31 #define _PTR_TRAITS_H 1
33 #if __cplusplus >= 201103L
37 #if __cplusplus > 201703L
39 #define __cpp_lib_constexpr_memory 201811L
40 namespace __gnu_debug {
struct _Safe_iterator_base; }
43 namespace std _GLIBCXX_VISIBILITY(default)
45 _GLIBCXX_BEGIN_NAMESPACE_VERSION
51 template<
typename _Tp>
52 struct __get_first_arg
53 {
using type = __undefined; };
55 template<
template<
typename,
typename...>
class _SomeTemplate,
typename _Tp,
57 struct __get_first_arg<_SomeTemplate<_Tp, _Types...>>
58 {
using type = _Tp; };
62 template<
typename _Tp,
typename _Up>
63 struct __replace_first_arg
66 template<
template<
typename,
typename...>
class _SomeTemplate,
typename _Up,
67 typename _Tp,
typename... _Types>
68 struct __replace_first_arg<_SomeTemplate<_Tp, _Types...>, _Up>
69 {
using type = _SomeTemplate<_Up, _Types...>; };
74 template<
typename _Ptr>
75 using __ptr_traits_elem_t =
typename __get_first_arg<_Ptr>::type;
78 template<
typename _Ptr,
typename =
void>
79 struct __ptr_traits_elem : __get_first_arg<_Ptr>
83 template<
typename _Ptr>
84 struct __ptr_traits_elem<_Ptr, __void_t<typename _Ptr::element_type>>
85 {
using type =
typename _Ptr::element_type; };
87 template<
typename _Ptr>
88 using __ptr_traits_elem_t =
typename __ptr_traits_elem<_Ptr>::type;
92 template<typename _Ptr, typename _Elt, bool = is_void<_Elt>::value>
93 struct __ptr_traits_ptr_to
96 using element_type = _Elt;
105 pointer_to(element_type& __e)
106 #if __cpp_lib_concepts
108 { pointer::pointer_to(__e) } -> convertible_to<pointer>;
111 {
return pointer::pointer_to(__e); }
115 template<
typename _Ptr,
typename _Elt>
116 struct __ptr_traits_ptr_to<_Ptr, _Elt, true>
120 template<
typename _Tp>
121 struct __ptr_traits_ptr_to<_Tp*, _Tp,
false>
123 using pointer = _Tp*;
124 using element_type = _Tp;
131 static _GLIBCXX20_CONSTEXPR pointer
132 pointer_to(element_type& __r) noexcept
136 template<
typename _Ptr,
typename _Elt>
137 struct __ptr_traits_impl : __ptr_traits_ptr_to<_Ptr, _Elt>
140 template<
typename _Tp,
typename =
void>
141 struct __difference {
using type = ptrdiff_t; };
143 template<
typename _Tp>
145 requires requires {
typename _Tp::difference_type; }
146 struct __difference<_Tp>
148 struct __difference<_Tp, __void_t<typename _Tp::difference_type>>
150 {
using type =
typename _Tp::difference_type; };
152 template<
typename _Tp,
typename _Up,
typename =
void>
153 struct __rebind : __replace_first_arg<_Tp, _Up> { };
155 template<
typename _Tp,
typename _Up>
157 requires requires {
typename _Tp::template rebind<_Up>; }
158 struct __rebind<_Tp, _Up>
160 struct __rebind<_Tp, _Up, __void_t<typename _Tp::template rebind<_Up>>>
162 {
using type =
typename _Tp::template rebind<_Up>; };
166 using pointer = _Ptr;
169 using element_type = _Elt;
172 using difference_type =
typename __difference<_Ptr>::type;
175 template<
typename _Up>
176 using rebind =
typename __rebind<_Ptr, _Up>::type;
181 template<
typename _Ptr>
182 struct __ptr_traits_impl<_Ptr, __undefined>
190 template<
typename _Ptr>
195 template<
typename _Ptr> requires requires {
typename _Ptr::element_type; }
196 struct pointer_traits<_Ptr>
197 : __ptr_traits_impl<_Ptr, typename _Ptr::element_type>
206 template<
typename _Tp>
216 template<
typename _Up>
using rebind = _Up*;
220 template<
typename _Ptr,
typename _Tp>
223 template<
typename _Tp>
225 __to_address(_Tp* __ptr) noexcept
231 #if __cplusplus <= 201703L
232 template<
typename _Ptr>
234 __to_address(
const _Ptr& __ptr)
235 {
return std::__to_address(__ptr.operator->()); }
237 template<
typename _Ptr>
239 __to_address(
const _Ptr& __ptr) noexcept
243 template<
typename _Ptr,
typename... _None>
245 __to_address(
const _Ptr& __ptr, _None...) noexcept
247 if constexpr (is_base_of_v<__gnu_debug::_Safe_iterator_base, _Ptr>)
248 return std::__to_address(__ptr.base().operator->());
250 return std::__to_address(__ptr.operator->());
253 #define __cpp_lib_to_address 201711L
261 template<
typename _Tp>
264 {
return std::__to_address(__ptr); }
273 template<
typename _Ptr>
276 {
return std::__to_address(__ptr); }
279 _GLIBCXX_END_NAMESPACE_VERSION
constexpr auto to_address(const _Ptr &__ptr) noexcept
Obtain address referenced by a pointer to an object.
constexpr _Tp * to_address(_Tp *__ptr) noexcept
Obtain address referenced by a pointer to an object.
constexpr _Tp * addressof(_Tp &__r) noexcept
Returns the actual address of the object or function referenced by r, even in the presence of an over...
ISO C++ entities toplevel namespace is std.
typename pointer_traits< _Ptr >::template rebind< _Tp > __ptr_rebind
Convenience alias for rebinding pointers.
GNU debug classes for public use.
Uniform interface to all pointer-like types.
_Tp * pointer
The pointer type.
ptrdiff_t difference_type
Type used to represent the difference between two pointers.
_Tp element_type
The type pointed to.
_Up * rebind
A pointer to a different type.