size guarantee for integral/arithmetic types in C and C++

Question

I know that the C++ standard explicitly guarantees the size of only char, signed char and unsigned char. Also it gives guarantees that

Answer 1

Be aware that the guaranteed ranges of these types are one less wide than on most machines:

signed char -127 ... +127 guranteed but most twos complement machines have -128 ... + 127

Likewise for the larger types.