EXIT_SUCCESS, EXIT_FAILURE
From Cppreference
| C++ Standard Library | 
|---|
| Utilities library | 
| Program support utilities | 
| Defined in header <cstdlib>
  | ||
| #define EXIT_SUCCESS /*implementation defined*/ | ||
| #define EXIT_FAILURE /*implementation defined*/ | ||
The EXIT_SUCCESS and EXIT_FAILURE macros expand into an integral expression and indicate program execution status.
| Constant | Explanation | 
| EXIT_SUCCESS | successful execution of a program | 
| EXIT_FAILURE | unsuccessful execution of a program |