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aka_zip_iterator.hh
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/**
* @file aka_zip_iterator.hh
*
* @author Nicolas Richart
*
* @date creation jeu déc 12 2019
*
* @brief A Documented file.
*
*
* Copyright (©) 2010-2011 EPFL (Ecole Polytechnique Fédérale de Lausanne)
* Laboratory (LSMS - Laboratoire de Simulation en Mécanique des Solides)
*
* akantu-iterators 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 of the License, or (at your
* option) any later version.
*
* akantu-iterators 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with akantu-iterators. If not, see <http://www.gnu.org/licenses/>.
*
*/
/* -------------------------------------------------------------------------- */
#include "aka_compatibilty_with_cpp_standard.hh"
#include "aka_iterator_tools.hh"
#include "aka_tuple_tools.hh"
/* -------------------------------------------------------------------------- */
#include <iterator>
#include <utility>
/* -------------------------------------------------------------------------- */
#ifndef AKA_ZIP_ITERATOR_HH
#define AKA_ZIP_ITERATOR_HH
#ifndef AKANTU_ITERATORS_NAMESPACE
#define AKANTU_ITERATORS_NAMESPACE akantu
#endif
#define FWD(x) std::forward<decltype(x)>(x)
namespace AKANTU_ITERATORS_NAMESPACE {
/* -------------------------------------------------------------------------- */
namespace iterators AKA_ITERATOR_EXPORT_NAMESPACE {
/* ------------------------------------------------------------------------ */
template <template <class...> class Tuple, class... Iterators>
class ZipIterator_
: public details::CopyAssignmentEnabler<
aka::conjunction<std::is_copy_assignable<Iterators>...,
std::is_copy_constructible<Iterators>...>::value>,
public details::MoveAssignmentEnabler<
aka::conjunction<std::is_move_assignable<Iterators>...,
std::is_move_constructible<Iterators>...>::value> {
private:
using tuple_t = Tuple<Iterators...>;
public:
using value_type =
Tuple<typename std::iterator_traits<Iterators>::value_type...>;
using difference_type = std::common_type_t<
typename std::iterator_traits<Iterators>::difference_type...>;
using pointer = Tuple<typename std::iterator_traits<Iterators>::pointer...>;
using reference =
Tuple<typename std::iterator_traits<Iterators>::reference...>;
using iterator_category = // std::input_iterator_tag;
std::common_type_t<
typename std::iterator_traits<Iterators>::iterator_category...>;
explicit ZipIterator_(tuple_t iterators)
: iterators(std::move(iterators)) {}
/* ---------------------------------------------------------------------- */
template <class iterator_category_ = iterator_category,
std::enable_if_t<aka::is_iterator_category_at_least<
iterator_category_,
std::bidirectional_iterator_tag>::value> * = nullptr>
auto operator--() -> ZipIterator_ & {
tuple::foreach ([](auto && it) { --it; }, iterators);
return *this;
}
template <class iterator_category_ = iterator_category,
std::enable_if_t<aka::is_iterator_category_at_least<
iterator_category_,
std::bidirectional_iterator_tag>::value> * = nullptr>
auto operator--(int) -> ZipIterator_ {
auto cpy = *this;
this->operator--();
return cpy;
}
// input iterator ++it
auto operator++() -> ZipIterator_ & {
tuple::foreach ([](auto && it) { ++it; }, iterators);
return *this;
}
// input iterator it++
auto operator++(int) -> ZipIterator_ {
auto cpy = *this;
this->operator++();
return cpy;
}
// input iterator it != other_it
auto operator!=(const ZipIterator_ & other) const -> bool {
// return tuple::are_not_equal(iterators, other.iterators);
return std::get<0>(iterators) !=
std::get<0>(other.iterators); // helps the compiler to optimize
}
// input iterator dereference *it
auto operator*() -> decltype(auto) {
return tuple::transform([](auto && it) -> decltype(auto) { return *it; },
iterators);
}
template <class iterator_category_ = iterator_category,
std::enable_if_t<aka::is_iterator_category_at_least<
iterator_category_,
std::random_access_iterator_tag>::value> * = nullptr>
auto operator-(const ZipIterator_ & other) const -> difference_type {
return std::get<0>(this->iterators) - std::get<0>(other.iterators);
}
// random iterator it[idx]
template <class iterator_category_ = iterator_category,
std::enable_if_t<aka::is_iterator_category_at_least<
iterator_category_,
std::random_access_iterator_tag>::value> * = nullptr>
auto operator[](std::size_t idx) -> decltype(auto) {
return tuple::transform(
[idx](auto && it) -> decltype(auto) { return it[idx]; }, iterators);
}
// random iterator it + n
template <class iterator_category_ = iterator_category,
std::enable_if_t<aka::is_iterator_category_at_least<
iterator_category_,
std::random_access_iterator_tag>::value> * = nullptr>
auto operator+(std::size_t n) const -> decltype(auto) {
return ZipIterator_(std::forward<tuple_t>(tuple::transform(
[n](auto && it) -> decltype(auto) { return it + n; }, iterators)));
}
// random iterator it - n
template <class iterator_category_ = iterator_category,
std::enable_if_t<aka::is_iterator_category_at_least<
iterator_category_,
std::random_access_iterator_tag>::value> * = nullptr>
auto operator-(std::size_t n) const -> decltype(auto) {
return ZipIterator_(std::forward<tuple_t>(tuple::transform(
[n](auto && it) -> decltype(auto) { return it - n; }, iterators)));
}
template <
class iterator_category_ = iterator_category,
std::enable_if_t<aka::is_iterator_category_at_least<
iterator_category_, std::forward_iterator_tag>::value> * = nullptr>
auto operator==(const ZipIterator_ & other) const -> bool {
return not tuple::are_not_equal(iterators, other.iterators);
}
private:
tuple_t iterators;
};
template <class... Iterators>
using ZipIterator = ZipIterator_<std::tuple, Iterators...>;
template <class... Iterators>
using NamedZipIterator = ZipIterator_<tuple::named_tuple, Iterators...>;
} // namespace AKA_ITERATOR_EXPORT_NAMESPACE
/* -------------------------------------------------------------------------- */
template <class... Iterators>
auto zip_iterator(std::tuple<Iterators...> && iterators_tuple)
-> decltype(auto) {
auto zip = iterators::ZipIterator<Iterators...>(FWD(iterators_tuple));
return zip;
}
template <class... Iterators>
auto zip_iterator(tuple::named_tuple<Iterators...> && iterators_tuple)
-> decltype(auto) {
auto zip = iterators::NamedZipIterator<Iterators...>(FWD(iterators_tuple));
return zip;
}
/* -------------------------------------------------------------------------- */
namespace containers AKA_ITERATOR_EXPORT_NAMESPACE {
template <template <class...> class Tuple, class... Containers>
class ZipContainer_ {
public:
using containers_t = Tuple<Containers...>;
using size_type = std::common_type_t<aka::size_type_t<Containers>...>;
explicit ZipContainer_(Containers &&... containers)
: containers(std::forward<Containers>(containers)...) {}
auto begin() const -> decltype(auto) {
return zip_iterator(
tuple::transform([](auto && c) { return c.begin(); },
std::forward<containers_t>(containers)));
}
auto end() const -> decltype(auto) {
return zip_iterator(
tuple::transform([](auto && c) { return c.end(); },
std::forward<containers_t>(containers)));
}
auto begin() -> decltype(auto) {
return zip_iterator(
tuple::transform([](auto && c) { return c.begin(); },
std::forward<containers_t>(containers)));
}
auto end() -> decltype(auto) {
return zip_iterator(
tuple::transform([](auto && c) { return c.end(); },
std::forward<containers_t>(containers)));
}
template <class... OtherContainers>
static inline auto append(ZipContainer_ && zip_container,
OtherContainers &&... cont);
template <typename Tag, class OtherContainers>
static inline auto replace(ZipContainer_ && zip_container,
OtherContainers && cont);
template <typename Tag>
static inline auto remove(ZipContainer_ && zip_container);
private:
template <template <class...> class OtherTuple, class... OtherContainers>
friend class ZipContainer_;
containers_t containers;
};
template <class... Containers>
using ZipContainer = ZipContainer_<std::tuple, Containers...>;
template <class... Containers>
using NamedZipContainer = ZipContainer_<tuple::named_tuple, Containers...>;
} // namespace AKA_ITERATOR_EXPORT_NAMESPACE
/* -------------------------------------------------------------------------- */
template <class... Containers,
std::enable_if_t<not aka::conjunction<tuple::is_named_tag<
std::decay_t<Containers>>...>::value> * = nullptr>
constexpr auto zip(Containers &&... conts)
-> containers::ZipContainer<Containers...> {
return containers::ZipContainer<Containers...>(
std::forward<Containers>(conts)...);
}
template <class... Containers,
std::enable_if_t<aka::conjunction<tuple::is_named_tag<
std::decay_t<Containers>>...>::value> * = nullptr>
constexpr auto zip(Containers &&... conts)
-> containers::NamedZipContainer<Containers...> {
return containers::NamedZipContainer<Containers...>(
std::forward<Containers>(conts)...);
}
/* -------------------------------------------------------------------------- */
template <class... ZipContainer> inline auto zip_cat(ZipContainer &&... cont) {
return make_transform_adaptor(
zip(std::forward<ZipContainer>(cont)...),
[](auto && value) { return tuple::flatten(value); });
}
template <class ZipContainer, class... OtherContainers,
std::enable_if_t<std::is_rvalue_reference<ZipContainer &&>::value> * =
nullptr>
constexpr inline auto zip_append(ZipContainer && zip_container,
OtherContainers &&... cont) {
return std::decay_t<ZipContainer>::append(FWD(zip_container), FWD(cont)...);
}
template <typename Tag, class ZipContainer, class OtherContainer,
std::enable_if_t<std::is_rvalue_reference<ZipContainer &&>::value> * =
nullptr>
constexpr inline auto zip_replace(ZipContainer && zip_container,
OtherContainer && cont) {
return std::decay_t<ZipContainer>::template replace<Tag>(FWD(zip_container),
FWD(cont));
}
template <class ZipContainer, class OtherContainer,
std::enable_if_t<std::is_rvalue_reference_v<ZipContainer &&> and
tuple::is_named_tag_v<OtherContainer>> * = nullptr>
constexpr inline auto zip_replace(ZipContainer && zip_container,
OtherContainer && cont) {
using Tag = decltype(tuple::make_named_tag<
typename std::decay_t<OtherContainer>::_tag>());
return std::decay_t<ZipContainer>::template replace<Tag>(FWD(zip_container),
FWD(cont._value));
}
template <typename Tag, class ZipContainer,
std::enable_if_t<std::is_rvalue_reference<ZipContainer &&>::value> * =
nullptr>
constexpr inline auto zip_remove(ZipContainer && zip_container) {
return std::decay_t<ZipContainer>::template remove<Tag>(FWD(zip_container));
}
/* -------------------------------------------------------------------------- */
namespace details AKA_ITERATOR_EXPORT_NAMESPACE {
template <class Tuple, std::size_t... Is,
std::enable_if_t<not tuple::is_named_tuple<
std::decay_t<Tuple>>::value> * = nullptr>
constexpr inline auto
make_zip_from_tuple_impl(std::index_sequence<Is...> && /*unused*/,
Tuple && tuple) {
return zip(FWD(std::get<Is>(FWD(tuple)))...);
}
template <class Tuple, std::size_t... Is,
std::enable_if_t<
tuple::is_named_tuple<std::decay_t<Tuple>>::value> * = nullptr>
constexpr inline auto
make_zip_from_tuple_impl(std::index_sequence<Is...> && /*unused*/,
Tuple && tuple) {
using namespace tuple;
return zip(make_named_tag<tuple_name_tag_t<Is, std::decay_t<Tuple>>>() =
FWD(std::get<Is>(FWD(tuple)))...);
}
} // namespace AKA_ITERATOR_EXPORT_NAMESPACE
template <class Tuple>
constexpr inline auto make_zip_from_tuple(Tuple && tuple) {
return details::make_zip_from_tuple_impl(
std::make_index_sequence<
std::tuple_size<typename std::decay_t<Tuple>>::value>{},
std::forward<Tuple>(tuple));
}
namespace containers AKA_ITERATOR_EXPORT_NAMESPACE {
template <template <class...> class Tuple, class... Containers>
template <class... OtherContainers>
inline auto
ZipContainer_<Tuple, Containers...>::append(ZipContainer_ && zip_container,
OtherContainers &&... cont) {
return make_zip_from_tuple(
tuple::append(FWD(zip_container.containers), FWD(cont)...));
}
template <template <class...> class Tuple, class... Containers>
template <typename Tag, class OtherContainer>
inline auto
ZipContainer_<Tuple, Containers...>::replace(ZipContainer_ && zip_container,
OtherContainer && cont) {
return make_zip_from_tuple(
tuple::replace<Tag>(FWD(zip_container.containers), FWD(cont)));
}
template <template <class...> class Tuple, class... Containers>
template <typename Tag>
inline auto
ZipContainer_<Tuple, Containers...>::remove(ZipContainer_ && zip_container) {
return make_zip_from_tuple(
tuple::remove<Tag>(FWD(zip_container.containers)));
}
} // namespace AKA_ITERATOR_EXPORT_NAMESPACE
} // namespace AKANTU_ITERATORS_NAMESPACE
#undef FWD
namespace std {
template <template <class...> class Tuple, typename... Its>
struct iterator_traits<
::AKANTU_ITERATORS_NAMESPACE::iterators::ZipIterator_<Tuple, Its...>> {
private:
using iterator_type =
typename ::AKANTU_ITERATORS_NAMESPACE::iterators::ZipIterator_<Tuple,
Its...>;
public:
using iterator_category = typename iterator_type::iterator_category;
using value_type = typename iterator_type::value_type;
using difference_type = typename iterator_type::difference_type;
using pointer = typename iterator_type::pointer;
using reference = typename iterator_type::reference;
};
} // namespace std
#endif /* AKA_ZIP_ITERATOR_HH */
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