stdbool.h

The stdbool.h header provides macros for the _Bool data type.

Macros

bool: Expands to _Bool
Macro for the built-in boolean data type.
true: Expands to 1
Macro for an integer representing boolean true.
false: Expands to 0
Macro for an integer representing boolean false.
__bool_true_false_are_defined: Expands to 1
Macro for an integer representing a boolean value which indicates whether the macros true and false are declares by the standard library implementation. Testing for the declaration of these macros is unnecessary when using the GNU Compiler Collection (GNU C Library) on x86 and x86-64 as they will always have been declared.