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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>
Marshall Clow0a1e7502018-09-12 19:41:40 +000094#include <version>
Eric Fiselier279c3192016-09-06 21:25:27 +000095#ifdef _LIBCPP_NO_EXCEPTIONS
96#include <cstdlib>
97#endif
Howard Hinnantc51e1022010-05-11 19:42:16 +000098
Shoaib Meenaicfd19602017-10-09 19:25:17 +000099#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselierec3a1672017-02-10 08:57:35 +0000100#include <new.h>
101#endif
102
Howard Hinnantaaaa52b2011-10-17 20:05:10 +0000103#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
Howard Hinnantc51e1022010-05-11 19:42:16 +0000104#pragma GCC system_header
Howard Hinnantaaaa52b2011-10-17 20:05:10 +0000105#endif
Howard Hinnantc51e1022010-05-11 19:42:16 +0000106
Eric Fiselierff4c8a22018-10-11 00:17:24 +0000107#if !defined(_LIBCPP_BUILDING_LIBRARY) && _LIBCPP_STD_VER < 14
108# define _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
109#endif
110
111#if defined(_LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION) || \
112 !defined(__cpp_sized_deallocation) || __cpp_sized_deallocation < 201309
Eric Fiselier162922f2016-10-14 06:46:30 +0000113# define _LIBCPP_HAS_NO_SIZED_DEALLOCATION
114#endif
115
Eric Fiselier06548ab2018-03-22 04:42:56 +0000116#if !__has_builtin(__builtin_operator_new) || \
Eric Fiselierff4c8a22018-10-11 00:17:24 +0000117 __has_builtin(__builtin_operator_new) < 201802L
118#define _LIBCPP_HAS_NO_BUILTIN_OVERLOADED_OPERATOR_NEW_DELETE
Eric Fiselier06548ab2018-03-22 04:42:56 +0000119#endif
120
Howard Hinnantc51e1022010-05-11 19:42:16 +0000121namespace std // purposefully not using versioning namespace
122{
123
Shoaib Meenaicfd19602017-10-09 19:25:17 +0000124#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselierec3a1672017-02-10 08:57:35 +0000125struct _LIBCPP_TYPE_VIS nothrow_t {};
126extern _LIBCPP_FUNC_VIS const nothrow_t nothrow;
127
Howard Hinnantc51e1022010-05-11 19:42:16 +0000128class _LIBCPP_EXCEPTION_ABI bad_alloc
129 : public exception
130{
131public:
Howard Hinnant1bc52cf2011-05-26 18:23:59 +0000132 bad_alloc() _NOEXCEPT;
133 virtual ~bad_alloc() _NOEXCEPT;
134 virtual const char* what() const _NOEXCEPT;
Howard Hinnantc51e1022010-05-11 19:42:16 +0000135};
136
137class _LIBCPP_EXCEPTION_ABI bad_array_new_length
138 : public bad_alloc
139{
140public:
Howard Hinnant1bc52cf2011-05-26 18:23:59 +0000141 bad_array_new_length() _NOEXCEPT;
142 virtual ~bad_array_new_length() _NOEXCEPT;
143 virtual const char* what() const _NOEXCEPT;
Howard Hinnantc51e1022010-05-11 19:42:16 +0000144};
145
Eric Fiselierec3a1672017-02-10 08:57:35 +0000146typedef void (*new_handler)();
147_LIBCPP_FUNC_VIS new_handler set_new_handler(new_handler) _NOEXCEPT;
148_LIBCPP_FUNC_VIS new_handler get_new_handler() _NOEXCEPT;
149
Shoaib Meenaicfd19602017-10-09 19:25:17 +0000150#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
Eric Fiselierec3a1672017-02-10 08:57:35 +0000151
Marshall Clow8fea1612016-08-25 15:09:01 +0000152_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void __throw_bad_alloc(); // not in C++ spec
153
Eric Fiselierec3a1672017-02-10 08:57:35 +0000154#if defined(_LIBCPP_BUILDING_LIBRARY) || (_LIBCPP_STD_VER > 11)
Howard Hinnant4582a2b2013-11-07 17:15:51 +0000155
Mehdi Amini228053d2017-05-04 17:08:54 +0000156class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_BAD_ARRAY_LENGTH
157 bad_array_length : public bad_alloc {
Marshall Clow3bf77132013-09-11 01:38:42 +0000158public:
159 bad_array_length() _NOEXCEPT;
160 virtual ~bad_array_length() _NOEXCEPT;
161 virtual const char* what() const _NOEXCEPT;
162};
Howard Hinnant4582a2b2013-11-07 17:15:51 +0000163
164#define _LIBCPP_BAD_ARRAY_LENGTH_DEFINED
165
Louis Dionne5e0eadd2018-08-01 02:08:59 +0000166#endif // defined(_LIBCPP_BUILDING_LIBRARY) || (_LIBCPP_STD_VER > 11)
Marshall Clow3bf77132013-09-11 01:38:42 +0000167
Eric Fiselierff4c8a22018-10-11 00:17:24 +0000168#if !defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION) && \
169 !defined(_LIBCPP_DEFER_NEW_TO_VCRUNTIME)
Eric Fiselier162922f2016-10-14 06:46:30 +0000170#ifndef _LIBCPP_CXX03_LANG
171enum class _LIBCPP_ENUM_VIS align_val_t : size_t { };
172#else
173enum align_val_t { __zero = 0, __max = (size_t)-1 };
174#endif
175#endif
176
Howard Hinnantc51e1022010-05-11 19:42:16 +0000177} // std
178
Eric Fiselier499a0a52017-01-02 23:27:42 +0000179#if defined(_LIBCPP_CXX03_LANG)
Eric Fiselier162922f2016-10-14 06:46:30 +0000180#define _THROW_BAD_ALLOC throw(std::bad_alloc)
181#else
182#define _THROW_BAD_ALLOC
Howard Hinnant1bc52cf2011-05-26 18:23:59 +0000183#endif
Eric Fiselier162922f2016-10-14 06:46:30 +0000184
Eric Fiselierff4c8a22018-10-11 00:17:24 +0000185#if !defined(_LIBCPP_DEFER_NEW_TO_VCRUNTIME)
Eric Fiselierec3a1672017-02-10 08:57:35 +0000186
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000187_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz) _THROW_BAD_ALLOC;
188_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 +0000189_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p) _NOEXCEPT;
190_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, const std::nothrow_t&) _NOEXCEPT;
Eric Fiselierff4c8a22018-10-11 00:17:24 +0000191#ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
Mehdi Amini228053d2017-05-04 17:08:54 +0000192_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 +0000193#endif
Howard Hinnanta37d3cf2013-08-12 18:38:34 +0000194
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000195_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz) _THROW_BAD_ALLOC;
196_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 +0000197_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p) _NOEXCEPT;
198_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, const std::nothrow_t&) _NOEXCEPT;
Eric Fiselierff4c8a22018-10-11 00:17:24 +0000199#ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
Mehdi Amini228053d2017-05-04 17:08:54 +0000200_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 +0000201#endif
Howard Hinnanta37d3cf2013-08-12 18:38:34 +0000202
Eric Fiselierff4c8a22018-10-11 00:17:24 +0000203#ifndef _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000204_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
205_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 +0000206_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::align_val_t) _NOEXCEPT;
207_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
Eric Fiselierff4c8a22018-10-11 00:17:24 +0000208#ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
Akira Hatanaka8c77d152017-06-30 18:50:23 +0000209_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 +0000210#endif
211
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000212_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
213_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 +0000214_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::align_val_t) _NOEXCEPT;
215_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
Eric Fiselierff4c8a22018-10-11 00:17:24 +0000216#ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
Akira Hatanaka8c77d152017-06-30 18:50:23 +0000217_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 +0000218#endif
219#endif
220
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000221_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new (std::size_t, void* __p) _NOEXCEPT {return __p;}
222_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 +0000223inline _LIBCPP_INLINE_VISIBILITY void operator delete (void*, void*) _NOEXCEPT {}
224inline _LIBCPP_INLINE_VISIBILITY void operator delete[](void*, void*) _NOEXCEPT {}
Howard Hinnantc51e1022010-05-11 19:42:16 +0000225
Eric Fiselierff4c8a22018-10-11 00:17:24 +0000226#endif // !_LIBCPP_DEFER_NEW_TO_VCRUNTIME
Eric Fiselierec3a1672017-02-10 08:57:35 +0000227
Richard Smith1f1c1472014-06-04 19:54:15 +0000228_LIBCPP_BEGIN_NAMESPACE_STD
229
Eric Fiselier06548ab2018-03-22 04:42:56 +0000230_LIBCPP_CONSTEXPR inline _LIBCPP_INLINE_VISIBILITY bool __is_overaligned_for_new(size_t __align) _NOEXCEPT {
231#ifdef __STDCPP_DEFAULT_NEW_ALIGNMENT__
232 return __align > __STDCPP_DEFAULT_NEW_ALIGNMENT__;
233#else
234 return __align > alignment_of<max_align_t>::value;
235#endif
236}
237
238inline _LIBCPP_INLINE_VISIBILITY void *__libcpp_allocate(size_t __size, size_t __align) {
239#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
240 if (__is_overaligned_for_new(__align)) {
241 const align_val_t __align_val = static_cast<align_val_t>(__align);
242# ifdef _LIBCPP_HAS_NO_BUILTIN_ALIGNED_OPERATOR_NEW_DELETE
243 return ::operator new(__size, __align_val);
244# else
245 return __builtin_operator_new(__size, __align_val);
246# endif
247 }
248#else
249 ((void)__align);
250#endif
Richard Smith1f1c1472014-06-04 19:54:15 +0000251#ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
252 return ::operator new(__size);
253#else
254 return __builtin_operator_new(__size);
255#endif
256}
257
Eric Fiselier06548ab2018-03-22 04:42:56 +0000258inline _LIBCPP_INLINE_VISIBILITY void __libcpp_deallocate(void* __ptr, size_t __align) {
259#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
260 if (__is_overaligned_for_new(__align)) {
261 const align_val_t __align_val = static_cast<align_val_t>(__align);
Eric Fiselierff4c8a22018-10-11 00:17:24 +0000262# ifdef _LIBCPP_HAS_NO_BUILTIN_OVERLOADED_OPERATOR_NEW_DELETE
Eric Fiselier06548ab2018-03-22 04:42:56 +0000263 return ::operator delete(__ptr, __align_val);
264# else
265 return __builtin_operator_delete(__ptr, __align_val);
266# endif
267 }
Richard Smith1f1c1472014-06-04 19:54:15 +0000268#else
Eric Fiselier06548ab2018-03-22 04:42:56 +0000269 ((void)__align);
270#endif
271#ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
272 return ::operator delete(__ptr);
273#else
274 return __builtin_operator_delete(__ptr);
Richard Smith1f1c1472014-06-04 19:54:15 +0000275#endif
276}
277
Marshall Clow8fea1612016-08-25 15:09:01 +0000278#ifdef _LIBCPP_BAD_ARRAY_LENGTH_DEFINED
Louis Dionne16fe2952018-07-11 23:14:33 +0000279_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
Mehdi Amini228053d2017-05-04 17:08:54 +0000280#ifndef _LIBCPP_NO_EXCEPTIONS
281_LIBCPP_AVAILABILITY_BAD_ARRAY_LENGTH
282#endif
Marshall Clow8fea1612016-08-25 15:09:01 +0000283void __throw_bad_array_length()
284{
285#ifndef _LIBCPP_NO_EXCEPTIONS
286 throw bad_array_length();
287#else
Louis Dionne44bcff92018-08-03 22:36:53 +0000288 _VSTD::abort();
Marshall Clow8fea1612016-08-25 15:09:01 +0000289#endif
290}
291#endif
292
Marshall Clowdf5a11f2017-11-22 19:49:03 +0000293template <class _Tp>
Louis Dionne44bcff92018-08-03 22:36:53 +0000294_LIBCPP_NODISCARD_AFTER_CXX17 inline
Marshall Clowdf5a11f2017-11-22 19:49:03 +0000295_LIBCPP_CONSTEXPR _Tp* __launder(_Tp* __p) _NOEXCEPT
296{
297 static_assert (!(is_function<_Tp>::value), "can't launder functions" );
298 static_assert (!(is_same<void, typename remove_cv<_Tp>::type>::value), "can't launder cv-void" );
299#ifdef _LIBCPP_COMPILER_HAS_BUILTIN_LAUNDER
300 return __builtin_launder(__p);
301#else
302 return __p;
303#endif
304}
305
306
307#if _LIBCPP_STD_VER > 14
308template <class _Tp>
309_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
310constexpr _Tp* launder(_Tp* __p) noexcept
311{
Marshall Clow6ac349c2017-11-23 01:25:03 +0000312 return _VSTD::__launder(__p);
Marshall Clowdf5a11f2017-11-22 19:49:03 +0000313}
314#endif
315
Richard Smith1f1c1472014-06-04 19:54:15 +0000316_LIBCPP_END_NAMESPACE_STD
317
Howard Hinnantc51e1022010-05-11 19:42:16 +0000318#endif // _LIBCPP_NEW