[boost] Re: Type Traits, Take Two

From: Gabriel Dos Reis (Gabriel.Dos-Reis_at_[hidden])
Date: 2000-01-07 23:36:00

scleary_at_[hidden] writes:

[...]

| P.S. I just looked at the active issue list, and I don't see anything
| relating to the signedness of char.

hum, maybe because it is not (yet) publically available.  But Beman is
more knowledgeable about this than I.

| P.P.S. Question: under C, char may be signed, unsigned, or psuedo-unsigned
| (C:ARM 5.1.3).  If I read 3.9.1p1 right, then in C++ char may be only signed
| or unsigned.  Why was this change made?

'signed char', 'char' and 'unsigned char' are distincts types in C++.
However, I believe (i.e. I have to check) that an implementation don't
have much choice regarding 'char' *internal* representation: a plain
'char' will internally be represented as a 'signed char' or an
'unsigned char'. It is precisely those implementation-defined aspects
that numeric_limits has to document.

-- Gaby