29 #ifndef _GLIBCXX_EXPERIMENTAL_MEMORY_RESOURCE
30 #define _GLIBCXX_EXPERIMENTAL_MEMORY_RESOURCE 1
39 _GLIBCXX_BEGIN_NAMESPACE_VERSION
41 namespace experimental {
42 inline namespace fundamentals_v2 {
44 #define __cpp_lib_experimental_memory_resources 201402L
46 class memory_resource;
48 template <
typename _Tp>
49 class polymorphic_allocator;
51 template <
typename _Alloc>
52 class __resource_adaptor_imp;
54 template <
typename _Alloc>
55 using resource_adaptor = __resource_adaptor_imp<
56 typename allocator_traits<_Alloc>::template rebind_alloc<char>>;
58 template <
typename _Tp>
59 struct __uses_allocator_construction_helper;
62 memory_resource* new_delete_resource()
noexcept;
63 memory_resource* null_memory_resource()
noexcept;
66 memory_resource* get_default_resource() noexcept;
67 memory_resource* set_default_resource(memory_resource* __r) noexcept;
75 static constexpr
size_t _S_max_align =
alignof(max_align_t);
78 virtual ~memory_resource() { }
81 allocate(
size_t __bytes,
size_t __alignment = _S_max_align)
82 {
return do_allocate(__bytes, __alignment); }
85 deallocate(
void* __p,
size_t __bytes,
size_t __alignment = _S_max_align)
86 {
return do_deallocate(__p, __bytes, __alignment); }
89 is_equal(
const memory_resource& __other)
const noexcept
90 {
return do_is_equal(__other); }
94 do_allocate(
size_t __bytes,
size_t __alignment) = 0;
97 do_deallocate(
void* __p,
size_t __bytes,
size_t __alignment) = 0;
100 do_is_equal(
const memory_resource& __other)
const noexcept = 0;
104 operator==(
const memory_resource& __a,
105 const memory_resource& __b)
noexcept
106 {
return &__a == &__b || __a.is_equal(__b); }
109 operator!=(
const memory_resource& __a,
110 const memory_resource& __b)
noexcept
111 {
return !(__a == __b); }
116 class polymorphic_allocator
118 using __uses_alloc1_ = __uses_alloc1<memory_resource*>;
119 using __uses_alloc2_ = __uses_alloc2<memory_resource*>;
121 template<
typename _Tp1,
typename... _Args>
123 _M_construct(__uses_alloc0, _Tp1* __p, _Args&&... __args)
124 { ::new(__p) _Tp1(std::
forward<_Args>(__args)...); }
126 template<typename _Tp1, typename... _Args>
128 _M_construct(__uses_alloc1_, _Tp1* __p, _Args&&... __args)
129 { ::new(__p) _Tp1(allocator_arg, this->resource(),
130 std::
forward<_Args>(__args)...); }
132 template<typename _Tp1, typename... _Args>
134 _M_construct(__uses_alloc2_, _Tp1* __p, _Args&&... __args)
135 { ::new(__p) _Tp1(std::
forward<_Args>(__args)...,
139 using value_type = _Tp;
142 : _M_resource(get_default_resource())
145 polymorphic_allocator(memory_resource* __r)
147 { _GLIBCXX_DEBUG_ASSERT(__r); }
149 polymorphic_allocator(
const polymorphic_allocator& __other) =
default;
151 template <
typename _Up>
152 polymorphic_allocator(
const polymorphic_allocator<_Up>&
154 : _M_resource(__other.resource())
157 polymorphic_allocator&
158 operator=(
const polymorphic_allocator& __rhs) =
default;
160 _Tp* allocate(
size_t __n)
161 {
return static_cast<_Tp*
>(_M_resource->allocate(__n *
sizeof(_Tp),
164 void deallocate(_Tp* __p,
size_t __n)
165 { _M_resource->deallocate(__p, __n *
sizeof(_Tp),
alignof(_Tp)); }
167 template <
typename _Tp1,
typename... _Args>
168 void construct(_Tp1* __p, _Args&&... __args)
170 memory_resource*
const __resource = this->resource();
172 = __use_alloc<_Tp1, memory_resource*, _Args...>(__resource);
173 _M_construct(__use_tag, __p, std::forward<_Args>(__args)...);
177 template <
typename _Tp1,
typename _Tp2,
178 typename... _Args1,
typename... _Args2>
179 void construct(pair<_Tp1, _Tp2>* __p, piecewise_construct_t,
180 tuple<_Args1...> __x,
181 tuple<_Args2...> __y)
183 memory_resource*
const __resource = this->resource();
185 __use_alloc<_Tp1, memory_resource*, _Args1...>(__resource);
187 __use_alloc<_Tp2, memory_resource*, _Args2...>(__resource);
190 _M_construct_p(__x_use_tag, __x),
191 _M_construct_p(__y_use_tag, __y));
194 template <typename _Tp1, typename _Tp2>
195 void construct(pair<_Tp1,_Tp2>* __p)
196 { this->construct(__p, piecewise_construct, tuple<>(), tuple<>()); }
198 template <
typename _Tp1,
typename _Tp2,
typename _Up,
typename _Vp>
199 void construct(pair<_Tp1,_Tp2>* __p, _Up&& __x, _Vp&& __y)
200 { this->construct(__p, piecewise_construct,
201 forward_as_tuple(std::forward<_Up>(__x)),
202 forward_as_tuple(std::forward<_Vp>(__y))); }
204 template <
typename _Tp1,
typename _Tp2,
typename _Up,
typename _Vp>
206 { this->construct(__p, piecewise_construct, forward_as_tuple(__pr.
first),
207 forward_as_tuple(__pr.
second)); }
209 template <
typename _Tp1,
typename _Tp2,
typename _Up,
typename _Vp>
210 void construct(pair<_Tp1,_Tp2>* __p, pair<_Up, _Vp>&& __pr)
211 { this->construct(__p, piecewise_construct,
212 forward_as_tuple(std::forward<_Up>(__pr.
first)),
213 forward_as_tuple(std::forward<_Vp>(__pr.
second))); }
215 template <
typename _Up>
216 void destroy(_Up* __p)
220 polymorphic_allocator select_on_container_copy_construction()
const
221 {
return polymorphic_allocator(); }
223 memory_resource* resource()
const
224 {
return _M_resource; }
227 template<
typename _Tuple>
229 _M_construct_p(__uses_alloc0, _Tuple& __t)
230 {
return std::move(__t); }
232 template<
typename... _Args>
234 _M_construct_p(__uses_alloc1_ __ua, tuple<_Args...>& __t)
235 {
return tuple_cat(make_tuple(allocator_arg, *(__ua._M_a)),
238 template<
typename... _Args>
240 _M_construct_p(__uses_alloc2_ __ua, tuple<_Args...>& __t)
241 {
return tuple_cat(std::move(__t), make_tuple(*(__ua._M_a))); }
243 memory_resource* _M_resource;
246 template <
class _Tp1,
class _Tp2>
247 bool operator==(
const polymorphic_allocator<_Tp1>& __a,
248 const polymorphic_allocator<_Tp2>& __b)
noexcept
249 {
return *__a.resource() == *__b.resource(); }
251 template <
class _Tp1,
class _Tp2>
252 bool operator!=(
const polymorphic_allocator<_Tp1>& __a,
253 const polymorphic_allocator<_Tp2>& __b)
noexcept
254 {
return !(__a == __b); }
257 template <
typename _Alloc>
258 class __resource_adaptor_imp :
public memory_resource
260 static_assert(is_same<
char,
261 typename allocator_traits<_Alloc>::value_type>::value,
262 "Allocator's value_type is char");
263 static_assert(is_same<
char*,
264 typename allocator_traits<_Alloc>::pointer>::value,
265 "Allocator's pointer type is value_type*");
266 static_assert(is_same<
const char*,
267 typename allocator_traits<_Alloc>::const_pointer>::value,
268 "Allocator's const_pointer type is value_type const*");
269 static_assert(is_same<
void*,
270 typename allocator_traits<_Alloc>::void_pointer>::value,
271 "Allocator's void_pointer type is void*");
272 static_assert(is_same<
const void*,
273 typename allocator_traits<_Alloc>::const_void_pointer>::value,
274 "Allocator's const_void_pointer type is void const*");
277 using allocator_type = _Alloc;
279 __resource_adaptor_imp() =
default;
280 __resource_adaptor_imp(
const __resource_adaptor_imp&) =
default;
281 __resource_adaptor_imp(__resource_adaptor_imp&&) =
default;
283 explicit __resource_adaptor_imp(
const _Alloc& __a2)
287 explicit __resource_adaptor_imp(_Alloc&& __a2)
288 : _M_alloc(std::move(__a2))
291 __resource_adaptor_imp&
292 operator=(
const __resource_adaptor_imp&) =
default;
294 allocator_type get_allocator() const
noexcept {
return _M_alloc; }
298 do_allocate(
size_t __bytes,
size_t __alignment)
300 using _Aligned_alloc = std::__alloc_rebind<_Alloc, char>;
301 size_t __new_size = _S_aligned_size(__bytes,
302 _S_supported(__alignment) ?
303 __alignment : _S_max_align);
304 return _Aligned_alloc(_M_alloc).allocate(__new_size);
308 do_deallocate(
void* __p,
size_t __bytes,
size_t __alignment)
310 using _Aligned_alloc = std::__alloc_rebind<_Alloc, char>;
311 size_t __new_size = _S_aligned_size(__bytes,
312 _S_supported(__alignment) ?
313 __alignment : _S_max_align);
314 using _Ptr =
typename allocator_traits<_Aligned_alloc>::pointer;
315 _Aligned_alloc(_M_alloc).deallocate(static_cast<_Ptr>(__p),
320 do_is_equal(
const memory_resource& __other)
const noexcept
322 auto __p =
dynamic_cast<const __resource_adaptor_imp*
>(&__other);
323 return __p ? (_M_alloc == __p->_M_alloc) :
false;
331 _S_aligned_size(
size_t __size,
size_t __alignment)
332 {
return ((__size - 1)|(__alignment - 1)) + 1; }
338 _S_supported (
size_t __x)
339 {
return ((__x != 0) && !(__x & (__x - 1))); }
346 inline memory_resource*
349 using type = resource_adaptor<std::allocator<char>>;
350 alignas(type)
static unsigned char __buf[
sizeof(type)];
351 static type* __r =
new(__buf) type;
355 inline memory_resource*
358 class type final :
public memory_resource
361 do_allocate(
size_t,
size_t)
override
362 { std::__throw_bad_alloc(); }
365 do_deallocate(
void*,
size_t,
size_t)
noexcept override
369 do_is_equal(
const memory_resource& __other)
const noexcept override
370 {
return this == &__other; }
373 alignas(type)
static unsigned char __buf[
sizeof(type)];
374 static type* __r =
new(__buf) type;
381 __get_default_resource()
383 using type = atomic<memory_resource*>;
384 alignas(type)
static unsigned char __buf[
sizeof(type)];
385 static type* __r =
new(__buf) type(new_delete_resource());
389 inline memory_resource*
391 {
return __get_default_resource().load(); }
393 inline memory_resource*
394 set_default_resource(memory_resource* __r)
noexcept
397 __r = new_delete_resource();
398 return __get_default_resource().exchange(__r);
404 _GLIBCXX_END_NAMESPACE_VERSION
enable_if< ::__array_traits< _Tp, _Nm >::_Is_swappable::value >::type noexcept(noexcept(__one.swap(__two)))
swap
_GLIBCXX17_INLINE constexpr piecewise_construct_t piecewise_construct
piecewise_construct
Struct holding two objects of arbitrary type.
constexpr _Tp && forward(typename std::remove_reference< _Tp >::type &__t) noexcept
Forward an lvalue.
_T2 second
first is a copy of the first object
Generic atomic type, primary class template.
_T1 first
second_type is the second bound type