| /* |
| Copyright 2017-2018 Glen Joseph Fernandes |
| (glenjofe@gmail.com) |
| |
| Distributed under the Boost Software License, Version 1.0. |
| (http://www.boost.org/LICENSE_1_0.txt) |
| */ |
| #ifndef BOOST_CORE_POINTER_TRAITS_HPP |
| #define BOOST_CORE_POINTER_TRAITS_HPP |
| |
| #include <boost/config.hpp> |
| #if !defined(BOOST_NO_CXX11_POINTER_TRAITS) |
| #include <memory> |
| #else |
| #include <boost/core/addressof.hpp> |
| #include <cstddef> |
| #endif |
| |
| namespace boost { |
| |
| #if !defined(BOOST_NO_CXX11_POINTER_TRAITS) |
| template<class T> |
| struct pointer_traits |
| : std::pointer_traits<T> { |
| template<class U> |
| struct rebind_to { |
| typedef typename std::pointer_traits<T>::template rebind<U> type; |
| }; |
| }; |
| |
| template<class T> |
| struct pointer_traits<T*> |
| : std::pointer_traits<T*> { |
| template<class U> |
| struct rebind_to { |
| typedef U* type; |
| }; |
| }; |
| #else |
| namespace detail { |
| |
| template<class> |
| struct ptr_void { |
| typedef void type; |
| }; |
| |
| template<class T> |
| struct ptr_first; |
| |
| #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) |
| template<template<class, class...> class T, class U, class... Args> |
| struct ptr_first<T<U, Args...> > { |
| typedef U type; |
| }; |
| #else |
| template<template<class> class T, class U> |
| struct ptr_first<T<U> > { |
| typedef U type; |
| }; |
| |
| template<template<class, class> class T, class U1, class U2> |
| struct ptr_first<T<U1, U2> > { |
| typedef U1 type; |
| }; |
| |
| template<template<class, class, class> class T, class U1, class U2, class U3> |
| struct ptr_first<T<U1, U2, U3> > { |
| typedef U1 type; |
| }; |
| #endif |
| |
| template<class T, class = void> |
| struct ptr_element { |
| typedef typename ptr_first<T>::type type; |
| }; |
| |
| template<class T> |
| struct ptr_element<T, typename ptr_void<typename T::element_type>::type> { |
| typedef typename T::element_type type; |
| }; |
| |
| template<class, class = void> |
| struct ptr_difference { |
| typedef std::ptrdiff_t type; |
| }; |
| |
| template<class T> |
| struct ptr_difference<T, |
| typename ptr_void<typename T::difference_type>::type> { |
| typedef typename T::difference_type type; |
| }; |
| |
| template<class T, class V> |
| struct ptr_transform; |
| |
| #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) |
| template<template<class, class...> class T, class U, class... Args, class V> |
| struct ptr_transform<T<U, Args...>, V> { |
| typedef T<V, Args...> type; |
| }; |
| #else |
| template<template<class> class T, class U, class V> |
| struct ptr_transform<T<U>, V> { |
| typedef T<V> type; |
| }; |
| |
| template<template<class, class> class T, class U1, class U2, class V> |
| struct ptr_transform<T<U1, U2>, V> { |
| typedef T<V, U2> type; |
| }; |
| |
| template<template<class, class, class> class T, |
| class U1, class U2, class U3, class V> |
| struct ptr_transform<T<U1, U2, U3>, V> { |
| typedef T<V, U2, U3> type; |
| }; |
| #endif |
| |
| template<class T, class U, class = void> |
| struct ptr_rebind { |
| typedef typename ptr_transform<T, U>::type type; |
| }; |
| |
| #if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) |
| template<class T, class U> |
| struct ptr_rebind<T, U, |
| typename ptr_void<typename T::template rebind<U> >::type> { |
| typedef typename T::template rebind<U> type; |
| }; |
| #endif |
| |
| template<class T> |
| struct ptr_value { |
| typedef T type; |
| }; |
| |
| template<> |
| struct ptr_value<void> { |
| typedef struct { } type; |
| }; |
| |
| } /* detail */ |
| |
| template<class T> |
| struct pointer_traits { |
| typedef T pointer; |
| typedef typename detail::ptr_element<T>::type element_type; |
| typedef typename detail::ptr_difference<T>::type difference_type; |
| template<class U> |
| struct rebind_to { |
| typedef typename detail::ptr_rebind<T, U>::type type; |
| }; |
| #if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) |
| template<class U> |
| using rebind = typename detail::ptr_rebind<T, U>::type; |
| #endif |
| static pointer |
| pointer_to(typename detail::ptr_value<element_type>::type& v) { |
| return pointer::pointer_to(v); |
| } |
| }; |
| |
| template<class T> |
| struct pointer_traits<T*> { |
| typedef T* pointer; |
| typedef T element_type; |
| typedef std::ptrdiff_t difference_type; |
| template<class U> |
| struct rebind_to { |
| typedef U* type; |
| }; |
| #if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) |
| template<class U> |
| using rebind = U*; |
| #endif |
| static T* |
| pointer_to(typename detail::ptr_value<T>::type& v) BOOST_NOEXCEPT { |
| return boost::addressof(v); |
| } |
| }; |
| #endif |
| |
| template<class T> |
| BOOST_CONSTEXPR inline T* |
| to_address(T* v) BOOST_NOEXCEPT |
| { |
| return v; |
| } |
| |
| #if !defined(BOOST_NO_CXX14_RETURN_TYPE_DEDUCTION) |
| namespace detail { |
| |
| template<class T> |
| inline T* |
| ptr_address(T* v, int) BOOST_NOEXCEPT |
| { |
| return v; |
| } |
| |
| template<class T> |
| inline auto |
| ptr_address(const T& v, int) BOOST_NOEXCEPT |
| -> decltype(boost::pointer_traits<T>::to_address(v)) |
| { |
| return boost::pointer_traits<T>::to_address(v); |
| } |
| |
| template<class T> |
| inline auto |
| ptr_address(const T& v, long) BOOST_NOEXCEPT |
| { |
| return boost::detail::ptr_address(v.operator->(), 0); |
| } |
| |
| } /* detail */ |
| |
| template<class T> |
| inline auto |
| to_address(const T& v) BOOST_NOEXCEPT |
| { |
| return boost::detail::ptr_address(v, 0); |
| } |
| #else |
| template<class T> |
| inline typename pointer_traits<T>::element_type* |
| to_address(const T& v) BOOST_NOEXCEPT |
| { |
| return boost::to_address(v.operator->()); |
| } |
| #endif |
| |
| } /* boost */ |
| |
| #endif |