standard boolean types
<stdbool.h> header defines
- bool, which expands to
- true, which expands to the integer constant 1;
- false, which expands to the integer constant 0;
- __bool_true_false_are_defined, which expands to the
The ability to undefine and redefine the macros
bool, true, and
false is an obsolescent feature that may be withdrawn
in a future version of a standard.
<stdbool.h> header conforms
to ISO/IEC 9899:1999 (“ISO C99”)
and IEEE Std 1003.1-2001 (“POSIX.1”).
<stdbool.h> header was first
introduced in NetBSD 1.6.