Re: Concatenation with empty string -- good enough to force physical copy?

[dave_the_m]

Basically you're trying to defeat perl's copy-on-write optimisation. Concatting an empty string will currently do this, but there are no future guarantees. If you want your code to be robust you really need to handle this at the C level.

Dave.

[vr]

Exactly, word "CoW" was on my mind but somehow omitted when re-phrasing the question. Thank you for sharing your insight. As there's no "idiom" apparently (but wouldn't it be nice... concatenation with compile time constant treated as such), the trick with side-effect should better be avoided.