failure message.
 GTEST_DECLARE_int32_(stack_trace_depth);
 
 // When this flag is specified, a failed assertion will throw an
 // exception if exceptions are enabled, or exit the program with a
 // non-zero code otherwise. For use with an external test framework.
 GTEST_DECLARE_bool_(throw_on_failure);
 
 // When this flag is set with a "host:port" string, on supported
 // platforms test results are streamed to the specified port on
 // the specified host machine.
 GTEST_DECLARE_string_(stream_result_to);
 
 #if GTEST_USE_OWN_FLAGFILE_FLAG_
 GTEST_DECLARE_string_(flagfile);
 #endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
 
 // The upper limit for valid stack trace depths.
 const int kMaxStackTraceDepth = 100;
 
 namespace internal {
 
 class AssertHelper;
 class DefaultGlobalTestPartResultReporter;
 class ExecDeathTest;
 class NoExecDeathTest;
 class FinalSuccessChecker;
 class GTestFlagSaver;
 class StreamingListenerTest;
 class TestResultAccessor;
 class TestEventListenersAccessor;
 class TestEventRepeater;
 class UnitTestRecordPropertyTestHelper;
 class WindowsDeathTest;
 class FuchsiaDeathTest;
 class UnitTestImpl* GetUnitTestImpl();
 void ReportFailureInUnknownLocation(TestPartResult::Type result_type,
                                     const std::string& message);
 
 }  // namespace internal
 
 // The friend relationship of some of these classes is cyclic.
 // If we don't forward declare them the compiler might confuse the classes
 // in friendship clauses with same named classes on the scope.
 class Test;
 class TestSuite;
 
 // Old API is still available but deprecated
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 using TestCase = TestSuite;
 #endif
 class TestInfo;
 class UnitTest;
 
 // A class for indicating whether an assertion was successful.  When
 // the assertion wasn't successful, the AssertionResult object
 // remembers a non-empty message that describes how it failed.
 //
 // To create an instance of this class, use one of the factory functions
 // (AssertionSuccess() and AssertionFailure()).
 //
 // This class is useful for two purposes:
 //   1. Defining predicate functions to be used with Boolean test assertions
 //      EXPECT_TRUE/EXPECT_FALSE and their ASSERT_ counterparts
 //   2. Defining predicate-format functions to be
 //      used with predicate assertions (ASSERT_PRED_FORMAT*, etc).
 //
 // For example, if you define IsEven predicate:
 //
 //   testing::AssertionResult IsEven(int n) {
 //     if ((n % 2) == 0)
 //       return testing::AssertionSuccess();
 //     else
 //       return testing::AssertionFailure() << n << " is odd";
 //   }
 //
 // Then the failed expectation EXPECT_TRUE(IsEven(Fib(5)))
 // will print the message
 //
 //   Value of: IsEven(Fib(5))
 //     Actual: false (5 is odd)
 //   Expected: true
 //
 // instead of a more opaque
 //
 //   Value of: IsEven(Fib(5))
 //     Actual: false
 //   Expected: true
 //
 // in case IsEven is a simple Boolean predicate.
 //
 // If you expect your predicate to be reused and want to support informative
 // messages in EXPECT_FALSE and ASSERT_FALSE (negative assertions show up
 // about half as often as positive ones in our tests), supply messages for
 // both success and failure cases:
 //
 //   testing::AssertionResult IsEven(int n) {
 //     if ((n % 2) == 0)
 //       return testing::AssertionSuccess() << n << " is even";
 //     else
 //       return testing::AssertionFailure() << n << " is odd";
 //   }
 //
 // Then a statement EXPECT_FALSE(IsEven(Fib(6))) will print
 //
 //   Value of: IsEven(Fib(6))
 //     Actual: true (8 is even)
 //   Expected: false
 //
 // NB: Predicates that support negative Boolean assertions have reduced
 // performance in positive ones so be careful not to use them in tests
 // that have lots (tens of thousands) of positive Boolean assertions.
 //
 // To use this class with EXPECT_PRED_FORMAT assertions such as:
 //
 //   // Verifies that Foo() returns an even number.
 //   EXPECT_PRED_FORMAT1(IsEven, Foo());
 //
 // you need to define:
 //
 //   testing::AssertionResult IsEven(const char* expr, int n) {
 //     if ((n % 2) == 0)
 //       return testing::AssertionSuccess();
 //     else
 //       return testing::AssertionFailure()
 //         << "Expected: " << expr << " is even\n  Actual: it's " << n;
 //   }
 //
 // If Foo() returns 5, you will see the following message:
 //
 //   Expected: Foo() is even
 //     Actual: it's 5
 //
 class GTEST_API_ AssertionResult {
  public:
   // Copy constructor.
   // Used in EXPECT_TRUE/FALSE(assertion_result).
   AssertionResult(const AssertionResult& other);
 
 #if defined(_MSC_VER) && _MSC_VER < 1910
   GTEST_DISABLE_MSC_WARNINGS_PUSH_(4800 /* forcing value to bool */)
 #endif
 
   // Used in the EXPECT_TRUE/FALSE(bool_expression).
   //
   // T must be contextually convertible to bool.
   //
   // The second parameter prevents this overload from being considered if
   // the argument is implicitly convertible to AssertionResult. In that case
   // we want AssertionResult's copy constructor to be used.
   template <typename T>
   explicit AssertionResult(
       const T& success,
-      typename internal::EnableIf<
+      typename std::enable_if<
           !std::is_convertible<T, AssertionResult>::value>::type*
       /*enabler*/
       = nullptr)
       : success_(success) {}
 
 #if defined(_MSC_VER) && _MSC_VER < 1910
   GTEST_DISABLE_MSC_WARNINGS_POP_()
 #endif
 
   // Assignment operator.
   AssertionResult& operator=(AssertionResult other) {
     swap(other);
     return *this;
   }
 
   // Returns true if the assertion succeeded.
   operator bool() const { return success_; }  // NOLINT
 
   // Returns the assertion's negation. Used with EXPECT/ASSERT_FALSE.
   AssertionResult operator!() const;
 
   // Returns the text streamed into this AssertionResult. Test assertions
   // use it when they fail (i.e., the predicate's outcome doesn't match the
   // assertion's expectation). When nothing has been streamed into the
   // object, returns an empty string.
   const char* message() const {
     return message_.get() != nullptr ? message_->c_str() : "";
   }
   // Deprecated; please use message() instead.
   const char* failure_message() const { return message(); }
 
   // Streams a custom failure message into this object.
   template <typename T> AssertionResult& operator<<(const T& value) {
     AppendMessage(Message() << value);
     return *this;
   }
 
   // Allows streaming basic output manipulators such as endl or flush into
   // this object.
   AssertionResult& operator<<(
       ::std::ostream& (*basic_manipulator)(::std::ostream& stream)) {
     AppendMessage(Message() << basic_manipulator);
     return *this;
   }
 
  private:
   // Appends the contents of message to message_.
   void AppendMessage(const Message& a_message) {
     if (message_.get() == nullptr) message_.reset(new ::std::string);
     message_->append(a_message.GetString().c_str());
   }
 
   // Swap the contents of this AssertionResult with other.
   void swap(AssertionResult& other);
 
   // Stores result of the assertion predicate.
   bool success_;
   // Stores the message describing the condition in case the expectation
   // construct is not satisfied with the predicate's outcome.
   // Referenced via a pointer to avoid taking too much stack frame space
   // with test assertions.
   std::unique_ptr< ::std::string> message_;
 };
 
 // Makes a successful assertion result.
 GTEST_API_ AssertionResult AssertionSuccess();
 
 // Makes a failed assertion result.
 GTEST_API_ AssertionResult AssertionFailure();
 
 // Makes a failed assertion result with the given failure message.
 // Deprecated; use AssertionFailure() << msg.
 GTEST_API_ AssertionResult AssertionFailure(const Message& msg);
 
 }  // namespace testing
 
 // Includes the auto-generated header that implements a family of generic
 // predicate assertion macros. This include comes late because it relies on
 // APIs declared above.
 #include "gtest/gtest_pred_impl.h"
 
 namespace testing {
 
 // The abstract class that all tests inherit from.
 //
 // In Google Test, a unit test program contains one or many TestSuites, and
 // each TestSuite contains one or many Tests.
 //
 // When you define a test using the TEST macro, you don't need to
 // explicitly derive from Test - the TEST macro automatically does
 // this for you.
 //
 // The only time you derive from Test is when defining a test fixture
 // to be used in a TEST_F.  For example:
 //
 //   class FooTest : public testing::Test {
 //    protected:
 //     void SetUp() override { ... }
 //     void TearDown() override { ... }
 //     ...
 //   };
 //
 //   TEST_F(FooTest, Bar) { ... }
 //   TEST_F(FooTest, Baz) { ... }
 //
 // Test is not copyable.
 class GTEST_API_ Test {
  public:
   friend class TestInfo;
 
   // The d'tor is virtual as we intend to inherit from Test.
   virtual ~Test();
 
   // Sets up the stuff shared by all tests in this test case.
   //
   // Google Test will call Foo::SetUpTestSuite() before running the first
   // test in test case Foo.  Hence a sub-class can define its own
   // SetUpTestSuite() method to shadow the one defined in the super
   // class.
   // Failures that happen during SetUpTestSuite are logged but otherwise
   // ignored.
   static void SetUpTestSuite() {}
 
   // Tears down the stuff shared by all tests in this test suite.
   //
   // Google Test will call Foo::TearDownTestSuite() after running the last
   // test in test case Foo.  Hence a sub-class can define its own
   // TearDownTestSuite() method to shadow the one defined in the super
   // class.
   // Failures that happen during TearDownTestSuite are logged but otherwise
   // ignored.
   static void TearDownTestSuite() {}
 
   // Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   static void TearDownTestCase() {}
   static void SetUpTestCase() {}
 #endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
   // Returns true if the current test has a fatal failure.
   static bool HasFatalFailure();
 
   // Returns true if the current test has a non-fatal failure.
   static bool HasNonfatalFailure();
 
   // Returns true if the current test was skipped.
   static bool IsSkipped();
 
   // Returns true if the current test has a (either fatal or
   // non-fatal) failure.
   static bool HasFailure() { return HasFatalFailure() || HasNonfatalFailure(); }
 
   // Logs a property for the current test, test suite, or for the entire
   // invocation of the test program when used outside of the context of a
   // test suite.  Only the last value for a given key is remembered.  These
   // are public static so they can be called from utility functions that are
   // not members of the test fixture.  Calls to RecordProperty made during
   // lifespan of the test (from the moment its constructor starts to the
   // moment its destructor finishes) will be output in XML as attributes of
   // the <testcase> element.  Properties recorded from fixture's
   // SetUpTestSuite or TearDownTestSuite are logged as attributes of the
   // corresponding <testsuite> element.  Calls to RecordProperty made in the
   // global context (before or after invocation of RUN_ALL_TESTS and from
   // SetUp/TearDown method of Environment objects registered with Google
   // Test) will be output as attributes of the <testsuites> element.
   static void RecordProperty(const std::string& key, const std::string& value);
   static void RecordProperty(const std::string& key, int value);
 
  protected:
   // Creates a Test object.
   Test();
 
   // Sets up the test fixture.
   virtual void SetUp();
 
   // Tears down the test fixture.
   virtual void TearDown();
 
  private:
   // Returns true if the current test has the same fixture class as
   // the first test in the current test suite.
   static bool HasSameFixtureClass();
 
   // Runs the test after the test fixture has been set up.
   //
   // A sub-class must implement this to define the test logic.
   //
   // DO NOT OVERRIDE THIS FUNCTION DIRECTLY IN A USER PROGRAM.
   // Instead, use the TEST or TEST_F macro.
   virtual void TestBody() = 0;
 
   // Sets up, executes, and tears down the test.
   void Run();
 
   // Deletes self.  We deliberately pick an unusual name for this
   // internal method to avoid clashing with names used in user TESTs.
   void DeleteSelf_() { delete this; }
 
   const std::unique_ptr<GTEST_FLAG_SAVER_> gtest_flag_saver_;
 
   // Often a user misspells SetUp() as Setup() and spends a long time
   // wondering why it is never called by Google Test.  The declaration of
   // the following method is solely for catching such an error at
   // compile time:
   //
   //   - The return type is deliberately chosen to be not void, so it
   //   will be a conflict if void Setup() is declared in the user's
   //   test fixture.
   //
   //   - This method is private, so it will be another compiler error
   //   if the method is called from the user's test fixture.
   //
   // DO NOT OVERRIDE THIS FUNCTION.
   //
   // If you see an error about overriding the following function or
   // about it being private, you have mis-spelled SetUp() as Setup().
   struct Setup_should_be_spelled_SetUp {};
   virtual Setup_should_be_spelled_SetUp* Setup() { return nullptr; }
 
   // We disallow copying Tests.
   GTEST_DISALLOW_COPY_AND_ASSIGN_(Test);
 };
 
 typedef internal::TimeInMillis TimeInMillis;
 
 // A copyable object representing a user specified test property which can be
 // output as a key/value string pair.
 //
 // Don't inherit from TestProperty as its destructor is not virtual.
 class TestProperty {
  public:
   // C'tor.  TestProperty does NOT have a default constructor.
   // Always use this constructor (with parameters) to create a
   // TestProperty object.
   TestProperty(const std::string& a_key, const std::string& a_value) :
     key_(a_key), value_(a_value) {
   }
 
   // Gets the user supplied key.
   const char* key() const {
     return key_.c_str();
   }
 
   // Gets the user supplied value.
   const char* value() const {
     return value_.c_str();
   }
 
   // Sets a new value, overriding the one supplied in the constructor.
   void SetValue(const std::string& new_value) {
     value_ = new_value;
   }
 
  private:
   // The key supplied by the user.
   std::string key_;
   // The value supplied by the user.
   std::string value_;
 };
 
 // The result of a single Test.  This includes a list of
 // TestPartResults, a list of TestProperties, a count of how many
 // death tests there are in the Test, and how much time it took to run
 // the Test.
 //
 // TestResult is not copyable.
 class GTEST_API_ TestResult {
  public:
   // Creates an empty TestResult.
   TestResult();
 
   // D'tor.  Do not inherit from TestResult.
   ~TestResult();
 
   // Gets the number of all test parts.  This is the sum of the number
   // of successful test parts and the number of failed test parts.
   int total_part_count() const;
 
   // Returns the number of the test properties.
   int test_property_count() const;
 
   // Returns true if the test passed (i.e. no test part failed).
   bool Passed() const { return !Skipped() && !Failed(); }
 
   // Returns true if the test was skipped.
   bool Skipped() const;
 
   // Returns true if the test failed.
   bool Failed() const;
 
   // Returns true if the test fatally failed.
   bool HasFatalFailure() const;
 
   // Returns true if the test has a non-fatal failure.
   bool HasNonfatalFailure() const;
 
   // Returns the elapsed time, in milliseconds.
   TimeInMillis elapsed_time() const { return elapsed_time_; }
 
   // Gets the time of the test case start, in ms from the start of the
   // UNIX epoch.
   TimeInMillis start_timestamp() const { return start_timestamp_; }
 
   // Returns the i-th test part result among all the results. i can range from 0
   // to total_part_count() - 1. If i is not in that range, aborts the program.
   const TestPartResult& GetTestPartResult(int i) const;
 
   // Returns the i-th test property. i can range from 0 to
   // test_property_count() - 1. If i is not in that range, aborts the
   // program.
   const TestProperty& GetTestProperty(int i) const;
 
  private:
   friend class TestInfo;
   friend class TestSuite;
   friend class UnitTest;
   friend class internal::DefaultGlobalTestPartResultReporter;
   friend class internal::ExecDeathTest;
   friend class internal::TestResultAccessor;
   friend class internal::UnitTestImpl;
   friend class internal::WindowsDeathTest;
   friend class internal::FuchsiaDeathTest;
 
   // Gets the vector of TestPartResults.
   const std::vector<TestPartResult>& test_part_results() const {
     return test_part_results_;
   }
 
   // Gets the vector of TestProperties.
   const std::vector<TestProperty>& test_properties() const {
     return test_properties_;
   }
 
   // Sets the start time.
   void set_start_timestamp(TimeInMillis start) { start_timestamp_ = start; }
 
   // Sets the elapsed time.
   void set_elapsed_time(TimeInMillis elapsed) { elapsed_time_ = elapsed; }
 
   // Adds a test property to the list. The property is validated and may add
   // a non-fatal failure if invalid (e.g., if it conflicts with reserved
   // key names). If a property is already recorded for the same key, the
   // value will be updated, rather than storing multiple values for the same
   // key.  xml_element specifies the element for which the property is being
   // recorded and is used for validation.
   void RecordProperty(const std::string& xml_element,
                       const TestProperty& test_property);
 
   // Adds a failure if the key is a reserved attribute of Google Test
   // testsuite tags.  Returns true if the property is valid.
   // FIXME: Validate attribute names are legal and human readable.
   static bool ValidateTestProperty(const std::string& xml_element,
                                    const TestProperty& test_property);
 
   // Adds a test part result to the list.
   void AddTestPartResult(const TestPartResult& test_part_result);
 
   // Returns the death test count.
   int death_test_count() const { return death_test_count_; }
 
   // Increments the death test count, returning the new count.
   int increment_death_test_count() { return ++death_test_count_; }
 
   // Clears the test part results.
   void ClearTestPartResults();
 
   // Clears the object.
   void Clear();
 
   // Protects mutable state of the property vector and of owned
   // properties, whose values may be updated.
   internal::Mutex test_properites_mutex_;
 
   // The vector of TestPartResults
   std::vector<TestPartResult> test_part_results_;
   // The vector of TestProperties
   std::vector<TestProperty> test_properties_;
   // Running count of death tests.
   int death_test_count_;
   // The start time, in milliseconds since UNIX Epoch.
   TimeInMillis start_timestamp_;
   // The elapsed time, in milliseconds.
   TimeInMillis elapsed_time_;
 
   // We disallow copying TestResult.
   GTEST_DISALLOW_COPY_AND_ASSIGN_(TestResult);
 };  // class TestResult
 
 // A TestInfo object stores the following information about a test:
 //
 //   Test suite name
 //   Test name
 //   Whether the test should be run
 //   A function pointer that creates the test object when invoked
 //   Test result
 //
 // The constructor of TestInfo registers itself with the UnitTest
 // singleton such that the RUN_ALL_TESTS() macro knows which tests to
 // run.
 class GTEST_API_ TestInfo {
  public:
   // Destructs a TestInfo object.  This function is not virtual, so
   // don't inherit from TestInfo.
   ~TestInfo();
 
   // Returns the test suite name.
   const char* test_suite_name() const { return test_suite_name_.c_str(); }
 
 // Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   const char* test_case_name() const { return test_suite_name(); }
 #endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
   // Returns the test name.
   const char* name() const { return name_.c_str(); }
 
   // Returns the name of the parameter type, or NULL if this is not a typed
   // or a type-parameterized test.
   const char* type_param() const {
     if (type_param_.get() != nullptr) return type_param_->c_str();
     return nullptr;
   }
 
   // Returns the text representation of the value parameter, or NULL if this
   // is not a value-parameterized test.
   const char* value_param() const {
     if (value_param_.get() != nullptr) return value_param_->c_str();
     return nullptr;
   }
 
   // Returns the file name where this test is defined.
   const char* file() const { return location_.file.c_str(); }
 
   // Returns the line where this test is defined.
   int line() const { return location_.line; }
 
   // Return true if this test should not be run because it's in another shard.
   bool is_in_another_shard() const { return is_in_another_shard_; }
 
   // Returns true if this test should run, that is if the test is not
   // disabled (or it is disabled but the also_run_disabled_tests flag has
   // been specified) and its full name matches the user-specified filter.
   //
   // Google Test allows the user to filter the tests by their full names.
   // The full name of a test Bar in test suite Foo is defined as
   // "Foo.Bar".  Only the tests that match the filter will run.
   //
   // A filter is a colon-separated list of glob (not regex) patterns,
   // optionally followed by a '-' and a colon-separated list of
   // negative patterns (tests to exclude).  A test is run if it
   // matches one of the positive patterns and does not match any of
   // the negative patterns.
   //
   // For example, *A*:Foo.* is a filter that matches any string that
   // contains the character 'A' or starts with "Foo.".
   bool should_run() const { return should_run_; }
 
   // Returns true if this test will appear in the XML report.
   bool is_reportable() const {
     // The XML report includes tests matching the filter, excluding those
     // run in other shards.
     return matches_filter_ && !is_in_another_shard_;
   }
 
   // Returns the result of the test.
   const TestResult* result() const { return &result_; }
 
  private:
 #if GTEST_HAS_DEATH_TEST
   friend class internal::DefaultDeathTestFactory;
 #endif  // GTEST_HAS_DEATH_TEST
   friend class Test;
   friend class TestSuite;
   friend class internal::UnitTestImpl;
   friend class internal::StreamingListenerTest;
   friend TestInfo* internal::MakeAndRegisterTestInfo(
       const char* test_suite_name, const char* name, const char* type_param,
       const char* value_param, internal::CodeLocation code_location,
       internal::TypeId fixture_class_id, internal::SetUpTestSuiteFunc set_up_tc,
       internal::TearDownTestSuiteFunc tear_down_tc,
       internal::TestFactoryBase* factory);
 
   // Constructs a TestInfo object. The newly constructed instance assumes
   // ownership of the factory object.
   TestInfo(const std::string& test_suite_name, const std::string& name,
            const char* a_type_param,   // NULL if not a type-parameterized test
            const char* a_value_param,  // NULL if not a value-parameterized test
            internal::CodeLocation a_code_location,
            internal::TypeId fixture_class_id,
            internal::TestFactoryBase* factory);
 
   // Increments the number of death tests encountered in this test so
   // far.
   int increment_death_test_count() {
     return result_.increment_death_test_count();
   }
 
   // Creates the test object, runs it, records its result, and then
   // deletes it.
   void Run();
 
   static void ClearTestResult(TestInfo* test_info) {
     test_info->result_.Clear();
   }
 
   // These fields are immutable properties of the test.
   const std::string test_suite_name_;    // test suite name
   const std::string name_;               // Test name
   // Name of the parameter type, or NULL if this is not a typed or a
   // type-parameterized test.
   const std::unique_ptr<const ::std::string> type_param_;
   // Text representation of the value parameter, or NULL if this is not a
   // value-parameterized test.
   const std::unique_ptr<const ::std::string> value_param_;
   internal::CodeLocation location_;
   const internal::TypeId fixture_class_id_;   // ID of the test fixture class
   bool should_run_;                 // True if this test should run
   bool is_disabled_;                // True if this test is disabled
   bool matches_filter_;             // True if this test matches the
                                     // user-specified filter.
   bool is_in_another_shard_;        // Will be run in another shard.
   internal::TestFactoryBase* const factory_;  // The factory that creates
                                               // the test object
 
   // This field is mutable and needs to be reset before running the
   // test for the second time.
   TestResult result_;
 
   GTEST_DISALLOW_COPY_AND_ASSIGN_(TestInfo);
 };
 
 // A test suite, which consists of a vector of TestInfos.
 //
 // TestSuite is not copyable.
 class GTEST_API_ TestSuite {
  public:
   // Creates a TestSuite with the given name.
   //
   // TestSuite does NOT have a default constructor.  Always use this
   // constructor to create a TestSuite object.
   //
   // Arguments:
   //
   //   name:         name of the test suite
   //   a_type_param: the name of the test's type parameter, or NULL if
   //                 this is not a type-parameterized test.
   //   set_up_tc:    pointer to the function that sets up the test suite
   //   tear_down_tc: pointer to the function that tears down the test suite
   TestSuite(const char* name, const char* a_type_param,
             internal::SetUpTestSuiteFunc set_up_tc,
             internal::TearDownTestSuiteFunc tear_down_tc);
 
   // Destructor of TestSuite.
   virtual ~TestSuite();
 
   // Gets the name of the TestSuite.
   const char* name() const { return name_.c_str(); }
 
   // Returns the name of the parameter type, or NULL if this is not a
   // type-parameterized test suite.
   const char* type_param() const {
     if (type_param_.get() != nullptr) return type_param_->c_str();
     return nullptr;
   }
 
   // Returns true if any test in this test suite should run.
   bool should_run() const { return should_run_; }
 
   // Gets the number of successful tests in this test suite.
   int successful_test_count() const;
 
   // Gets the number of skipped tests in this test suite.
   int skipped_test_count() const;
 
   // Gets the number of failed tests in this test suite.
   int failed_test_count() const;
 
   // Gets the number of disabled tests that will be reported in the XML report.
   int reportable_disabled_test_count() const;
 
   // Gets the number of disabled tests in this test suite.
   int disabled_test_count() const;
 
   // Gets the number of tests to be printed in the XML report.
   int reportable_test_count() const;
 
   // Get the number of tests in this test suite that should run.
   int test_to_run_count() const;
 
   // Gets the number of all tests in this test suite.
   int total_test_count() const;
 
   // Returns true if the test suite passed.
   bool Passed() const { return !Failed(); }
 
   // Returns true if the test suite failed.
   bool Failed() const { return failed_test_count() > 0; }
 
   // Returns the elapsed time, in milliseconds.
   TimeInMillis elapsed_time() const { return elapsed_time_; }
 
   // Gets the time of the test suite start, in ms from the start of the
   // UNIX epoch.
   TimeInMillis start_timestamp() const { return start_timestamp_; }
 
   // Returns the i-th test among all the tests. i can range from 0 to
   // total_test_count() - 1. If i is not in that range, returns NULL.
   const TestInfo* GetTestInfo(int i) const;
 
   // Returns the TestResult that holds test properties recorded during
   // execution of SetUpTestSuite and TearDownTestSuite.
   const TestResult& ad_hoc_test_result() const { return ad_hoc_test_result_; }
 
  private:
   friend class Test;
   friend class internal::UnitTestImpl;
 
   // Gets the (mutable) vector of TestInfos in this TestSuite.
   std::vector<TestInfo*>& test_info_list() { return test_info_list_; }
 
   // Gets the (immutable) vector of TestInfos in this TestSuite.
   const std::vector<TestInfo*>& test_info_list() const {
     return test_info_list_;
   }
 
   // Returns the i-th test among all the tests. i can range from 0 to
   // total_test_count() - 1. If i is not in that range, returns NULL.
   TestInfo* GetMutableTestInfo(int i);
 
   // Sets the should_run member.
   void set_should_run(bool should) { should_run_ = should; }
 
   // Adds a TestInfo to this test suite.  Will delete the TestInfo upon
   // destruction of the TestSuite object.
   void AddTestInfo(TestInfo * test_info);
 
   // Clears the results of all tests in this test suite.
   void ClearResult();
 
   // Clears the results of all tests in the given test suite.
   static void ClearTestSuiteResult(TestSuite* test_suite) {
     test_suite->ClearResult();
   }
 
   // Runs every test in this TestSuite.
   void Run();
 
   // Runs SetUpTestSuite() for this TestSuite.  This wrapper is needed
   // for catching exceptions thrown from SetUpTestSuite().
   void RunSetUpTestSuite() {
     if (set_up_tc_ != nullptr) {
       (*set_up_tc_)();
     }
   }
 
   // Runs TearDownTestSuite() for this TestSuite.  This wrapper is
   // needed for catching exceptions thrown from TearDownTestSuite().
   void RunTearDownTestSuite() {
     if (tear_down_tc_ != nullptr) {
       (*tear_down_tc_)();
     }
   }
 
   // Returns true if test passed.
   static bool TestPassed(const TestInfo* test_info) {
     return test_info->should_run() && test_info->result()->Passed();
   }
 
   // Returns true if test skipped.
   static bool TestSkipped(const TestInfo* test_info) {
     return test_info->should_run() && test_info->result()->Skipped();
   }
 
   // Returns true if test failed.
   static bool TestFailed(const TestInfo* test_info) {
     return test_info->should_run() && test_info->result()->Failed();
   }
 
   // Returns true if the test is disabled and will be reported in the XML
   // report.
   static bool TestReportableDisabled(const TestInfo* test_info) {
     return test_info->is_reportable() && test_info->is_disabled_;
   }
 
   // Returns true if test is disabled.
   static bool TestDisabled(const TestInfo* test_info) {
     return test_info->is_disabled_;
   }
 
   // Returns true if this test will appear in the XML report.
   static bool TestReportable(const TestInfo* test_info) {
     return test_info->is_reportable();
   }
 
   // Returns true if the given test should run.
   static bool ShouldRunTest(const TestInfo* test_info) {
     return test_info->should_run();
   }
 
   // Shuffles the tests in this test suite.
   void ShuffleTests(internal::Random* random);
 
   // Restores the test order to before the first shuffle.
   void UnshuffleTests();
 
   // Name of the test suite.
   std::string name_;
   // Name of the parameter type, or NULL if this is not a typed or a
   // type-parameterized test.
   const std::unique_ptr<const ::std::string> type_param_;
   // The vector of TestInfos in their original order.  It owns the
   // elements in the vector.
   std::vector<TestInfo*> test_info_list_;
   // Provides a level of indirection for the test list to allow easy
   // shuffling and restoring the test order.  The i-th element in this
   // vector is the index of the i-th test in the shuffled test list.
   std::vector<int> test_indices_;
   // Pointer to the function that sets up the test suite.
   internal::SetUpTestSuiteFunc set_up_tc_;
   // Pointer to the function that tears down the test suite.
   internal::TearDownTestSuiteFunc tear_down_tc_;
   // True if any test in this test suite should run.
   bool should_run_;
   // The start time, in milliseconds since UNIX Epoch.
   TimeInMillis start_timestamp_;
   // Elapsed time, in milliseconds.
   TimeInMillis elapsed_time_;
   // Holds test properties recorded during execution of SetUpTestSuite and
   // TearDownTestSuite.
   TestResult ad_hoc_test_result_;
 
   // We disallow copying TestSuites.
   GTEST_DISALLOW_COPY_AND_ASSIGN_(TestSuite);
 };
 
 // An Environment object is capable of setting up and tearing down an
 // environment.  You should subclass this to define your own
 // environment(s).
 //
 // An Environment object does the set-up and tear-down in virtual
 // methods SetUp() and TearDown() instead of the constructor and the
 // destructor, as:
 //
 //   1. You cannot safely throw from a destructor.  This is a problem
 //      as in some cases Google Test is used where exceptions are enabled, and
 //      we may want to implement ASSERT_* using exceptions where they are
 //      available.
 //   2. You cannot use ASSERT_* directly in a constructor or
 //      destructor.
 class Environment {
  public:
   // The d'tor is virtual as we need to subclass Environment.
   virtual ~Environment() {}
 
   // Override this to define how to set up the environment.
   virtual void SetUp() {}
 
   // Override this to define how to tear down the environment.
   virtual void TearDown() {}
  private:
   // If you see an error about overriding the following function or
   // about it being private, you have mis-spelled SetUp() as Setup().
   struct Setup_should_be_spelled_SetUp {};
   virtual Setup_should_be_spelled_SetUp* Setup() { return nullptr; }
 };
 
 #if GTEST_HAS_EXCEPTIONS
 
 // Exception which can be thrown from TestEventListener::OnTestPartResult.
 class GTEST_API_ AssertionException
     : public internal::GoogleTestFailureException {
  public:
   explicit AssertionException(const TestPartResult& result)
       : GoogleTestFailureException(result) {}
 };
 
 #endif  // GTEST_HAS_EXCEPTIONS
 
 // The interface for tracing execution of tests. The methods are organized in
 // the order the corresponding events are fired.
 class TestEventListener {
  public:
   virtual ~TestEventListener() {}
 
   // Fired before any test activity starts.
   virtual void OnTestProgramStart(const UnitTest& unit_test) = 0;
 
   // Fired before each iteration of tests starts.  There may be more than
   // one iteration if GTEST_FLAG(repeat) is set. iteration is the iteration
   // index, starting from 0.
   virtual void OnTestIterationStart(const UnitTest& unit_test,
                                     int iteration) = 0;
 
   // Fired before environment set-up for each iteration of tests starts.
   virtual void OnEnvironmentsSetUpStart(const UnitTest& unit_test) = 0;
 
   // Fired after environment set-up for each iteration of tests ends.
   virtual void OnEnvironmentsSetUpEnd(const UnitTest& unit_test) = 0;
 
   // Fired before the test suite starts.
   virtual void OnTestSuiteStart(const TestSuite& /*test_suite*/) {}
 
   //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   virtual void OnTestCaseStart(const TestCase& /*test_case*/) {}
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
   // Fired before the test starts.
   virtual void OnTestStart(const TestInfo& test_info) = 0;
 
   // Fired after a failed assertion or a SUCCEED() invocation.
   // If you want to throw an exception from this function to skip to the next
   // TEST, it must be AssertionException defined above, or inherited from it.
   virtual void OnTestPartResult(const TestPartResult& test_part_result) = 0;
 
   // Fired after the test ends.
   virtual void OnTestEnd(const TestInfo& test_info) = 0;
 
   // Fired after the test suite ends.
   virtual void OnTestSuiteEnd(const TestSuite& /*test_suite*/) {}
 
 //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   virtual void OnTestCaseEnd(const TestCase& /*test_case*/) {}
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
   // Fired before environment tear-down for each iteration of tests starts.
   virtual void OnEnvironmentsTearDownStart(const UnitTest& unit_test) = 0;
 
   // Fired after environment tear-down for each iteration of tests ends.
   virtual void OnEnvironmentsTearDownEnd(const UnitTest& unit_test) = 0;
 
   // Fired after each iteration of tests finishes.
   virtual void OnTestIterationEnd(const UnitTest& unit_test,
                                   int iteration) = 0;
 
   // Fired after all test activities have ended.
   virtual void OnTestProgramEnd(const UnitTest& unit_test) = 0;
 };
 
 // The convenience class for users who need to override just one or two
 // methods and are not concerned that a possible change to a signature of
 // the methods they override will not be caught during the build.  For
 // comments about each method please see the definition of TestEventListener
 // above.
 class EmptyTestEventListener : public TestEventListener {
  public:
   void OnTestProgramStart(const UnitTest& /*unit_test*/) override {}
   void OnTestIterationStart(const UnitTest& /*unit_test*/,
                             int /*iteration*/) override {}
   void OnEnvironmentsSetUpStart(const UnitTest& /*unit_test*/) override {}
   void OnEnvironmentsSetUpEnd(const UnitTest& /*unit_test*/) override {}
   void OnTestSuiteStart(const TestSuite& /*test_suite*/) override {}
 //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   void OnTestCaseStart(const TestCase& /*test_case*/) override {}
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
   void OnTestStart(const TestInfo& /*test_info*/) override {}
   void OnTestPartResult(const TestPartResult& /*test_part_result*/) override {}
   void OnTestEnd(const TestInfo& /*test_info*/) override {}
   void OnTestSuiteEnd(const TestSuite& /*test_suite*/) override {}
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   void OnTestCaseEnd(const TestCase& /*test_case*/) override {}
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
   void OnEnvironmentsTearDownStart(const UnitTest& /*unit_test*/) override {}
   void OnEnvironmentsTearDownEnd(const UnitTest& /*unit_test*/) override {}
   void OnTestIterationEnd(const UnitTest& /*unit_test*/,
                           int /*iteration*/) override {}
   void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {}
 };
 
 // TestEventListeners lets users add listeners to track events in Google Test.
 class GTEST_API_ TestEventListeners {
  public:
   TestEventListeners();
   ~TestEventListeners();
 
   // Appends an event listener to the end of the list. Google Test assumes
   // the ownership of the listener (i.e. it will delete the listener when
   // the test program finishes).
   void Append(TestEventListener* listener);
 
   // Removes the given event listener from the list and returns it.  It then
   // becomes the caller's responsibility to delete the listener. Returns
   // NULL if the listener is not found in the list.
   TestEventListener* Release(TestEventListener* listener);
 
   // Returns the standard listener responsible for the default console
   // output.  Can be removed from the listeners list to shut down default
   // console output.  Note that removing this object from the listener list
   // with Release transfers its ownership to the caller and makes this
   // function return NULL the next time.
   TestEventListener* default_result_printer() const {
     return default_result_printer_;
   }
 
   // Returns the standard listener responsible for the default XML output
   // controlled by the --gtest_output=xml flag.  Can be removed from the
   // listeners list by users who want to shut down the default XML output
   // controlled by this flag and substitute it with custom one.  Note that
   // removing this object from the listener list with Release transfers its
   // ownership to the caller and makes this function return NULL the next
   // time.
   TestEventListener* default_xml_generator() const {
     return default_xml_generator_;
   }
 
  private:
   friend class TestSuite;
   friend class TestInfo;
   friend class internal::DefaultGlobalTestPartResultReporter;
   friend class internal::NoExecDeathTest;
   friend class internal::TestEventListenersAccessor;
   friend class internal::UnitTestImpl;
 
   // Returns repeater that broadcasts the TestEventListener events to all
   // subscribers.
   TestEventListener* repeater();
 
   // Sets the default_result_printer attribute to the provided listener.
   // The listener is also added to the listener list and previous
   // default_result_printer is removed from it and deleted. The listener can
   // also be NULL in which case it will not be added to the list. Does
   // nothing if the previous and the current listener objects are the same.
   void SetDefaultResultPrinter(TestEventListener* listener);
 
   // Sets the default_xml_generator attribute to the provided listener.  The
   // listener is also added to the listener list and previous
   // default_xml_generator is removed from it and deleted. The listener can
   // also be NULL in which case it will not be added to the list. Does
   // nothing if the previous and the current listener objects are the same.
   void SetDefaultXmlGenerator(TestEventListener* listener);
 
   // Controls whether events will be forwarded by the repeater to the
   // listeners in the list.
   bool EventForwardingEnabled() const;
   void SuppressEventForwarding();
 
   // The actual list of listeners.
   internal::TestEventRepeater* repeater_;
   // Listener responsible for the standard result output.
   TestEventListener* default_result_printer_;
   // Listener responsible for the creation of the XML output file.
   TestEventListener* default_xml_generator_;
 
   // We disallow copying TestEventListeners.
   GTEST_DISALLOW_COPY_AND_ASSIGN_(TestEventListeners);
 };
 
 // A UnitTest consists of a vector of TestSuites.
 //
 // This is a singleton class.  The only instance of UnitTest is
 // created when UnitTest::GetInstance() is first called.  This
 // instance is never deleted.
 //
 // UnitTest is not copyable.
 //
 // This class is thread-safe as long as the methods are called
 // according to their specification.
 class GTEST_API_ UnitTest {
  public:
   // Gets the singleton UnitTest object.  The first time this method
   // is called, a UnitTest object is constructed and returned.
   // Consecutive calls will return the same object.
   static UnitTest* GetInstance();
 
   // Runs all tests in this UnitTest object and prints the result.
   // Returns 0 if successful, or 1 otherwise.
   //
   // This method can only be called from the main thread.
   //
   // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
   int Run() GTEST_MUST_USE_RESULT_;
 
   // Returns the working directory when the first TEST() or TEST_F()
   // was executed.  The UnitTest object owns the string.
   const char* original_working_dir() const;
 
   // Returns the TestSuite object for the test that's currently running,
   // or NULL if no test is running.
   const TestSuite* current_test_suite() const GTEST_LOCK_EXCLUDED_(mutex_);
 
 // Legacy API is still available but deprecated
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   const TestCase* current_test_case() const GTEST_LOCK_EXCLUDED_(mutex_);
 #endif
 
   // Returns the TestInfo object for the test that's currently running,
   // or NULL if no test is running.
   const TestInfo* current_test_info() const
       GTEST_LOCK_EXCLUDED_(mutex_);
 
   // Returns the random seed used at the start of the current test run.
   int random_seed() const;
 
   // Returns the ParameterizedTestSuiteRegistry object used to keep track of
   // value-parameterized tests and instantiate and register them.
   //
   // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
   internal::ParameterizedTestSuiteRegistry& parameterized_test_registry()
       GTEST_LOCK_EXCLUDED_(mutex_);
 
   // Gets the number of successful test suites.
   int successful_test_suite_count() const;
 
   // Gets the number of failed test suites.
   int failed_test_suite_count() const;
 
   // Gets the number of all test suites.
   int total_test_suite_count() const;
 
   // Gets the number of all test suites that contain at least one test
   // that should run.
   int test_suite_to_run_count() const;
 
   //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   int successful_test_case_count() const;
   int failed_test_case_count() const;
   int total_test_case_count() const;
   int test_case_to_run_count() const;
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
   // Gets the number of successful tests.
   int successful_test_count() const;
 
   // Gets the number of skipped tests.
   int skipped_test_count() const;
 
   // Gets the number of failed tests.
   int failed_test_count() const;
 
   // Gets the number of disabled tests that will be reported in the XML report.
   int reportable_disabled_test_count() const;
 
   // Gets the number of disabled tests.
   int disabled_test_count() const;
 
   // Gets the number of tests to be printed in the XML report.
   int reportable_test_count() const;
 
   // Gets the number of all tests.
   int total_test_count() const;
 
   // Gets the number of tests that should run.
   int test_to_run_count() const;
 
   // Gets the time of the test program start, in ms from the start of the
   // UNIX epoch.
   TimeInMillis start_timestamp() const;
 
   // Gets the elapsed time, in milliseconds.
   TimeInMillis elapsed_time() const;
 
   // Returns true if the unit test passed (i.e. all test suites passed).
   bool Passed() const;
 
   // Returns true if the unit test failed (i.e. some test suite failed
   // or something outside of all tests failed).
   bool Failed() const;
 
   // Gets the i-th test suite among all the test suites. i can range from 0 to
   // total_test_suite_count() - 1. If i is not in that range, returns NULL.
   const TestSuite* GetTestSuite(int i) const;
 
 //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   const TestCase* GetTestCase(int i) const;
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
   // Returns the TestResult containing information on test failures and
   // properties logged outside of individual test suites.
   const TestResult& ad_hoc_test_result() const;
 
   // Returns the list of event listeners that can be used to track events
   // inside Google Test.
   TestEventListeners& listeners();
 
  private:
   // Registers and returns a global test environment.  When a test
   // program is run, all global test environments will be set-up in
   // the order they were registered.  After all tests in the program
   // have finished, all global test environments will be torn-down in
   // the *reverse* order they were registered.
   //
   // The UnitTest object takes ownership of the given environment.
   //
   // This method can only be called from the main thread.
   Environment* AddEnvironment(Environment* env);
 
   // Adds a TestPartResult to the current TestResult object.  All
   // Google Test assertion macros (e.g. ASSERT_TRUE, EXPECT_EQ, etc)
   // eventually call this to report their results.  The user code
   // should use the assertion macros instead of calling this directly.
   void AddTestPartResult(TestPartResult::Type result_type,
                          const char* file_name,
                          int line_number,
                          const std::string& message,
                          const std::string& os_stack_trace)
       GTEST_LOCK_EXCLUDED_(mutex_);
 
   // Adds a TestProperty to the current TestResult object when invoked from
   // inside a test, to current TestSuite's ad_hoc_test_result_ when invoked
   // from SetUpTestSuite or TearDownTestSuite, or to the global property set
   // when invoked elsewhere.  If the result already contains a property with
   // the same key, the value will be updated.
   void RecordProperty(const std::string& key, const std::string& value);
 
   // Gets the i-th test suite among all the test suites. i can range from 0 to
   // total_test_suite_count() - 1. If i is not in that range, returns NULL.
   TestSuite* GetMutableTestSuite(int i);
 
   // Accessors for the implementation object.
   internal::UnitTestImpl* impl() { return impl_; }
   const internal::UnitTestImpl* impl() const { return impl_; }
 
   // These classes and functions are friends as they need to access private
   // members of UnitTest.
   friend class ScopedTrace;
   friend class Test;
   friend class internal::AssertHelper;
   friend class internal::StreamingListenerTest;
   friend class internal::UnitTestRecordPropertyTestHelper;
   friend Environment* AddGlobalTestEnvironment(Environment* env);
   friend internal::UnitTestImpl* internal::GetUnitTestImpl();
   friend void internal::ReportFailureInUnknownLocation(
       TestPartResult::Type result_type,
       const std::string& message);
 
   // Creates an empty UnitTest.
   UnitTest();
 
   // D'tor
   virtual ~UnitTest();
 
   // Pushes a trace defined by SCOPED_TRACE() on to the per-thread
   // Google Test trace stack.
   void PushGTestTrace(const internal::TraceInfo& trace)
       GTEST_LOCK_EXCLUDED_(mutex_);
 
   // Pops a trace from the per-thread Google Test trace stack.
   void PopGTestTrace()
       GTEST_LOCK_EXCLUDED_(mutex_);
 
   // Protects mutable state in *impl_.  This is mutable as some const
   // methods need to lock it too.
   mutable internal::Mutex mutex_;
 
   // Opaque implementation object.  This field is never changed once
   // the object is constructed.  We don't mark it as const here, as
   // doing so will cause a warning in the constructor of UnitTest.
   // Mutable state in *impl_ is protected by mutex_.
   internal::UnitTestImpl* impl_;
 
   // We disallow copying UnitTest.
   GTEST_DISALLOW_COPY_AND_ASSIGN_(UnitTest);
 };
 
 // A convenient wrapper for adding an environment for the test
 // program.
 //
 // You should call this before RUN_ALL_TESTS() is called, probably in
 // main().  If you use gtest_main, you need to call this before main()
 // starts for it to take effect.  For example, you can define a global
 // variable like this:
 //
 //   testing::Environment* const foo_env =
 //       testing::AddGlobalTestEnvironment(new FooEnvironment);
 //
 // However, we strongly recommend you to write your own main() and
 // call AddGlobalTestEnvironment() there, as relying on initialization
 // of global variables makes the code harder to read and may cause
 // problems when you register multiple environments from different
 // translation units and the environments have dependencies among them
 // (remember that the compiler doesn't guarantee the order in which
 // global variables from different translation units are initialized).
 inline Environment* AddGlobalTestEnvironment(Environment* env) {
   return UnitTest::GetInstance()->AddEnvironment(env);
 }
 
 // Initializes Google Test.  This must be called before calling
 // RUN_ALL_TESTS().  In particular, it parses a command line for the
 // flags that Google Test recognizes.  Whenever a Google Test flag is
 // seen, it is removed from argv, and *argc is decremented.
 //
 // No value is returned.  Instead, the Google Test flag variables are
 // updated.
 //
 // Calling the function for the second time has no user-visible effect.
 GTEST_API_ void InitGoogleTest(int* argc, char** argv);
 
 // This overloaded version can be used in Windows programs compiled in
 // UNICODE mode.
 GTEST_API_ void InitGoogleTest(int* argc, wchar_t** argv);
 
 // This overloaded version can be used on Arduino/embedded platforms where
 // there is no argc/argv.
 GTEST_API_ void InitGoogleTest();
 
 namespace internal {
 
 // Separate the error generating code from the code path to reduce the stack
 // frame size of CmpHelperEQ. This helps reduce the overhead of some sanitizers
 // when calling EXPECT_* in a tight loop.
 template <typename T1, typename T2>
 AssertionResult CmpHelperEQFailure(const char* lhs_expression,
                                    const char* rhs_expression,
                                    const T1& lhs, const T2& rhs) {
   return EqFailure(lhs_expression,
                    rhs_expression,
                    FormatForComparisonFailureMessage(lhs, rhs),
                    FormatForComparisonFailureMessage(rhs, lhs),
                    false);
 }
 
 // This block of code defines operator==/!=
 // to block lexical scope lookup.
 // It prevents using invalid operator==/!= defined at namespace scope.
 struct faketype {};
 inline bool operator==(faketype, faketype) { return true; }
 inline bool operator!=(faketype, faketype) { return false; }
 
 // The helper function for {ASSERT|EXPECT}_EQ.
 template <typename T1, typename T2>
 AssertionResult CmpHelperEQ(const char* lhs_expression,
                             const char* rhs_expression,
                             const T1& lhs,
                             const T2& rhs) {
   if (lhs == rhs) {
     return AssertionSuccess();
   }
 
   return CmpHelperEQFailure(lhs_expression, rhs_expression, lhs, rhs);
 }
 
 // With this overloaded version, we allow anonymous enums to be used
 // in {ASSERT|EXPECT}_EQ when compiled with gcc 4, as anonymous enums
 // can be implicitly cast to BiggestInt.
 GTEST_API_ AssertionResult CmpHelperEQ(const char* lhs_expression,
                                        const char* rhs_expression,
                                        BiggestInt lhs,
                                        BiggestInt rhs);
 
 class EqHelper {
  public:
   // This templatized version is for the general case.
   template <
       typename T1, typename T2,
       // Disable this overload for cases where one argument is a pointer
       // and the other is the null pointer constant.
       typename std::enable_if<!std::is_integral<T1>::value ||
                               !std::is_pointer<T2>::value>::type* = nullptr>
   static AssertionResult Compare(const char* lhs_expression,
                                  const char* rhs_expression, const T1& lhs,
                                  const T2& rhs) {
     return CmpHelperEQ(lhs_expression, rhs_expression, lhs, rhs);
   }
 
   // With this overloaded version, we allow anonymous enums to be used
   // in {ASSERT|EXPECT}_EQ when compiled with gcc 4, as anonymous
   // enums can be implicitly cast to BiggestInt.
   //
   // Even though its body looks the same as the above version, we
   // cannot merge the two, as it will make anonymous enums unhappy.
   static AssertionResult Compare(const char* lhs_expression,
                                  const char* rhs_expression,
                                  BiggestInt lhs,
                                  BiggestInt rhs) {
     return CmpHelperEQ(lhs_expression, rhs_expression, lhs, rhs);
   }
 
   template <typename T>
   static AssertionResult Compare(
       const char* lhs_expression, const char* rhs_expression,
       // Handle cases where '0' is used as a null pointer literal.
       std::nullptr_t /* lhs */, T* rhs) {
     // We already know that 'lhs' is a null pointer.
     return CmpHelperEQ(lhs_expression, rhs_expression, static_cast<T*>(nullptr),
                        rhs);
   }
 };
 
 // Separate the error generating code from the code path to reduce the stack
 // frame size of CmpHelperOP. This helps reduce the overhead of some sanitizers
 // when calling EXPECT_OP in a tight loop.
 template <typename T1, typename T2>
 AssertionResult CmpHelperOpFailure(const char* expr1, const char* expr2,
                                    const T1& val1, const T2& val2,
                                    const char* op) {
   return AssertionFailure()
          << "Expected: (" << expr1 << ") " << op << " (" << expr2
          << "), actual: " << FormatForComparisonFailureMessage(val1, val2)
          << " vs " << FormatForComparisonFailureMessage(val2, val1);
 }
 
 // A macro for implementing the helper functions needed to implement
 // ASSERT_?? and EXPECT_??.  It is here just to avoid copy-and-paste
 // of similar code.
 //
 // For each templatized helper function, we also define an overloaded
 // version for BiggestInt in order to reduce code bloat and allow
 // anonymous enums to be used with {ASSERT|EXPECT}_?? when compiled
 // with gcc 4.
 //
 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
 
 #define GTEST_IMPL_CMP_HELPER_(op_name, op)\
 template <typename T1, typename T2>\
 AssertionResult CmpHelper##op_name(const char* expr1, const char* expr2, \
                                    const T1& val1, const T2& val2) {\
   if (val1 op val2) {\
     return AssertionSuccess();\
   } else {\
     return CmpHelperOpFailure(expr1, expr2, val1, val2, #op);\
   }\
 }\
 GTEST_API_ AssertionResult CmpHelper##op_name(\
     const char* expr1, const char* expr2, BiggestInt val1, BiggestInt val2)
 
 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
 
 // Implements the helper function for {ASSERT|EXPECT}_NE
 GTEST_IMPL_CMP_HELPER_(NE, !=);
 // Implements the helper function for {ASSERT|EXPECT}_LE
 GTEST_IMPL_CMP_HELPER_(LE, <=);
 // Implements the helper function for {ASSERT|EXPECT}_LT
 GTEST_IMPL_CMP_HELPER_(LT, <);
 // Implements the helper function for {ASSERT|EXPECT}_GE
 GTEST_IMPL_CMP_HELPER_(GE, >=);
 // Implements the helper function for {ASSERT|EXPECT}_GT
 GTEST_IMPL_CMP_HELPER_(GT, >);
 
 #undef GTEST_IMPL_CMP_HELPER_
 
 // The helper function for {ASSERT|EXPECT}_STREQ.
 //
 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
 GTEST_API_ AssertionResult CmpHelperSTREQ(const char* s1_expression,
                                           const char* s2_expression,
                                           const char* s1,
                                           const char* s2);
 
 // The helper function for {ASSERT|EXPECT}_STRCASEEQ.
 //
 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
 GTEST_API_ AssertionResult CmpHelperSTRCASEEQ(const char* s1_expression,
                                               const char* s2_expression,
                                               const char* s1,
                                               const char* s2);
 
 // The helper function for {ASSERT|EXPECT}_STRNE.
 //
 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
 GTEST_API_ AssertionResult CmpHelperSTRNE(const char* s1_expression,
                                           const char* s2_expression,
                                           const char* s1,
                                           const char* s2);
 
 // The helper function for {ASSERT|EXPECT}_STRCASENE.
 //
 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
 GTEST_API_ AssertionResult CmpHelperSTRCASENE(const char* s1_expression,
                                               const char* s2_expression,
                                               const char* s1,
                                               const char* s2);
 
 
 // Helper function for *_STREQ on wide strings.
 //
 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
 GTEST_API_ AssertionResult CmpHelperSTREQ(const char* s1_expression,
                                           const char* s2_expression,
                                           const wchar_t* s1,
                                           const wchar_t* s2);
 
 // Helper function for *_STRNE on wide strings.
 //
 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
 GTEST_API_ AssertionResult CmpHelperSTRNE(const char* s1_expression,
                                           const char* s2_expression,
                                           const wchar_t* s1,
                                           const wchar_t* s2);
 
 }  // namespace internal
 
 // IsSubstring() and IsNotSubstring() are intended to be used as the
 // first argument to {EXPECT,ASSERT}_PRED_FORMAT2(), not by
 // themselves.  They check whether needle is a substring of haystack
 // (NULL is considered a substring of itself only), and return an
 // appropriate error message when they fail.
 //
 // The {needle,haystack}_expr arguments are the stringified
 // expressions that generated the two real arguments.
 GTEST_API_ AssertionResult IsSubstring(
     const char* needle_expr, const char* haystack_expr,
     const char* needle, const char* haystack);
 GTEST_API_ AssertionResult IsSubstring(
     const char* needle_expr, const char* haystack_expr,
     const wchar_t* needle, const wchar_t* haystack);
 GTEST_API_ AssertionResult IsNotSubstring(
     const char* needle_expr, const char* haystack_expr,
     const char* needle, const char* haystack);
 GTEST_API_ AssertionResult IsNotSubstring(
     const char* needle_expr, const char* haystack_expr,
     const wchar_t* needle, const wchar_t* haystack);
 GTEST_API_ AssertionResult IsSubstring(
     const char* needle_expr, const char* haystack_expr,
     const ::std::string& needle, const ::std::string& haystack);
 GTEST_API_ AssertionResult IsNotSubstring(
     const char* needle_expr, const char* haystack_expr,
     const ::std::string& needle, const ::std::string& haystack);
 
 #if GTEST_HAS_STD_WSTRING
 GTEST_API_ AssertionResult IsSubstring(
     const char* needle_expr, const char* haystack_expr,
     const ::std::wstring& needle, const ::std::wstring& haystack);
 GTEST_API_ AssertionResult IsNotSubstring(
     const char* needle_expr, const char* haystack_expr,
     const ::std::wstring& needle, const ::std::wstring& haystack);
 #endif  // GTEST_HAS_STD_WSTRING
 
 namespace internal {
 
 // Helper template function for comparing floating-points.
 //
 // Template parameter:
 //
 //   RawType: the raw floating-point type (either float or double)
 //
 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
 template <typename RawType>
 AssertionResult CmpHelperFloatingPointEQ(const char* lhs_expression,
                                          const char* rhs_expression,
                                          RawType lhs_value,
                                          RawType rhs_value) {
   const FloatingPoint<RawType> lhs(lhs_value), rhs(rhs_value);
 
   if (lhs.AlmostEquals(rhs)) {
     return AssertionSuccess();
   }
 
   ::std::stringstream lhs_ss;
   lhs_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
          << lhs_value;
 
   ::std::stringstream rhs_ss;
   rhs_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
          << rhs_value;
 
   return EqFailure(lhs_expression,
                    rhs_expression,
                    StringStreamToString(&lhs_ss),
                    StringStreamToString(&rhs_ss),
                    false);
 }
 
 // Helper function for implementing ASSERT_NEAR.
 //
 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
 GTEST_API_ AssertionResult DoubleNearPredFormat(const char* expr1,
                                                 const char* expr2,
                                                 const char* abs_error_expr,
                                                 double val1,
                                                 double val2,
                                                 double abs_error);
 
 // INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
 // A class that enables one to stream messages to assertion macros
 class GTEST_API_ AssertHelper {
  public:
   // Constructor.
   AssertHelper(TestPartResult::Type type,
                const char* file,
                int line,
                const char* message);
   ~AssertHelper();
 
   // Message assignment is a semantic trick to enable assertion
   // streaming; see the GTEST_MESSAGE_ macro below.
   void operator=(const Message& message) const;
 
  private:
   // We put our data in a struct so that the size of the AssertHelper class can
   // be as small as possible.  This is important because gcc is incapable of
   // re-using stack space even for temporary variables, so every EXPECT_EQ
   // reserves stack space for another AssertHelper.
   struct AssertHelperData {
     AssertHelperData(TestPartResult::Type t,
                      const char* srcfile,
                      int line_num,
                      const char* msg)
         : type(t), file(srcfile), line(line_num), message(msg) { }
 
     TestPartResult::Type const type;
     const char* const file;
     int const line;
     std::string const message;
 
    private:
     GTEST_DISALLOW_COPY_AND_ASSIGN_(AssertHelperData);
   };
 
   AssertHelperData* const data_;
 
   GTEST_DISALLOW_COPY_AND_ASSIGN_(AssertHelper);
 };
 
 enum GTestColor { COLOR_DEFAULT, COLOR_RED, COLOR_GREEN, COLOR_YELLOW };
 
 GTEST_API_ GTEST_ATTRIBUTE_PRINTF_(2, 3) void ColoredPrintf(GTestColor color,
                                                             const char* fmt,
                                                             ...);
 
 }  // namespace internal
 
 // The pure interface class that all value-parameterized tests inherit from.
 // A value-parameterized class must inherit from both ::testing::Test and
 // ::testing::WithParamInterface. In most cases that just means inheriting
 // from ::testing::TestWithParam, but more complicated test hierarchies
 // may need to inherit from Test and WithParamInterface at different levels.
 //
 // This interface has support for accessing the test parameter value via
 // the GetParam() method.
 //
 // Use it with one of the parameter generator defining functions, like Range(),
 // Values(), ValuesIn(), Bool(), and Combine().
 //
 // class FooTest : public ::testing::TestWithParam<int> {
 //  protected:
 //   FooTest() {
 //     // Can use GetParam() here.
 //   }
 //   ~FooTest() override {
 //     // Can use GetParam() here.
 //   }
 //   void SetUp() override {
 //     // Can use GetParam() here.
 //   }
 //   void TearDown override {
 //     // Can use GetParam() here.
 //   }
 // };
 // TEST_P(FooTest, DoesBar) {
 //   // Can use GetParam() method here.
 //   Foo foo;
 //   ASSERT_TRUE(foo.DoesBar(GetParam()));
 // }
 // INSTANTIATE_TEST_SUITE_P(OneToTenRange, FooTest, ::testing::Range(1, 10));
 
 template <typename T>
 class WithParamInterface {
  public:
   typedef T ParamType;
   virtual ~WithParamInterface() {}
 
   // The current parameter value. Is also available in the test fixture's
   // constructor.
   static const ParamType& GetParam() {
     GTEST_CHECK_(parameter_ != nullptr)
         << "GetParam() can only be called inside a value-parameterized test "
         << "-- did you intend to write TEST_P instead of TEST_F?";
     return *parameter_;
   }
 
  private:
   // Sets parameter value. The caller is responsible for making sure the value
   // remains alive and unchanged throughout the current test.
   static void SetParam(const ParamType* parameter) {
     parameter_ = parameter;
   }
 
   // Static value used for accessing parameter during a test lifetime.
   static const ParamType* parameter_;
 
   // TestClass must be a subclass of WithParamInterface<T> and Test.
   template <class TestClass> friend class internal::ParameterizedTestFactory;
 };
 
 template <typename T>
 const T* WithParamInterface<T>::parameter_ = nullptr;
 
 // Most value-parameterized classes can ignore the existence of
 // WithParamInterface, and can just inherit from ::testing::TestWithParam.
 
 template <typename T>
 class TestWithParam : public Test, public WithParamInterface<T> {
 };
 
 // Macros for indicating success/failure in test code.
 
 // Skips test in runtime.
 // Skipping test aborts current function.
 // Skipped tests are neither successful nor failed.
 #define GTEST_SKIP() GTEST_SKIP_("Skipped")
 
 // ADD_FAILURE unconditionally adds a failure to the current test.
 // SUCCEED generates a success - it doesn't automatically make the
 // current test successful, as a test is only successful when it has
 // no failure.
 //
 // EXPECT_* verifies that a certain condition is satisfied.  If not,
 // it behaves like ADD_FAILURE.  In particular:
 //
 //   EXPECT_TRUE  verifies that a Boolean condition is true.
 //   EXPECT_FALSE verifies that a Boolean condition is false.
 //
 // FAIL and ASSERT_* are similar to ADD_FAILURE and EXPECT_*, except
 // that they will also abort the current function on failure.  People
 // usually want the fail-fast behavior of FAIL and ASSERT_*, but those
 // writing data-driven tests often find themselves using ADD_FAILURE
 // and EXPECT_* more.
 
 // Generates a nonfatal failure with a generic message.
 #define ADD_FAILURE() GTEST_NONFATAL_FAILURE_("Failed")
 
 // Generates a nonfatal failure at the given source file location with
 // a generic message.
 #define ADD_FAILURE_AT(file, line) \
   GTEST_MESSAGE_AT_(file, line, "Failed", \
                     ::testing::TestPartResult::kNonFatalFailure)
 
 // Generates a fatal failure with a generic message.
 #define GTEST_FAIL() GTEST_FATAL_FAILURE_("Failed")
 
 // Like GTEST_FAIL(), but at the given source file location.
 #define GTEST_FAIL_AT(file, line)         \
   GTEST_MESSAGE_AT_(file, line, "Failed", \
                     ::testing::TestPartResult::kFatalFailure)
 
 // Define this macro to 1 to omit the definition of FAIL(), which is a
 // generic name and clashes with some other libraries.
 #if !GTEST_DONT_DEFINE_FAIL
 # define FAIL() GTEST_FAIL()
 #endif
 
 // Generates a success with a generic message.
 #define GTEST_SUCCEED() GTEST_SUCCESS_("Succeeded")
 
 // Define this macro to 1 to omit the definition of SUCCEED(), which
 // is a generic name and clashes with some other libraries.
 #if !GTEST_DONT_DEFINE_SUCCEED
 # define SUCCEED() GTEST_SUCCEED()
 #endif
 
 // Macros for testing exceptions.
 //
 //    * {ASSERT|EXPECT}_THROW(statement, expected_exception):
 //         Tests that the statement throws the expected exception.
 //    * {ASSERT|EXPECT}_NO_THROW(statement):
 //         Tests that the statement doesn't throw any exception.
 //    * {ASSERT|EXPECT}_ANY_THROW(statement):
 //         Tests that the statement throws an exception.
 
 #define EXPECT_THROW(statement, expected_exception) \
   GTEST_TEST_THROW_(statement, expected_exception, GTEST_NONFATAL_FAILURE_)
 #define EXPECT_NO_THROW(statement) \
   GTEST_TEST_NO_THROW_(statement, GTEST_NONFATAL_FAILURE_)
 #define EXPECT_ANY_THROW(statement) \
   GTEST_TEST_ANY_THROW_(statement, GTEST_NONFATAL_FAILURE_)
 #define ASSERT_THROW(statement, expected_exception) \
   GTEST_TEST_THROW_(statement, expected_exception, GTEST_FATAL_FAILURE_)
 #define ASSERT_NO_THROW(statement) \
   GTEST_TEST_NO_THROW_(statement, GTEST_FATAL_FAILURE_)
 #define ASSERT_ANY_THROW(statement) \
   GTEST_TEST_ANY_THROW_(statement, GTEST_FATAL_FAILURE_)
 
 // Boolean assertions. Condition can be either a Boolean expression or an
 // AssertionResult. For more information on how to use AssertionResult with
 // these macros see comments on that class.
 #define EXPECT_TRUE(condition) \
   GTEST_TEST_BOOLEAN_(condition, #condition, false, true, \
                       GTEST_NONFATAL_FAILURE_)
 #define EXPECT_FALSE(condition) \
   GTEST_TEST_BOOLEAN_(!(condition), #condition, true, false, \
                       GTEST_NONFATAL_FAILURE_)
 #define ASSERT_TRUE(condition) \
   GTEST_TEST_BOOLEAN_(condition, #condition, false, true, \
                       GTEST_FATAL_FAILURE_)
 #define ASSERT_FALSE(condition) \
   GTEST_TEST_BOOLEAN_(!(condition), #condition, true, false, \
                       GTEST_FATAL_FAILURE_)
 
 // Macros for testing equalities and inequalities.
 //
 //    * {ASSERT|EXPECT}_EQ(v1, v2): Tests that v1 == v2
 //    * {ASSERT|EXPECT}_NE(v1, v2): Tests that v1 != v2
 //    * {ASSERT|EXPECT}_LT(v1, v2): Tests that v1 < v2
 //    * {ASSERT|EXPECT}_LE(v1, v2): Tests that v1 <= v2
 //    * {ASSERT|EXPECT}_GT(v1, v2): Tests that v1 > v2
 //    * {ASSERT|EXPECT}_GE(v1, v2): Tests that v1 >= v2
 //
 // When they are not, Google Test prints both the tested expressions and
 // their actual values.  The values must be compatible built-in types,
 // or you will get a compiler error.  By "compatible" we mean that the
 // values can be compared by the respective operator.
 //
 // Note:
 //
 //   1. It is possible to make a user-defined type work with
 //   {ASSERT|EXPECT}_??(), but that requires overloading the
 //   comparison operators and is thus discouraged by the Google C++
 //   Usage Guide.  Therefore, you are advised to use the
 //   {ASSERT|EXPECT}_TRUE() macro to assert that two objects are
 //   equal.
 //
 //   2. The {ASSERT|EXPECT}_??() macros do pointer comparisons on
 //   pointers (in particular, C strings).  Therefore, if you use it
 //   with two C strings, you are testing how their locations in memory
 //   are related, not how their content is related.  To compare two C
 //   strings by content, use {ASSERT|EXPECT}_STR*().
 //
 //   3. {ASSERT|EXPECT}_EQ(v1, v2) is preferred to
 //   {ASSERT|EXPECT}_TRUE(v1 == v2), as the former tells you
 //   what the actual value is when it fails, and similarly for the
 //   other comparisons.
 //
 //   4. Do not depend on the order in which {ASSERT|EXPECT}_??()
 //   evaluate their arguments, which is undefined.
 //
 //   5. These macros evaluate their arguments exactly once.
 //
 // Examples:
 //
 //   EXPECT_NE(Foo(), 5);
 //   EXPECT_EQ(a_pointer, NULL);
 //   ASSERT_LT(i, array_size);
 //   ASSERT_GT(records.size(), 0) << "There is no record left.";
 
 #define EXPECT_EQ(val1, val2) \
   EXPECT_PRED_FORMAT2(::testing::internal::EqHelper::Compare, val1, val2)
 #define EXPECT_NE(val1, val2) \
   EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperNE, val1, val2)
 #define EXPECT_LE(val1, val2) \
   EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperLE, val1, val2)
 #define EXPECT_LT(val1, val2) \
   EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperLT, val1, val2)
 #define EXPECT_GE(val1, val2) \
   EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperGE, val1, val2)
 #define EXPECT_GT(val1, val2) \
   EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperGT, val1, val2)
 
 #define GTEST_ASSERT_EQ(val1, val2) \
   ASSERT_PRED_FORMAT2(::testing::internal::EqHelper::Compare, val1, val2)
 #define GTEST_ASSERT_NE(val1, val2) \
   ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperNE, val1, val2)
 #define GTEST_ASSERT_LE(val1, val2) \
   ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperLE, val1, val2)
 #define GTEST_ASSERT_LT(val1, val2) \
   ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperLT, val1, val2)
 #define GTEST_ASSERT_GE(val1, val2) \
   ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperGE, val1, val2)
 #define GTEST_ASSERT_GT(val1, val2) \
   ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperGT, val1, val2)
 
 // Define macro GTEST_DONT_DEFINE_ASSERT_XY to 1 to omit the definition of
 // ASSERT_XY(), which clashes with some users' own code.
 
 #if !GTEST_DONT_DEFINE_ASSERT_EQ
 # define ASSERT_EQ(val1, val2) GTEST_ASSERT_EQ(val1, val2)
 #endif
 
 #if !GTEST_DONT_DEFINE_ASSERT_NE
 # define ASSERT_NE(val1, val2) GTEST_ASSERT_NE(val1, val2)
 #endif
 
 #if !GTEST_DONT_DEFINE_ASSERT_LE
 # define ASSERT_LE(val1, val2) GTEST_ASSERT_LE(val1, val2)
 #endif
 
 #if !GTEST_DONT_DEFINE_ASSERT_LT
 # define ASSERT_LT(val1, val2) GTEST_ASSERT_LT(val1, val2)
 #endif
 
 #if !GTEST_DONT_DEFINE_ASSERT_GE
 # define ASSERT_GE(val1, val2) GTEST_ASSERT_GE(val1, val2)
 #endif
 
 #if !GTEST_DONT_DEFINE_ASSERT_GT
 # define ASSERT_GT(val1, val2) GTEST_ASSERT_GT(val1, val2)
 #endif
 
 // C-string Comparisons.  All tests treat NULL and any non-NULL string
 // as different.  Two NULLs are equal.
 //
 //    * {ASSERT|EXPECT}_STREQ(s1, s2):     Tests that s1 == s2
 //    * {ASSERT|EXPECT}_STRNE(s1, s2):     Tests that s1 != s2
 //    * {ASSERT|EXPECT}_STRCASEEQ(s1, s2): Tests that s1 == s2, ignoring case
 //    * {ASSERT|EXPECT}_STRCASENE(s1, s2): Tests that s1 != s2, ignoring case
 //
 // For wide or narrow string objects, you can use the
 // {ASSERT|EXPECT}_??() macros.
 //
 // Don't depend on the order in which the arguments are evaluated,
 // which is undefined.
 //
 // These macros evaluate their arguments exactly once.
 
 #define EXPECT_STREQ(s1, s2) \
   EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTREQ, s1, s2)
 #define EXPECT_STRNE(s1, s2) \
   EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTRNE, s1, s2)
 #define EXPECT_STRCASEEQ(s1, s2) \
   EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASEEQ, s1, s2)
 #define EXPECT_STRCASENE(s1, s2)\
   EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASENE, s1, s2)
 
 #define ASSERT_STREQ(s1, s2) \
   ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTREQ, s1, s2)
 #define ASSERT_STRNE(s1, s2) \
   ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTRNE, s1, s2)
 #define ASSERT_STRCASEEQ(s1, s2) \
   ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASEEQ, s1, s2)
 #define ASSERT_STRCASENE(s1, s2)\
   ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperSTRCASENE, s1, s2)
 
 // Macros for comparing floating-point numbers.
 //
 //    * {ASSERT|EXPECT}_FLOAT_EQ(val1, val2):
 //         Tests that two float values are almost equal.
 //    * {ASSERT|EXPECT}_DOUBLE_EQ(val1, val2):
 //         Tests that two double values are almost equal.
 //    * {ASSERT|EXPECT}_NEAR(v1, v2, abs_error):
 //         Tests that v1 and v2 are within the given distance to each other.
 //
 // Google Test uses ULP-based comparison to automatically pick a default
 // error bound that is appropriate for the operands.  See the
 // FloatingPoint template class in gtest-internal.h if you are
 // interested in the implementation details.
 
 #define EXPECT_FLOAT_EQ(val1, val2)\
   EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<float>, \
                       val1, val2)
 
 #define EXPECT_DOUBLE_EQ(val1, val2)\
   EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<double>, \
                       val1, val2)
 
 #define ASSERT_FLOAT_EQ(val1, val2)\
   ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<float>, \
                       val1, val2)
 
 #define ASSERT_DOUBLE_EQ(val1, val2)\
   ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperFloatingPointEQ<double>, \
                       val1, val2)
 
 #define EXPECT_NEAR(val1, val2, abs_error)\
   EXPECT_PRED_FORMAT3(::testing::internal::DoubleNearPredFormat, \
                       val1, val2, abs_error)
 
 #define ASSERT_NEAR(val1, val2, abs_error)\
   ASSERT_PRED_FORMAT3(::testing::internal::DoubleNearPredFormat, \
                       val1, val2, abs_error)
 
 // These predicate format functions work on floating-point values, and
 // can be used in {ASSERT|EXPECT}_PRED_FORMAT2*(), e.g.
 //
 //   EXPECT_PRED_FORMAT2(testing::DoubleLE, Foo(), 5.0);
 
 // Asserts that val1 is less than, or almost equal to, val2.  Fails
 // otherwise.  In particular, it fails if either val1 or val2 is NaN.
 GTEST_API_ AssertionResult FloatLE(const char* expr1, const char* expr2,
                                    float val1, float val2);
 GTEST_API_ AssertionResult DoubleLE(const char* expr1, const char* expr2,
                                     double val1, double val2);
 
 
 #if GTEST_OS_WINDOWS
 
 // Macros that test for HRESULT failure and success, these are only useful
 // on Windows, and rely on Windows SDK macros and APIs to compile.
 //
 //    * {ASSERT|EXPECT}_HRESULT_{SUCCEEDED|FAILED}(expr)
 //
 // When expr unexpectedly fails or succeeds, Google Test prints the
 // expected result and the actual result with both a human-readable
 // string representation of the error, if available, as well as the
 // hex result code.
 # define EXPECT_HRESULT_SUCCEEDED(expr) \
     EXPECT_PRED_FORMAT1(::testing::internal::IsHRESULTSuccess, (expr))
 
 # define ASSERT_HRESULT_SUCCEEDED(expr) \
     ASSERT_PRED_FORMAT1(::testing::internal::IsHRESULTSuccess, (expr))
 
 # define EXPECT_HRESULT_FAILED(expr) \
     EXPECT_PRED_FORMAT1(::testing::internal::IsHRESULTFailure, (expr))
 
 # define ASSERT_HRESULT_FAILED(expr) \
     ASSERT_PRED_FORMAT1(::testing::internal::IsHRESULTFailure, (expr))
 
 #endif  // GTEST_OS_WINDOWS
 
 // Macros that execute statement and check that it doesn't generate new fatal
 // failures in the current thread.
 //
 //   * {ASSERT|EXPECT}_NO_FATAL_FAILURE(statement);
 //
 // Examples:
 //
 //   EXPECT_NO_FATAL_FAILURE(Process());
 //   ASSERT_NO_FATAL_FAILURE(Process()) << "Process() failed";
 //
 #define ASSERT_NO_FATAL_FAILURE(statement) \
     GTEST_TEST_NO_FATAL_FAILURE_(statement, GTEST_FATAL_FAILURE_)
 #define EXPECT_NO_FATAL_FAILURE(statement) \
     GTEST_TEST_NO_FATAL_FAILURE_(statement, GTEST_NONFATAL_FAILURE_)
 
 // Causes a trace (including the given source file path and line number,
 // and the given message) to be included in every test failure message generated
 // by code in the scope of the lifetime of an instance of this class. The effect
 // is undone with the destruction of the instance.
 //
 // The message argument can be anything streamable to std::ostream.
 //
 // Example:
 //   testing::ScopedTrace trace("file.cc", 123, "message");
 //
 class GTEST_API_ ScopedTrace {
  public:
   // The c'tor pushes the given source file location and message onto
   // a trace stack maintained by Google Test.
 
   // Template version. Uses Message() to convert the values into strings.
   // Slow, but flexible.
   template <typename T>
   ScopedTrace(const char* file, int line, const T& message) {
     PushTrace(file, line, (Message() << message).GetString());
   }
 
   // Optimize for some known types.
   ScopedTrace(const char* file, int line, const char* message) {
     PushTrace(file, line, message ? message : "(null)");
   }
 
   ScopedTrace(const char* file, int line, const std::string& message) {
     PushTrace(file, line, message);
   }
 
   // The d'tor pops the info pushed by the c'tor.
   //
   // Note that the d'tor is not virtual in order to be efficient.
   // Don't inherit from ScopedTrace!
   ~ScopedTrace();
 
  private:
   void PushTrace(const char* file, int line, std::string message);
 
   GTEST_DISALLOW_COPY_AND_ASSIGN_(ScopedTrace);
 } GTEST_ATTRIBUTE_UNUSED_;  // A ScopedTrace object does its job in its
                             // c'tor and d'tor.  Therefore it doesn't
                             // need to be used otherwise.
 
 // Causes a trace (including the source file path, the current line
 // number, and the given message) to be included in every test failure
 // message generated by code in the current scope.  The effect is
 // undone when the control leaves the current scope.
 //
 // The message argument can be anything streamable to std::ostream.
 //
 // In the implementation, we include the current line number as part
 // of the dummy variable name, thus allowing multiple SCOPED_TRACE()s
 // to appear in the same block - as long as they are on different
 // lines.
 //
 // Assuming that each thread maintains its own stack of traces.
 // Therefore, a SCOPED_TRACE() would (correctly) only affect the
 // assertions in its own thread.
 #define SCOPED_TRACE(message) \
   ::testing::ScopedTrace GTEST_CONCAT_TOKEN_(gtest_trace_, __LINE__)(\
     __FILE__, __LINE__, (message))
 
 
 // Compile-time assertion for type equality.
 // StaticAssertTypeEq<type1, type2>() compiles if type1 and type2 are
 // the same type.  The value it returns is not interesting.
 //
 // Instead of making StaticAssertTypeEq a class template, we make it a
 // function template that invokes a helper class template.  This
 // prevents a user from misusing StaticAssertTypeEq<T1, T2> by
 // defining objects of that type.
 //
 // CAVEAT:
 //
 // When used inside a method of a class template,
 // StaticAssertTypeEq<T1, T2>() is effective ONLY IF the method is
 // instantiated.  For example, given:
 //
 //   template <typename T> class Foo {
 //    public:
 //     void Bar() { testing::StaticAssertTypeEq<int, T>(); }
 //   };
 //
 // the code:
 //
 //   void Test1() { Foo<bool> foo; }
 //
 // will NOT generate a compiler error, as Foo<bool>::Bar() is never
 // actually instantiated.  Instead, you need:
 //
 //   void Test2() { Foo<bool> foo; foo.Bar(); }
 //
 // to cause a compiler error.
 template <typename T1, typename T2>
 bool StaticAssertTypeEq() {
   (void)internal::StaticAssertTypeEqHelper<T1, T2>();
   return true;
 }
 
 // Defines a test.
 //
 // The first parameter is the name of the test suite, and the second
 // parameter is the name of the test within the test suite.
 //
 // The convention is to end the test suite name with "Test".  For
 // example, a test suite for the Foo class can be named FooTest.
 //
 // Test code should appear between braces after an invocation of
 // this macro.  Example:
 //
 //   TEST(FooTest, InitializesCorrectly) {
 //     Foo foo;
 //     EXPECT_TRUE(foo.StatusIsOK());
 //   }
 
 // Note that we call GetTestTypeId() instead of GetTypeId<
 // ::testing::Test>() here to get the type ID of testing::Test.  This
 // is to work around a suspected linker bug when using Google Test as
 // a framework on Mac OS X.  The bug causes GetTypeId<
 // ::testing::Test>() to return different values depending on whether
 // the call is from the Google Test framework itself or from user test
 // code.  GetTestTypeId() is guaranteed to always return the same
 // value, as it always calls GetTypeId<>() from the Google Test
 // framework.
 #define GTEST_TEST(test_suite_name, test_name)             \
   GTEST_TEST_(test_suite_name, test_name, ::testing::Test, \
               ::testing::internal::GetTestTypeId())
 
 // Define this macro to 1 to omit the definition of TEST(), which
 // is a generic name and clashes with some other libraries.
 #if !GTEST_DONT_DEFINE_TEST
 #define TEST(test_suite_name, test_name) GTEST_TEST(test_suite_name, test_name)
 #endif
 
 // Defines a test that uses a test fixture.
 //
 // The first parameter is the name of the test fixture class, which
 // also doubles as the test suite name.  The second parameter is the
 // name of the test within the test suite.
 //
 // A test fixture class must be declared earlier.  The user should put
 // the test code between braces after using this macro.  Example:
 //
 //   class FooTest : public testing::Test {
 //    protected:
 //     void SetUp() override { b_.AddElement(3); }
 //
 //     Foo a_;
 //     Foo b_;
 //   };
 //
 //   TEST_F(FooTest, InitializesCorrectly) {
 //     EXPECT_TRUE(a_.StatusIsOK());
 //   }
 //
 //   TEST_F(FooTest, ReturnsElementCountCorrectly) {
 //     EXPECT_EQ(a_.size(), 0);
 //     EXPECT_EQ(b_.size(), 1);
 //   }
 //
 // GOOGLETEST_CM0011 DO NOT DELETE
 #define TEST_F(test_fixture, test_name)\
   GTEST_TEST_(test_fixture, test_name, test_fixture, \
               ::testing::internal::GetTypeId<test_fixture>())
 
 // Returns a path to temporary directory.
 // Tries to determine an appropriate directory for the platform.
 GTEST_API_ std::string TempDir();
 
 #ifdef _MSC_VER
 #  pragma warning(pop)
 #endif
 
 // Dynamically registers a test with the framework.
 //
 // This is an advanced API only to be used when the `TEST` macros are
 // insufficient. The macros should be preferred when possible, as they avoid
 // most of the complexity of calling this function.
 //
 // The `factory` argument is a factory callable (move-constructible) object or
 // function pointer that creates a new instance of the Test object. It
 // handles ownership to the caller. The signature of the callable is
 // `Fixture*()`, where `Fixture` is the test fixture class for the test. All
 // tests registered with the same `test_suite_name` must return the same
 // fixture type. This is checked at runtime.
 //
 // The framework will infer the fixture class from the factory and will call
 // the `SetUpTestSuite` and `TearDownTestSuite` for it.
 //
 // Must be called before `RUN_ALL_TESTS()` is invoked, otherwise behavior is
 // undefined.
 //
 // Use case example:
 //
 // class MyFixture : public ::testing::Test {
 //  public:
 //   // All of these optional, just like in regular macro usage.
 //   static void SetUpTestSuite() { ... }
 //   static void TearDownTestSuite() { ... }
 //   void SetUp() override { ... }
 //   void TearDown() override { ... }
 // };
 //
 // class MyTest : public MyFixture {
 //  public:
 //   explicit MyTest(int data) : data_(data) {}
 //   void TestBody() override { ... }
 //
 //  private:
 //   int data_;
 // };
 //
 // void RegisterMyTests(const std::vector<int>& values) {
 //   for (int v : values) {
 //     ::testing::RegisterTest(
 //         "MyFixture", ("Test" + std::to_string(v)).c_str(), nullptr,
 //         std::to_string(v).c_str(),
 //         __FILE__, __LINE__,
 //         // Important to use the fixture type as the return type here.
 //         [=]() -> MyFixture* { return new MyTest(v); });
 //   }
 // }
 // ...
 // int main(int argc, char** argv) {
 //   std::vector<int> values_to_test = LoadValuesFromConfig();
 //   RegisterMyTests(values_to_test);
 //   ...
 //   return RUN_ALL_TESTS();
 // }
 //
 template <int&... ExplicitParameterBarrier, typename Factory>
 TestInfo* RegisterTest(const char* test_suite_name, const char* test_name,
                        const char* type_param, const char* value_param,
                        const char* file, int line, Factory factory) {
   using TestT = typename std::remove_pointer<decltype(factory())>::type;
 
   class FactoryImpl : public internal::TestFactoryBase {
    public:
     explicit FactoryImpl(Factory f) : factory_(std::move(f)) {}
     Test* CreateTest() override { return factory_(); }
 
    private:
     Factory factory_;
   };
 
   return internal::MakeAndRegisterTestInfo(
       test_suite_name, test_name, type_param, value_param,
       internal::CodeLocation(file, line), internal::GetTypeId<TestT>(),
       internal::SuiteApiResolver<TestT>::GetSetUpCaseOrSuite(file, line),
       internal::SuiteApiResolver<TestT>::GetTearDownCaseOrSuite(file, line),
       new FactoryImpl{std::move(factory)});
 }
 
 }  // namespace testing
 
 // Use this function in main() to run all tests.  It returns 0 if all
 // tests are successful, or 1 otherwise.
 //
 // RUN_ALL_TESTS() should be invoked after the command line has been
 // parsed by InitGoogleTest().
 //
 // This function was formerly a macro; thus, it is in the global
 // namespace and has an all-caps name.
 int RUN_ALL_TESTS() GTEST_MUST_USE_RESULT_;
 
 inline int RUN_ALL_TESTS() {
   return ::testing::UnitTest::GetInstance()->Run();
 }
 
 GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
 
 #endif  // GTEST_INCLUDE_GTEST_GTEST_H_
diff --git a/googletest/include/gtest/internal/gtest-internal.h b/googletest/include/gtest/internal/gtest-internal.h
index 08531d8c..8b05062c 100644
--- a/googletest/include/gtest/internal/gtest-internal.h
+++ b/googletest/include/gtest/internal/gtest-internal.h
@@ -1,1428 +1,1421 @@
 // Copyright 2005, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //
 // The Google C++ Testing and Mocking Framework (Google Test)
 //
 // This header file declares functions and macros used internally by
 // Google Test.  They are subject to change without notice.
 
 // GOOGLETEST_CM0001 DO NOT DELETE
 
 #ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
 #define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
 
 #include "gtest/internal/gtest-port.h"
 
 #if GTEST_OS_LINUX
 # include <stdlib.h>
 # include <sys/types.h>
 # include <sys/wait.h>
 # include <unistd.h>
 #endif  // GTEST_OS_LINUX
 
 #if GTEST_HAS_EXCEPTIONS
 # include <stdexcept>
 #endif
 
 #include <ctype.h>
 #include <float.h>
 #include <string.h>
 #include <iomanip>
 #include <limits>
 #include <map>
 #include <set>
 #include <string>
 #include <type_traits>
 #include <vector>
 
 #include "gtest/gtest-message.h"
 #include "gtest/internal/gtest-filepath.h"
 #include "gtest/internal/gtest-string.h"
 #include "gtest/internal/gtest-type-util.h"
 
 // Due to C++ preprocessor weirdness, we need double indirection to
 // concatenate two tokens when one of them is __LINE__.  Writing
 //
 //   foo ## __LINE__
 //
 // will result in the token foo__LINE__, instead of foo followed by
 // the current line number.  For more details, see
 // http://www.parashift.com/c++-faq-lite/misc-technical-issues.html#faq-39.6
 #define GTEST_CONCAT_TOKEN_(foo, bar) GTEST_CONCAT_TOKEN_IMPL_(foo, bar)
 #define GTEST_CONCAT_TOKEN_IMPL_(foo, bar) foo ## bar
 
 // Stringifies its argument.
 #define GTEST_STRINGIFY_(name) #name
 
 namespace proto2 { class Message; }
 
 namespace testing {
 
 // Forward declarations.
 
 class AssertionResult;                 // Result of an assertion.
 class Message;                         // Represents a failure message.
 class Test;                            // Represents a test.
 class TestInfo;                        // Information about a test.
 class TestPartResult;                  // Result of a test part.
 class UnitTest;                        // A collection of test suites.
 
 template <typename T>
 ::std::string PrintToString(const T& value);
 
 namespace internal {
 
 struct TraceInfo;                      // Information about a trace point.
 class TestInfoImpl;                    // Opaque implementation of TestInfo
 class UnitTestImpl;                    // Opaque implementation of UnitTest
 
 // The text used in failure messages to indicate the start of the
 // stack trace.
 GTEST_API_ extern const char kStackTraceMarker[];
 
 // An IgnoredValue object can be implicitly constructed from ANY value.
 class IgnoredValue {
   struct Sink {};
  public:
   // This constructor template allows any value to be implicitly
   // converted to IgnoredValue.  The object has no data member and
   // doesn't try to remember anything about the argument.  We
   // deliberately omit the 'explicit' keyword in order to allow the
   // conversion to be implicit.
   // Disable the conversion if T already has a magical conversion operator.
   // Otherwise we get ambiguity.
   template <typename T,
             typename std::enable_if<!std::is_convertible<T, Sink>::value,
                                     int>::type = 0>
   IgnoredValue(const T& /* ignored */) {}  // NOLINT(runtime/explicit)
 };
 
 // Appends the user-supplied message to the Google-Test-generated message.
 GTEST_API_ std::string AppendUserMessage(
     const std::string& gtest_msg, const Message& user_msg);
 
 #if GTEST_HAS_EXCEPTIONS
 
 GTEST_DISABLE_MSC_WARNINGS_PUSH_(4275 \
 /* an exported class was derived from a class that was not exported */)
 
 // This exception is thrown by (and only by) a failed Google Test
 // assertion when GTEST_FLAG(throw_on_failure) is true (if exceptions
 // are enabled).  We derive it from std::runtime_error, which is for
 // errors presumably detectable only at run time.  Since
 // std::runtime_error inherits from std::exception, many testing
 // frameworks know how to extract and print the message inside it.
 class GTEST_API_ GoogleTestFailureException : public ::std::runtime_error {
  public:
   explicit GoogleTestFailureException(const TestPartResult& failure);
 };
 
 GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4275
 
 #endif  // GTEST_HAS_EXCEPTIONS
 
 namespace edit_distance {
 // Returns the optimal edits to go from 'left' to 'right'.
 // All edits cost the same, with replace having lower priority than
 // add/remove.
 // Simple implementation of the Wagner-Fischer algorithm.
 // See http://en.wikipedia.org/wiki/Wagner-Fischer_algorithm
 enum EditType { kMatch, kAdd, kRemove, kReplace };
 GTEST_API_ std::vector<EditType> CalculateOptimalEdits(
     const std::vector<size_t>& left, const std::vector<size_t>& right);
 
 // Same as above, but the input is represented as strings.
 GTEST_API_ std::vector<EditType> CalculateOptimalEdits(
     const std::vector<std::string>& left,
     const std::vector<std::string>& right);
 
 // Create a diff of the input strings in Unified diff format.
 GTEST_API_ std::string CreateUnifiedDiff(const std::vector<std::string>& left,
                                          const std::vector<std::string>& right,
                                          size_t context = 2);
 
 }  // namespace edit_distance
 
 // Calculate the diff between 'left' and 'right' and return it in unified diff
 // format.
 // If not null, stores in 'total_line_count' the total number of lines found
 // in left + right.
 GTEST_API_ std::string DiffStrings(const std::string& left,
                                    const std::string& right,
                                    size_t* total_line_count);
 
 // Constructs and returns the message for an equality assertion
 // (e.g. ASSERT_EQ, EXPECT_STREQ, etc) failure.
 //
 // The first four parameters are the expressions used in the assertion
 // and their values, as strings.  For example, for ASSERT_EQ(foo, bar)
 // where foo is 5 and bar is 6, we have:
 //
 //   expected_expression: "foo"
 //   actual_expression:   "bar"
 //   expected_value:      "5"
 //   actual_value:        "6"
 //
 // The ignoring_case parameter is true if the assertion is a
 // *_STRCASEEQ*.  When it's true, the string " (ignoring case)" will
 // be inserted into the message.
 GTEST_API_ AssertionResult EqFailure(const char* expected_expression,
                                      const char* actual_expression,
                                      const std::string& expected_value,
                                      const std::string& actual_value,
                                      bool ignoring_case);
 
 // Constructs a failure message for Boolean assertions such as EXPECT_TRUE.
 GTEST_API_ std::string GetBoolAssertionFailureMessage(
     const AssertionResult& assertion_result,
     const char* expression_text,
     const char* actual_predicate_value,
     const char* expected_predicate_value);
 
 // This template class represents an IEEE floating-point number
 // (either single-precision or double-precision, depending on the
 // template parameters).
 //
 // The purpose of this class is to do more sophisticated number
 // comparison.  (Due to round-off error, etc, it's very unlikely that
 // two floating-points will be equal exactly.  Hence a naive
 // comparison by the == operation often doesn't work.)
 //
 // Format of IEEE floating-point:
 //
 //   The most-significant bit being the leftmost, an IEEE
 //   floating-point looks like
 //
 //     sign_bit exponent_bits fraction_bits
 //
 //   Here, sign_bit is a single bit that designates the sign of the
 //   number.
 //
 //   For float, there are 8 exponent bits and 23 fraction bits.
 //
 //   For double, there are 11 exponent bits and 52 fraction bits.
 //
 //   More details can be found at
 //   http://en.wikipedia.org/wiki/IEEE_floating-point_standard.
 //
 // Template parameter:
 //
 //   RawType: the raw floating-point type (either float or double)
 template <typename RawType>
 class FloatingPoint {
  public:
   // Defines the unsigned integer type that has the same size as the
   // floating point number.
   typedef typename TypeWithSize<sizeof(RawType)>::UInt Bits;
 
   // Constants.
 
   // # of bits in a number.
   static const size_t kBitCount = 8*sizeof(RawType);
 
   // # of fraction bits in a number.
   static const size_t kFractionBitCount =
     std::numeric_limits<RawType>::digits - 1;
 
   // # of exponent bits in a number.
   static const size_t kExponentBitCount = kBitCount - 1 - kFractionBitCount;
 
   // The mask for the sign bit.
   static const Bits kSignBitMask = static_cast<Bits>(1) << (kBitCount - 1);
 
   // The mask for the fraction bits.
   static const Bits kFractionBitMask =
     ~static_cast<Bits>(0) >> (kExponentBitCount + 1);
 
   // The mask for the exponent bits.
   static const Bits kExponentBitMask = ~(kSignBitMask | kFractionBitMask);
 
   // How many ULP's (Units in the Last Place) we want to tolerate when
   // comparing two numbers.  The larger the value, the more error we
   // allow.  A 0 value means that two numbers must be exactly the same
   // to be considered equal.
   //
   // The maximum error of a single floating-point operation is 0.5
   // units in the last place.  On Intel CPU's, all floating-point
   // calculations are done with 80-bit precision, while double has 64
   // bits.  Therefore, 4 should be enough for ordinary use.
   //
   // See the following article for more details on ULP:
   // http://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/
   static const size_t kMaxUlps = 4;
 
   // Constructs a FloatingPoint from a raw floating-point number.
   //
   // On an Intel CPU, passing a non-normalized NAN (Not a Number)
   // around may change its bits, although the new value is guaranteed
   // to be also a NAN.  Therefore, don't expect this constructor to
   // preserve the bits in x when x is a NAN.
   explicit FloatingPoint(const RawType& x) { u_.value_ = x; }
 
   // Static methods
 
   // Reinterprets a bit pattern as a floating-point number.
   //
   // This function is needed to test the AlmostEquals() method.
   static RawType ReinterpretBits(const Bits bits) {
     FloatingPoint fp(0);
     fp.u_.bits_ = bits;
     return fp.u_.value_;
   }
 
   // Returns the floating-point number that represent positive infinity.
   static RawType Infinity() {
     return ReinterpretBits(kExponentBitMask);
   }
 
   // Returns the maximum representable finite floating-point number.
   static RawType Max();
 
   // Non-static methods
 
   // Returns the bits that represents this number.
   const Bits &bits() const { return u_.bits_; }
 
   // Returns the exponent bits of this number.
   Bits exponent_bits() const { return kExponentBitMask & u_.bits_; }
 
   // Returns the fraction bits of this number.
   Bits fraction_bits() const { return kFractionBitMask & u_.bits_; }
 
   // Returns the sign bit of this number.
   Bits sign_bit() const { return kSignBitMask & u_.bits_; }
 
   // Returns true if this is NAN (not a number).
   bool is_nan() const {
     // It's a NAN if the exponent bits are all ones and the fraction
     // bits are not entirely zeros.
     return (exponent_bits() == kExponentBitMask) && (fraction_bits() != 0);
   }
 
   // Returns true if this number is at most kMaxUlps ULP's away from
   // rhs.  In particular, this function:
   //
   //   - returns false if either number is (or both are) NAN.
   //   - treats really large numbers as almost equal to infinity.
   //   - thinks +0.0 and -0.0 are 0 DLP's apart.
   bool AlmostEquals(const FloatingPoint& rhs) const {
     // The IEEE standard says that any comparison operation involving
     // a NAN must return false.
     if (is_nan() || rhs.is_nan()) return false;
 
     return DistanceBetweenSignAndMagnitudeNumbers(u_.bits_, rhs.u_.bits_)
         <= kMaxUlps;
   }
 
  private:
   // The data type used to store the actual floating-point number.
   union FloatingPointUnion {
     RawType value_;  // The raw floating-point number.
     Bits bits_;      // The bits that represent the number.
   };
 
   // Converts an integer from the sign-and-magnitude representation to
   // the biased representation.  More precisely, let N be 2 to the
   // power of (kBitCount - 1), an integer x is represented by the
   // unsigned number x + N.
   //
   // For instance,
   //
   //   -N + 1 (the most negative number representable using
   //          sign-and-magnitude) is represented by 1;
   //   0      is represented by N; and
   //   N - 1  (the biggest number representable using
   //          sign-and-magnitude) is represented by 2N - 1.
   //
   // Read http://en.wikipedia.org/wiki/Signed_number_representations
   // for more details on signed number representations.
   static Bits SignAndMagnitudeToBiased(const Bits &sam) {
     if (kSignBitMask & sam) {
       // sam represents a negative number.
       return ~sam + 1;
     } else {
       // sam represents a positive number.
       return kSignBitMask | sam;
     }
   }
 
   // Given two numbers in the sign-and-magnitude representation,
   // returns the distance between them as an unsigned number.
   static Bits DistanceBetweenSignAndMagnitudeNumbers(const Bits &sam1,
                                                      const Bits &sam2) {
     const Bits biased1 = SignAndMagnitudeToBiased(sam1);
     const Bits biased2 = SignAndMagnitudeToBiased(sam2);
     return (biased1 >= biased2) ? (biased1 - biased2) : (biased2 - biased1);
   }
 
   FloatingPointUnion u_;
 };
 
 // We cannot use std::numeric_limits<T>::max() as it clashes with the max()
 // macro defined by <windows.h>.
 template <>
 inline float FloatingPoint<float>::Max() { return FLT_MAX; }
 template <>
 inline double FloatingPoint<double>::Max() { return DBL_MAX; }
 
 // Typedefs the instances of the FloatingPoint template class that we
 // care to use.
 typedef FloatingPoint<float> Float;
 typedef FloatingPoint<double> Double;
 
 // In order to catch the mistake of putting tests that use different
 // test fixture classes in the same test suite, we need to assign
 // unique IDs to fixture classes and compare them.  The TypeId type is
 // used to hold such IDs.  The user should treat TypeId as an opaque
 // type: the only operation allowed on TypeId values is to compare
 // them for equality using the == operator.
 typedef const void* TypeId;
 
 template <typename T>
 class TypeIdHelper {
  public:
   // dummy_ must not have a const type.  Otherwise an overly eager
   // compiler (e.g. MSVC 7.1 & 8.0) may try to merge
   // TypeIdHelper<T>::dummy_ for different Ts as an "optimization".
   static bool dummy_;
 };
 
 template <typename T>
 bool TypeIdHelper<T>::dummy_ = false;
 
 // GetTypeId<T>() returns the ID of type T.  Different values will be
 // returned for different types.  Calling the function twice with the
 // same type argument is guaranteed to return the same ID.
 template <typename T>
 TypeId GetTypeId() {
   // The compiler is required to allocate a different
   // TypeIdHelper<T>::dummy_ variable for each T used to instantiate
   // the template.  Therefore, the address of dummy_ is guaranteed to
   // be unique.
   return &(TypeIdHelper<T>::dummy_);
 }
 
 // Returns the type ID of ::testing::Test.  Always call this instead
 // of GetTypeId< ::testing::Test>() to get the type ID of
 // ::testing::Test, as the latter may give the wrong result due to a
 // suspected linker bug when compiling Google Test as a Mac OS X
 // framework.
 GTEST_API_ TypeId GetTestTypeId();
 
 // Defines the abstract factory interface that creates instances
 // of a Test object.
 class TestFactoryBase {
  public:
   virtual ~TestFactoryBase() {}
 
   // Creates a test instance to run. The instance is both created and destroyed
   // within TestInfoImpl::Run()
   virtual Test* CreateTest() = 0;
 
  protected:
   TestFactoryBase() {}
 
  private:
   GTEST_DISALLOW_COPY_AND_ASSIGN_(TestFactoryBase);
 };
 
 // This class provides implementation of TeastFactoryBase interface.
 // It is used in TEST and TEST_F macros.
 template <class TestClass>
 class TestFactoryImpl : public TestFactoryBase {
  public:
   Test* CreateTest() override { return new TestClass; }
 };
 
 #if GTEST_OS_WINDOWS
 
 // Predicate-formatters for implementing the HRESULT checking macros
 // {ASSERT|EXPECT}_HRESULT_{SUCCEEDED|FAILED}
 // We pass a long instead of HRESULT to avoid causing an
 // include dependency for the HRESULT type.
 GTEST_API_ AssertionResult IsHRESULTSuccess(const char* expr,
                                             long hr);  // NOLINT
 GTEST_API_ AssertionResult IsHRESULTFailure(const char* expr,
                                             long hr);  // NOLINT
 
 #endif  // GTEST_OS_WINDOWS
 
 // Types of SetUpTestSuite() and TearDownTestSuite() functions.
 using SetUpTestSuiteFunc = void (*)();
 using TearDownTestSuiteFunc = void (*)();
 
 struct CodeLocation {
   CodeLocation(const std::string& a_file, int a_line)
       : file(a_file), line(a_line) {}
 
   std::string file;
   int line;
 };
 
 //  Helper to identify which setup function for TestCase / TestSuite to call.
 //  Only one function is allowed, either TestCase or TestSute but not both.
 
 // Utility functions to help SuiteApiResolver
 using SetUpTearDownSuiteFuncType = void (*)();
 
 inline SetUpTearDownSuiteFuncType GetNotDefaultOrNull(
     SetUpTearDownSuiteFuncType a, SetUpTearDownSuiteFuncType def) {
   return a == def ? nullptr : a;
 }
 
 template <typename T>
 //  Note that SuiteApiResolver inherits from T because
 //  SetUpTestSuite()/TearDownTestSuite() could be protected. Ths way
 //  SuiteApiResolver can access them.
 struct SuiteApiResolver : T {
   // testing::Test is only forward declared at this point. So we make it a
   // dependend class for the compiler to be OK with it.
   using Test =
       typename std::conditional<sizeof(T) != 0, ::testing::Test, void>::type;
 
   static SetUpTearDownSuiteFuncType GetSetUpCaseOrSuite(const char* filename,
                                                         int line_num) {
     SetUpTearDownSuiteFuncType test_case_fp =
         GetNotDefaultOrNull(&T::SetUpTestCase, &Test::SetUpTestCase);
     SetUpTearDownSuiteFuncType test_suite_fp =
         GetNotDefaultOrNull(&T::SetUpTestSuite, &Test::SetUpTestSuite);
 
     GTEST_CHECK_(!test_case_fp || !test_suite_fp)
         << "Test can not provide both SetUpTestSuite and SetUpTestCase, please "
            "make sure there is only one present at "
         << filename << ":" << line_num;
 
     return test_case_fp != nullptr ? test_case_fp : test_suite_fp;
   }
 
   static SetUpTearDownSuiteFuncType GetTearDownCaseOrSuite(const char* filename,
                                                            int line_num) {
     SetUpTearDownSuiteFuncType test_case_fp =
         GetNotDefaultOrNull(&T::TearDownTestCase, &Test::TearDownTestCase);
     SetUpTearDownSuiteFuncType test_suite_fp =
         GetNotDefaultOrNull(&T::TearDownTestSuite, &Test::TearDownTestSuite);
 
     GTEST_CHECK_(!test_case_fp || !test_suite_fp)
         << "Test can not provide both TearDownTestSuite and TearDownTestCase,"
            " please make sure there is only one present at"
         << filename << ":" << line_num;
 
     return test_case_fp != nullptr ? test_case_fp : test_suite_fp;
   }
 };
 
 // Creates a new TestInfo object and registers it with Google Test;
 // returns the created object.
 //
 // Arguments:
 //
 //   test_suite_name:   name of the test suite
 //   name:             name of the test
 //   type_param        the name of the test's type parameter, or NULL if
 //                     this is not a typed or a type-parameterized test.
 //   value_param       text representation of the test's value parameter,
 //                     or NULL if this is not a type-parameterized test.
 //   code_location:    code location where the test is defined
 //   fixture_class_id: ID of the test fixture class
 //   set_up_tc:        pointer to the function that sets up the test suite
 //   tear_down_tc:     pointer to the function that tears down the test suite
 //   factory:          pointer to the factory that creates a test object.
 //                     The newly created TestInfo instance will assume
 //                     ownership of the factory object.
 GTEST_API_ TestInfo* MakeAndRegisterTestInfo(
     const char* test_suite_name, const char* name, const char* type_param,
     const char* value_param, CodeLocation code_location,
     TypeId fixture_class_id, SetUpTestSuiteFunc set_up_tc,
     TearDownTestSuiteFunc tear_down_tc, TestFactoryBase* factory);
 
 // If *pstr starts with the given prefix, modifies *pstr to be right
 // past the prefix and returns true; otherwise leaves *pstr unchanged
 // and returns false.  None of pstr, *pstr, and prefix can be NULL.
 GTEST_API_ bool SkipPrefix(const char* prefix, const char** pstr);
 
 #if GTEST_HAS_TYPED_TEST || GTEST_HAS_TYPED_TEST_P
 
 GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
 /* class A needs to have dll-interface to be used by clients of class B */)
 
 // State of the definition of a type-parameterized test suite.
 class GTEST_API_ TypedTestSuitePState {
  public:
   TypedTestSuitePState() : registered_(false) {}
 
   // Adds the given test name to defined_test_names_ and return true
   // if the test suite hasn't been registered; otherwise aborts the
   // program.
   bool AddTestName(const char* file, int line, const char* case_name,
                    const char* test_name) {
     if (registered_) {
       fprintf(stderr,
               "%s Test %s must be defined before "
               "REGISTER_TYPED_TEST_SUITE_P(%s, ...).\n",
               FormatFileLocation(file, line).c_str(), test_name, case_name);
       fflush(stderr);
       posix::Abort();
     }
     registered_tests_.insert(
         ::std::make_pair(test_name, CodeLocation(file, line)));
     return true;
   }
 
   bool TestExists(const std::string& test_name) const {
     return registered_tests_.count(test_name) > 0;
   }
 
   const CodeLocation& GetCodeLocation(const std::string& test_name) const {
     RegisteredTestsMap::const_iterator it = registered_tests_.find(test_name);
     GTEST_CHECK_(it != registered_tests_.end());
     return it->second;
   }
 
   // Verifies that registered_tests match the test names in
   // defined_test_names_; returns registered_tests if successful, or
   // aborts the program otherwise.
   const char* VerifyRegisteredTestNames(
       const char* file, int line, const char* registered_tests);
 
  private:
   typedef ::std::map<std::string, CodeLocation> RegisteredTestsMap;
 
   bool registered_;
   RegisteredTestsMap registered_tests_;
 };
 
 //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 using TypedTestCasePState = TypedTestSuitePState;
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
 GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
 
 // Skips to the first non-space char after the first comma in 'str';
 // returns NULL if no comma is found in 'str'.
 inline const char* SkipComma(const char* str) {
   const char* comma = strchr(str, ',');
   if (comma == nullptr) {
     return nullptr;
   }
   while (IsSpace(*(++comma))) {}
   return comma;
 }
 
 // Returns the prefix of 'str' before the first comma in it; returns
 // the entire string if it contains no comma.
 inline std::string GetPrefixUntilComma(const char* str) {
   const char* comma = strchr(str, ',');
   return comma == nullptr ? str : std::string(str, comma);
 }
 
 // Splits a given string on a given delimiter, populating a given
 // vector with the fields.
 void SplitString(const ::std::string& str, char delimiter,
                  ::std::vector< ::std::string>* dest);
 
 // The default argument to the template below for the case when the user does
 // not provide a name generator.
 struct DefaultNameGenerator {
   template <typename T>
   static std::string GetName(int i) {
     return StreamableToString(i);
   }
 };
 
 template <typename Provided = DefaultNameGenerator>
 struct NameGeneratorSelector {
   typedef Provided type;
 };
 
 template <typename NameGenerator>
 void GenerateNamesRecursively(Types0, std::vector<std::string>*, int) {}
 
 template <typename NameGenerator, typename Types>
 void GenerateNamesRecursively(Types, std::vector<std::string>* result, int i) {
   result->push_back(NameGenerator::template GetName<typename Types::Head>(i));
   GenerateNamesRecursively<NameGenerator>(typename Types::Tail(), result,
                                           i + 1);
 }
 
 template <typename NameGenerator, typename Types>
 std::vector<std::string> GenerateNames() {
   std::vector<std::string> result;
   GenerateNamesRecursively<NameGenerator>(Types(), &result, 0);
   return result;
 }
 
 // TypeParameterizedTest<Fixture, TestSel, Types>::Register()
 // registers a list of type-parameterized tests with Google Test.  The
 // return value is insignificant - we just need to return something
 // such that we can call this function in a namespace scope.
 //
 // Implementation note: The GTEST_TEMPLATE_ macro declares a template
 // template parameter.  It's defined in gtest-type-util.h.
 template <GTEST_TEMPLATE_ Fixture, class TestSel, typename Types>
 class TypeParameterizedTest {
  public:
   // 'index' is the index of the test in the type list 'Types'
   // specified in INSTANTIATE_TYPED_TEST_SUITE_P(Prefix, TestSuite,
   // Types).  Valid values for 'index' are [0, N - 1] where N is the
   // length of Types.
   static bool Register(const char* prefix, const CodeLocation& code_location,
                        const char* case_name, const char* test_names, int index,
                        const std::vector<std::string>& type_names =
                            GenerateNames<DefaultNameGenerator, Types>()) {
     typedef typename Types::Head Type;
     typedef Fixture<Type> FixtureClass;
     typedef typename GTEST_BIND_(TestSel, Type) TestClass;
 
     // First, registers the first type-parameterized test in the type
     // list.
     MakeAndRegisterTestInfo(
         (std::string(prefix) + (prefix[0] == '\0' ? "" : "/") + case_name +
          "/" + type_names[static_cast<size_t>(index)])
             .c_str(),
         StripTrailingSpaces(GetPrefixUntilComma(test_names)).c_str(),
         GetTypeName<Type>().c_str(),
         nullptr,  // No value parameter.
         code_location, GetTypeId<FixtureClass>(),
         SuiteApiResolver<TestClass>::GetSetUpCaseOrSuite(
             code_location.file.c_str(), code_location.line),
         SuiteApiResolver<TestClass>::GetTearDownCaseOrSuite(
             code_location.file.c_str(), code_location.line),
         new TestFactoryImpl<TestClass>);
 
     // Next, recurses (at compile time) with the tail of the type list.
     return TypeParameterizedTest<Fixture, TestSel,
                                  typename Types::Tail>::Register(prefix,
                                                                  code_location,
                                                                  case_name,
                                                                  test_names,
                                                                  index + 1,
                                                                  type_names);
   }
 };
 
 // The base case for the compile time recursion.
 template <GTEST_TEMPLATE_ Fixture, class TestSel>
 class TypeParameterizedTest<Fixture, TestSel, Types0> {
  public:
   static bool Register(const char* /*prefix*/, const CodeLocation&,
                        const char* /*case_name*/, const char* /*test_names*/,
                        int /*index*/,
                        const std::vector<std::string>& =
                            std::vector<std::string>() /*type_names*/) {
     return true;
   }
 };
 
 // TypeParameterizedTestSuite<Fixture, Tests, Types>::Register()
 // registers *all combinations* of 'Tests' and 'Types' with Google
 // Test.  The return value is insignificant - we just need to return
 // something such that we can call this function in a namespace scope.
 template <GTEST_TEMPLATE_ Fixture, typename Tests, typename Types>
 class TypeParameterizedTestSuite {
  public:
   static bool Register(const char* prefix, CodeLocation code_location,
                        const TypedTestSuitePState* state, const char* case_name,
                        const char* test_names,
                        const std::vector<std::string>& type_names =
                            GenerateNames<DefaultNameGenerator, Types>()) {
     std::string test_name = StripTrailingSpaces(
         GetPrefixUntilComma(test_names));
     if (!state->TestExists(test_name)) {
       fprintf(stderr, "Failed to get code location for test %s.%s at %s.",
               case_name, test_name.c_str(),
               FormatFileLocation(code_location.file.c_str(),
                                  code_location.line).c_str());
       fflush(stderr);
       posix::Abort();
     }
     const CodeLocation& test_location = state->GetCodeLocation(test_name);
 
     typedef typename Tests::Head Head;
 
     // First, register the first test in 'Test' for each type in 'Types'.
     TypeParameterizedTest<Fixture, Head, Types>::Register(
         prefix, test_location, case_name, test_names, 0, type_names);
 
     // Next, recurses (at compile time) with the tail of the test list.
     return TypeParameterizedTestSuite<Fixture, typename Tests::Tail,
                                       Types>::Register(prefix, code_location,
                                                        state, case_name,
                                                        SkipComma(test_names),
                                                        type_names);
   }
 };
 
 // The base case for the compile time recursion.
 template <GTEST_TEMPLATE_ Fixture, typename Types>
 class TypeParameterizedTestSuite<Fixture, Templates0, Types> {
  public:
   static bool Register(const char* /*prefix*/, const CodeLocation&,
                        const TypedTestSuitePState* /*state*/,
                        const char* /*case_name*/, const char* /*test_names*/,
                        const std::vector<std::string>& =
                            std::vector<std::string>() /*type_names*/) {
     return true;
   }
 };
 
 #endif  // GTEST_HAS_TYPED_TEST || GTEST_HAS_TYPED_TEST_P
 
 // Returns the current OS stack trace as an std::string.
 //
 // The maximum number of stack frames to be included is specified by
 // the gtest_stack_trace_depth flag.  The skip_count parameter
 // specifies the number of top frames to be skipped, which doesn't
 // count against the number of frames to be included.
 //
 // For example, if Foo() calls Bar(), which in turn calls
 // GetCurrentOsStackTraceExceptTop(..., 1), Foo() will be included in
 // the trace but Bar() and GetCurrentOsStackTraceExceptTop() won't.
 GTEST_API_ std::string GetCurrentOsStackTraceExceptTop(
     UnitTest* unit_test, int skip_count);
 
 // Helpers for suppressing warnings on unreachable code or constant
 // condition.
 
 // Always returns true.
 GTEST_API_ bool AlwaysTrue();
 
 // Always returns false.
 inline bool AlwaysFalse() { return !AlwaysTrue(); }
 
 // Helper for suppressing false warning from Clang on a const char*
 // variable declared in a conditional expression always being NULL in
 // the else branch.
 struct GTEST_API_ ConstCharPtr {
   ConstCharPtr(const char* str) : value(str) {}
   operator bool() const { return true; }
   const char* value;
 };
 
 // A simple Linear Congruential Generator for generating random
 // numbers with a uniform distribution.  Unlike rand() and srand(), it
 // doesn't use global state (and therefore can't interfere with user
 // code).  Unlike rand_r(), it's portable.  An LCG isn't very random,
 // but it's good enough for our purposes.
 class GTEST_API_ Random {
  public:
   static const UInt32 kMaxRange = 1u << 31;
 
   explicit Random(UInt32 seed) : state_(seed) {}
 
   void Reseed(UInt32 seed) { state_ = seed; }
 
   // Generates a random number from [0, range).  Crashes if 'range' is
   // 0 or greater than kMaxRange.
   UInt32 Generate(UInt32 range);
 
  private:
   UInt32 state_;
   GTEST_DISALLOW_COPY_AND_ASSIGN_(Random);
 };
 
 // Defining a variable of type CompileAssertTypesEqual<T1, T2> will cause a
 // compiler error if T1 and T2 are different types.
 template <typename T1, typename T2>
 struct CompileAssertTypesEqual;
 
 template <typename T>
 struct CompileAssertTypesEqual<T, T> {
 };
 
 // Removes the reference from a type if it is a reference type,
 // otherwise leaves it unchanged.  This is the same as
 // tr1::remove_reference, which is not widely available yet.
 template <typename T>
 struct RemoveReference { typedef T type; };  // NOLINT
 template <typename T>
 struct RemoveReference<T&> { typedef T type; };  // NOLINT
 
 // A handy wrapper around RemoveReference that works when the argument
 // T depends on template parameters.
 #define GTEST_REMOVE_REFERENCE_(T) \
     typename ::testing::internal::RemoveReference<T>::type
 
 // Removes const from a type if it is a const type, otherwise leaves
 // it unchanged.  This is the same as tr1::remove_const, which is not
 // widely available yet.
 template <typename T>
 struct RemoveConst { typedef T type; };  // NOLINT
 template <typename T>
 struct RemoveConst<const T> { typedef T type; };  // NOLINT
 
 // MSVC 8.0, Sun C++, and IBM XL C++ have a bug which causes the above
 // definition to fail to remove the const in 'const int[3]' and 'const
 // char[3][4]'.  The following specialization works around the bug.
 template <typename T, size_t N>
 struct RemoveConst<const T[N]> {
   typedef typename RemoveConst<T>::type type[N];
 };
 
 // A handy wrapper around RemoveConst that works when the argument
 // T depends on template parameters.
 #define GTEST_REMOVE_CONST_(T) \
     typename ::testing::internal::RemoveConst<T>::type
 
 // Turns const U&, U&, const U, and U all into U.
 #define GTEST_REMOVE_REFERENCE_AND_CONST_(T) \
     GTEST_REMOVE_CONST_(GTEST_REMOVE_REFERENCE_(T))
 
 // IsAProtocolMessage<T>::value is a compile-time bool constant that's
 // true if T is type proto2::Message or a subclass of it.
 template <typename T>
 struct IsAProtocolMessage
     : public bool_constant<
   std::is_convertible<const T*, const ::proto2::Message*>::value> {
 };
 
 // When the compiler sees expression IsContainerTest<C>(0), if C is an
 // STL-style container class, the first overload of IsContainerTest
 // will be viable (since both C::iterator* and C::const_iterator* are
 // valid types and NULL can be implicitly converted to them).  It will
 // be picked over the second overload as 'int' is a perfect match for
 // the type of argument 0.  If C::iterator or C::const_iterator is not
 // a valid type, the first overload is not viable, and the second
 // overload will be picked.  Therefore, we can determine whether C is
 // a container class by checking the type of IsContainerTest<C>(0).
 // The value of the expression is insignificant.
 //
 // In C++11 mode we check the existence of a const_iterator and that an
 // iterator is properly implemented for the container.
 //
 // For pre-C++11 that we look for both C::iterator and C::const_iterator.
 // The reason is that C++ injects the name of a class as a member of the
 // class itself (e.g. you can refer to class iterator as either
 // 'iterator' or 'iterator::iterator').  If we look for C::iterator
 // only, for example, we would mistakenly think that a class named
 // iterator is an STL container.
 //
 // Also note that the simpler approach of overloading
 // IsContainerTest(typename C::const_iterator*) and
 // IsContainerTest(...) doesn't work with Visual Age C++ and Sun C++.
 typedef int IsContainer;
 template <class C,
           class Iterator = decltype(::std::declval<const C&>().begin()),
           class = decltype(::std::declval<const C&>().end()),
           class = decltype(++::std::declval<Iterator&>()),
           class = decltype(*::std::declval<Iterator>()),
           class = typename C::const_iterator>
 IsContainer IsContainerTest(int /* dummy */) {
   return 0;
 }
 
 typedef char IsNotContainer;
 template <class C>
 IsNotContainer IsContainerTest(long /* dummy */) { return '\0'; }
 
 // Trait to detect whether a type T is a hash table.
 // The heuristic used is that the type contains an inner type `hasher` and does
 // not contain an inner type `reverse_iterator`.
 // If the container is iterable in reverse, then order might actually matter.
 template <typename T>
 struct IsHashTable {
  private:
   template <typename U>
   static char test(typename U::hasher*, typename U::reverse_iterator*);
   template <typename U>
   static int test(typename U::hasher*, ...);
   template <typename U>
   static char test(...);
 
  public:
   static const bool value = sizeof(test<T>(nullptr, nullptr)) == sizeof(int);
 };
 
 template <typename T>
 const bool IsHashTable<T>::value;
 
 template <typename C,
           bool = sizeof(IsContainerTest<C>(0)) == sizeof(IsContainer)>
 struct IsRecursiveContainerImpl;
 
 template <typename C>
 struct IsRecursiveContainerImpl<C, false> : public false_type {};
 
 // Since the IsRecursiveContainerImpl depends on the IsContainerTest we need to
 // obey the same inconsistencies as the IsContainerTest, namely check if
 // something is a container is relying on only const_iterator in C++11 and
 // is relying on both const_iterator and iterator otherwise
 template <typename C>
 struct IsRecursiveContainerImpl<C, true> {
   using value_type = decltype(*std::declval<typename C::const_iterator>());
   using type =
       is_same<typename std::remove_const<
                   typename std::remove_reference<value_type>::type>::type,
               C>;
 };
 
 // IsRecursiveContainer<Type> is a unary compile-time predicate that
 // evaluates whether C is a recursive container type. A recursive container
 // type is a container type whose value_type is equal to the container type
 // itself. An example for a recursive container type is
 // boost::filesystem::path, whose iterator has a value_type that is equal to
 // boost::filesystem::path.
 template <typename C>
 struct IsRecursiveContainer : public IsRecursiveContainerImpl<C>::type {};
 
-// EnableIf<condition>::type is void when 'Cond' is true, and
-// undefined when 'Cond' is false.  To use SFINAE to make a function
-// overload only apply when a particular expression is true, add
-// "typename EnableIf<expression>::type* = 0" as the last parameter.
-template<bool> struct EnableIf;
-template<> struct EnableIf<true> { typedef void type; };  // NOLINT
-
 // Utilities for native arrays.
 
 // ArrayEq() compares two k-dimensional native arrays using the
 // elements' operator==, where k can be any integer >= 0.  When k is
 // 0, ArrayEq() degenerates into comparing a single pair of values.
 
 template <typename T, typename U>
 bool ArrayEq(const T* lhs, size_t size, const U* rhs);
 
 // This generic version is used when k is 0.
 template <typename T, typename U>
 inline bool ArrayEq(const T& lhs, const U& rhs) { return lhs == rhs; }
 
 // This overload is used when k >= 1.
 template <typename T, typename U, size_t N>
 inline bool ArrayEq(const T(&lhs)[N], const U(&rhs)[N]) {
   return internal::ArrayEq(lhs, N, rhs);
 }
 
 // This helper reduces code bloat.  If we instead put its logic inside
 // the previous ArrayEq() function, arrays with different sizes would
 // lead to different copies of the template code.
 template <typename T, typename U>
 bool ArrayEq(const T* lhs, size_t size, const U* rhs) {
   for (size_t i = 0; i != size; i++) {
     if (!internal::ArrayEq(lhs[i], rhs[i]))
       return false;
   }
   return true;
 }
 
 // Finds the first element in the iterator range [begin, end) that
 // equals elem.  Element may be a native array type itself.
 template <typename Iter, typename Element>
 Iter ArrayAwareFind(Iter begin, Iter end, const Element& elem) {
   for (Iter it = begin; it != end; ++it) {
     if (internal::ArrayEq(*it, elem))
       return it;
   }
   return end;
 }
 
 // CopyArray() copies a k-dimensional native array using the elements'
 // operator=, where k can be any integer >= 0.  When k is 0,
 // CopyArray() degenerates into copying a single value.
 
 template <typename T, typename U>
 void CopyArray(const T* from, size_t size, U* to);
 
 // This generic version is used when k is 0.
 template <typename T, typename U>
 inline void CopyArray(const T& from, U* to) { *to = from; }
 
 // This overload is used when k >= 1.
 template <typename T, typename U, size_t N>
 inline void CopyArray(const T(&from)[N], U(*to)[N]) {
   internal::CopyArray(from, N, *to);
 }
 
 // This helper reduces code bloat.  If we instead put its logic inside
 // the previous CopyArray() function, arrays with different sizes
 // would lead to different copies of the template code.
 template <typename T, typename U>
 void CopyArray(const T* from, size_t size, U* to) {
   for (size_t i = 0; i != size; i++) {
     internal::CopyArray(from[i], to + i);
   }
 }
 
 // The relation between an NativeArray object (see below) and the
 // native array it represents.
 // We use 2 different structs to allow non-copyable types to be used, as long
 // as RelationToSourceReference() is passed.
 struct RelationToSourceReference {};
 struct RelationToSourceCopy {};
 
 // Adapts a native array to a read-only STL-style container.  Instead
 // of the complete STL container concept, this adaptor only implements
 // members useful for Google Mock's container matchers.  New members
 // should be added as needed.  To simplify the implementation, we only
 // support Element being a raw type (i.e. having no top-level const or
 // reference modifier).  It's the client's responsibility to satisfy
 // this requirement.  Element can be an array type itself (hence
 // multi-dimensional arrays are supported).
 template <typename Element>
 class NativeArray {
  public:
   // STL-style container typedefs.
   typedef Element value_type;
   typedef Element* iterator;
   typedef const Element* const_iterator;
 
   // Constructs from a native array. References the source.
   NativeArray(const Element* array, size_t count, RelationToSourceReference) {
     InitRef(array, count);
   }
 
   // Constructs from a native array. Copies the source.
   NativeArray(const Element* array, size_t count, RelationToSourceCopy) {
     InitCopy(array, count);
   }
 
   // Copy constructor.
   NativeArray(const NativeArray& rhs) {
     (this->*rhs.clone_)(rhs.array_, rhs.size_);
   }
 
   ~NativeArray() {
     if (clone_ != &NativeArray::InitRef)
       delete[] array_;
   }
 
   // STL-style container methods.
   size_t size() const { return size_; }
   const_iterator begin() const { return array_; }
   const_iterator end() const { return array_ + size_; }
   bool operator==(const NativeArray& rhs) const {
     return size() == rhs.size() &&
         ArrayEq(begin(), size(), rhs.begin());
   }
 
  private:
   enum {
     kCheckTypeIsNotConstOrAReference = StaticAssertTypeEqHelper<
         Element, GTEST_REMOVE_REFERENCE_AND_CONST_(Element)>::value
   };
 
   // Initializes this object with a copy of the input.
   void InitCopy(const Element* array, size_t a_size) {
     Element* const copy = new Element[a_size];
     CopyArray(array, a_size, copy);
     array_ = copy;
     size_ = a_size;
     clone_ = &NativeArray::InitCopy;
   }
 
   // Initializes this object with a reference of the input.
   void InitRef(const Element* array, size_t a_size) {
     array_ = array;
     size_ = a_size;
     clone_ = &NativeArray::InitRef;
   }
 
   const Element* array_;
   size_t size_;
   void (NativeArray::*clone_)(const Element*, size_t);
 
   GTEST_DISALLOW_ASSIGN_(NativeArray);
 };
 
 // Backport of std::index_sequence.
 template <size_t... Is>
 struct IndexSequence {
   using type = IndexSequence;
 };
 
 // Double the IndexSequence, and one if plus_one is true.
 template <bool plus_one, typename T, size_t sizeofT>
 struct DoubleSequence;
 template <size_t... I, size_t sizeofT>
 struct DoubleSequence<true, IndexSequence<I...>, sizeofT> {
   using type = IndexSequence<I..., (sizeofT + I)..., 2 * sizeofT>;
 };
 template <size_t... I, size_t sizeofT>
 struct DoubleSequence<false, IndexSequence<I...>, sizeofT> {
   using type = IndexSequence<I..., (sizeofT + I)...>;
 };
 
 // Backport of std::make_index_sequence.
 // It uses O(ln(N)) instantiation depth.
 template <size_t N>
 struct MakeIndexSequence
     : DoubleSequence<N % 2 == 1, typename MakeIndexSequence<N / 2>::type,
                      N / 2>::type {};
 
 template <>
 struct MakeIndexSequence<0> : IndexSequence<> {};
 
 // FIXME: This implementation of ElemFromList is O(1) in instantiation depth,
 // but it is O(N^2) in total instantiations. Not sure if this is the best
 // tradeoff, as it will make it somewhat slow to compile.
 template <typename T, size_t, size_t>
 struct ElemFromListImpl {};
 
 template <typename T, size_t I>
 struct ElemFromListImpl<T, I, I> {
   using type = T;
 };
 
 // Get the Nth element from T...
 // It uses O(1) instantiation depth.
 template <size_t N, typename I, typename... T>
 struct ElemFromList;
 
 template <size_t N, size_t... I, typename... T>
 struct ElemFromList<N, IndexSequence<I...>, T...>
     : ElemFromListImpl<T, N, I>... {};
 
 template <typename... T>
 class FlatTuple;
 
 template <typename Derived, size_t I>
 struct FlatTupleElemBase;
 
 template <typename... T, size_t I>
 struct FlatTupleElemBase<FlatTuple<T...>, I> {
   using value_type =
       typename ElemFromList<I, typename MakeIndexSequence<sizeof...(T)>::type,
                             T...>::type;
   FlatTupleElemBase() = default;
   explicit FlatTupleElemBase(value_type t) : value(std::move(t)) {}
   value_type value;
 };
 
 template <typename Derived, typename Idx>
 struct FlatTupleBase;
 
 template <size_t... Idx, typename... T>
 struct FlatTupleBase<FlatTuple<T...>, IndexSequence<Idx...>>
     : FlatTupleElemBase<FlatTuple<T...>, Idx>... {
   using Indices = IndexSequence<Idx...>;
   FlatTupleBase() = default;
   explicit FlatTupleBase(T... t)
       : FlatTupleElemBase<FlatTuple<T...>, Idx>(std::move(t))... {}
 };
 
 // Analog to std::tuple but with different tradeoffs.
 // This class minimizes the template instantiation depth, thus allowing more
 // elements that std::tuple would. std::tuple has been seen to require an
 // instantiation depth of more than 10x the number of elements in some
 // implementations.
 // FlatTuple and ElemFromList are not recursive and have a fixed depth
 // regardless of T...
 // MakeIndexSequence, on the other hand, it is recursive but with an
 // instantiation depth of O(ln(N)).
 template <typename... T>
 class FlatTuple
     : private FlatTupleBase<FlatTuple<T...>,
                             typename MakeIndexSequence<sizeof...(T)>::type> {
   using Indices = typename FlatTuple::FlatTupleBase::Indices;
 
  public:
   FlatTuple() = default;
   explicit FlatTuple(T... t) : FlatTuple::FlatTupleBase(std::move(t)...) {}
 
   template <size_t I>
   const typename ElemFromList<I, Indices, T...>::type& Get() const {
     return static_cast<const FlatTupleElemBase<FlatTuple, I>*>(this)->value;
   }
 
   template <size_t I>
   typename ElemFromList<I, Indices, T...>::type& Get() {
     return static_cast<FlatTupleElemBase<FlatTuple, I>*>(this)->value;
   }
 };
 
 // Utility functions to be called with static_assert to induce deprecation
 // warnings.
 GTEST_INTERNAL_DEPRECATED(
     "INSTANTIATE_TEST_CASE_P is deprecated, please use "
     "INSTANTIATE_TEST_SUITE_P")
 constexpr bool InstantiateTestCase_P_IsDeprecated() { return true; }
 
 GTEST_INTERNAL_DEPRECATED(
     "TYPED_TEST_CASE_P is deprecated, please use "
     "TYPED_TEST_SUITE_P")
 constexpr bool TypedTestCase_P_IsDeprecated() { return true; }
 
 GTEST_INTERNAL_DEPRECATED(
     "TYPED_TEST_CASE is deprecated, please use "
     "TYPED_TEST_SUITE")
 constexpr bool TypedTestCaseIsDeprecated() { return true; }
 
 GTEST_INTERNAL_DEPRECATED(
     "REGISTER_TYPED_TEST_CASE_P is deprecated, please use "
     "REGISTER_TYPED_TEST_SUITE_P")
 constexpr bool RegisterTypedTestCase_P_IsDeprecated() { return true; }
 
 GTEST_INTERNAL_DEPRECATED(
     "INSTANTIATE_TYPED_TEST_CASE_P is deprecated, please use "
     "INSTANTIATE_TYPED_TEST_SUITE_P")
 constexpr bool InstantiateTypedTestCase_P_IsDeprecated() { return true; }
 
 }  // namespace internal
 }  // namespace testing
 
 #define GTEST_MESSAGE_AT_(file, line, message, result_type) \
   ::testing::internal::AssertHelper(result_type, file, line, message) \
     = ::testing::Message()
 
 #define GTEST_MESSAGE_(message, result_type) \
   GTEST_MESSAGE_AT_(__FILE__, __LINE__, message, result_type)
 
 #define GTEST_FATAL_FAILURE_(message) \
   return GTEST_MESSAGE_(message, ::testing::TestPartResult::kFatalFailure)
 
 #define GTEST_NONFATAL_FAILURE_(message) \
   GTEST_MESSAGE_(message, ::testing::TestPartResult::kNonFatalFailure)
 
 #define GTEST_SUCCESS_(message) \
   GTEST_MESSAGE_(message, ::testing::TestPartResult::kSuccess)
 
 #define GTEST_SKIP_(message) \
   return GTEST_MESSAGE_(message, ::testing::TestPartResult::kSkip)
 
 // Suppress MSVC warning 4072 (unreachable code) for the code following
 // statement if it returns or throws (or doesn't return or throw in some
 // situations).
 #define GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement) \
   if (::testing::internal::AlwaysTrue()) { statement; }
 
 #define GTEST_TEST_THROW_(statement, expected_exception, fail) \
   GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
   if (::testing::internal::ConstCharPtr gtest_msg = "") { \
     bool gtest_caught_expected = false; \
     try { \
       GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
     } \
     catch (expected_exception const&) { \
       gtest_caught_expected = true; \
     } \
     catch (...) { \
       gtest_msg.value = \
           "Expected: " #statement " throws an exception of type " \
           #expected_exception ".\n  Actual: it throws a different type."; \
       goto GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__); \
     } \
     if (!gtest_caught_expected) { \
       gtest_msg.value = \
           "Expected: " #statement " throws an exception of type " \
           #expected_exception ".\n  Actual: it throws nothing."; \
       goto GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__); \
     } \
   } else \
     GTEST_CONCAT_TOKEN_(gtest_label_testthrow_, __LINE__): \
       fail(gtest_msg.value)
 
 #define GTEST_TEST_NO_THROW_(statement, fail) \
   GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
   if (::testing::internal::AlwaysTrue()) { \
     try { \
       GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
     } \
     catch (...) { \
       goto GTEST_CONCAT_TOKEN_(gtest_label_testnothrow_, __LINE__); \
     } \
   } else \
     GTEST_CONCAT_TOKEN_(gtest_label_testnothrow_, __LINE__): \
       fail("Expected: " #statement " doesn't throw an exception.\n" \
            "  Actual: it throws.")
 
 #define GTEST_TEST_ANY_THROW_(statement, fail) \
   GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
   if (::testing::internal::AlwaysTrue()) { \
     bool gtest_caught_any = false; \
     try { \
       GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
     } \
     catch (...) { \
       gtest_caught_any = true; \
     } \
     if (!gtest_caught_any) { \
       goto GTEST_CONCAT_TOKEN_(gtest_label_testanythrow_, __LINE__); \
     } \
   } else \
     GTEST_CONCAT_TOKEN_(gtest_label_testanythrow_, __LINE__): \
       fail("Expected: " #statement " throws an exception.\n" \
            "  Actual: it doesn't.")
 
 
 // Implements Boolean test assertions such as EXPECT_TRUE. expression can be
 // either a boolean expression or an AssertionResult. text is a textual
 // represenation of expression as it was passed into the EXPECT_TRUE.
 #define GTEST_TEST_BOOLEAN_(expression, text, actual, expected, fail) \
   GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
   if (const ::testing::AssertionResult gtest_ar_ = \
       ::testing::AssertionResult(expression)) \
     ; \
   else \
     fail(::testing::internal::GetBoolAssertionFailureMessage(\
         gtest_ar_, text, #actual, #expected).c_str())
 
 #define GTEST_TEST_NO_FATAL_FAILURE_(statement, fail) \
   GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
   if (::testing::internal::AlwaysTrue()) { \
     ::testing::internal::HasNewFatalFailureHelper gtest_fatal_failure_checker; \
     GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
     if (gtest_fatal_failure_checker.has_new_fatal_failure()) { \
       goto GTEST_CONCAT_TOKEN_(gtest_label_testnofatal_, __LINE__); \
     } \
   } else \
     GTEST_CONCAT_TOKEN_(gtest_label_testnofatal_, __LINE__): \
       fail("Expected: " #statement " doesn't generate new fatal " \
            "failures in the current thread.\n" \
            "  Actual: it does.")
 
 // Expands to the name of the class that implements the given test.
 #define GTEST_TEST_CLASS_NAME_(test_suite_name, test_name) \
   test_suite_name##_##test_name##_Test
 
 // Helper macro for defining tests.
 #define GTEST_TEST_(test_suite_name, test_name, parent_class, parent_id)      \
   class GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)                    \
       : public parent_class {                                                 \
    public:                                                                    \
     GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)() {}                   \
                                                                               \
    private:                                                                   \
     virtual void TestBody();                                                  \
     static ::testing::TestInfo* const test_info_ GTEST_ATTRIBUTE_UNUSED_;     \
     GTEST_DISALLOW_COPY_AND_ASSIGN_(GTEST_TEST_CLASS_NAME_(test_suite_name,   \
                                                            test_name));       \
   };                                                                          \
                                                                               \
   ::testing::TestInfo* const GTEST_TEST_CLASS_NAME_(test_suite_name,          \
                                                     test_name)::test_info_ =  \
       ::testing::internal::MakeAndRegisterTestInfo(                           \
           #test_suite_name, #test_name, nullptr, nullptr,                     \
           ::testing::internal::CodeLocation(__FILE__, __LINE__), (parent_id), \
           ::testing::internal::SuiteApiResolver<                              \
               parent_class>::GetSetUpCaseOrSuite(__FILE__, __LINE__),         \
           ::testing::internal::SuiteApiResolver<                              \
               parent_class>::GetTearDownCaseOrSuite(__FILE__, __LINE__),      \
           new ::testing::internal::TestFactoryImpl<GTEST_TEST_CLASS_NAME_(    \
               test_suite_name, test_name)>);                                  \
   void GTEST_TEST_CLASS_NAME_(test_suite_name, test_name)::TestBody()
 
 #endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_