Gunther Nikl <gnikl@xxxxxxxxxxxxxxxxxxxxx> writes: > Ian Lance Taylor schrieb: >> Gunther Nikl <gnikl@xxxxxxxxxxxxxxxxxxxxx> writes: >> >>> Is there a special requirement about the value of the limits >>> macros for fastest minimum-width integers? Eg. would it be legal >>> to use the limits of a a "signed char" if int_fast8_t is defined >>> in terms of an int? Or is it required to use the proper limit of >>> int? >> >> I don't understand what you mean. Can you show us some example code >> that you are uncertain about? > > Here is an example for int_fast8_t: > > typedef signed char int_fast8_t; > #define INT_FAST8_MIN INT8_MIN > #define INT_FAST8_MAX INT8_MAX > > Now if int_fast8_t uses "int" as underlying type like this: > > typedef int int_fast8_t; > > which value is its MIN/MAX macros supposed to have? Is it > allowed to use the same "char" limits as above or do I need > to use > > #define INT_FAST8_MIN INT32_MIN > #define INT_FAST8_MAX INT32_MAX > > in that case? > > So this is not about user code but an implementation question. The value of INT_FAST8_MIN is implementation defined, so you can choose whatever value you like (as long as it is <= -128). That said, the standard seems to suggest that the value should correspond to the value of the underlying type. That is, if int_fast8_t is defined as int, then the value of INT_FAST8_MIN should be INT_MIN. That at least makes INT_FAST8_MIN useful, as otherwise it would always simply have the value -128. Ian
