From: Mike Guy <mjtg@cam.ac.uk>
Date: Wed, 25 Apr 2001 18:31:47 +0000 (+0100)
Subject: Re: Useless use of constants other than 0,1 in void context?
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=960b42539bbb489e5a078c4ee6ab12205929606c;p=p5sagit%2Fp5-mst-13.2.git

Re: Useless use of constants other than 0,1 in void context?
Message-Id: <E14sT8l-0004IE-00@libra.cus.cam.ac.uk>

p4raw-id: //depot/perl@9838
---

diff --git a/op.c b/op.c
index 207e762..7d28e36 100644
--- a/op.c
+++ b/op.c
@@ -1137,6 +1137,9 @@ Perl_scalarvoid(pTHX_ OP *o)
 	else {
 	    if (ckWARN(WARN_VOID)) {
 		useless = "a constant";
+		/* the constants 0 and 1 are permitted as they are
+		   conventionally used as dummies in constructs like
+		        1 while some_condition_with_side_effects;  */
 		if (SvNIOK(sv) && (SvNV(sv) == 0.0 || SvNV(sv) == 1.0))
 		    useless = 0;
 		else if (SvPOK(sv)) {