> I would have assumed that you don't want to use uint_fast16_t to store anything that doesn't fit in 16 bits. I could have a 16 bit wide bitmask in it, lets f

> I would have assumed that you don't want to use uint_fast16_t to store anything that doesn't fit in 16 bits. I could have a 16 bit wide bitmask in it, lets flip them ~myMaskFast16, that leaves the higher order bits set to 0xFF... whether I care about them or not. > The point is, use a conversion, cast to a simple type, make your code compatible. Casting to a type that depending on platform may or may not hold enough space to represent the value is not "making it compatible" it makes it non portable.