diff options
Diffstat (limited to 'boost/core/pointer_traits.hpp')
-rw-r--r-- | boost/core/pointer_traits.hpp | 185 |
1 files changed, 80 insertions, 105 deletions
diff --git a/boost/core/pointer_traits.hpp b/boost/core/pointer_traits.hpp index ff1a5321db..e0ebfb0769 100644 --- a/boost/core/pointer_traits.hpp +++ b/boost/core/pointer_traits.hpp @@ -1,5 +1,5 @@ /* -Copyright 2017 Glen Joseph Fernandes +Copyright 2017-2018 Glen Joseph Fernandes (glenjofe@gmail.com) Distributed under the Boost Software License, Version 1.0. @@ -17,20 +17,6 @@ Distributed under the Boost Software License, Version 1.0. namespace boost { -template<class T> -struct pointer_traits; - -namespace detail { - -template<class U> -inline typename boost::pointer_traits<U>::element_type* -ptr_traits_address(const U& v) BOOST_NOEXCEPT -{ - return boost::pointer_traits<U>::to_address(v); -} - -} /* detail */ - #if !defined(BOOST_NO_CXX11_POINTER_TRAITS) template<class T> struct pointer_traits @@ -39,10 +25,6 @@ struct pointer_traits struct rebind_to { typedef typename std::pointer_traits<T>::template rebind<U> type; }; - static typename std::pointer_traits<T>::element_type* - to_address(const T& v) BOOST_NOEXCEPT { - return detail::ptr_traits_address(v.operator->()); - } }; template<class T> @@ -52,143 +34,107 @@ struct pointer_traits<T*> struct rebind_to { typedef U* type; }; - static T* to_address(T* v) BOOST_NOEXCEPT { - return v; - } }; #else namespace detail { -struct ptr_traits_none { char first, second; }; - -template<class T> -struct ptr_traits_has_element { -private: - template<class U> - static ptr_traits_none call(...); - template<class U> - static char call(typename U::element_type* = 0); -public: - static const bool value = sizeof(call<T>(0)) == 1; +template<class> +struct ptr_void { + typedef void type; }; template<class T> -struct ptr_traits_first; +struct ptr_first; #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) template<template<class, class...> class T, class U, class... Args> -struct ptr_traits_first<T<U, Args...> > { +struct ptr_first<T<U, Args...> > { typedef U type; }; #else template<template<class> class T, class U> -struct ptr_traits_first<T<U> > { +struct ptr_first<T<U> > { typedef U type; }; template<template<class, class> class T, class U1, class U2> -struct ptr_traits_first<T<U1, 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_traits_first<T<U1, U2, U3> > { +struct ptr_first<T<U1, U2, U3> > { typedef U1 type; }; #endif -template<class T, bool = ptr_traits_has_element<T>::value> -struct ptr_traits_element { - typedef typename T::element_type type; +template<class T, class = void> +struct ptr_element { + typedef typename ptr_first<T>::type type; }; template<class T> -struct ptr_traits_element<T, false> { - typedef typename ptr_traits_first<T>::type type; -}; - -template<class T> -struct ptr_traits_has_difference { -private: - template<class U> - static ptr_traits_none call(...); - template<class U> - static char call(typename U::difference_type* = 0); -public: - static const bool value = sizeof(call<T>(0)) == 1; -}; - -template<class T, bool = ptr_traits_has_difference<T>::value> -struct ptr_traits_difference { - typedef typename T::difference_type type; +struct ptr_element<T, typename ptr_void<typename T::element_type>::type> { + typedef typename T::element_type type; }; -template<class T> -struct ptr_traits_difference<T, false> { +template<class, class = void> +struct ptr_difference { typedef std::ptrdiff_t type; }; -template<class T, class V> -struct ptr_traits_has_rebind { -private: - template<class U> - static ptr_traits_none call(...); - template<class U> - static char call(typename U::template rebind<V>* = 0); -public: - static const bool value = sizeof(call<T>(0)) == 1; +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_traits_rebind_to; +struct ptr_transform; #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) template<template<class, class...> class T, class U, class... Args, class V> -struct ptr_traits_rebind_to<T<U, Args...>, 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_traits_rebind_to<T<U>, 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_traits_rebind_to<T<U1, U2>, 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_traits_rebind_to<T<U1, U2, U3>, V> { +struct ptr_transform<T<U1, U2, U3>, V> { typedef T<V, U2, U3> type; }; #endif -#if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) -template<class T, class U, bool = ptr_traits_has_rebind<T, U>::value> -struct ptr_traits_rebind { - typedef typename T::template rebind<U> type; +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_traits_rebind<T, U, false> { - typedef typename ptr_traits_rebind_to<T, U>::type type; -}; -#else -template<class T, class U> -struct ptr_traits_rebind { - typedef typename ptr_traits_rebind_to<T, U>::type type; +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_traits_value { +struct ptr_value { typedef T type; }; template<> -struct ptr_traits_value<void> { +struct ptr_value<void> { typedef struct { } type; }; @@ -197,23 +143,20 @@ struct ptr_traits_value<void> { template<class T> struct pointer_traits { typedef T pointer; - typedef typename detail::ptr_traits_element<T>::type element_type; - typedef typename detail::ptr_traits_difference<T>::type difference_type; + 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_traits_rebind<T, U>::type type; + typedef typename detail::ptr_rebind<T, U>::type type; }; #if !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) template<class U> - using rebind = typename detail::ptr_traits_rebind<T, U>::type; + using rebind = typename detail::ptr_rebind<T, U>::type; #endif static pointer - pointer_to(typename detail::ptr_traits_value<element_type>::type& v) { + pointer_to(typename detail::ptr_value<element_type>::type& v) { return pointer::pointer_to(v); } - static element_type* to_address(const pointer& v) BOOST_NOEXCEPT { - return detail::ptr_traits_address(v.operator->()); - } }; template<class T> @@ -230,29 +173,61 @@ struct pointer_traits<T*> { using rebind = U*; #endif static T* - pointer_to(typename detail::ptr_traits_value<T>::type& v) BOOST_NOEXCEPT { - return addressof(v); - } - static T* to_address(T* v) BOOST_NOEXCEPT { - return v; + pointer_to(typename detail::ptr_value<T>::type& v) BOOST_NOEXCEPT { + return boost::addressof(v); } }; #endif template<class T> -inline typename pointer_traits<T>::element_type* -to_address(const T& v) BOOST_NOEXCEPT +BOOST_CONSTEXPR inline T* +to_address(T* v) BOOST_NOEXCEPT { - return pointer_traits<T>::to_address(v); + return v; } +#if !defined(BOOST_NO_CXX14_RETURN_TYPE_DEDUCTION) +namespace detail { + template<class T> inline T* -to_address(T* v) BOOST_NOEXCEPT +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 |