atomic
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// -*- C++ -*- header.
// Copyright (C) 2008-2021 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file include/atomic
* This is a Standard C++ Library header.
*/
// Based on "C++ Atomic Types and Operations" by Hans Boehm and Lawrence Crowl.
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2427.html
#ifndef _GLIBCXX_ATOMIC
#define _GLIBCXX_ATOMIC 1
#pragma GCC system_header
#if __cplusplus < 201103L
# include <bits/c++0x_warning.h>
#else
#include <bits/atomic_base.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @addtogroup atomics
* @{
*/
#if __cplusplus >= 201703L
# define __cpp_lib_atomic_is_always_lock_free 201603
#endif
template<typename _Tp>
struct atomic;
/// atomic<bool>
// NB: No operators or fetch-operations for this type.
template<>
struct atomic<bool>
{
using value_type = bool;
private:
__atomic_base<bool> _M_base;
public:
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(bool __i) noexcept : _M_base(__i) { }
bool
operator=(bool __i) noexcept
{ return _M_base.operator=(__i); }
bool
operator=(bool __i) volatile noexcept
{ return _M_base.operator=(__i); }
operator bool() const noexcept
{ return _M_base.load(); }
operator bool() const volatile noexcept
{ return _M_base.load(); }
bool
is_lock_free() const noexcept { return _M_base.is_lock_free(); }
bool
is_lock_free() const volatile noexcept { return _M_base.is_lock_free(); }
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_BOOL_LOCK_FREE == 2;
#endif
void
store(bool __i, memory_order __m = memory_order_seq_cst) noexcept
{ _M_base.store(__i, __m); }
void
store(bool __i, memory_order __m = memory_order_seq_cst) volatile noexcept
{ _M_base.store(__i, __m); }
bool
load(memory_order __m = memory_order_seq_cst) const noexcept
{ return _M_base.load(__m); }
bool
load(memory_order __m = memory_order_seq_cst) const volatile noexcept
{ return _M_base.load(__m); }
bool
exchange(bool __i, memory_order __m = memory_order_seq_cst) noexcept
{ return _M_base.exchange(__i, __m); }
bool
exchange(bool __i,
memory_order __m = memory_order_seq_cst) volatile noexcept
{ return _M_base.exchange(__i, __m); }
bool
compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1,
memory_order __m2) noexcept
{ return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); }
bool
compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1,
memory_order __m2) volatile noexcept
{ return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); }
bool
compare_exchange_weak(bool& __i1, bool __i2,
memory_order __m = memory_order_seq_cst) noexcept
{ return _M_base.compare_exchange_weak(__i1, __i2, __m); }
bool
compare_exchange_weak(bool& __i1, bool __i2,
memory_order __m = memory_order_seq_cst) volatile noexcept
{ return _M_base.compare_exchange_weak(__i1, __i2, __m); }
bool
compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1,
memory_order __m2) noexcept
{ return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); }
bool
compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1,
memory_order __m2) volatile noexcept
{ return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); }
bool
compare_exchange_strong(bool& __i1, bool __i2,
memory_order __m = memory_order_seq_cst) noexcept
{ return _M_base.compare_exchange_strong(__i1, __i2, __m); }
bool
compare_exchange_strong(bool& __i1, bool __i2,
memory_order __m = memory_order_seq_cst) volatile noexcept
{ return _M_base.compare_exchange_strong(__i1, __i2, __m); }
#if __cpp_lib_atomic_wait
void
wait(bool __old, memory_order __m = memory_order_seq_cst) const noexcept
{ _M_base.wait(__old, __m); }
// TODO add const volatile overload
void
notify_one() const noexcept
{ _M_base.notify_one(); }
void
notify_all() const noexcept
{ _M_base.notify_all(); }
#endif // __cpp_lib_atomic_wait
};
#if __cplusplus <= 201703L
# define _GLIBCXX20_INIT(I)
#else
# define _GLIBCXX20_INIT(I) = I
#endif
/**
* @brief Generic atomic type, primary class template.
*
* @tparam _Tp Type to be made atomic, must be trivially copyable.
*/
template<typename _Tp>
struct atomic
{
using value_type = _Tp;
private:
// Align 1/2/4/8/16-byte types to at least their size.
static constexpr int _S_min_alignment
= (sizeof(_Tp) & (sizeof(_Tp) - 1)) || sizeof(_Tp) > 16
? 0 : sizeof(_Tp);
static constexpr int _S_alignment
= _S_min_alignment > alignof(_Tp) ? _S_min_alignment : alignof(_Tp);
alignas(_S_alignment) _Tp _M_i _GLIBCXX20_INIT(_Tp());
static_assert(__is_trivially_copyable(_Tp),
"std::atomic requires a trivially copyable type");
static_assert(sizeof(_Tp) > 0,
"Incomplete or zero-sized types are not supported");
#if __cplusplus > 201703L
static_assert(is_copy_constructible_v<_Tp>);
static_assert(is_move_constructible_v<_Tp>);
static_assert(is_copy_assignable_v<_Tp>);
static_assert(is_move_assignable_v<_Tp>);
#endif
public:
atomic() = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(_Tp __i) noexcept : _M_i(__i) { }
operator _Tp() const noexcept
{ return load(); }
operator _Tp() const volatile noexcept
{ return load(); }
_Tp
operator=(_Tp __i) noexcept
{ store(__i); return __i; }
_Tp
operator=(_Tp __i) volatile noexcept
{ store(__i); return __i; }
bool
is_lock_free() const noexcept
{
// Produce a fake, minimally aligned pointer.
return __atomic_is_lock_free(sizeof(_M_i),
reinterpret_cast<void *>(-_S_alignment));
}
bool
is_lock_free() const volatile noexcept
{
// Produce a fake, minimally aligned pointer.
return __atomic_is_lock_free(sizeof(_M_i),
reinterpret_cast<void *>(-_S_alignment));
}
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free
= __atomic_always_lock_free(sizeof(_M_i), 0);
#endif
void
store(_Tp __i, memory_order __m = memory_order_seq_cst) noexcept
{
__atomic_store(std::__addressof(_M_i), std::__addressof(__i), int(__m));
}
void
store(_Tp __i, memory_order __m = memory_order_seq_cst) volatile noexcept
{
__atomic_store(std::__addressof(_M_i), std::__addressof(__i), int(__m));
}
_Tp
load(memory_order __m = memory_order_seq_cst) const noexcept
{
alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
_Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
__atomic_load(std::__addressof(_M_i), __ptr, int(__m));
return *__ptr;
}
_Tp
load(memory_order __m = memory_order_seq_cst) const volatile noexcept
{
alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
_Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
__atomic_load(std::__addressof(_M_i), __ptr, int(__m));
return *__ptr;
}
_Tp
exchange(_Tp __i, memory_order __m = memory_order_seq_cst) noexcept
{
alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
_Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
__atomic_exchange(std::__addressof(_M_i), std::__addressof(__i),
__ptr, int(__m));
return *__ptr;
}
_Tp
exchange(_Tp __i,
memory_order __m = memory_order_seq_cst) volatile noexcept
{
alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
_Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
__atomic_exchange(std::__addressof(_M_i), std::__addressof(__i),
__ptr, int(__m));
return *__ptr;
}
bool
compare_exchange_weak(_Tp& __e, _Tp __i, memory_order __s,
memory_order __f) noexcept
{
return __atomic_compare_exchange(std::__addressof(_M_i),
std::__addressof(__e),
std::__addressof(__i),
true, int(__s), int(__f));
}
bool
compare_exchange_weak(_Tp& __e, _Tp __i, memory_order __s,
memory_order __f) volatile noexcept
{
return __atomic_compare_exchange(std::__addressof(_M_i),
std::__addressof(__e),
std::__addressof(__i),
true, int(__s), int(__f));
}
bool
compare_exchange_weak(_Tp& __e, _Tp __i,
memory_order __m = memory_order_seq_cst) noexcept
{ return compare_exchange_weak(__e, __i, __m,
__cmpexch_failure_order(__m)); }
bool
compare_exchange_weak(_Tp& __e, _Tp __i,
memory_order __m = memory_order_seq_cst) volatile noexcept
{ return compare_exchange_weak(__e, __i, __m,
__cmpexch_failure_order(__m)); }
bool
compare_exchange_strong(_Tp& __e, _Tp __i, memory_order __s,
memory_order __f) noexcept
{
return __atomic_compare_exchange(std::__addressof(_M_i),
std::__addressof(__e),
std::__addressof(__i),
false, int(__s), int(__f));
}
bool
compare_exchange_strong(_Tp& __e, _Tp __i, memory_order __s,
memory_order __f) volatile noexcept
{
return __atomic_compare_exchange(std::__addressof(_M_i),
std::__addressof(__e),
std::__addressof(__i),
false, int(__s), int(__f));
}
bool
compare_exchange_strong(_Tp& __e, _Tp __i,
memory_order __m = memory_order_seq_cst) noexcept
{ return compare_exchange_strong(__e, __i, __m,
__cmpexch_failure_order(__m)); }
bool
compare_exchange_strong(_Tp& __e, _Tp __i,
memory_order __m = memory_order_seq_cst) volatile noexcept
{ return compare_exchange_strong(__e, __i, __m,
__cmpexch_failure_order(__m)); }
#if __cpp_lib_atomic_wait
void
wait(_Tp __old, memory_order __m = memory_order_seq_cst) const noexcept
{
std::__atomic_wait_address_v(&_M_i, __old,
[__m, this] { return this->load(__m); });
}
// TODO add const volatile overload
void
notify_one() const noexcept
{ std::__atomic_notify_address(&_M_i, false); }
void
notify_all() const noexcept
{ std::__atomic_notify_address(&_M_i, true); }
#endif // __cpp_lib_atomic_wait
};
#undef _GLIBCXX20_INIT
/// Partial specialization for pointer types.
template<typename _Tp>
struct atomic<_Tp*>
{
using value_type = _Tp*;
using difference_type = ptrdiff_t;
typedef _Tp* __pointer_type;
typedef __atomic_base<_Tp*> __base_type;
__base_type _M_b;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__pointer_type __p) noexcept : _M_b(__p) { }
operator __pointer_type() const noexcept
{ return __pointer_type(_M_b); }
operator __pointer_type() const volatile noexcept
{ return __pointer_type(_M_b); }
__pointer_type
operator=(__pointer_type __p) noexcept
{ return _M_b.operator=(__p); }
__pointer_type
operator=(__pointer_type __p) volatile noexcept
{ return _M_b.operator=(__p); }
__pointer_type
operator++(int) noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return _M_b++;
}
__pointer_type
operator++(int) volatile noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return _M_b++;
}
__pointer_type
operator--(int) noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return _M_b--;
}
__pointer_type
operator--(int) volatile noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return _M_b--;
}
__pointer_type
operator++() noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return ++_M_b;
}
__pointer_type
operator++() volatile noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return ++_M_b;
}
__pointer_type
operator--() noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return --_M_b;
}
__pointer_type
operator--() volatile noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return --_M_b;
}
__pointer_type
operator+=(ptrdiff_t __d) noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return _M_b.operator+=(__d);
}
__pointer_type
operator+=(ptrdiff_t __d) volatile noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return _M_b.operator+=(__d);
}
__pointer_type
operator-=(ptrdiff_t __d) noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return _M_b.operator-=(__d);
}
__pointer_type
operator-=(ptrdiff_t __d) volatile noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return _M_b.operator-=(__d);
}
bool
is_lock_free() const noexcept
{ return _M_b.is_lock_free(); }
bool
is_lock_free() const volatile noexcept
{ return _M_b.is_lock_free(); }
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_POINTER_LOCK_FREE == 2;
#endif
void
store(__pointer_type __p,
memory_order __m = memory_order_seq_cst) noexcept
{ return _M_b.store(__p, __m); }
void
store(__pointer_type __p,
memory_order __m = memory_order_seq_cst) volatile noexcept
{ return _M_b.store(__p, __m); }
__pointer_type
load(memory_order __m = memory_order_seq_cst) const noexcept
{ return _M_b.load(__m); }
__pointer_type
load(memory_order __m = memory_order_seq_cst) const volatile noexcept
{ return _M_b.load(__m); }
__pointer_type
exchange(__pointer_type __p,
memory_order __m = memory_order_seq_cst) noexcept
{ return _M_b.exchange(__p, __m); }
__pointer_type
exchange(__pointer_type __p,
memory_order __m = memory_order_seq_cst) volatile noexcept
{ return _M_b.exchange(__p, __m); }
bool
compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
memory_order __m1, memory_order __m2) noexcept
{ return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
bool
compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
memory_order __m1,
memory_order __m2) volatile noexcept
{ return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
bool
compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
memory_order __m = memory_order_seq_cst) noexcept
{
return compare_exchange_weak(__p1, __p2, __m,
__cmpexch_failure_order(__m));
}
bool
compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
memory_order __m = memory_order_seq_cst) volatile noexcept
{
return compare_exchange_weak(__p1, __p2, __m,
__cmpexch_failure_order(__m));
}
bool
compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
memory_order __m1, memory_order __m2) noexcept
{ return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
bool
compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
memory_order __m1,
memory_order __m2) volatile noexcept
{ return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
bool
compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
memory_order __m = memory_order_seq_cst) noexcept
{
return _M_b.compare_exchange_strong(__p1, __p2, __m,
__cmpexch_failure_order(__m));
}
bool
compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
memory_order __m = memory_order_seq_cst) volatile noexcept
{
return _M_b.compare_exchange_strong(__p1, __p2, __m,
__cmpexch_failure_order(__m));
}
#if __cpp_lib_atomic_wait
void
wait(__pointer_type __old, memory_order __m = memory_order_seq_cst) const noexcept
{ _M_b.wait(__old, __m); }
// TODO add const volatile overload
void
notify_one() const noexcept
{ _M_b.notify_one(); }
void
notify_all() const noexcept
{ _M_b.notify_all(); }
#endif // __cpp_lib_atomic_wait
__pointer_type
fetch_add(ptrdiff_t __d,
memory_order __m = memory_order_seq_cst) noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return _M_b.fetch_add(__d, __m);
}
__pointer_type
fetch_add(ptrdiff_t __d,
memory_order __m = memory_order_seq_cst) volatile noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return _M_b.fetch_add(__d, __m);
}
__pointer_type
fetch_sub(ptrdiff_t __d,
memory_order __m = memory_order_seq_cst) noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return _M_b.fetch_sub(__d, __m);
}
__pointer_type
fetch_sub(ptrdiff_t __d,
memory_order __m = memory_order_seq_cst) volatile noexcept
{
#if __cplusplus >= 201703L
static_assert( is_object<_Tp>::value, "pointer to object type" );
#endif
return _M_b.fetch_sub(__d, __m);
}
};
/// Explicit specialization for char.
template<>
struct atomic<char> : __atomic_base<char>
{
typedef char __integral_type;
typedef __atomic_base<char> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_CHAR_LOCK_FREE == 2;
#endif
};
/// Explicit specialization for signed char.
template<>
struct atomic<signed char> : __atomic_base<signed char>
{
typedef signed char __integral_type;
typedef __atomic_base<signed char> __base_type;
atomic() noexcept= default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_CHAR_LOCK_FREE == 2;
#endif
};
/// Explicit specialization for unsigned char.
template<>
struct atomic<unsigned char> : __atomic_base<unsigned char>
{
typedef unsigned char __integral_type;
typedef __atomic_base<unsigned char> __base_type;
atomic() noexcept= default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_CHAR_LOCK_FREE == 2;
#endif
};
/// Explicit specialization for short.
template<>
struct atomic<short> : __atomic_base<short>
{
typedef short __integral_type;
typedef __atomic_base<short> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_SHORT_LOCK_FREE == 2;
#endif
};
/// Explicit specialization for unsigned short.
template<>
struct atomic<unsigned short> : __atomic_base<unsigned short>
{
typedef unsigned short __integral_type;
typedef __atomic_base<unsigned short> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_SHORT_LOCK_FREE == 2;
#endif
};
/// Explicit specialization for int.
template<>
struct atomic<int> : __atomic_base<int>
{
typedef int __integral_type;
typedef __atomic_base<int> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_INT_LOCK_FREE == 2;
#endif
};
/// Explicit specialization for unsigned int.
template<>
struct atomic<unsigned int> : __atomic_base<unsigned int>
{
typedef unsigned int __integral_type;
typedef __atomic_base<unsigned int> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_INT_LOCK_FREE == 2;
#endif
};
/// Explicit specialization for long.
template<>
struct atomic<long> : __atomic_base<long>
{
typedef long __integral_type;
typedef __atomic_base<long> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_LONG_LOCK_FREE == 2;
#endif
};
/// Explicit specialization for unsigned long.
template<>
struct atomic<unsigned long> : __atomic_base<unsigned long>
{
typedef unsigned long __integral_type;
typedef __atomic_base<unsigned long> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_LONG_LOCK_FREE == 2;
#endif
};
/// Explicit specialization for long long.
template<>
struct atomic<long long> : __atomic_base<long long>
{
typedef long long __integral_type;
typedef __atomic_base<long long> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_LLONG_LOCK_FREE == 2;
#endif
};
/// Explicit specialization for unsigned long long.
template<>
struct atomic<unsigned long long> : __atomic_base<unsigned long long>
{
typedef unsigned long long __integral_type;
typedef __atomic_base<unsigned long long> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_LLONG_LOCK_FREE == 2;
#endif
};
/// Explicit specialization for wchar_t.
template<>
struct atomic<wchar_t> : __atomic_base<wchar_t>
{
typedef wchar_t __integral_type;
typedef __atomic_base<wchar_t> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_WCHAR_T_LOCK_FREE == 2;
#endif
};
#ifdef _GLIBCXX_USE_CHAR8_T
/// Explicit specialization for char8_t.
template<>
struct atomic<char8_t> : __atomic_base<char8_t>
{
typedef char8_t __integral_type;
typedef __atomic_base<char8_t> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus > 201402L
static constexpr bool is_always_lock_free = ATOMIC_CHAR8_T_LOCK_FREE == 2;
#endif
};
#endif
/// Explicit specialization for char16_t.
template<>
struct atomic<char16_t> : __atomic_base<char16_t>
{
typedef char16_t __integral_type;
typedef __atomic_base<char16_t> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_CHAR16_T_LOCK_FREE == 2;
#endif
};
/// Explicit specialization for char32_t.
template<>
struct atomic<char32_t> : __atomic_base<char32_t>
{
typedef char32_t __integral_type;
typedef __atomic_base<char32_t> __base_type;
atomic() noexcept = default;
~atomic() noexcept = default;
atomic(const atomic&) = delete;
atomic& operator=(const atomic&) = delete;
atomic& operator=(const atomic&) volatile = delete;
constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
using __base_type::operator __integral_type;
using __base_type::operator=;
#if __cplusplus >= 201703L
static constexpr bool is_always_lock_free = ATOMIC_CHAR32_T_LOCK_FREE == 2;
#endif
};
/// atomic_bool
typedef atomic<bool> atomic_bool;
/// atomic_char
typedef atomic<char> atomic_char;
/// atomic_schar
typedef atomic<signed char> atomic_schar;
/// atomic_uchar
typedef atomic<unsigned char> atomic_uchar;
/// atomic_short
typedef atomic<short> atomic_short;
/// atomic_ushort
typedef atomic<unsigned short> atomic_ushort;
/// atomic_int
typedef atomic<int> atomic_int;
/// atomic_uint
typedef atomic<unsigned int> atomic_uint;
/// atomic_long
typedef atomic<long> atomic_long;
/// atomic_ulong
typedef atomic<unsigned long> atomic_ulong;
/// atomic_llong
typedef atomic<long long> atomic_llong;
/// atomic_ullong
typedef atomic<unsigned long long> atomic_ullong;
/// atomic_wchar_t
typedef atomic<wchar_t> atomic_wchar_t;
#ifdef _GLIBCXX_USE_CHAR8_T
/// atomic_char8_t
typedef atomic<char8_t> atomic_char8_t;
#endif
/// atomic_char16_t
typedef atomic<char16_t> atomic_char16_t;
/// atomic_char32_t
typedef atomic<char32_t> atomic_char32_t;
#ifdef _GLIBCXX_USE_C99_STDINT_TR1
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2441. Exact-width atomic typedefs should be provided
/// atomic_int8_t
typedef atomic<int8_t> atomic_int8_t;
/// atomic_uint8_t
typedef atomic<uint8_t> atomic_uint8_t;
/// atomic_int16_t
typedef atomic<int16_t> atomic_int16_t;
/// atomic_uint16_t
typedef atomic<uint16_t> atomic_uint16_t;
/// atomic_int32_t
typedef atomic<int32_t> atomic_int32_t;
/// atomic_uint32_t
typedef atomic<uint32_t> atomic_uint32_t;
/// atomic_int64_t
typedef atomic<int64_t> atomic_int64_t;
/// atomic_uint64_t
typedef atomic<uint64_t> atomic_uint64_t;
/// atomic_int_least8_t
typedef atomic<int_least8_t> atomic_int_least8_t;
/// atomic_uint_least8_t
typedef atomic<uint_least8_t> atomic_uint_least8_t;
/// atomic_int_least16_t
typedef atomic<int_least16_t> atomic_int_least16_t;
/// atomic_uint_least16_t
typedef atomic<uint_least16_t> atomic_uint_least16_t;
/// atomic_int_least32_t
typedef atomic<int_least32_t> atomic_int_least32_t;
/// atomic_uint_least32_t
typedef atomic<uint_least32_t> atomic_uint_least32_t;
/// atomic_int_least64_t
typedef atomic<int_least64_t> atomic_int_least64_t;
/// atomic_uint_least64_t
typedef atomic<uint_least64_t> atomic_uint_least64_t;
/// atomic_int_fast8_t
typedef atomic<int_fast8_t> atomic_int_fast8_t;
/// atomic_uint_fast8_t
typedef atomic<uint_fast8_t> atomic_uint_fast8_t;
/// atomic_int_fast16_t
typedef atomic<int_fast16_t> atomic_int_fast16_t;
/// atomic_uint_fast16_t
typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
/// atomic_int_fast32_t
typedef atomic<int_fast32_t> atomic_int_fast32_t;
/// atomic_uint_fast32_t
typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
/// atomic_int_fast64_t
typedef atomic<int_fast64_t> atomic_int_fast64_t;
/// atomic_uint_fast64_t
typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
#endif
/// atomic_intptr_t
typedef atomic<intptr_t> atomic_intptr_t;
/// atomic_uintptr_t
typedef atomic<uintptr_t> atomic_uintptr_t;
/// atomic_size_t
typedef atomic<size_t> atomic_size_t;
/// atomic_ptrdiff_t
typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
#ifdef _GLIBCXX_USE_C99_STDINT_TR1
/// atomic_intmax_t
typedef atomic<intmax_t> atomic_intmax_t;
/// atomic_uintmax_t
typedef atomic<uintmax_t> atomic_uintmax_t;
#endif
// Function definitions, atomic_flag operations.
inline bool
atomic_flag_test_and_set_explicit(atomic_flag* __a,
memory_order __m) noexcept
{ return __a->test_and_set(__m); }
inline bool
atomic_flag_test_and_set_explicit(volatile atomic_flag* __a,
memory_order __m) noexcept
{ return __a->test_and_set(__m); }
inline void
atomic_flag_clear_explicit(atomic_flag* __a, memory_order __m) noexcept
{ __a->clear(__m); }
inline void
atomic_flag_clear_explicit(volatile atomic_flag* __a,
memory_order __m) noexcept
{ __a->clear(__m); }
inline bool
atomic_flag_test_and_set(atomic_flag* __a) noexcept
{ return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }
inline bool
atomic_flag_test_and_set(volatile atomic_flag* __a) noexcept
{ return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }
inline void
atomic_flag_clear(atomic_flag* __a) noexcept
{ atomic_flag_clear_explicit(__a, memory_order_seq_cst); }
inline void
atomic_flag_clear(volatile atomic_flag* __a) noexcept
{ atomic_flag_clear_explicit(__a, memory_order_seq_cst); }
template<typename _Tp>
using __atomic_val_t = typename atomic<_Tp>::value_type;
template<typename _Tp>
using __atomic_diff_t = typename atomic<_Tp>::difference_type;
// [atomics.nonmembers] Non-member functions.
// Function templates generally applicable to atomic types.
template<typename _ITp>
inline bool
atomic_is_lock_free(const atomic<_ITp>* __a) noexcept
{ return __a->is_lock_free(); }
template<typename _ITp>
inline bool
atomic_is_lock_free(const volatile atomic<_ITp>* __a) noexcept
{ return __a->is_lock_free(); }
template<typename _ITp>
inline void
atomic_init(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
{ __a->store(__i, memory_order_relaxed); }
template<typename _ITp>
inline void
atomic_init(volatile atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
{ __a->store(__i, memory_order_relaxed); }
template<typename _ITp>
inline void
atomic_store_explicit(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i,
memory_order __m) noexcept
{ __a->store(__i, __m); }
template<typename _ITp>
inline void
atomic_store_explicit(volatile atomic<_ITp>* __a, __atomic_val_t<_ITp> __i,
memory_order __m) noexcept
{ __a->store(__i, __m); }
template<typename _ITp>
inline _ITp
atomic_load_explicit(const atomic<_ITp>* __a, memory_order __m) noexcept
{ return __a->load(__m); }
template<typename _ITp>
inline _ITp
atomic_load_explicit(const volatile atomic<_ITp>* __a,
memory_order __m) noexcept
{ return __a->load(__m); }
template<typename _ITp>
inline _ITp
atomic_exchange_explicit(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i,
memory_order __m) noexcept
{ return __a->exchange(__i, __m); }
template<typename _ITp>
inline _ITp
atomic_exchange_explicit(volatile atomic<_ITp>* __a,
__atomic_val_t<_ITp> __i,
memory_order __m) noexcept
{ return __a->exchange(__i, __m); }
template<typename _ITp>
inline bool
atomic_compare_exchange_weak_explicit(atomic<_ITp>* __a,
__atomic_val_t<_ITp>* __i1,
__atomic_val_t<_ITp> __i2,
memory_order __m1,
memory_order __m2) noexcept
{ return __a->compare_exchange_weak(*__i1, __i2, __m1, __m2); }
template<typename _ITp>
inline bool
atomic_compare_exchange_weak_explicit(volatile atomic<_ITp>* __a,
__atomic_val_t<_ITp>* __i1,
__atomic_val_t<_ITp> __i2,
memory_order __m1,
memory_order __m2) noexcept
{ return __a->compare_exchange_weak(*__i1, __i2, __m1, __m2); }
template<typename _ITp>
inline bool
atomic_compare_exchange_strong_explicit(atomic<_ITp>* __a,
__atomic_val_t<_ITp>* __i1,
__atomic_val_t<_ITp> __i2,
memory_order __m1,
memory_order __m2) noexcept
{ return __a->compare_exchange_strong(*__i1, __i2, __m1, __m2); }
template<typename _ITp>
inline bool
atomic_compare_exchange_strong_explicit(volatile atomic<_ITp>* __a,
__atomic_val_t<_ITp>* __i1,
__atomic_val_t<_ITp> __i2,
memory_order __m1,
memory_order __m2) noexcept
{ return __a->compare_exchange_strong(*__i1, __i2, __m1, __m2); }
template<typename _ITp>
inline void
atomic_store(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
{ atomic_store_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline void
atomic_store(volatile atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
{ atomic_store_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_load(const atomic<_ITp>* __a) noexcept
{ return atomic_load_explicit(__a, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_load(const volatile atomic<_ITp>* __a) noexcept
{ return atomic_load_explicit(__a, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_exchange(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
{ return atomic_exchange_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_exchange(volatile atomic<_ITp>* __a,
__atomic_val_t<_ITp> __i) noexcept
{ return atomic_exchange_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline bool
atomic_compare_exchange_weak(atomic<_ITp>* __a,
__atomic_val_t<_ITp>* __i1,
__atomic_val_t<_ITp> __i2) noexcept
{
return atomic_compare_exchange_weak_explicit(__a, __i1, __i2,
memory_order_seq_cst,
memory_order_seq_cst);
}
template<typename _ITp>
inline bool
atomic_compare_exchange_weak(volatile atomic<_ITp>* __a,
__atomic_val_t<_ITp>* __i1,
__atomic_val_t<_ITp> __i2) noexcept
{
return atomic_compare_exchange_weak_explicit(__a, __i1, __i2,
memory_order_seq_cst,
memory_order_seq_cst);
}
template<typename _ITp>
inline bool
atomic_compare_exchange_strong(atomic<_ITp>* __a,
__atomic_val_t<_ITp>* __i1,
__atomic_val_t<_ITp> __i2) noexcept
{
return atomic_compare_exchange_strong_explicit(__a, __i1, __i2,
memory_order_seq_cst,
memory_order_seq_cst);
}
template<typename _ITp>
inline bool
atomic_compare_exchange_strong(volatile atomic<_ITp>* __a,
__atomic_val_t<_ITp>* __i1,
__atomic_val_t<_ITp> __i2) noexcept
{
return atomic_compare_exchange_strong_explicit(__a, __i1, __i2,
memory_order_seq_cst,
memory_order_seq_cst);
}
#if __cpp_lib_atomic_wait
template<typename _Tp>
inline void
atomic_wait(const atomic<_Tp>* __a,
typename std::atomic<_Tp>::value_type __old) noexcept
{ __a->wait(__old); }
template<typename _Tp>
inline void
atomic_wait_explicit(const atomic<_Tp>* __a,
typename std::atomic<_Tp>::value_type __old,
std::memory_order __m) noexcept
{ __a->wait(__old, __m); }
template<typename _Tp>
inline void
atomic_notify_one(const atomic<_Tp>* __a) noexcept
{ __a->notify_one(); }
template<typename _Tp>
inline void
atomic_notify_all(const atomic<_Tp>* __a) noexcept
{ __a->notify_all(); }
#endif // __cpp_lib_atomic_wait
// Function templates for atomic_integral and atomic_pointer operations only.
// Some operations (and, or, xor) are only available for atomic integrals,
// which is implemented by taking a parameter of type __atomic_base<_ITp>*.
template<typename _ITp>
inline _ITp
atomic_fetch_add_explicit(atomic<_ITp>* __a,
__atomic_diff_t<_ITp> __i,
memory_order __m) noexcept
{ return __a->fetch_add(__i, __m); }
template<typename _ITp>
inline _ITp
atomic_fetch_add_explicit(volatile atomic<_ITp>* __a,
__atomic_diff_t<_ITp> __i,
memory_order __m) noexcept
{ return __a->fetch_add(__i, __m); }
template<typename _ITp>
inline _ITp
atomic_fetch_sub_explicit(atomic<_ITp>* __a,
__atomic_diff_t<_ITp> __i,
memory_order __m) noexcept
{ return __a->fetch_sub(__i, __m); }
template<typename _ITp>
inline _ITp
atomic_fetch_sub_explicit(volatile atomic<_ITp>* __a,
__atomic_diff_t<_ITp> __i,
memory_order __m) noexcept
{ return __a->fetch_sub(__i, __m); }
template<typename _ITp>
inline _ITp
atomic_fetch_and_explicit(__atomic_base<_ITp>* __a,
__atomic_val_t<_ITp> __i,
memory_order __m) noexcept
{ return __a->fetch_and(__i, __m); }
template<typename _ITp>
inline _ITp
atomic_fetch_and_explicit(volatile __atomic_base<_ITp>* __a,
__atomic_val_t<_ITp> __i,
memory_order __m) noexcept
{ return __a->fetch_and(__i, __m); }
template<typename _ITp>
inline _ITp
atomic_fetch_or_explicit(__atomic_base<_ITp>* __a,
__atomic_val_t<_ITp> __i,
memory_order __m) noexcept
{ return __a->fetch_or(__i, __m); }
template<typename _ITp>
inline _ITp
atomic_fetch_or_explicit(volatile __atomic_base<_ITp>* __a,
__atomic_val_t<_ITp> __i,
memory_order __m) noexcept
{ return __a->fetch_or(__i, __m); }
template<typename _ITp>
inline _ITp
atomic_fetch_xor_explicit(__atomic_base<_ITp>* __a,
__atomic_val_t<_ITp> __i,
memory_order __m) noexcept
{ return __a->fetch_xor(__i, __m); }
template<typename _ITp>
inline _ITp
atomic_fetch_xor_explicit(volatile __atomic_base<_ITp>* __a,
__atomic_val_t<_ITp> __i,
memory_order __m) noexcept
{ return __a->fetch_xor(__i, __m); }
template<typename _ITp>
inline _ITp
atomic_fetch_add(atomic<_ITp>* __a,
__atomic_diff_t<_ITp> __i) noexcept
{ return atomic_fetch_add_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_fetch_add(volatile atomic<_ITp>* __a,
__atomic_diff_t<_ITp> __i) noexcept
{ return atomic_fetch_add_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_fetch_sub(atomic<_ITp>* __a,
__atomic_diff_t<_ITp> __i) noexcept
{ return atomic_fetch_sub_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_fetch_sub(volatile atomic<_ITp>* __a,
__atomic_diff_t<_ITp> __i) noexcept
{ return atomic_fetch_sub_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_fetch_and(__atomic_base<_ITp>* __a,
__atomic_val_t<_ITp> __i) noexcept
{ return atomic_fetch_and_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_fetch_and(volatile __atomic_base<_ITp>* __a,
__atomic_val_t<_ITp> __i) noexcept
{ return atomic_fetch_and_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_fetch_or(__atomic_base<_ITp>* __a,
__atomic_val_t<_ITp> __i) noexcept
{ return atomic_fetch_or_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_fetch_or(volatile __atomic_base<_ITp>* __a,
__atomic_val_t<_ITp> __i) noexcept
{ return atomic_fetch_or_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_fetch_xor(__atomic_base<_ITp>* __a,
__atomic_val_t<_ITp> __i) noexcept
{ return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }
template<typename _ITp>
inline _ITp
atomic_fetch_xor(volatile __atomic_base<_ITp>* __a,
__atomic_val_t<_ITp> __i) noexcept
{ return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }
#if __cplusplus > 201703L
#define __cpp_lib_atomic_float 201711L
template<>
struct atomic<float> : __atomic_float<float>
{
atomic() noexcept = default;
constexpr
atomic(float __fp) noexcept : __atomic_float<float>(__fp)
{ }
atomic& operator=(const atomic&) volatile = delete;
atomic& operator=(const atomic&) = delete;
using __atomic_float<float>::operator=;
};
template<>
struct atomic<double> : __atomic_float<double>
{
atomic() noexcept = default;
constexpr
atomic(double __fp) noexcept : __atomic_float<double>(__fp)
{ }
atomic& operator=(const atomic&) volatile = delete;
atomic& operator=(const atomic&) = delete;
using __atomic_float<double>::operator=;
};
template<>
struct atomic<long double> : __atomic_float<long double>
{
atomic() noexcept = default;
constexpr
atomic(long double __fp) noexcept : __atomic_float<long double>(__fp)
{ }
atomic& operator=(const atomic&) volatile = delete;
atomic& operator=(const atomic&) = delete;
using __atomic_float<long double>::operator=;
};
#define __cpp_lib_atomic_ref 201806L
/// Class template to provide atomic operations on a non-atomic variable.
template<typename _Tp>
struct atomic_ref : __atomic_ref<_Tp>
{
explicit
atomic_ref(_Tp& __t) noexcept : __atomic_ref<_Tp>(__t)
{ }
atomic_ref& operator=(const atomic_ref&) = delete;
atomic_ref(const atomic_ref&) = default;
using __atomic_ref<_Tp>::operator=;
};
#endif // C++2a
/// @} group atomics
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif // C++11
#endif // _GLIBCXX_ATOMIC