Subtracts one value of type SIZE_T from another.
NTSTATUS RtlSizeTSub( _In_ SIZE_T Minuend, _In_ SIZE_T Subtrahend, _Out_ SIZE_T *pResult );
The value from which Subtrahend is subtracted.
The value to subtract from Minuend.
A pointer to the result. If the operation results in a value that overflows or underflows the capacity of the type, the function returns STATUS_INTEGER_OVERFLOW and this parameter is not valid.
This is one of a set of inline functions designed to provide arithmetic operations and perform validity checks with minimal impact on performance.