C Reference Unsigned integral type size_t

The unsigned integral type (size_t) corresponds to the integral data type returned by the language operator sizeof. It is used in (among others) in the time.h header file as an unsigned integral type.

In the header file time.h it is used by the function strftime as the type of its parameter maxsize. It is also used as the return type of this function. It is used to express counts of characters.