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From: Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups: comp.lang.c
Subject: Re: relearning C: why does an in-place change to a char* segfault?
Date: Tue, 13 Aug 2024 20:49:45 -0700
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Kaz Kylheku <643-408-1753@kylheku.com> writes:
[...]
> Also, <string.h> could have type generic functions where it
> makes sense to support both const char * and char *.
>
> E.g. strchr should could return const char * if the
> parameter is const char *, and char * when the parameter is char *.
> The one function we have now strips the qualifier, which is bad;
> when you find a character in a const string, you get a non-const
> pointer to it.

C23 does exactly this.  It changes memchr, strchr, strpbrk, strrchr, and
strstr into generic functions (macros, presumably using _Generic) whose
return type is pointer-to-const if and only if the appropriate argument
is pointer-to-const.  If you suppress the macro definition, you get a
function that takes a const-qualified argument and returns a non-const
result.

(C++ does something similar for its functions in <cstring>, imported
from C, but by making them templates.)

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */