Defined in header
#define EXIT_SUCCESS /*implementation defined*/
#define EXIT_FAILURE /*implementation defined*/
EXIT_FAILURE macros expand into integral expressions that can be used as arguments to the std::exit function (and, therefore, as the values to return from the main function), and indicate program execution status.
||successful execution of a program|
||unsuccessful execution of a program|
EXIT_SUCCESS and the value zero indicate successful program execution status (see std::exit), although it is not required that
EXIT_SUCCESS equals zero.
 See also
C documentation for EXIT_SUCCESS, EXIT_FAILURE