История изменений

$ cat main.c
int main() {
    while(true){}
}

$ gcc main.c -std=c99
main.c: In function 'main':
main.c:2:11: error: 'true' undeclared (first use in this function)
    2 |     while(true){}
      |           ^~~~
main.c:1:1: note: 'true' is defined in header '<stdbool.h>'; did you forget to '#include <stdbool.h>'?
  +++ |+#include <stdbool.h>
    1 | int main() {
main.c:2:11: note: each undeclared identifier is reported only once for each function it appears in
    2 |     while(true){}
      |           ^~~~