It's because unlike += the ++ perl operator (prefix or postfix) returns an rvalue, not an lvalue. You can't do ++$a = 8 or $a++ = 8 either.

Update: swapped rvalue and lvalue, as noted by calin.

In reply to Re: Pre-increment *and* Post-increment by ambrus
in thread Pre-increment *and* Post-increment by cog

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