std::atomic_ref::exchange - cppreference.com (original) (raw)
Atomically replaces the value of the referenced object with desired. The operation is a read-modify-write operation. Memory is affected according to the value of order.
This overload participates in overload resolution only if std::is_const_v<T> is false.
[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 for const T | constrained to accept only non-const T |