In truth they've been careful about introducing names and not breaking existing code. For example, when they finally did a bool type, they called it _Bool to pr

In truth they've been careful about introducing names and not breaking existing code. For example, when they finally did a bool type, they called it _Bool to prevent incompatibilities with nonstandard bool types. You needed to include <stdbool.h> to get a friendly, usable name of "bool". There was a similar thing for _Complex.