$x[12]=$x[123]=$x=$_="";
print "match one\n" if /$x[123]/;
print "match two\n" if /$x[12]/;

##</code><code>##

/* This is the one truly awful dwimmer necessary to conflate C and sed. */
...
/* this is terrifying, and it works */
int weight = 2;		/* let's weigh the evidence */
[almost 100 lines of scary code snipped]
if (weight >= 0)	/* probably a character class */