NAME¶

std::atomic_ref::fetch_sub - std::atomic_ref::fetch_sub

Synopsis¶

member only of atomic_ref<Integral> and atomic_ref<Floating>
template specializations
T fetch_sub( T arg,
std::memory_order order = std::memory_order_seq_cst ) (1) (since C++20)
const noexcept;
member only of atomic_ref<T*> template specialization
T* fetch_sub( std::ptrdiff_t arg,
std::memory_order order = std::memory_order_seq_cst (2) (since C++20)
) const noexcept;

Atomically replaces the current value of the referenced object with the result of
arithmetic subtraction of the value and arg. This operation is a read-modify-write
operation. Memory is affected according to the value of order.

For signed integral types, arithmetic is defined to use two’s complement
representation. There are no undefined results.

For floating-point types, the floating-point environment in effect may be different
from the calling thread's floating-point environment. The operation need not be
conform to the corresponding std::numeric_limits traits but is encouraged to do so.
If the result is not a representable value for its type, the result is unspecified
but the operation otherwise has no undefined behavior.

For T* types, the result may be an undefined address, but the operation otherwise
has no undefined behavior. The program is ill-formed if T is not an object type.

Parameters¶

arg - the other argument of arithmetic subtraction
order - memory order constraints to enforce

Return value¶

The value of the referenced object, immediately preceding the effects of this
function.

Example¶

This section is incomplete
Reason: no example

Category:¶

* Todo no example