On Jan 10, 2004, at 17:50, Philippe Verdy wrote:
From: "Clark Cox" <[EMAIL PROTECTED]>Actually, both the C and C++ standards require that the char type be at least 8-bits. that is, the signed char type must be able to represent the values in the range [-127, 127], and the unsigned char type must be able to represent the values in the range [0, 255]. Any C or C++ compiler that cannot meet those requirements is non-conformant.
Yes of course (however this depends on which standard you discuss here...
No, it doesn't, my assertion holds true in *every* version of the C and C++ standards.
The language itself does not require it, just the implementation guidelines
for applications on generic OS.
If you look at some C compilers created for microcontrolers or hardware
devices, you'll see that it supports the full core language, but not always
with the "standard" library which usually comes bundled with compilers for
generic OS platforms, because this library is too fat to be incorporated in
the device's firmware).
You'll see for example that most BIOS software is written today with a
significant part written in C, because it's easier to maintain than assembly
language when optimal performance is not a real issue. But the same BIOS
will typically never use the standard library. And so a C compiler tuned for
writing a BIOS software may ignore the library requirements defined in a C
standard made for applications supported by general purpose OS.
I'm not talking about library requirements, I'm talking about core language requirements. Any conforming C or C++ compiler must accept the following code, if it doesn't, then it is not a conforming C or C++ compiler:
int main(int argc, char *argv[])
{
unsigned char uc = 0;
unsigned char uc2 = 255;
signed char c = -127;
signed char c = 127;
return 0;
}
In such cases, as soon as you start ignoring the POSIX standard (which is
not by itself part of the core C language), you can't assert that "char"
needs to be at least 8 bits.
That's my point, yes you can. Both the C and C++ standards explicitly state the minimal ranges that various types must be able to represent. In order to support a smaller addressable unit, the language definitions would have to be changed.
-- Clark S. Cox III [EMAIL PROTECTED] http://homepage.mac.com/clarkcox3/ http://homepage.mac.com/clarkcox3/blog/B1196589870/index.html
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