std::atomic_ref<T>::exchange

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std::atomic_ref

Member functions
atomic_ref::atomic_ref
atomic_ref::operator=
atomic_ref::is_lock_free
atomic_ref::store
atomic_ref::load
atomic_ref::operator value_type
atomic_ref::exchange
atomic_ref::compare_exchange_strongatomic_ref::compare_exchange_weak
atomic_ref::wait
atomic_ref::notify_one
atomic_ref::notify_all
atomic_ref::address (C++26)
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atomic_ref::fetch_add
atomic_ref::fetch_sub
atomic_ref::operator+=atomic_ref::operator-=
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atomic_ref::fetch_max (C++26)
atomic_ref::fetch_min (C++26)
atomic_ref::operator++atomic_ref::operator++(int)atomic_ref::operator--atomic_ref::operator--(int)
Operations for integral types (except`bool`)
atomic_ref::fetch_and
atomic_ref::fetch_or
atomic_ref::fetch_xor
atomic_ref::operator&=atomic_ref::operator\|=atomic_ref::operator^=
Constants
atomic_ref::is_always_lock_free
atomic_ref::required_alignment

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value_type exchange( value_type desired, std::memory_order order= std::memory_order_seq_cst)constnoexcept;		(constexpr since C++26)

Atomically replaces the value of the referenced object withdesired. The operation is a read-modify-write operation. Memory is affected according to the value oforder.

This overload participates in overload resolution only ifstd::is_const_v<T> isfalse.

[edit]Parameters

desired	-	value to assign
order	-	memory order constraints to enforce

[edit]Return value

The value of the referenced object before the call.

[edit]Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 3508 (P3323R1)	C++20	`exchange` was meaningless forconst T	constrained to accept only non-const`T`

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std::atomic_ref<T>::exchange

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