[PATCH] Add simplistic reimplementation of strcasestr to compat library
Anthony Towns
aj at erisian.com.au
Mon Apr 12 22:59:24 PDT 2010
On Tue, Apr 13, 2010 at 14:10, Dirk Hohndel <hohndel at infradead.org> wrote:
> +/* the semantic here actually puzzles me:
> + how can haystack be const char * - yet the return value is char *
> + after all, it points to a sub-string of haystack... */
Dunno if this is a question from the original source, but the answer
if anyone's interested is probably because C doesn't have templates --
you'd ideally like to have it treated as:
char *strcasestr(char *haystack, const char *needle);
for when you're doing a search and replace on the needle (say), and:
const char *strcasestr(const char *haystack, const char *needle);
for when you're doing a search for the needle in something you can't
modify. But C isn't clever enough to let you say that with just one
function (and no fancy #defines), so you have to drop some of the
typechecking with the (char*) cast on the return value if you want to
handle both use cases, without the compiler complaining about
const->non-const conversions in otherwise correct code in one case or
the other.
Cheers,
aj
--
Anthony Towns <aj at erisian.com.au>
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