How does memchr() work under the hood?

Question

Background: I\'m trying to create a pure D language implementation of functionality that\'s roughly equivalent to C\'s memchr but uses arrays and indices i

Answer 1

Here is FreeBSD's (BSD-licensed) memchr() from memchr.c. FreeBSD's online source code browser is a good reference for time-tested, BSD-licensed code examples.

void *
memchr(s, c, n)
    const void *s;
    unsigned char c;
    size_t n;
{
    if (n != 0) {
        const unsigned char *p = s;

        do {
            if (*p++ == c)
                return ((void *)(p - 1));
        } while (--n != 0);
    }
    return (NULL);
}