Why C and C++ hate signed char so much?

Question

Why does C allow accessing object using "character type":

6.5 Expressions (C)

An object shall have its stored value acc

Answer 1

I think what you're really asking is why signed char is disqualified from all the rules allowing type-punning to char* as a special case. To be honest, I don't know, especially since — as far as I can tell — signed char cannot have padding either:

[C++11: 3.9.1/1]: [..] A char, a signed char, and an unsigned char occupy the same amount of storage and have the same alignment requirements (3.11); that is, they have the same object representation. For character types, all bits of the object representation participate in the value representation. [..]

Empirical evidence suggests that it's not much more than convention:

• char is seen as a byte of ASCII;
• unsigned char is seen as a byte with arbitrary "binary" content; and
• signed char is left flapping in the wind.

To me, it doesn't seem like enough of a reason to exclude it from these standard rules, but I honestly can't find any evidence to the contrary. I'm going to put it down to a mildly inexplicable oddity in the standard wording.

^{(It may be that we have to ask the std-discussion list about this.)}