Question

I was reading the C++ FAQ and it says

The C++ language guarantees a byte must always have at least 8 bits

So what does that mean for the <cstdint> types?

Side question – if I want an array of bytes should I use int8_t or char and why?

Answer 1

C++ (and C as well) defines intX_t (i.e. the exact width integer types) typedefs as optional. So, it just won’t be there if there is no addressable unit that’s exactly 8-bit wide.

If you want an array of bytes, you should use char, as sizeof char (and signed char and unsigned char) is well-defined to always be 1 byte.