[atomics.types.generic.general] (original) (raw)

32 Concurrency support library [thread]

32.5 Atomic operations [atomics]

32.5.8 Class template atomic [atomics.types.generic]

32.5.8.1 General [atomics.types.generic.general]

namespace std { template<class T> struct atomic { using value_type = T;static constexpr bool is_always_lock_free = implementation-defined;bool is_lock_free() const volatile noexcept;bool is_lock_free() const noexcept;constexpr atomic() noexcept(is_nothrow_default_constructible_v<T>);constexpr atomic(T) noexcept; atomic(const atomic&) = delete; atomic& operator=(const atomic&) = delete; atomic& operator=(const atomic&) volatile = delete; T load(memory_order = memory_order::seq_cst) const volatile noexcept;constexpr T load(memory_order = memory_order::seq_cst) const noexcept;operator T() const volatile noexcept;constexpr operator T() const noexcept;void store(T, memory_order = memory_order::seq_cst) volatile noexcept;constexpr void store(T, memory_order = memory_order::seq_cst) noexcept; T operator=(T) volatile noexcept;constexpr T operator=(T) noexcept; T exchange(T, memory_order = memory_order::seq_cst) volatile noexcept;constexpr T exchange(T, memory_order = memory_order::seq_cst) noexcept;bool compare_exchange_weak(T&, T, memory_order, memory_order) volatile noexcept;constexpr bool compare_exchange_weak(T&, T, memory_order, memory_order) noexcept;bool compare_exchange_strong(T&, T, memory_order, memory_order) volatile noexcept;constexpr 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;constexpr 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;constexpr bool compare_exchange_strong(T&, T, memory_order = memory_order::seq_cst) noexcept;void wait(T, memory_order = memory_order::seq_cst) const volatile noexcept;constexpr void wait(T, memory_order = memory_order::seq_cst) const noexcept;void notify_one() volatile noexcept;constexpr void notify_one() noexcept;void notify_all() volatile noexcept;constexpr void notify_all() noexcept;};}

The program is ill-formed if any of

• is_trivially_copyable_v<T>,
• is_copy_constructible_v<T>,
• is_move_constructible_v<T>,
• is_copy_assignable_v<T>,
• is_move_assignable_v<T>, or
• same_as<T, remove_cv_t<T>>,

is false.

[Note 1:

Type arguments that are not also statically initializable can be difficult to use.

— _end note_]

The specialization atomic<bool> is a standard-layout struct.

It has a trivial destructor.

[Note 2:

The representation of an atomic specialization need not have the same size and alignment requirement as its corresponding argument type.

— _end note_]