Re: Cast abuse

[Brian Stafford <brian stafford uklinux net>]

On Tue, 20 November 10:38 Pawel Salek wrote:
> 
> On 2001.11.20 11:17 Brian Stafford wrote:
>>> where inbuf is often passed from a const char * variable.  There are a 
>>> couple of files in libmutt that do this, and gcc gripes each time it sees 
>>> them.  I imagine that's why the casts that Brian complained about in the 
>>> ldap code were there.
>> 
>> I just checked glibc 2's iconv.h and the one distributed with GNU 
>> libiconv.  Both declare inbuf to be const.  SUSv2 declares it const too.  
>> So I'd say the linux man page is incorrect.
> 
> glibc-devel-2.2.4-19:/usr/include/iconv.h contains:
> 
> extern size_t iconv (iconv_t __cd, char **__restrict __inbuf,
>                      size_t *__restrict __inbytesleft,
>                      char **__restrict __outbuf,
>                      size_t *__restrict __outbytesleft);
> 
> I do not know what '__restrict' means (anybody knows?) but it does not 
> appear to be equivalent to 'const'.

Hmmm... something of a moving target it seems.  AFAIK, GNU libc is like 
libiconv (same code actually), LIBICONV_CONST is substituted with const or is 
empty according to what configure detects.  The distributed file is iconv.h.in 
and declares

extern size_t iconv (iconv_t cd, @LIBICONV_CONST@ char* * inbuf,
                      size_t *inbytesleft, char* * outbuf, size_t 
*outbytesleft);

 From SUSv2's description of iconv()

...
SYNOPSIS

#include <iconv.h>

size_t iconv(iconv_t cd, const char **inbuf, size_t *inbytesleft,
     char **outbuf, size_t *outbytesleft);
...

Brian