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.

In reply to Re^2: Concatenation with empty string -- good enough to force physical copy? by vr
in thread Concatenation with empty string -- good enough to force physical copy? by vr

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