diff --git a/src/common/utilities.hh b/src/common/utilities.hh
index 3fe50a4..f918ed1 100644
--- a/src/common/utilities.hh
+++ b/src/common/utilities.hh
@@ -1,308 +1,306 @@
 /**
  * @file   utilities.hh
  *
  * @author Till Junge <till.junge@epfl.ch>
  *
  * @date   17 Nov 2017
  *
  * @brief  additions to the standard name space to anticipate C++17 features
  *
  * Copyright © 2017 Till Junge
  *
  * µSpectre is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License as
  * published by the Free Software Foundation, either version 3, or (at
  * your option) any later version.
  *
  * µSpectre is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public License
  * along with µSpectre; see the file COPYING. If not, write to the
  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  * * Boston, MA 02111-1307, USA.
  *
  * Additional permission under GNU GPL version 3 section 7
  *
  * If you modify this Program, or any covered work, by linking or combining it
  * with proprietary FFT implementations or numerical libraries, containing parts
  * covered by the terms of those libraries' licenses, the licensors of this
  * Program grant you additional permission to convey the resulting work.
  */
 
 
 #ifndef UTILITIES_H
 #define UTILITIES_H
 
-#include <boost/tuple/tuple.hpp>
-
 #include <tuple>
 
 #ifdef NO_EXPERIMENTAL
 #  include <boost/optional.hpp>
 #else
 #  include <experimental/optional>
 #endif
 
 namespace std_replacement {
 
   namespace detail {
     template <class T>
     struct is_reference_wrapper : std::false_type {};
     template <class U>
     struct is_reference_wrapper<std::reference_wrapper<U>> : std::true_type {};
 
     //! from cppreference
     template <class Base, class T, class Derived, class... Args>
     auto INVOKE(T Base::*pmf, Derived&& ref, Args&&... args)
       noexcept(noexcept((std::forward<Derived>(ref).*pmf)(std::forward<Args>(args)...)))
       -> std::enable_if_t<std::is_function<T>::value &&
                           std::is_base_of<Base, std::decay_t<Derived>>::value,
                           decltype((std::forward<Derived>(ref).*pmf)(std::forward<Args>(args)...))>
     {
       return (std::forward<Derived>(ref).*pmf)(std::forward<Args>(args)...);
     }
 
     //! from cppreference
     template <class Base, class T, class RefWrap, class... Args>
     auto INVOKE(T Base::*pmf, RefWrap&& ref, Args&&... args)
       noexcept(noexcept((ref.get().*pmf)(std::forward<Args>(args)...)))
       -> std::enable_if_t<std::is_function<T>::value &&
                           is_reference_wrapper<std::decay_t<RefWrap>>::value,
                           decltype((ref.get().*pmf)(std::forward<Args>(args)...))>
 
     {
       return (ref.get().*pmf)(std::forward<Args>(args)...);
     }
 
     //! from cppreference
     template <class Base, class T, class Pointer, class... Args>
     auto INVOKE(T Base::*pmf, Pointer&& ptr, Args&&... args)
       noexcept(noexcept(((*std::forward<Pointer>(ptr)).*pmf)(std::forward<Args>(args)...)))
       -> std::enable_if_t<std::is_function<T>::value &&
                           !is_reference_wrapper<std::decay_t<Pointer>>::value &&
                           !std::is_base_of<Base, std::decay_t<Pointer>>::value,
                           decltype(((*std::forward<Pointer>(ptr)).*pmf)(std::forward<Args>(args)...))>
     {
       return ((*std::forward<Pointer>(ptr)).*pmf)(std::forward<Args>(args)...);
     }
 
     //! from cppreference
     template <class Base, class T, class Derived>
     auto INVOKE(T Base::*pmd, Derived&& ref)
       noexcept(noexcept(std::forward<Derived>(ref).*pmd))
       -> std::enable_if_t<!std::is_function<T>::value &&
                           std::is_base_of<Base, std::decay_t<Derived>>::value,
                           decltype(std::forward<Derived>(ref).*pmd)>
     {
       return std::forward<Derived>(ref).*pmd;
     }
 
     //! from cppreference
     template <class Base, class T, class RefWrap>
     auto INVOKE(T Base::*pmd, RefWrap&& ref)
       noexcept(noexcept(ref.get().*pmd))
       -> std::enable_if_t<!std::is_function<T>::value &&
                           is_reference_wrapper<std::decay_t<RefWrap>>::value,
                           decltype(ref.get().*pmd)>
     {
       return ref.get().*pmd;
     }
 
     //! from cppreference
     template <class Base, class T, class Pointer>
     auto INVOKE(T Base::*pmd, Pointer&& ptr)
       noexcept(noexcept((*std::forward<Pointer>(ptr)).*pmd))
       -> std::enable_if_t<!std::is_function<T>::value &&
                           !is_reference_wrapper<std::decay_t<Pointer>>::value &&
                           !std::is_base_of<Base, std::decay_t<Pointer>>::value,
                           decltype((*std::forward<Pointer>(ptr)).*pmd)>
     {
       return (*std::forward<Pointer>(ptr)).*pmd;
     }
 
     //! from cppreference
     template <class F, class... Args>
     auto INVOKE(F&& f, Args&&... args)
       noexcept(noexcept(std::forward<F>(f)(std::forward<Args>(args)...)))
       -> std::enable_if_t<!std::is_member_pointer<std::decay_t<F>>::value,
                           decltype(std::forward<F>(f)(std::forward<Args>(args)...))>
     {
       return std::forward<F>(f)(std::forward<Args>(args)...);
     }
   } // namespace detail
 
   //! from cppreference
   template< class F, class... ArgTypes >
   auto invoke(F&& f, ArgTypes&&... args)
   // exception specification for QoI
     noexcept(noexcept(detail::INVOKE(std::forward<F>(f), std::forward<ArgTypes>(args)...)))
     -> decltype(detail::INVOKE(std::forward<F>(f), std::forward<ArgTypes>(args)...))
   {
     return detail::INVOKE(std::forward<F>(f), std::forward<ArgTypes>(args)...);
   }
 
   namespace detail {
     //! from cppreference
     template <class F, class Tuple, std::size_t... I>
     constexpr decltype(auto) apply_impl(F &&f, Tuple &&t, std::index_sequence<I...>)
     {
       return std_replacement::invoke(std::forward<F>(f), std::get<I>(std::forward<Tuple>(t))...);
     }
   }  // namespace detail
 
   //! from cppreference
   template <class F, class Tuple>
   constexpr decltype(auto) apply(F &&f, Tuple &&t)
   {
     return detail::apply_impl
       (std::forward<F>(f), std::forward<Tuple>(t),
        std::make_index_sequence<std::tuple_size<std::decay_t<Tuple>>::value>{});
   }
 
 
 } //namespace std_replacement
 
 
 namespace muSpectre {
 
   namespace internal {
 
     /**
      * helper struct template to compute the type of a tuple with a
      * given number of entries of the same type
      */
     template <size_t size, typename T, typename... tail>
     struct tuple_array_helper {
       //! underlying tuple
       using type = typename tuple_array_helper<size-1, T, T, tail...>::type;
     };
 
     /**
      * helper struct template to compute the type of a tuple with a
      * given number of entries of the same type
      */
     template< typename T, typename... tail>
     struct tuple_array_helper<0, T, tail...> {
       //! underlying tuple
       using type = std::tuple<tail...>;
     };
 
     /**
      * helper struct for runtime index access to
      * tuples. RecursionLevel indicates how much more we can recurse
      * down
      */
     template <class TupArr, size_t Index=0, size_t RecursionLevel=TupArr::Size-1>
     struct Accessor {
       using Stored_t = typename TupArr::Stored_t;
 
       inline static Stored_t
       get(const size_t & index, TupArr & container) {
         if (index == Index) {
           return std::get<Index>(container);
         } else {
           return Accessor<TupArr, Index+1, RecursionLevel-1>::get(index, container);
         }
       }
       inline static const Stored_t
       get(const size_t & index, const TupArr & container) {
         if (index == Index) {
           return std::get<Index>(container);
         } else {
           return Accessor<TupArr, Index+1, RecursionLevel-1>::get(index, container);
         }
       }
     };
 
     /**
      * specialisation for recursion end
      */
     template <class TupArr, size_t Index>
     struct Accessor<TupArr, Index, 0> {
       using Stored_t = typename TupArr::Stored_t;
 
       inline static Stored_t
       get(const size_t & index, TupArr & container) {
         if (index == Index) {
           return std::get<Index>(container);
         } else {
           std::stringstream err{};
           err << "Index " << index << "is out of range.";
           throw std::runtime_error(err.str());
         }
       }
 
       inline static const Stored_t
       get(const size_t & index, const TupArr & container) {
         if (index == Index) {
           return std::get<Index>(container);
         } else {
           std::stringstream err{};
           err << "Index " << index << "is out of range.";
           throw std::runtime_error(err.str());
         }
       }
     };
 
     /**
      * helper struct that provides the tuple_array.
      */
     template <typename T, size_t size>
     struct tuple_array_provider {
       //! tuple type that can be used (almost) like an `std::array`
       class type: public tuple_array_helper<size, T>::type {
       public:
         //! short-hand
         using Parent = typename tuple_array_helper<size, T>::type;
         using Stored_t = T;
         constexpr static size_t Size{size};
 
         //! constructor
         inline type(Parent && parent):Parent{parent}{};
 
         //! element access
         T operator[] (const size_t & index) {
           return Accessor<type>::get(index, *this);
         }
 
         //! element access
         const T operator[](const size_t & index) const  {
           return Accessor<type>::get(index, *this);
         }
       protected:
       };
     };
   }  // internal
 
   /**
    * This is a convenience structure to create a tuple of `nb_elem`
    * entries of type `T`. It is named tuple_array, because it is
    * somewhat similar to an `std::array<T, nb_elem>`. The reason for
    * this structure is that the `std::array` is not allowed by the
    * standard to store references (8.3.2 References, paragraph 5:
    * "There shall be no references to references, no arrays of
    * references, and no pointers to references.") use this, if you
    * want to have a statically known number of references to store,
    * and you wish to do so efficiently.
    */
   template <typename T, size_t nb_elem>
   using tuple_array = typename internal::tuple_array_provider<T, nb_elem>::type;
 
   using std_replacement::apply;
 
   /**
    * emulation `std::optional` (a C++17 feature)
    */
   template <class T>
 #ifdef NO_EXPERIMENTAL
   using optional = typename boost::optional<T>;
 #else
   using optional = typename std::experimental::optional<T>;
 #endif
 
 }  // muSpectre
 
 #endif /* UTILITIES_H */