Where is stdbool.h?

Question

I want to find the _Bool definition on my system, so for systems where it\'s missing I can implement it. I\'ve seen various definitions for it here and on other

Answer 1

_Bool is a predefined type in C99, much like int or double. You will not find the definition for int in any header file either.

What you can do is

• check the compiler is C99
• if it is use _Bool
• otherwise use some other type (int or unsigned char)

For example:

#if defined __STDC__ && defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L
/* have a C99 compiler */
typedef _Bool boolean;
#else
/* do not have a C99 compiler */
typedef unsigned char boolean;
#endif