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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
Louis Dionne5e0eadd2018-08-01 02:08:59 +0000107#if !(defined(_LIBCPP_BUILDING_LIBRARY) || _LIBCPP_STD_VER >= 14 || \
Eric Fiselier162922f2016-10-14 06:46:30 +0000108 (defined(__cpp_sized_deallocation) && __cpp_sized_deallocation >= 201309))
109# define _LIBCPP_HAS_NO_SIZED_DEALLOCATION
110#endif
111
Eric Fiselier06548ab2018-03-22 04:42:56 +0000112#if !__has_builtin(__builtin_operator_new) || \
113 __has_builtin(__builtin_operator_new) < 201802L || \
114 defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION) || \
115 !defined(__cpp_aligned_new) || __cpp_aligned_new < 201606
116#define _LIBCPP_HAS_NO_BUILTIN_ALIGNED_OPERATOR_NEW_DELETE
117#endif
118
Howard Hinnantc51e1022010-05-11 19:42:16 +0000119namespace std // purposefully not using versioning namespace
120{
121
Shoaib Meenaicfd19602017-10-09 19:25:17 +0000122#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselierec3a1672017-02-10 08:57:35 +0000123struct _LIBCPP_TYPE_VIS nothrow_t {};
124extern _LIBCPP_FUNC_VIS const nothrow_t nothrow;
125
Howard Hinnantc51e1022010-05-11 19:42:16 +0000126class _LIBCPP_EXCEPTION_ABI bad_alloc
127 : public exception
128{
129public:
Howard Hinnant1bc52cf2011-05-26 18:23:59 +0000130 bad_alloc() _NOEXCEPT;
131 virtual ~bad_alloc() _NOEXCEPT;
132 virtual const char* what() const _NOEXCEPT;
Howard Hinnantc51e1022010-05-11 19:42:16 +0000133};
134
135class _LIBCPP_EXCEPTION_ABI bad_array_new_length
136 : public bad_alloc
137{
138public:
Howard Hinnant1bc52cf2011-05-26 18:23:59 +0000139 bad_array_new_length() _NOEXCEPT;
140 virtual ~bad_array_new_length() _NOEXCEPT;
141 virtual const char* what() const _NOEXCEPT;
Howard Hinnantc51e1022010-05-11 19:42:16 +0000142};
143
Eric Fiselierec3a1672017-02-10 08:57:35 +0000144typedef void (*new_handler)();
145_LIBCPP_FUNC_VIS new_handler set_new_handler(new_handler) _NOEXCEPT;
146_LIBCPP_FUNC_VIS new_handler get_new_handler() _NOEXCEPT;
147
Shoaib Meenaicfd19602017-10-09 19:25:17 +0000148#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
Eric Fiselierec3a1672017-02-10 08:57:35 +0000149
Marshall Clow8fea1612016-08-25 15:09:01 +0000150_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void __throw_bad_alloc(); // not in C++ spec
151
Eric Fiselierec3a1672017-02-10 08:57:35 +0000152#if defined(_LIBCPP_BUILDING_LIBRARY) || (_LIBCPP_STD_VER > 11)
Howard Hinnant4582a2b2013-11-07 17:15:51 +0000153
Mehdi Amini228053d2017-05-04 17:08:54 +0000154class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_BAD_ARRAY_LENGTH
155 bad_array_length : public bad_alloc {
Marshall Clow3bf77132013-09-11 01:38:42 +0000156public:
157 bad_array_length() _NOEXCEPT;
158 virtual ~bad_array_length() _NOEXCEPT;
159 virtual const char* what() const _NOEXCEPT;
160};
Howard Hinnant4582a2b2013-11-07 17:15:51 +0000161
162#define _LIBCPP_BAD_ARRAY_LENGTH_DEFINED
163
Louis Dionne5e0eadd2018-08-01 02:08:59 +0000164#endif // defined(_LIBCPP_BUILDING_LIBRARY) || (_LIBCPP_STD_VER > 11)
Marshall Clow3bf77132013-09-11 01:38:42 +0000165
Eric Fiseliere67336f2018-02-11 22:00:19 +0000166#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselier9bb114e2017-01-21 14:42:44 +0000167#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION) || _LIBCPP_STD_VER > 14
Eric Fiselier162922f2016-10-14 06:46:30 +0000168#ifndef _LIBCPP_CXX03_LANG
169enum class _LIBCPP_ENUM_VIS align_val_t : size_t { };
170#else
171enum align_val_t { __zero = 0, __max = (size_t)-1 };
172#endif
173#endif
Eric Fiselier7ded9a02018-10-01 04:08:06 +0000174#elif !defined(__cpp_aligned_new)
175// We're defering to Microsoft's STL to provide aligned new et al. We don't
176// have it unless the language feature test macro is defined.
177#define _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
Eric Fiseliere67336f2018-02-11 22:00:19 +0000178#endif
Eric Fiselier162922f2016-10-14 06:46:30 +0000179
Howard Hinnantc51e1022010-05-11 19:42:16 +0000180} // std
181
Eric Fiselier499a0a52017-01-02 23:27:42 +0000182#if defined(_LIBCPP_CXX03_LANG)
Eric Fiselier162922f2016-10-14 06:46:30 +0000183#define _THROW_BAD_ALLOC throw(std::bad_alloc)
184#else
185#define _THROW_BAD_ALLOC
Howard Hinnant1bc52cf2011-05-26 18:23:59 +0000186#endif
Eric Fiselier162922f2016-10-14 06:46:30 +0000187
Shoaib Meenaicfd19602017-10-09 19:25:17 +0000188#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
Eric Fiselierec3a1672017-02-10 08:57:35 +0000189
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000190_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz) _THROW_BAD_ALLOC;
191_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 +0000192_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p) _NOEXCEPT;
193_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, const std::nothrow_t&) _NOEXCEPT;
Eric Fiselier162922f2016-10-14 06:46:30 +0000194#ifndef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
Mehdi Amini228053d2017-05-04 17:08:54 +0000195_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 +0000196#endif
Howard Hinnanta37d3cf2013-08-12 18:38:34 +0000197
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000198_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz) _THROW_BAD_ALLOC;
199_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 +0000200_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p) _NOEXCEPT;
201_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, const std::nothrow_t&) _NOEXCEPT;
Shoaib Meenaia2ee1d42016-11-18 04:31:09 +0000202#ifndef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
Mehdi Amini228053d2017-05-04 17:08:54 +0000203_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 +0000204#endif
Howard Hinnanta37d3cf2013-08-12 18:38:34 +0000205
Eric Fiselier162922f2016-10-14 06:46:30 +0000206#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000207_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
208_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 +0000209_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::align_val_t) _NOEXCEPT;
210_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 +0000211#ifndef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
Akira Hatanaka8c77d152017-06-30 18:50:23 +0000212_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 +0000213#endif
214
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000215_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
216_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 +0000217_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::align_val_t) _NOEXCEPT;
218_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 +0000219#ifndef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
Akira Hatanaka8c77d152017-06-30 18:50:23 +0000220_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 +0000221#endif
222#endif
223
Marshall Clowbe8b84d2017-12-04 23:03:42 +0000224_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new (std::size_t, void* __p) _NOEXCEPT {return __p;}
225_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 +0000226inline _LIBCPP_INLINE_VISIBILITY void operator delete (void*, void*) _NOEXCEPT {}
227inline _LIBCPP_INLINE_VISIBILITY void operator delete[](void*, void*) _NOEXCEPT {}
Howard Hinnantc51e1022010-05-11 19:42:16 +0000228
Shoaib Meenaicfd19602017-10-09 19:25:17 +0000229#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
Eric Fiselierec3a1672017-02-10 08:57:35 +0000230
Richard Smith1f1c1472014-06-04 19:54:15 +0000231_LIBCPP_BEGIN_NAMESPACE_STD
232
Eric Fiselier06548ab2018-03-22 04:42:56 +0000233_LIBCPP_CONSTEXPR inline _LIBCPP_INLINE_VISIBILITY bool __is_overaligned_for_new(size_t __align) _NOEXCEPT {
234#ifdef __STDCPP_DEFAULT_NEW_ALIGNMENT__
235 return __align > __STDCPP_DEFAULT_NEW_ALIGNMENT__;
236#else
237 return __align > alignment_of<max_align_t>::value;
238#endif
239}
240
241inline _LIBCPP_INLINE_VISIBILITY void *__libcpp_allocate(size_t __size, size_t __align) {
242#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
243 if (__is_overaligned_for_new(__align)) {
244 const align_val_t __align_val = static_cast<align_val_t>(__align);
245# ifdef _LIBCPP_HAS_NO_BUILTIN_ALIGNED_OPERATOR_NEW_DELETE
246 return ::operator new(__size, __align_val);
247# else
248 return __builtin_operator_new(__size, __align_val);
249# endif
250 }
251#else
252 ((void)__align);
253#endif
Richard Smith1f1c1472014-06-04 19:54:15 +0000254#ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
255 return ::operator new(__size);
256#else
257 return __builtin_operator_new(__size);
258#endif
259}
260
Eric Fiselier06548ab2018-03-22 04:42:56 +0000261inline _LIBCPP_INLINE_VISIBILITY void __libcpp_deallocate(void* __ptr, size_t __align) {
262#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
263 if (__is_overaligned_for_new(__align)) {
264 const align_val_t __align_val = static_cast<align_val_t>(__align);
265# ifdef _LIBCPP_HAS_NO_BUILTIN_ALIGNED_OPERATOR_NEW_DELETE
266 return ::operator delete(__ptr, __align_val);
267# else
268 return __builtin_operator_delete(__ptr, __align_val);
269# endif
270 }
Richard Smith1f1c1472014-06-04 19:54:15 +0000271#else
Eric Fiselier06548ab2018-03-22 04:42:56 +0000272 ((void)__align);
273#endif
274#ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
275 return ::operator delete(__ptr);
276#else
277 return __builtin_operator_delete(__ptr);
Richard Smith1f1c1472014-06-04 19:54:15 +0000278#endif
279}
280
Marshall Clow8fea1612016-08-25 15:09:01 +0000281#ifdef _LIBCPP_BAD_ARRAY_LENGTH_DEFINED
Louis Dionne16fe2952018-07-11 23:14:33 +0000282_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
Mehdi Amini228053d2017-05-04 17:08:54 +0000283#ifndef _LIBCPP_NO_EXCEPTIONS
284_LIBCPP_AVAILABILITY_BAD_ARRAY_LENGTH
285#endif
Marshall Clow8fea1612016-08-25 15:09:01 +0000286void __throw_bad_array_length()
287{
288#ifndef _LIBCPP_NO_EXCEPTIONS
289 throw bad_array_length();
290#else
Louis Dionne44bcff92018-08-03 22:36:53 +0000291 _VSTD::abort();
Marshall Clow8fea1612016-08-25 15:09:01 +0000292#endif
293}
294#endif
295
Marshall Clowdf5a11f2017-11-22 19:49:03 +0000296template <class _Tp>
Louis Dionne44bcff92018-08-03 22:36:53 +0000297_LIBCPP_NODISCARD_AFTER_CXX17 inline
Marshall Clowdf5a11f2017-11-22 19:49:03 +0000298_LIBCPP_CONSTEXPR _Tp* __launder(_Tp* __p) _NOEXCEPT
299{
300 static_assert (!(is_function<_Tp>::value), "can't launder functions" );
301 static_assert (!(is_same<void, typename remove_cv<_Tp>::type>::value), "can't launder cv-void" );
302#ifdef _LIBCPP_COMPILER_HAS_BUILTIN_LAUNDER
303 return __builtin_launder(__p);
304#else
305 return __p;
306#endif
307}
308
309
310#if _LIBCPP_STD_VER > 14
311template <class _Tp>
312_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
313constexpr _Tp* launder(_Tp* __p) noexcept
314{
Marshall Clow6ac349c2017-11-23 01:25:03 +0000315 return _VSTD::__launder(__p);
Marshall Clowdf5a11f2017-11-22 19:49:03 +0000316}
317#endif
318
Richard Smith1f1c1472014-06-04 19:54:15 +0000319_LIBCPP_END_NAMESPACE_STD
320
Howard Hinnantc51e1022010-05-11 19:42:16 +0000321#endif // _LIBCPP_NEW