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Howard Hinnantc51e1022010-05-11 19:42:16 +00001// -*- C++ -*-
2//===----------------------------- new ------------------------------------===//
3//
Howard Hinnantc566dc32010-05-11 21:36:01 +00004// The LLVM Compiler Infrastructure
Howard Hinnantc51e1022010-05-11 19:42:16 +00005//
Howard Hinnantee11c312010-11-16 22:09:02 +00006// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
Howard Hinnantc51e1022010-05-11 19:42:16 +00008//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_NEW
12#define _LIBCPP_NEW
13
14/*
15 new synopsis
16
17namespace std
18{
19
20class bad_alloc
21 : public exception
22{
23public:
Howard Hinnant1bc52cf2011-05-26 18:23:59 +000024 bad_alloc() noexcept;
25 bad_alloc(const bad_alloc&) noexcept;
26 bad_alloc& operator=(const bad_alloc&) noexcept;
27 virtual const char* what() const noexcept;
Howard Hinnantc51e1022010-05-11 19:42:16 +000028};
29
Eric Fiselier162922f2016-10-14 06:46:30 +000030class bad_array_length : public bad_alloc // FIXME: Not part of C++
Marshall Clow3bf77132013-09-11 01:38:42 +000031{
32public:
33 bad_array_length() noexcept;
34};
35
Eric Fiselier162922f2016-10-14 06:46:30 +000036class bad_array_new_length : public bad_alloc // C++14
Marshall Clow3bf77132013-09-11 01:38:42 +000037{
38public:
39 bad_array_new_length() noexcept;
40};
41
Eric Fiselier162922f2016-10-14 06:46:30 +000042enum class align_val_t : size_t {}; // C++17
Howard Hinnantc51e1022010-05-11 19:42:16 +000043struct nothrow_t {};
44extern const nothrow_t nothrow;
45typedef void (*new_handler)();
Howard Hinnant1bc52cf2011-05-26 18:23:59 +000046new_handler set_new_handler(new_handler new_p) noexcept;
47new_handler get_new_handler() noexcept;
Howard Hinnantc51e1022010-05-11 19:42:16 +000048
Marshall Clowdf5a11f2017-11-22 19:49:03 +000049// 21.6.4, pointer optimization barrier
50template <class T> constexpr T* launder(T* p) noexcept; // C++17
Howard Hinnantc51e1022010-05-11 19:42:16 +000051} // std
52
Marshall Clowbe8b84d2017-12-04 23:03:42 +000053void* operator new(std::size_t size); // replaceable, nodiscard in C++2a
54void* operator new(std::size_t size, std::align_val_t alignment); // replaceable, C++17, nodiscard in C++2a
55void* operator new(std::size_t size, const std::nothrow_t&) noexcept; // replaceable, nodiscard in C++2a
Eric Fiselier162922f2016-10-14 06:46:30 +000056void* operator new(std::size_t size, std::align_val_t alignment,
Marshall Clowbe8b84d2017-12-04 23:03:42 +000057 const std::nothrow_t&) noexcept; // replaceable, C++17, nodiscard in C++2a
Howard Hinnant1bc52cf2011-05-26 18:23:59 +000058void operator delete(void* ptr) noexcept; // replaceable
Larisse Voufo574190d2015-02-15 05:18:55 +000059void operator delete(void* ptr, std::size_t size) noexcept; // replaceable, C++14
Eric Fiselier162922f2016-10-14 06:46:30 +000060void operator delete(void* ptr, std::align_val_t alignment) noexcept; // replaceable, C++17
61void operator delete(void* ptr, std::size_t size,
62 std::align_val_t alignment) noexcept; // replaceable, C++17
Howard Hinnant1bc52cf2011-05-26 18:23:59 +000063void operator delete(void* ptr, const std::nothrow_t&) noexcept; // replaceable
Eric Fiselier162922f2016-10-14 06:46:30 +000064void operator delete(void* ptr, std:align_val_t alignment,
65 const std::nothrow_t&) noexcept; // replaceable, C++17
Howard Hinnantc51e1022010-05-11 19:42:16 +000066
Marshall Clowbe8b84d2017-12-04 23:03:42 +000067void* operator new[](std::size_t size); // replaceable, nodiscard in C++2a
Eric Fiselier162922f2016-10-14 06:46:30 +000068void* operator new[](std::size_t size,
Marshall Clowbe8b84d2017-12-04 23:03:42 +000069 std::align_val_t alignment) noexcept; // replaceable, C++17, nodiscard in C++2a
70void* operator new[](std::size_t size, const std::nothrow_t&) noexcept; // replaceable, nodiscard in C++2a
Eric Fiselier162922f2016-10-14 06:46:30 +000071void* operator new[](std::size_t size, std::align_val_t alignment,
Marshall Clowbe8b84d2017-12-04 23:03:42 +000072 const std::nothrow_t&) noexcept; // replaceable, C++17, nodiscard in C++2a
Howard Hinnant1bc52cf2011-05-26 18:23:59 +000073void operator delete[](void* ptr) noexcept; // replaceable
Larisse Voufo574190d2015-02-15 05:18:55 +000074void operator delete[](void* ptr, std::size_t size) noexcept; // replaceable, C++14
Eric Fiselier162922f2016-10-14 06:46:30 +000075void operator delete[](void* ptr,
76 std::align_val_t alignment) noexcept; // replaceable, C++17
77void operator delete[](void* ptr, std::size_t size,
78 std::align_val_t alignment) noexcept; // replaceable, C++17
Howard Hinnant1bc52cf2011-05-26 18:23:59 +000079void operator delete[](void* ptr, const std::nothrow_t&) noexcept; // replaceable
Eric Fiselier162922f2016-10-14 06:46:30 +000080void operator delete[](void* ptr, std::align_val_t alignment,
81 const std::nothrow_t&) noexcept; // replaceable, C++17
Howard Hinnantc51e1022010-05-11 19:42:16 +000082
Marshall Clowbe8b84d2017-12-04 23:03:42 +000083void* operator new (std::size_t size, void* ptr) noexcept; // nodiscard in C++2a
84void* operator new[](std::size_t size, void* ptr) noexcept; // nodiscard in C++2a
Howard Hinnant1bc52cf2011-05-26 18:23:59 +000085void operator delete (void* ptr, void*) noexcept;
86void operator delete[](void* ptr, void*) noexcept;
Howard Hinnantc51e1022010-05-11 19:42:16 +000087
88*/
89
90#include <__config>
91#include <exception>
Eric Fiselier06548ab2018-03-22 04:42:56 +000092#include <type_traits>
Howard Hinnantc51e1022010-05-11 19:42:16 +000093#include <cstddef>
Eric Fiselier279c3192016-09-06 21:25:27 +000094#ifdef _LIBCPP_NO_EXCEPTIONS
95#include <cstdlib>
96#endif
Howard Hinnantc51e1022010-05-11 19:42:16 +000097
Shoaib Meenaicfd19602017-10-09 19:25:17 +000098#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselierec3a1672017-02-10 08:57:35 +000099#include <new.h>
100#endif
101
Howard Hinnantaaaa52b2011-10-17 20:05:10 +0000102#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
Howard Hinnantc51e1022010-05-11 19:42:16 +0000103#pragma GCC system_header
Howard Hinnantaaaa52b2011-10-17 20:05:10 +0000104#endif
Howard Hinnantc51e1022010-05-11 19:42:16 +0000105
Louis Dionne5e0eadd2018-08-01 02:08:59 +0000106#if !(defined(_LIBCPP_BUILDING_LIBRARY) || _LIBCPP_STD_VER >= 14 || \
Eric Fiselier162922f2016-10-14 06:46:30 +0000107 (defined(__cpp_sized_deallocation) && __cpp_sized_deallocation >= 201309))
108# define _LIBCPP_HAS_NO_SIZED_DEALLOCATION
109#endif
110
Eric Fiselier06548ab2018-03-22 04:42:56 +0000111#if !__has_builtin(__builtin_operator_new) || \
112 __has_builtin(__builtin_operator_new) < 201802L || \
113 defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION) || \
114 !defined(__cpp_aligned_new) || __cpp_aligned_new < 201606
115#define _LIBCPP_HAS_NO_BUILTIN_ALIGNED_OPERATOR_NEW_DELETE
116#endif
117
Howard Hinnantc51e1022010-05-11 19:42:16 +0000118namespace std // purposefully not using versioning namespace
119{
120
Shoaib Meenaicfd19602017-10-09 19:25:17 +0000121#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselierec3a1672017-02-10 08:57:35 +0000122struct _LIBCPP_TYPE_VIS nothrow_t {};
123extern _LIBCPP_FUNC_VIS const nothrow_t nothrow;
124
Howard Hinnantc51e1022010-05-11 19:42:16 +0000125class _LIBCPP_EXCEPTION_ABI bad_alloc
126 : public exception
127{
128public:
Howard Hinnant1bc52cf2011-05-26 18:23:59 +0000129 bad_alloc() _NOEXCEPT;
130 virtual ~bad_alloc() _NOEXCEPT;
131 virtual const char* what() const _NOEXCEPT;
Howard Hinnantc51e1022010-05-11 19:42:16 +0000132};
133
134class _LIBCPP_EXCEPTION_ABI bad_array_new_length
135 : public bad_alloc
136{
137public:
Howard Hinnant1bc52cf2011-05-26 18:23:59 +0000138 bad_array_new_length() _NOEXCEPT;
139 virtual ~bad_array_new_length() _NOEXCEPT;
140 virtual const char* what() const _NOEXCEPT;
Howard Hinnantc51e1022010-05-11 19:42:16 +0000141};
142
Eric Fiselierec3a1672017-02-10 08:57:35 +0000143typedef void (*new_handler)();
144_LIBCPP_FUNC_VIS new_handler set_new_handler(new_handler) _NOEXCEPT;
145_LIBCPP_FUNC_VIS new_handler get_new_handler() _NOEXCEPT;
146
Shoaib Meenaicfd19602017-10-09 19:25:17 +0000147#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
Eric Fiselierec3a1672017-02-10 08:57:35 +0000148
Marshall Clow8fea1612016-08-25 15:09:01 +0000149_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void __throw_bad_alloc(); // not in C++ spec
150
Eric Fiselierec3a1672017-02-10 08:57:35 +0000151#if defined(_LIBCPP_BUILDING_LIBRARY) || (_LIBCPP_STD_VER > 11)
Howard Hinnant4582a2b2013-11-07 17:15:51 +0000152
Mehdi Amini228053d2017-05-04 17:08:54 +0000153class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_BAD_ARRAY_LENGTH
154 bad_array_length : public bad_alloc {
Marshall Clow3bf77132013-09-11 01:38:42 +0000155public:
156 bad_array_length() _NOEXCEPT;
157 virtual ~bad_array_length() _NOEXCEPT;
158 virtual const char* what() const _NOEXCEPT;
159};
Howard Hinnant4582a2b2013-11-07 17:15:51 +0000160
161#define _LIBCPP_BAD_ARRAY_LENGTH_DEFINED
162
Louis Dionne5e0eadd2018-08-01 02:08:59 +0000163#endif // defined(_LIBCPP_BUILDING_LIBRARY) || (_LIBCPP_STD_VER > 11)
Marshall Clow3bf77132013-09-11 01:38:42 +0000164
Eric Fiseliere67336f2018-02-11 22:00:19 +0000165#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselier9bb114e2017-01-21 14:42:44 +0000166#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION) || _LIBCPP_STD_VER > 14
Eric Fiselier162922f2016-10-14 06:46:30 +0000167#ifndef _LIBCPP_CXX03_LANG
168enum class _LIBCPP_ENUM_VIS align_val_t : size_t { };
169#else
170enum align_val_t { __zero = 0, __max = (size_t)-1 };
171#endif
172#endif
Eric Fiseliere67336f2018-02-11 22:00:19 +0000173#endif
Eric Fiselier162922f2016-10-14 06:46:30 +0000174
Howard Hinnantc51e1022010-05-11 19:42:16 +0000175} // std
176
Eric Fiselier499a0a52017-01-02 23:27:42 +0000177#if defined(_LIBCPP_CXX03_LANG)
Eric Fiselier162922f2016-10-14 06:46:30 +0000178#define _THROW_BAD_ALLOC throw(std::bad_alloc)
179#else
180#define _THROW_BAD_ALLOC
Howard Hinnant1bc52cf2011-05-26 18:23:59 +0000181#endif
Eric Fiselier162922f2016-10-14 06:46:30 +0000182
Shoaib Meenaicfd19602017-10-09 19:25:17 +0000183#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselierec3a1672017-02-10 08:57:35 +0000184
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000185_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz) _THROW_BAD_ALLOC;
186_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
Shoaib Meenai2d71db42016-11-16 22:18:10 +0000187_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p) _NOEXCEPT;
188_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, const std::nothrow_t&) _NOEXCEPT;
Eric Fiselier162922f2016-10-14 06:46:30 +0000189#ifndef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
Mehdi Amini228053d2017-05-04 17:08:54 +0000190_LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void operator delete(void* __p, std::size_t __sz) _NOEXCEPT;
Larisse Voufoa744a7e2015-02-20 06:13:05 +0000191#endif
Howard Hinnanta37d3cf2013-08-12 18:38:34 +0000192
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000193_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz) _THROW_BAD_ALLOC;
194_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
Shoaib Meenai2d71db42016-11-16 22:18:10 +0000195_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p) _NOEXCEPT;
196_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, const std::nothrow_t&) _NOEXCEPT;
Shoaib Meenaia2ee1d42016-11-18 04:31:09 +0000197#ifndef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
Mehdi Amini228053d2017-05-04 17:08:54 +0000198_LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void operator delete[](void* __p, std::size_t __sz) _NOEXCEPT;
Larisse Voufoa744a7e2015-02-20 06:13:05 +0000199#endif
Howard Hinnanta37d3cf2013-08-12 18:38:34 +0000200
Eric Fiselier162922f2016-10-14 06:46:30 +0000201#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000202_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
203_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
Akira Hatanaka8c77d152017-06-30 18:50:23 +0000204_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::align_val_t) _NOEXCEPT;
205_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
Eric Fiselier162922f2016-10-14 06:46:30 +0000206#ifndef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
Akira Hatanaka8c77d152017-06-30 18:50:23 +0000207_LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void operator delete(void* __p, std::size_t __sz, std::align_val_t) _NOEXCEPT;
Eric Fiselier162922f2016-10-14 06:46:30 +0000208#endif
209
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000210_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
211_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
Akira Hatanaka8c77d152017-06-30 18:50:23 +0000212_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::align_val_t) _NOEXCEPT;
213_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
Eric Fiselier162922f2016-10-14 06:46:30 +0000214#ifndef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
Akira Hatanaka8c77d152017-06-30 18:50:23 +0000215_LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void operator delete[](void* __p, std::size_t __sz, std::align_val_t) _NOEXCEPT;
Eric Fiselier162922f2016-10-14 06:46:30 +0000216#endif
217#endif
218
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000219_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new (std::size_t, void* __p) _NOEXCEPT {return __p;}
220_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new[](std::size_t, void* __p) _NOEXCEPT {return __p;}
Howard Hinnantb8a8ca22013-10-04 22:09:00 +0000221inline _LIBCPP_INLINE_VISIBILITY void operator delete (void*, void*) _NOEXCEPT {}
222inline _LIBCPP_INLINE_VISIBILITY void operator delete[](void*, void*) _NOEXCEPT {}
Howard Hinnantc51e1022010-05-11 19:42:16 +0000223
Shoaib Meenaicfd19602017-10-09 19:25:17 +0000224#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
Eric Fiselierec3a1672017-02-10 08:57:35 +0000225
Richard Smith1f1c1472014-06-04 19:54:15 +0000226_LIBCPP_BEGIN_NAMESPACE_STD
227
Eric Fiselier06548ab2018-03-22 04:42:56 +0000228_LIBCPP_CONSTEXPR inline _LIBCPP_INLINE_VISIBILITY bool __is_overaligned_for_new(size_t __align) _NOEXCEPT {
229#ifdef __STDCPP_DEFAULT_NEW_ALIGNMENT__
230 return __align > __STDCPP_DEFAULT_NEW_ALIGNMENT__;
231#else
232 return __align > alignment_of<max_align_t>::value;
233#endif
234}
235
236inline _LIBCPP_INLINE_VISIBILITY void *__libcpp_allocate(size_t __size, size_t __align) {
237#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
238 if (__is_overaligned_for_new(__align)) {
239 const align_val_t __align_val = static_cast<align_val_t>(__align);
240# ifdef _LIBCPP_HAS_NO_BUILTIN_ALIGNED_OPERATOR_NEW_DELETE
241 return ::operator new(__size, __align_val);
242# else
243 return __builtin_operator_new(__size, __align_val);
244# endif
245 }
246#else
247 ((void)__align);
248#endif
Richard Smith1f1c1472014-06-04 19:54:15 +0000249#ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
250 return ::operator new(__size);
251#else
252 return __builtin_operator_new(__size);
253#endif
254}
255
Eric Fiselier06548ab2018-03-22 04:42:56 +0000256inline _LIBCPP_INLINE_VISIBILITY void __libcpp_deallocate(void* __ptr, size_t __align) {
257#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
258 if (__is_overaligned_for_new(__align)) {
259 const align_val_t __align_val = static_cast<align_val_t>(__align);
260# ifdef _LIBCPP_HAS_NO_BUILTIN_ALIGNED_OPERATOR_NEW_DELETE
261 return ::operator delete(__ptr, __align_val);
262# else
263 return __builtin_operator_delete(__ptr, __align_val);
264# endif
265 }
Richard Smith1f1c1472014-06-04 19:54:15 +0000266#else
Eric Fiselier06548ab2018-03-22 04:42:56 +0000267 ((void)__align);
268#endif
269#ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
270 return ::operator delete(__ptr);
271#else
272 return __builtin_operator_delete(__ptr);
Richard Smith1f1c1472014-06-04 19:54:15 +0000273#endif
274}
275
Marshall Clow8fea1612016-08-25 15:09:01 +0000276#ifdef _LIBCPP_BAD_ARRAY_LENGTH_DEFINED
Louis Dionne16fe2952018-07-11 23:14:33 +0000277_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
Mehdi Amini228053d2017-05-04 17:08:54 +0000278#ifndef _LIBCPP_NO_EXCEPTIONS
279_LIBCPP_AVAILABILITY_BAD_ARRAY_LENGTH
280#endif
Marshall Clow8fea1612016-08-25 15:09:01 +0000281void __throw_bad_array_length()
282{
283#ifndef _LIBCPP_NO_EXCEPTIONS
284 throw bad_array_length();
285#else
Louis Dionne44bcff92018-08-03 22:36:53 +0000286 _VSTD::abort();
Marshall Clow8fea1612016-08-25 15:09:01 +0000287#endif
288}
289#endif
290
Marshall Clowdf5a11f2017-11-22 19:49:03 +0000291template <class _Tp>
Louis Dionne44bcff92018-08-03 22:36:53 +0000292_LIBCPP_NODISCARD_AFTER_CXX17 inline
Marshall Clowdf5a11f2017-11-22 19:49:03 +0000293_LIBCPP_CONSTEXPR _Tp* __launder(_Tp* __p) _NOEXCEPT
294{
295 static_assert (!(is_function<_Tp>::value), "can't launder functions" );
296 static_assert (!(is_same<void, typename remove_cv<_Tp>::type>::value), "can't launder cv-void" );
297#ifdef _LIBCPP_COMPILER_HAS_BUILTIN_LAUNDER
298 return __builtin_launder(__p);
299#else
300 return __p;
301#endif
302}
303
304
305#if _LIBCPP_STD_VER > 14
306template <class _Tp>
307_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
308constexpr _Tp* launder(_Tp* __p) noexcept
309{
Marshall Clow6ac349c2017-11-23 01:25:03 +0000310 return _VSTD::__launder(__p);
Marshall Clowdf5a11f2017-11-22 19:49:03 +0000311}
312#endif
313
Richard Smith1f1c1472014-06-04 19:54:15 +0000314_LIBCPP_END_NAMESPACE_STD
315
Howard Hinnantc51e1022010-05-11 19:42:16 +0000316#endif // _LIBCPP_NEW