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Editing: sequence_container_interface.hpp
// Copyright (C) 2019 T. Zachary Laine // // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #ifndef BOOST_STL_INTERFACES_CONTAINER_INTERFACE_HPP #define BOOST_STL_INTERFACES_CONTAINER_INTERFACE_HPP #include <boost/stl_interfaces/reverse_iterator.hpp> #include <boost/assert.hpp> #include <boost/config.hpp> #include <algorithm> #include <stdexcept> #include <cstddef> namespace boost { namespace stl_interfaces { namespace detail { template<typename T, typename SizeType> struct n_iter : iterator_interface< n_iter<T, SizeType>, std::random_access_iterator_tag, T> { n_iter() : x_(nullptr), n_(0) {} n_iter(T const & x, SizeType n) : x_(&x), n_(n) {} constexpr std::ptrdiff_t operator-(n_iter other) const noexcept { return std::ptrdiff_t(n_) - std::ptrdiff_t(other.n_); } n_iter & operator+=(std::ptrdiff_t offset) { n_ += offset; return *this; } private: friend access; constexpr T const *& base_reference() noexcept { return x_; } constexpr T const * base_reference() const noexcept { return x_; } T const * x_; SizeType n_; }; template<typename T, typename SizeType> constexpr auto make_n_iter(T const & x, SizeType n) noexcept( noexcept(n_iter<T, SizeType>(x, n))) { using result_type = n_iter<T, SizeType>; return result_type(x, SizeType(0)); } template<typename T, typename SizeType> constexpr auto make_n_iter_end(T const & x, SizeType n) noexcept( noexcept(n_iter<T, SizeType>(x, n))) { return n_iter<T, SizeType>(x, n); } template<typename Container> std::size_t fake_capacity(Container const & c) { return SIZE_MAX; } template< typename Container, typename Enable = decltype( std::size_t() = std::declval<Container const &>().capacity())> std::size_t fake_capacity(Container const & c) { return c.capacity(); } }}} namespace boost { namespace stl_interfaces { inline namespace v1 { /** A CRTP template that one may derive from to make it easier to define container types. The template parameter `D` for `sequence_container_interface` may be an incomplete type. Before any member of the resulting specialization of `sequence_container_interface` other than special member functions is referenced, `D` shall be complete; shall model `std::derived_from<sequence_container_interface<D>>`, `std::semiregular`, and `std::forward_range`; and shall contain all the nested types required in Table 72: Container requirements and, for those whose iterator nested type models `std::bidirectinal_iterator`, those in Table 73: Reversible container requirements. For an object `d` of type `D`, a call to `std::ranges::begin(d)` sxhall not mutate any data members of `d`, and `d`'s destructor shall end the lifetimes of the objects in `[std::ranges::begin(d), std::ranges::end(d))`. */ template< typename Derived, element_layout Contiguity = element_layout::discontiguous #ifndef BOOST_STL_INTERFACES_DOXYGEN , typename E = std::enable_if_t< std::is_class<Derived>::value && std::is_same<Derived, std::remove_cv_t<Derived>>::value> #endif > struct sequence_container_interface; namespace v1_dtl { template<typename Iter> using in_iter = std::is_convertible< typename std::iterator_traits<Iter>::iterator_category, std::input_iterator_tag>; template<typename D, typename = void> struct clear_impl { static constexpr void call(D & d) noexcept {} }; template<typename D> struct clear_impl<D, void_t<decltype(std::declval<D>().clear())>> { static constexpr void call(D & d) noexcept { d.clear(); } }; template<typename D, element_layout Contiguity> void derived_container(sequence_container_interface<D, Contiguity> const &); } template< typename Derived, element_layout Contiguity #ifndef BOOST_STL_INTERFACES_DOXYGEN , typename E #endif > struct sequence_container_interface { #ifndef BOOST_STL_INTERFACES_DOXYGEN private: constexpr Derived & derived() noexcept { return static_cast<Derived &>(*this); } constexpr const Derived & derived() const noexcept { return static_cast<Derived const &>(*this); } constexpr Derived & mutable_derived() const noexcept { return const_cast<Derived &>(static_cast<Derived const &>(*this)); } #endif public: template<typename D = Derived> constexpr auto empty() noexcept( noexcept(std::declval<D &>().begin() == std::declval<D &>().end())) -> decltype( std::declval<D &>().begin() == std::declval<D &>().end()) { return derived().begin() == derived().end(); } template<typename D = Derived> constexpr auto empty() const noexcept(noexcept( std::declval<D const &>().begin() == std::declval<D const &>().end())) -> decltype( std::declval<D const &>().begin() == std::declval<D const &>().end()) { return derived().begin() == derived().end(); } template< typename D = Derived, element_layout C = Contiguity, typename Enable = std::enable_if_t<C == element_layout::contiguous>> constexpr auto data() noexcept(noexcept(std::declval<D &>().begin())) -> decltype(std::addressof(*std::declval<D &>().begin())) { return std::addressof(*derived().begin()); } template< typename D = Derived, element_layout C = Contiguity, typename Enable = std::enable_if_t<C == element_layout::contiguous>> constexpr auto data() const noexcept(noexcept(std::declval<D const &>().begin())) -> decltype(std::addressof(*std::declval<D const &>().begin())) { return std::addressof(*derived().begin()); } template<typename D = Derived> constexpr auto size() #if !BOOST_CLANG noexcept(noexcept( std::declval<D &>().end() - std::declval<D &>().begin())) #endif -> decltype(typename D::size_type( std::declval<D &>().end() - std::declval<D &>().begin())) { return derived().end() - derived().begin(); } template<typename D = Derived> constexpr auto size() const noexcept(noexcept( std::declval<D const &>().end() - std::declval<D const &>().begin())) -> decltype(typename D::size_type( #if !BOOST_CLANG std::declval<D const &>().end() - std::declval<D const &>().begin() #endif )) { return derived().end() - derived().begin(); } template<typename D = Derived> constexpr auto front() noexcept(noexcept(*std::declval<D &>().begin())) -> decltype(*std::declval<D &>().begin()) { return *derived().begin(); } template<typename D = Derived> constexpr auto front() const noexcept(noexcept(*std::declval<D const &>().begin())) -> decltype(*std::declval<D const &>().begin()) { return *derived().begin(); } template<typename D = Derived> constexpr auto push_front(typename D::value_type const & x) noexcept( noexcept(std::declval<D &>().emplace_front(x))) -> decltype((void)std::declval<D &>().emplace_front(x)) { derived().emplace_front(x); } template<typename D = Derived> constexpr auto push_front(typename D::value_type && x) noexcept( noexcept(std::declval<D &>().emplace_front(std::move(x)))) -> decltype((void)std::declval<D &>().emplace_front(std::move(x))) { derived().emplace_front(std::move(x)); } template<typename D = Derived> constexpr auto pop_front() noexcept -> decltype( std::declval<D &>().emplace_front( std::declval<typename D::value_type &>()), (void)std::declval<D &>().erase(std::declval<D &>().begin())) { derived().erase(derived().begin()); } template< typename D = Derived, typename Enable = std::enable_if_t< v1_dtl::decrementable_sentinel<D>::value && v1_dtl::common_range<D>::value>> constexpr auto back() noexcept(noexcept(*std::prev(std::declval<D &>().end()))) -> decltype(*std::prev(std::declval<D &>().end())) { return *std::prev(derived().end()); } template< typename D = Derived, typename Enable = std::enable_if_t< v1_dtl::decrementable_sentinel<D>::value && v1_dtl::common_range<D>::value>> constexpr auto back() const noexcept(noexcept(*std::prev(std::declval<D const &>().end()))) -> decltype(*std::prev(std::declval<D const &>().end())) { return *std::prev(derived().end()); } template<typename D = Derived> constexpr auto push_back(typename D::value_type const & x) noexcept( noexcept(std::declval<D &>().emplace_back(x))) -> decltype((void)std::declval<D &>().emplace_back(x)) { derived().emplace_back(x); } template<typename D = Derived> constexpr auto push_back(typename D::value_type && x) noexcept( noexcept(std::declval<D &>().emplace_back(std::move(x)))) -> decltype((void)std::declval<D &>().emplace_back(std::move(x))) { derived().emplace_back(std::move(x)); } template<typename D = Derived> constexpr auto pop_back() noexcept -> decltype( std::declval<D &>().emplace_back( std::declval<typename D::value_type &>()), (void)std::declval<D &>().erase( std::prev(std::declval<D &>().end()))) { derived().erase(std::prev(derived().end())); } template<typename D = Derived> constexpr auto operator[](typename D::size_type n) noexcept( noexcept(std::declval<D &>().begin()[n])) -> decltype(std::declval<D &>().begin()[n]) { return derived().begin()[n]; } template<typename D = Derived> constexpr auto operator[](typename D::size_type n) const noexcept(noexcept(std::declval<D const &>().begin()[n])) -> decltype(std::declval<D const &>().begin()[n]) { return derived().begin()[n]; } template<typename D = Derived> constexpr auto at(typename D::size_type i) -> decltype(std::declval<D &>().size(), std::declval<D &>()[i]) { if (derived().size() <= i) { throw std::out_of_range( "Bounds check failed in sequence_container_interface::at()"); } return derived()[i]; } template<typename D = Derived> constexpr auto at(typename D::size_type i) const -> decltype( std::declval<D const &>().size(), std::declval<D const &>()[i]) { if (derived().size() <= i) { throw std::out_of_range( "Bounds check failed in sequence_container_interface::at()"); } return derived()[i]; } template<typename D = Derived, typename Iter = typename D::const_iterator> constexpr Iter begin() const noexcept(noexcept(std::declval<D &>().begin())) { return Iter(mutable_derived().begin()); } template<typename D = Derived, typename Iter = typename D::const_iterator> constexpr Iter end() const noexcept(noexcept(std::declval<D &>().end())) { return Iter(mutable_derived().end()); } template<typename D = Derived> constexpr auto cbegin() const noexcept(noexcept(std::declval<D const &>().begin())) -> decltype(std::declval<D const &>().begin()) { return derived().begin(); } template<typename D = Derived> constexpr auto cend() const noexcept(noexcept(std::declval<D const &>().end())) -> decltype(std::declval<D const &>().end()) { return derived().end(); } template< typename D = Derived, typename Enable = std::enable_if_t<v1_dtl::common_range<D>::value>> constexpr auto rbegin() noexcept(noexcept( stl_interfaces::make_reverse_iterator(std::declval<D &>().end()))) { return stl_interfaces::make_reverse_iterator(derived().end()); } template< typename D = Derived, typename Enable = std::enable_if_t<v1_dtl::common_range<D>::value>> constexpr auto rend() noexcept(noexcept( stl_interfaces::make_reverse_iterator(std::declval<D &>().begin()))) { return stl_interfaces::make_reverse_iterator(derived().begin()); } template<typename D = Derived> constexpr auto rbegin() const noexcept(noexcept(std::declval<D &>().rbegin())) { return typename D::const_reverse_iterator(mutable_derived().rbegin()); } template<typename D = Derived> constexpr auto rend() const noexcept(noexcept(std::declval<D &>().rend())) { return typename D::const_reverse_iterator(mutable_derived().rend()); } template<typename D = Derived> constexpr auto crbegin() const noexcept(noexcept(std::declval<D const &>().rbegin())) -> decltype(std::declval<D const &>().rbegin()) { return derived().rbegin(); } template<typename D = Derived> constexpr auto crend() const noexcept(noexcept(std::declval<D const &>().rend())) -> decltype(std::declval<D const &>().rend()) { return derived().rend(); } template<typename D = Derived> constexpr auto insert( typename D::const_iterator pos, typename D::value_type const & x) noexcept(noexcept(std::declval<D &>().emplace(pos, x))) -> decltype(std::declval<D &>().emplace(pos, x)) { return derived().emplace(pos, x); } template<typename D = Derived> constexpr auto insert( typename D::const_iterator pos, typename D::value_type && x) noexcept(noexcept(std::declval<D &>() .emplace(pos, std::move(x)))) -> decltype(std::declval<D &>().emplace(pos, std::move(x))) { return derived().emplace(pos, std::move(x)); } template<typename D = Derived> constexpr auto insert( typename D::const_iterator pos, typename D::size_type n, typename D::value_type const & x) // If you see an error in this noexcept() expression, that's // because this function is not properly constrained. In other // words, Derived does not have a "range" insert like // insert(position, first, last). If that is the case, this // function should be removed via SFINAE from overload resolution. // However, both the trailing decltype code below and a // std::enable_if in the template parameters do not work. Sorry // about that. See below for details. noexcept(noexcept(std::declval<D &>().insert( pos, detail::make_n_iter(x, n), detail::make_n_iter_end(x, n)))) // This causes the compiler to infinitely recurse into this function's // declaration, even though the call below does not match the // signature of this function. #if 0 -> decltype(std::declval<D &>().insert( pos, detail::make_n_iter(x, n), detail::make_n_iter_end(x, n))) #endif { return derived().insert( pos, detail::make_n_iter(x, n), detail::make_n_iter_end(x, n)); } template<typename D = Derived> constexpr auto insert( typename D::const_iterator pos, std::initializer_list<typename D::value_type> il) noexcept(noexcept(std::declval<D &>() .insert(pos, il.begin(), il.end()))) -> decltype(std::declval<D &>().insert(pos, il.begin(), il.end())) { return derived().insert(pos, il.begin(), il.end()); } template<typename D = Derived> constexpr auto erase(typename D::const_iterator pos) noexcept -> decltype(std::declval<D &>().erase(pos, std::next(pos))) { return derived().erase(pos, std::next(pos)); } template< typename InputIterator, typename D = Derived, typename Enable = std::enable_if_t<v1_dtl::in_iter<InputIterator>::value>> constexpr auto assign(InputIterator first, InputIterator last) noexcept( noexcept(std::declval<D &>().insert( std::declval<D &>().begin(), first, last))) -> decltype( std::declval<D &>().erase( std::declval<D &>().begin(), std::declval<D &>().end()), (void)std::declval<D &>().insert( std::declval<D &>().begin(), first, last)) { auto out = derived().begin(); auto const out_last = derived().end(); for (; out != out_last && first != last; ++first, ++out) { *out = *first; } if (out != out_last) derived().erase(out, out_last); if (first != last) derived().insert(derived().end(), first, last); } template<typename D = Derived> constexpr auto assign( typename D::size_type n, typename D::value_type const & x) noexcept(noexcept(std::declval<D &>() .insert( std::declval<D &>().begin(), detail::make_n_iter(x, n), detail::make_n_iter_end(x, n)))) -> decltype( std::declval<D &>().size(), std::declval<D &>().erase( std::declval<D &>().begin(), std::declval<D &>().end()), (void)std::declval<D &>().insert( std::declval<D &>().begin(), detail::make_n_iter(x, n), detail::make_n_iter_end(x, n))) { if (detail::fake_capacity(derived()) < n) { Derived temp(n, x); derived().swap(temp); } else { auto const min_size = std::min<std::ptrdiff_t>(n, derived().size()); auto const fill_end = std::fill_n(derived().begin(), min_size, x); if (min_size < (std::ptrdiff_t)derived().size()) { derived().erase(fill_end, derived().end()); } else { n -= min_size; derived().insert( derived().begin(), detail::make_n_iter(x, n), detail::make_n_iter_end(x, n)); } } } template<typename D = Derived> constexpr auto assign(std::initializer_list<typename D::value_type> il) noexcept( noexcept(std::declval<D &>().assign(il.begin(), il.end()))) -> decltype((void)std::declval<D &>().assign(il.begin(), il.end())) { derived().assign(il.begin(), il.end()); } template<typename D = Derived> constexpr auto operator=(std::initializer_list<typename D::value_type> il) noexcept( noexcept(std::declval<D &>().assign(il.begin(), il.end()))) -> decltype( std::declval<D &>().assign(il.begin(), il.end()), std::declval<D &>()) { derived().assign(il.begin(), il.end()); return *this; } template<typename D = Derived> constexpr auto clear() noexcept -> decltype((void)std::declval<D &>().erase( std::declval<D &>().begin(), std::declval<D &>().end())) { derived().erase(derived().begin(), derived().end()); } }; /** Implementation of free function `swap()` for all containers derived from `sequence_container_interface`. */ template<typename ContainerInterface> constexpr auto swap( ContainerInterface & lhs, ContainerInterface & rhs) noexcept(noexcept(lhs.swap(rhs))) -> decltype(v1_dtl::derived_container(lhs), lhs.swap(rhs)) { return lhs.swap(rhs); } /** Implementation of `operator==()` for all containers derived from `sequence_container_interface`. */ template<typename ContainerInterface> constexpr auto operator==(ContainerInterface const & lhs, ContainerInterface const & rhs) noexcept( noexcept(lhs.size() == rhs.size()) && noexcept(*lhs.begin() == *rhs.begin())) -> decltype( v1_dtl::derived_container(lhs), lhs.size() == rhs.size(), *lhs.begin() == *rhs.begin(), true) { return lhs.size() == rhs.size() && std::equal(lhs.begin(), lhs.end(), rhs.begin()); } /** Implementation of `operator!=()` for all containers derived from `sequence_container_interface`. */ template<typename ContainerInterface> constexpr auto operator!=( ContainerInterface const & lhs, ContainerInterface const & rhs) noexcept(noexcept(lhs == rhs)) -> decltype(v1_dtl::derived_container(lhs), lhs == rhs) { return !(lhs == rhs); } /** Implementation of `operator<()` for all containers derived from `sequence_container_interface`. */ template<typename ContainerInterface> constexpr auto operator<( ContainerInterface const & lhs, ContainerInterface const & rhs) noexcept(noexcept(*lhs.begin() < *rhs.begin())) -> decltype( v1_dtl::derived_container(lhs), *lhs.begin() < *rhs.begin(), true) { auto it1 = lhs.begin(); auto const last1 = lhs.end(); auto it2 = rhs.begin(); auto const last2 = rhs.end(); for (; it1 != last1 && it2 != last2; ++it1, ++it2) { if (*it1 < *it2) return true; if (*it2 < *it1) return false; } return it1 == last1 && it2 != last2; } /** Implementation of `operator<=()` for all containers derived from `sequence_container_interface`. */ template<typename ContainerInterface> constexpr auto operator<=( ContainerInterface const & lhs, ContainerInterface const & rhs) noexcept(noexcept(lhs < rhs)) -> decltype(v1_dtl::derived_container(lhs), lhs < rhs) { return !(rhs < lhs); } /** Implementation of `operator>()` for all containers derived from `sequence_container_interface`. */ template<typename ContainerInterface> constexpr auto operator>( ContainerInterface const & lhs, ContainerInterface const & rhs) noexcept(noexcept(lhs < rhs)) -> decltype(v1_dtl::derived_container(lhs), lhs < rhs) { return rhs < lhs; } /** Implementation of `operator>=()` for all containers derived from `sequence_container_interface`. */ template<typename ContainerInterface> constexpr auto operator>=( ContainerInterface const & lhs, ContainerInterface const & rhs) noexcept(noexcept(lhs < rhs)) -> decltype(v1_dtl::derived_container(lhs), lhs < rhs) { return !(lhs < rhs); } }}} #endif
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