diff options
Diffstat (limited to 'libstdc++-v3/include/bits/alloc_traits.h')
| -rw-r--r-- | libstdc++-v3/include/bits/alloc_traits.h | 72 |
1 files changed, 46 insertions, 26 deletions
diff --git a/libstdc++-v3/include/bits/alloc_traits.h b/libstdc++-v3/include/bits/alloc_traits.h index d2d13c692af..25ad9486a5b 100644 --- a/libstdc++-v3/include/bits/alloc_traits.h +++ b/libstdc++-v3/include/bits/alloc_traits.h @@ -44,8 +44,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION struct __allocator_traits_base { - template<typename _Alloc, typename _Up> - using __rebind = typename _Alloc::template rebind<_Up>::other; + template<typename _Tp, typename _Up, typename = void> + struct __rebind : __replace_first_arg<_Tp, _Up> { }; + + template<typename _Tp, typename _Up> + struct __rebind<_Tp, _Up, + __void_t<typename _Tp::template rebind<_Up>::other>> + { using type = typename _Tp::template rebind<_Up>::other; }; protected: template<typename _Tp> @@ -57,10 +62,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Tp> using __cv_pointer = typename _Tp::const_void_pointer; template<typename _Tp> - using __diff_type = typename _Tp::difference_type; - template<typename _Tp> - using __size_type = typename _Tp::size_type; - template<typename _Tp> using __pocca = typename _Tp::propagate_on_container_copy_assignment; template<typename _Tp> using __pocma = typename _Tp::propagate_on_container_move_assignment; @@ -71,9 +72,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION }; template<typename _Alloc, typename _Up> - using __alloc_rebind = __detected_or_t_<__replace_first_arg_t, - __allocator_traits_base::__rebind, - _Alloc, _Up>; + using __alloc_rebind + = typename __allocator_traits_base::template __rebind<_Alloc, _Up>::type; /** * @brief Uniform interface to all allocator types. @@ -94,15 +94,45 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION */ using pointer = __detected_or_t<value_type*, __pointer, _Alloc>; + private: + // Select _Func<_Alloc> or pointer_traits<pointer>::rebind<_Tp> + template<template<typename> class _Func, typename _Tp, typename = void> + struct _Ptr + { + using type = typename pointer_traits<pointer>::template rebind<_Tp>; + }; + + template<template<typename> class _Func, typename _Tp> + struct _Ptr<_Func, _Tp, __void_t<_Func<_Alloc>>> + { + using type = _Func<_Alloc>; + }; + + // Select _A2::difference_type or pointer_traits<_Ptr>::difference_type + template<typename _A2, typename _PtrT, typename = void> + struct _Diff + { using type = typename pointer_traits<_PtrT>::difference_type; }; + + template<typename _A2, typename _PtrT> + struct _Diff<_A2, _PtrT, __void_t<typename _A2::difference_type>> + { using type = typename _A2::difference_type; }; + + // Select _A2::size_type or make_unsigned<_DiffT>::type + template<typename _A2, typename _DiffT, typename = void> + struct _Size : make_unsigned<_DiffT> { }; + + template<typename _A2, typename _DiffT> + struct _Size<_A2, _DiffT, __void_t<typename _A2::size_type>> + { using type = typename _A2::size_type; }; + + public: /** * @brief The allocator's const pointer type. * * @c Alloc::const_pointer if that type exists, otherwise * <tt> pointer_traits<pointer>::rebind<const value_type> </tt> */ - using const_pointer - = __detected_or_t<__ptr_rebind<pointer, const value_type>, - __c_pointer, _Alloc>; + using const_pointer = typename _Ptr<__c_pointer, const value_type>::type; /** * @brief The allocator's void pointer type. @@ -110,8 +140,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION * @c Alloc::void_pointer if that type exists, otherwise * <tt> pointer_traits<pointer>::rebind<void> </tt> */ - using void_pointer - = __detected_or_t<__ptr_rebind<pointer, void>, __v_pointer, _Alloc>; + using void_pointer = typename _Ptr<__v_pointer, void>::type; /** * @brief The allocator's const void pointer type. @@ -119,9 +148,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION * @c Alloc::const_void_pointer if that type exists, otherwise * <tt> pointer_traits<pointer>::rebind<const void> </tt> */ - using const_void_pointer - = __detected_or_t<__ptr_rebind<pointer, const void>, __cv_pointer, - _Alloc>; + using const_void_pointer = typename _Ptr<__cv_pointer, const void>::type; /** * @brief The allocator's difference type @@ -129,9 +156,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION * @c Alloc::difference_type if that type exists, otherwise * <tt> pointer_traits<pointer>::difference_type </tt> */ - using difference_type - = __detected_or_t<typename pointer_traits<pointer>::difference_type, - __diff_type, _Alloc>; + using difference_type = typename _Diff<_Alloc, pointer>::type; /** * @brief The allocator's size type @@ -139,9 +164,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION * @c Alloc::size_type if that type exists, otherwise * <tt> make_unsigned<difference_type>::type </tt> */ - using size_type - = __detected_or_t<typename make_unsigned<difference_type>::type, - __size_type, _Alloc>; + using size_type = typename _Size<_Alloc, difference_type>::type; /** * @brief How the allocator is propagated on copy assignment @@ -184,9 +207,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Tp> using rebind_traits = allocator_traits<rebind_alloc<_Tp>>; - static_assert(!is_same<rebind_alloc<value_type>, __undefined>::value, - "allocator defines rebind or is like Alloc<T, Args>"); - private: template<typename _Alloc2> static auto |