C++ Atomic Library - fetch sub

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Description

It atomically subtracts the argument from the value stored in the atomic object and obtains the value held previously.

Declaration

Following is the declaration for std::atomic::fetch_sub.

T fetch_sub( T arg, 
             std::memory_order order = std::memory_order_seq_cst ) volatile;

C++11

T fetch_sub( T arg, 
             std::memory_order order = std::memory_order_seq_cst );

Following is the declaration for std::atomic::fetch_sub(member only of atomic template specialization).

T* fetch_sub( std::ptrdiff_t arg, 
              std::memory_order order = std::memory_order_seq_cst ) volatile;

C++11

T* fetch_sub( std::ptrdiff_t arg, 
              std::memory_order order = std::memory_order_seq_cst );

Parameters

• arg − It is used put the other argument of arithmetic subtraction.

• order − It is used enforce the memory order for the value.

Return Value

It returns the value immediately preceding the effects of this function in the modification order of *this.

Exceptions

No-noexcept − this member function never throws exceptions.