A turning point for GNU libc [LWN.net]

A turning point for GNU libc

Posted Apr 5, 2012 15:32 UTC (Thu) by welinder (guest, #4699)
In reply to: A turning point for GNU libc by jengelh
Parent article: A turning point for GNU libc

> char is standardized by C, you know

Really?

What, exactly, is standardized about char in C?

* it's a numeric type.
* it is distinct from signed char and unsigned char, but has the same
range of values as one of the two
* it's a magic type for aliasing
* it's the element type of "foo"
* sizeof(char)==1

char c = 0; /* valid */
char c = -1; /* valid, but might not read as -1 */
char c = 128; /* implementation dependent: either valid or undefined */

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A turning point for GNU libc

Posted Apr 5, 2012 16:33 UTC (Thu) by nybble41 (subscriber, #55106) [Link]

True, but gchar is defined as a typedef for char, so it adds no additional guarantees. Why not just use char? At least "guchar" is shorter than "unsigned char"; I see no benefit at all in using gchar.

If you want guaranteed ranges, uint8_t and int8_t are standardized in C99 as integer types with exactly eight bits and (in the signed case) two's-complement representation. Both definitions are required unless the implementation has no compatible integer type.