[layer8]

The idiomatic

    void strcpy(char *s, char *t)
    {
        while (*s++ = *t++)
            ;
    }

(straight from K&R) wouldn’t work without it.

[n_plus_1_acc]

Which many people find unreadable compared to other versions.

[beeforpork]

And for several reasons.

  * is it (*s)++ or *(s++)?
  * it is not *++s nor ++*s

And I have seen

  *(*s)++

in some places!

It is concise syntax but very confusing.

[chongli]

K&R actually teaches this as a desirable idiom? People should not be recommending K&R to beginners today!

[trealira]

Kernighan spends a page whittling strcpy down to just that, with various intermediate versions. After showing you that version, he describes it like this:

Although this may seem cryptic at first sight, the notational convenience is considerable, and the idiom should be mastered, because you will see it frequently in C programs.