标准库头文件 <atomic>

 

C++

语言

头文件

具名要求

语言支持库

概念库 (C++20)

诊断库

工具库

字符串库

容器库

算法库

迭代器库

数值库

输入/输出库

本地化库

正则表达式库 (C++11)

原子操作库 (C++11)

线程支持库 (C++11)

文件系统库 (C++17)

技术规范

 

标准库头文件

语言支持
<cstddef> <limits> <climits> <version>	<cfloat> <cstdint> <new>	<typeinfo> <exception> <initializer_list>	<csignal> <csetjmp> <cstdarg>
概念
<concepts>
诊断
<stdexcept>	<cassert>	<cerrno>	<system_error>
通用工具
<utility> <memory> <memory_resource> <scoped_allocator>     <compare>	<bitset> <tuple> <optional> <any> <variant>	<type_traits> <ratio> <chrono> <typeindex> <functional>	<ctime> <cstdlib>
字符串
<string> <string_view>	<cctype> <cwctype>	<cwchar> <cuchar>	<cstring> <charconv>
本地化
<locale>	<codecvt>	<clocale>
容器
<span> <array> <vector>	<deque> <forward_list> <list>	<map> <set> <queue>	<unordered_map> <unordered_set> <stack>
迭代器
<iterator>
算法
<algorithm>	<execution>
数值
<complex> <random>	<valarray> <numeric>	<cfenv> <cmath>	<bit>
输入/输出
<iosfwd> <ios> <iomanip> <streambuf>	<istream> <ostream> <iostream>	<sstream> <fstream> <syncstream>	<cstdio> <cinttypes> <strstream>
正则表达式
<regex>
文件系统
<filesystem>
线程支持
<thread> <atomic>	<mutex> <shared_mutex>	<condition_variable> <future>
C 兼容
<ciso646> <cstdalign>	<cstdbool> <ccomplex>	<ctgmath>

 

此头文件是原子操作库的一部分。

类
atomic (C++11)	原子类模板及其布尔型，整型和指针类型的特化 (类模板)
atomic_flag (C++11)	免锁的布尔原子类型 (类)
memory_order (C++11)	为给定的原子操作定义内存顺序制约 (枚举)
typedef
std::atomic_bool	std::atomic<bool>
std::atomic_char	std::atomic<char>
std::atomic_schar	std::atomic<signed char>
std::atomic_uchar	std::atomic<unsigned char>
std::atomic_short	std::atomic<short>
std::atomic_ushort	std::atomic<unsigned short>
std::atomic_int	std::atomic<int>
std::atomic_uint	std::atomic<unsigned int>
std::atomic_long	std::atomic<long>
std::atomic_ulong	std::atomic<unsigned long>
std::atomic_llong	std::atomic<long long>
std::atomic_ullong	std::atomic<unsigned long long>
std::atomic_char16_t	std::atomic<char16_t>
std::atomic_char32_t	std::atomic<char32_t>
std::atomic_wchar_t	std::atomic<wchar_t>
std::atomic_int_least8_t	std::atomic<int_least8_t>
std::atomic_uint_least8_t	std::atomic<uint_least8_t>
std::atomic_int_least16_t	std::atomic<int_least16_t>
std::atomic_uint_least16_t	std::atomic<uint_least16_t>
std::atomic_int_least32_t	std::atomic<int_least32_t>
std::atomic_uint_least32_t	std::atomic<uint_least32_t>
std::atomic_int_least64_t	std::atomic<int_least64_t>
std::atomic_uint_least64_t	std::atomic<uint_least64_t>
std::atomic_int_fast8_t	std::atomic<int_fast8_t>
std::atomic_uint_fast8_t	std::atomic<uint_fast8_t>
std::atomic_int_fast16_t	std::atomic<int_fast16_t>
std::atomic_uint_fast16_t	std::atomic<uint_fast16_t>
std::atomic_int_fast32_t	std::atomic<int_fast32_t>
std::atomic_uint_fast32_t	std::atomic<uint_fast32_t>
std::atomic_int_fast64_t	std::atomic<int_fast64_t>
std::atomic_uint_fast64_t	std::atomic<uint_fast64_t>
std::atomic_intptr_t	std::atomic<intptr_t>
std::atomic_uintptr_t	std::atomic<uintptr_t>
std::atomic_size_t	std::atomic<size_t>
std::atomic_ptrdiff_t	std::atomic<ptrdiff_t>
std::atomic_intmax_t	std::atomic<intmax_t>
std::atomic_uintmax_t	std::atomic<uintmax_t>
函数
atomic_is_lock_free (C++11)	检查对该原子类型的操作是否是无锁的 (函数模板)
atomic_store atomic_store_explicit (C++11) (C++11)	原子地以非原子参数替换原子对象的值 (函数模板)
atomic_load atomic_load_explicit (C++11) (C++11)	原子地获得存储于原子对象的值 (函数模板)
atomic_exchange atomic_exchange_explicit (C++11) (C++11)	原子地以非原子参数的值替换原子对象的值，并返回该原子对象的旧值 (函数模板)
atomic_compare_exchange_weak atomic_compare_exchange_weak_explicit atomic_compare_exchange_strong atomic_compare_exchange_strong_explicit (C++11) (C++11) (C++11) (C++11)	原子地比较原子对象和非原子参数的值，若相等则进行 atomic_exchange ，若不相等则进行 atomic_load (函数模板)
atomic_fetch_add atomic_fetch_add_explicit (C++11) (C++11)	将非原子值加到原子对象，并获得原子对象的先前值 (函数模板)
atomic_fetch_sub atomic_fetch_sub_explicit (C++11) (C++11)	从原子对象减去非原子值，并获得原子对象的先前值 (函数模板)
atomic_fetch_and atomic_fetch_and_explicit (C++11) (C++11)	将原子对象替换为与非原子参数的逻辑与结果，并获得原子对象的先前值 (函数模板)
atomic_fetch_or atomic_fetch_or_explicit (C++11) (C++11)	将原子对象替换为与非原子参数逻辑或的结果，并获得原子对象的先前值 (函数模板)
atomic_fetch_xor atomic_fetch_xor_explicit (C++11) (C++11)	将原子对象替换为与非原子参数逻辑异或的结果，并获得原子对象的先前值 (函数模板)
atomic_flag_test_and_set atomic_flag_test_and_set_explicit (C++11) (C++11)	原子地设置标志为 true 并返回其先前值 (函数)
atomic_flag_clear atomic_flag_clear_explicit (C++11) (C++11)	原子地设置标志值为 false (函数)
atomic_init (C++11)	默认构造的原子对象的非原子初始化 (函数模板)
kill_dependency (C++11)	从 std::memory_order_consume 依赖树移除指定对象 (函数模板)
atomic_thread_fence (C++11)	通用的依赖内存顺序的栅栏同步原语 (函数)
atomic_signal_fence (C++11)	线程与执行于同一线程的信号处理函数间的栅栏 (函数)
预处理器宏
ATOMIC_VAR_INIT (C++11)	静态存储期的原子对象的常量初始化 (宏函数)
ATOMIC_FLAG_INIT (C++11)	将 std::atomic_flag 初始化为 false (宏常量)

概要

namespace std {
 
    /* C++17 前：
 
    typedef enum memory_order {
        memory_order_relaxed,
        memory_order_consume,
        memory_order_acquire,
        memory_order_release,
        memory_order_acq_rel,
        memory_order_seq_cst
    } memory_order;
 
    */
 
    enum class memory_order : /*unspecified*/ {
        relaxed, consume, acquire, release, acq_rel, seq_cst
    };
 
    inline constexpr memory_order memory_order_relaxed = memory_order::relaxed;
    inline constexpr memory_order memory_order_consume = memory_order::consume;
    inline constexpr memory_order memory_order_acquire = memory_order::acquire;
    inline constexpr memory_order memory_order_release = memory_order::release;
    inline constexpr memory_order memory_order_acq_rel = memory_order::acq_rel;
    inline constexpr memory_order memory_order_seq_cst = memory_order::seq_cst;
 
    template <class T>
    T kill_dependency(T y) noexcept;
 
    // 免锁属性
    #define ATOMIC_BOOL_LOCK_FREE /*unspecified*/
    #define ATOMIC_CHAR_LOCK_FREE /*unspecified*/
    #define ATOMIC_CHAR16_T_LOCK_FREE /*unspecified*/
    #define ATOMIC_CHAR32_T_LOCK_FREE /*unspecified*/
    #define ATOMIC_WCHAR_T_LOCK_FREE /*unspecified*/
    #define ATOMIC_SHORT_LOCK_FREE /*unspecified*/
    #define ATOMIC_INT_LOCK_FREE /*unspecified*/
    #define ATOMIC_LONG_LOCK_FREE /*unspecified*/
    #define ATOMIC_LLONG_LOCK_FREE /*unspecified*/
    #define ATOMIC_POINTER_LOCK_FREE /*unspecified*/
 
    // 泛型原子类型
    template<class T> struct atomic;
    // 对指针的特化
    template<class T> struct atomic<T*>;
 
    // 命名的 typedef
    using atomic_bool           = atomic<bool>;
    using atomic_char           = atomic<char>;
    using atomic_schar          = atomic<signed char>;
    using atomic_uchar          = atomic<unsigned char>;
    using atomic_short          = atomic<short>;
    using atomic_ushort         = atomic<unsigned short>;
    using atomic_int            = atomic<int>;
    using atomic_uint           = atomic<unsigned int>;
    using atomic_long           = atomic<long>;
    using atomic_ulong          = atomic<unsigned long>;
    using atomic_llong          = atomic<long long>;
    using atomic_ullong         = atomic<unsigned long long>;
    using atomic_char16_t       = atomic<char16_t>;
    using atomic_char32_t       = atomic<char32_t>;
    using atomic_wchar_t        = atomic<wchar_t>;
 
    using atomic_int8_t         = atomic<int8_t>;
    using atomic_uint8_t        = atomic<uint8_t>;
    using atomic_int16_t        = atomic<int16_t>;
    using atomic_uint16_t       = atomic<uint16_t>;
    using atomic_int32_t        = atomic<int32_t>;
    using atomic_uint32_t       = atomic<uint32_t>;
    using atomic_int64_t        = atomic<int64_t>;
    using atomic_uint64_t       = atomic<uint64_t>;
 
    using atomic_int_least8_t   = atomic<int_least8_t>;
    using atomic_uint_least8_t  = atomic<uint_least8_t>;
    using atomic_int_least16_t  = atomic<int_least16_t>;
    using atomic_uint_least16_t = atomic<uint_least16_t>;
    using atomic_int_least32_t  = atomic<int_least32_t>;
    using atomic_uint_least32_t = atomic<uint_least32_t>;
    using atomic_int_least64_t  = atomic<int_least64_t>;
    using atomic_uint_least64_t = atomic<uint_least64_t>;
 
    using atomic_int_fast8_t    = atomic<int_fast8_t>;
    using atomic_uint_fast8_t   = atomic<uint_fast8_t>;
    using atomic_int_fast16_t   = atomic<int_fast16_t>;
    using atomic_uint_fast16_t  = atomic<uint_fast16_t>;
    using atomic_int_fast32_t   = atomic<int_fast32_t>;
    using atomic_uint_fast32_t  = atomic<uint_fast32_t>;
    using atomic_int_fast64_t   = atomic<int_fast64_t>;
    using atomic_uint_fast64_t  = atomic<uint_fast64_t>;
 
    using atomic_intptr_t       = atomic<intptr_t>;
    using atomic_uintptr_t      = atomic<uintptr_t>;
    using atomic_size_t         = atomic<size_t>;
    using atomic_ptrdiff_t      = atomic<ptrdiff_t>;
    using atomic_intmax_t       = atomic<intmax_t>;
    using atomic_uintmax_t      = atomic<uintmax_t>;
 
    // 非成员函数
    template<class T>
    bool atomic_is_lock_free(const volatile atomic<T>*) noexcept;
    template<class T>
    bool atomic_is_lock_free(const atomic<T>*) noexcept;
    template<class T>
    void atomic_init(volatile atomic<T>*, typename atomic<T>::value_type) noexcept;
    template<class T>
    void atomic_init(atomic<T>*, typename atomic<T>::value_type) noexcept;
    template<class T>
    void atomic_store(volatile atomic<T>*, typename atomic<T>::value_type) noexcept;
    template<class T>
    void atomic_store(atomic<T>*, typename atomic<T>::value_type) noexcept;
    template<class T>
    void atomic_store_explicit(volatile atomic<T>*, typename atomic<T>::value_type,
                               memory_order) noexcept;
    template<class T>
    void atomic_store_explicit(atomic<T>*, typename atomic<T>::value_type,
                               memory_order) noexcept;
    template<class T>
    T atomic_load(const volatile atomic<T>*) noexcept;
    template<class T>
    T atomic_load(const atomic<T>*) noexcept;
    template<class T>
    T atomic_load_explicit(const volatile atomic<T>*, memory_order) noexcept;
    template<class T>
    T atomic_load_explicit(const atomic<T>*, memory_order) noexcept;
    template<class T>
    T atomic_exchange(volatile atomic<T>*, typename atomic<T>::value_type) noexcept;
    template<class T>
    T atomic_exchange(atomic<T>*, typename atomic<T>::value_type) noexcept;
    template<class T>
    T atomic_exchange_explicit(volatile atomic<T>*, typename atomic<T>::value_type,
                               memory_order) noexcept;
    template<class T>
    T atomic_exchange_explicit(atomic<T>*, typename atomic<T>::value_type,
                               memory_order) noexcept;
    template<class T>
    bool atomic_compare_exchange_weak(volatile atomic<T>*,
                                      typename atomic<T>::value_type*,
                                      typename atomic<T>::value_type) noexcept;
    template<class T>
    bool atomic_compare_exchange_weak(atomic<T>*,
                                      typename atomic<T>::value_type*,
                                      typename atomic<T>::value_type) noexcept;
    template<class T>
    bool atomic_compare_exchange_strong(volatile atomic<T>*,
                                        typename atomic<T>::value_type*,
                                        typename atomic<T>::value_type) noexcept;
    template<class T>
    bool atomic_compare_exchange_strong(atomic<T>*,
                                        typename atomic<T>::value_type*,
                                        typename atomic<T>::value_type) noexcept;
    template<class T>
    bool atomic_compare_exchange_weak_explicit(volatile atomic<T>*,
                                               typename atomic<T>::value_type*,
                                               typename atomic<T>::value_type,
                                               memory_order, memory_order) noexcept;
    template<class T>
    bool atomic_compare_exchange_weak_explicit(atomic<T>*,
                                               typename atomic<T>::value_type*,
                                               typename atomic<T>::value_type,
                                               memory_order, memory_order) noexcept;
    template<class T>
    bool atomic_compare_exchange_strong_explicit(volatile atomic<T>*,
                                                 typename atomic<T>::value_type*,
                                                 typename atomic<T>::value_type,
                                                 memory_order, memory_order) noexcept;
    template<class T>
    bool atomic_compare_exchange_strong_explicit(atomic<T>*,
                                                 typename atomic<T>::value_type*,
                                                 typename atomic<T>::value_type,
                                                 memory_order, memory_order) noexcept;
 
    template<class T>
    T atomic_fetch_add(volatile atomic<T>*, typename atomic<T>::difference_type) noexcept;
    template<class T>
    T atomic_fetch_add(atomic<T>*, typename atomic<T>::difference_type) noexcept;
    template<class T>
    T atomic_fetch_add_explicit(volatile atomic<T>*, typename atomic<T>::difference_type,
                                memory_order) noexcept;
    template<class T>
    T atomic_fetch_add_explicit(atomic<T>*, typename atomic<T>::difference_type,
                                memory_order) noexcept;
    template<class T>
    T atomic_fetch_sub(volatile atomic<T>*, typename atomic<T>::difference_type) noexcept;
    template<class T>
    T atomic_fetch_sub(atomic<T>*, typename atomic<T>::difference_type) noexcept;
    template<class T>
    T atomic_fetch_sub_explicit(volatile atomic<T>*, typename atomic<T>::difference_type,
                                memory_order) noexcept;
    template<class T>
    T atomic_fetch_sub_explicit(atomic<T>*, typename atomic<T>::difference_type,
                                memory_order) noexcept;
    template<class T>
    T atomic_fetch_and(volatile atomic<T>*, typename atomic<T>::value_type) noexcept;
    template<class T>
    T atomic_fetch_and(atomic<T>*, typename atomic<T>::value_type) noexcept;
    template<class T>
    T atomic_fetch_and_explicit(volatile atomic<T>*, typename atomic<T>::value_type,
                                memory_order) noexcept;
    template<class T>
    T atomic_fetch_and_explicit(atomic<T>*, typename atomic<T>::value_type,
                                memory_order) noexcept;
    template<class T>
    T atomic_fetch_or(volatile atomic<T>*, typename atomic<T>::value_type) noexcept;
    template<class T>
    T atomic_fetch_or(atomic<T>*, typename atomic<T>::value_type) noexcept;
    template<class T>
    T atomic_fetch_or_explicit(volatile atomic<T>*, typename atomic<T>::value_type,
                               memory_order) noexcept;
    template<class T>
    T atomic_fetch_or_explicit(atomic<T>*, typename atomic<T>::value_type,
                               memory_order) noexcept;
    template<class T>
    T atomic_fetch_xor(volatile atomic<T>*, typename atomic<T>::value_type) noexcept;
    template<class T>
    T atomic_fetch_xor(atomic<T>*, typename atomic<T>::value_type) noexcept;
    template<class T>
    T atomic_fetch_xor_explicit(volatile atomic<T>*, typename atomic<T>::value_type,
                                memory_order) noexcept;
    template<class T>
    T atomic_fetch_xor_explicit(atomic<T>*, typename atomic<T>::value_type,
                                memory_order) noexcept;
 
    // 初始化
    #define ATOMIC_VAR_INIT(value) /*see description*/
 
    // 标志类型与操作
    struct atomic_flag;
 
    bool atomic_flag_test_and_set(volatile atomic_flag*) noexcept;
    bool atomic_flag_test_and_set(atomic_flag*) noexcept;
    bool atomic_flag_test_and_set_explicit(volatile atomic_flag*,
                                           memory_order) noexcept;
    bool atomic_flag_test_and_set_explicit(atomic_flag*, memory_order) noexcept;
    void atomic_flag_clear(volatile atomic_flag*) noexcept;
    void atomic_flag_clear(atomic_flag*) noexcept;
    void atomic_flag_clear_explicit(volatile atomic_flag*, memory_order) noexcept;
    void atomic_flag_clear_explicit(atomic_flag*, memory_order) noexcept;
 
    #define ATOMIC_FLAG_INIT /*see description*/
 
    // 栅栏
    extern "C" void atomic_thread_fence(memory_order) noexcept;
    extern "C" void atomic_signal_fence(memory_order) noexcept;

类 std::atomic

template <class T> struct atomic {
    using value_type = T;
 
    bool is_lock_free() const volatile noexcept;
    bool is_lock_free() const noexcept;
    void store(T, memory_order = memory_order_seq_cst) volatile noexcept;
    void store(T, memory_order = memory_order_seq_cst) noexcept;
    T load(memory_order = memory_order_seq_cst) const volatile noexcept;
    T load(memory_order = memory_order_seq_cst) const noexcept;
    operator T() const volatile noexcept;
    operator T() const noexcept;
    T exchange(T, memory_order = memory_order_seq_cst) volatile noexcept;
    T exchange(T, memory_order = memory_order_seq_cst) noexcept;
    bool compare_exchange_weak(T&, T,
                               memory_order, memory_order) volatile noexcept;
    bool compare_exchange_weak(T&, T,
                               memory_order, memory_order) noexcept;
    bool compare_exchange_strong(T&, T,
                                 memory_order, memory_order) volatile noexcept;
    bool compare_exchange_strong(T&, T,
                                 memory_order, memory_order) noexcept;
    bool compare_exchange_weak(T&, T,
                               memory_order = memory_order_seq_cst) volatile noexcept;
    bool compare_exchange_weak(T&, T,
                               memory_order = memory_order_seq_cst) noexcept;
    bool compare_exchange_strong(T&, T,
                                 memory_order = memory_order_seq_cst) volatile noexcept;
    bool compare_exchange_strong(T&, T,
                                 memory_order = memory_order_seq_cst) noexcept;
 
    atomic() noexcept = default;
    constexpr atomic(T) noexcept;
    atomic(const atomic&) = delete;
    atomic& operator=(const atomic&) = delete;
    atomic& operator=(const atomic&) volatile = delete;
    T operator=(T) volatile noexcept;
    T operator=(T) noexcept;
};

std::atomic 对整数类型的特化

template<> struct atomic</*integral*/> {
    using value_type = /*integral*/;
    using difference_type = value_type;
 
    bool is_lock_free() const volatile noexcept;
    bool is_lock_free() const noexcept;
    void store(/*integral*/,
               memory_order = memory_order_seq_cst) volatile noexcept;
    void store(/*integral*/,
               memory_order = memory_order_seq_cst) noexcept;
    /*integral*/ load(memory_order = memory_order_seq_cst) const volatile noexcept;
    /*integral*/ load(memory_order = memory_order_seq_cst) const noexcept;
    operator /*integral*/() const volatile noexcept;
    operator /*integral*/() const noexcept;
    /*integral*/ exchange(/*integral*/,
                          memory_order = memory_order_seq_cst) volatile noexcept;
    /*integral*/ exchange(/*integral*/,
                          memory_order = memory_order_seq_cst) noexcept;
    bool compare_exchange_weak(/*integral*/&, /*integral*/,
                               memory_order, memory_order) volatile noexcept;
    bool compare_exchange_weak(/*integral*/&, /*integral*/,
                               memory_order, memory_order) noexcept;
    bool compare_exchange_strong(/*integral*/&, /*integral*/,
                                 memory_order, memory_order) volatile noexcept;
    bool compare_exchange_strong(/*integral*/&, /*integral*/,
                                 memory_order, memory_order) noexcept;
    bool compare_exchange_weak(/*integral*/&, /*integral*/,
                               memory_order = memory_order_seq_cst) volatile noexcept;
    bool compare_exchange_weak(/*integral*/&, /*integral*/,
                               memory_order = memory_order_seq_cst) noexcept;
    bool compare_exchange_strong(/*integral*/&, /*integral*/,
                                 memory_order = memory_order_seq_cst) volatile noexcept;
    bool compare_exchange_strong(/*integral*/&, /*integral*/,
                                 memory_order = memory_order_seq_cst) noexcept;
    /*integral*/ fetch_add(/*integral*/,
                           memory_order = memory_order_seq_cst) volatile noexcept;
    /*integral*/ fetch_add(/*integral*/,
                           memory_order = memory_order_seq_cst) noexcept;
    /*integral*/ fetch_sub(/*integral*/,
                           memory_order = memory_order_seq_cst) volatile noexcept;
    /*integral*/ fetch_sub(/*integral*/,
                           memory_order = memory_order_seq_cst) noexcept;
    /*integral*/ fetch_and(/*integral*/,
                           memory_order = memory_order_seq_cst) volatile noexcept;
    /*integral*/ fetch_and(/*integral*/,
                           memory_order = memory_order_seq_cst) noexcept;
    /*integral*/ fetch_or(/*integral*/,
                          memory_order = memory_order_seq_cst) volatile noexcept;
    /*integral*/ fetch_or(/*integral*/,
                          memory_order = memory_order_seq_cst) noexcept;
    /*integral*/ fetch_xor(/*integral*/,
                           memory_order = memory_order_seq_cst) volatile noexcept;
    /*integral*/ fetch_xor(/*integral*/,
                           memory_order = memory_order_seq_cst) noexcept;
 
    atomic() noexcept = default;
    constexpr atomic(/*integral*/) noexcept;
    atomic(const atomic&) = delete;
    atomic& operator=(const atomic&) = delete;
    atomic& operator=(const atomic&) volatile = delete;
    /*integral*/ operator=(/*integral*/) volatile noexcept;
    /*integral*/ operator=(/*integral*/) noexcept;
    /*integral*/ operator++(int) volatile noexcept;
    /*integral*/ operator++(int) noexcept;
    /*integral*/ operator--(int) volatile noexcept;
    /*integral*/ operator--(int) noexcept;
    /*integral*/ operator++() volatile noexcept;
    /*integral*/ operator++() noexcept;
    /*integral*/ operator--() volatile noexcept;
    /*integral*/ operator--() noexcept;
    /*integral*/ operator+=(/*integral*/) volatile noexcept;
    /*integral*/ operator+=(/*integral*/) noexcept;
    /*integral*/ operator-=(/*integral*/) volatile noexcept;
    /*integral*/ operator-=(/*integral*/) noexcept;
    /*integral*/ operator&=(/*integral*/) volatile noexcept;
    /*integral*/ operator&=(/*integral*/) noexcept;
    /*integral*/ operator|=(/*integral*/) volatile noexcept;
    /*integral*/ operator|=(/*integral*/) noexcept;
    /*integral*/ operator^=(/*integral*/) volatile noexcept;
    /*integral*/ operator^=(/*integral*/) noexcept;
};

std::atomic 对指针类型的特化

template <class T> struct atomic<T*> {
    using value_type = T*;
    using difference_type = ptrdiff_t;
 
    bool is_lock_free() const volatile noexcept;
    bool is_lock_free() const noexcept;
    void store(T*, memory_order = memory_order_seq_cst) volatile noexcept;
    void store(T*, memory_order = memory_order_seq_cst) noexcept;
    T* load(memory_order = memory_order_seq_cst) const volatile noexcept;
    T* load(memory_order = memory_order_seq_cst) const noexcept;
    operator T*() const volatile noexcept;
    operator T*() const noexcept;
    T* exchange(T*, memory_order = memory_order_seq_cst) volatile noexcept;
    T* exchange(T*, memory_order = memory_order_seq_cst) noexcept;
    bool compare_exchange_weak(T*&, T*, memory_order, memory_order) volatile noexcept;
    bool compare_exchange_weak(T*&, T*, memory_order, memory_order) noexcept;
    bool compare_exchange_strong(T*&, T*, memory_order, memory_order) volatile noexcept;
    bool compare_exchange_strong(T*&, T*, memory_order, memory_order) noexcept;
    bool compare_exchange_weak(T*&, T*,
                               memory_order = memory_order_seq_cst) volatile noexcept;
    bool compare_exchange_weak(T*&, T*,
                               memory_order = memory_order_seq_cst) noexcept;
    bool compare_exchange_strong(T*&, T*,
                                 memory_order = memory_order_seq_cst) volatile noexcept;
    bool compare_exchange_strong(T*&, T*,
                                 memory_order = memory_order_seq_cst) noexcept;
    T* fetch_add(ptrdiff_t, memory_order = memory_order_seq_cst) volatile noexcept;
    T* fetch_add(ptrdiff_t, memory_order = memory_order_seq_cst) noexcept;
    T* fetch_sub(ptrdiff_t, memory_order = memory_order_seq_cst) volatile noexcept;
    T* fetch_sub(ptrdiff_t, memory_order = memory_order_seq_cst) noexcept;
 
    atomic() noexcept = default;
    constexpr atomic(T*) noexcept;
    atomic(const atomic&) = delete;
    atomic& operator=(const atomic&) = delete;
    atomic& operator=(const atomic&) volatile = delete;
    T* operator=(T*) volatile noexcept;
    T* operator=(T*) noexcept;
    T* operator++(int) volatile noexcept;
    T* operator++(int) noexcept;
    T* operator--(int) volatile noexcept;
    T* operator--(int) noexcept;
    T* operator++() volatile noexcept;
    T* operator++() noexcept;
    T* operator--() volatile noexcept;
    T* operator--() noexcept;
    T* operator+=(ptrdiff_t) volatile noexcept;
    T* operator+=(ptrdiff_t) noexcept;
    T* operator-=(ptrdiff_t) volatile noexcept;
    T* operator-=(ptrdiff_t) noexcept;
};

类 std::atomic_flag

typedef struct atomic_flag {
    bool test_and_set(memory_order = memory_order_seq_cst) volatile noexcept;
    bool test_and_set(memory_order = memory_order_seq_cst) noexcept;
    void clear(memory_order = memory_order_seq_cst) volatile noexcept;
    void clear(memory_order = memory_order_seq_cst) noexcept;
    atomic_flag() noexcept = default;
    atomic_flag(const atomic_flag&) = delete;
    atomic_flag& operator=(const atomic_flag&) = delete;
    atomic_flag& operator=(const atomic_flag&) volatile = delete;
} atomic_flag;