Why does GTK+ define TRUE and FALSE?

Question

Why do GTK+ and several other frameworks provide TRUE and FALSE macros? Is there any advantage to using TRUE and FALSE instead of the built-in C values true and false ? You can see their implementation here: http://www.gtk.org/api/2.6/glib/glib-Standard-Macros.html#TRUE:CAPS

Answer 1

C99 has true and false , earlier versions do not. That is why you often see TRUE and FALSE #define d. As you can read here , true and false are 1 and 0 respectively, same as TRUE and FALSE .