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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: Difference between these pointer syntaxes
Date: Thu, 18 Aug 2016 10:34:48 -0700
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David Brown <david.brown@hesbynett.no> writes:
[...]
> That is a challenge for const correctness.  C takes the attitude that it
> can't be done nicely in C (you'd need two versions of the strchr
> function, and it would be up to the user to pick the right one) - so it
> gives you a single version that takes a "const char *" and returns a
> "char *".  This function can't be written by the user in a fully
> portable manner, because it contains undefined behaviour - but it's fine
> for the standard library because that can use whatever
> implementation-defined behaviour is needed to make it safe.  It is then
> up to the user to keep it safe - there is no compile-time checking.
[...]

In my opinion, the ANSI C committee made a mistake here.  It *could*
have been done nicely in C -- by having introducing two different
versions of the strchr function (perhaps strchr and strcchr).  Several
other standard library functions have the same problem.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"