Hello wise monks,

I'm unsure why these two lines produce different output. In particular, I don't know why the ${^MATCH} in the first line fails to be set to the matched part of the regular expression. 
perl -e '$x = "abcde";             $x =~ s/b../==${^MATCH}==/p;  print
+ "$x\n"'
perl -e '$x = "abcde"; $sub="b.."; $x =~ s/$sub/==${^MATCH}==/p; print
+ "$x\n"'

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Perl v5.12.4 produces: 
a====e
a==bcd==e

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The perlre documentation gives no restrictions on contexts in which {^MATCH} can be used, saying only that it's an optimized synonym for $&. And in fact, if I change the first line to use $& instead of {^MATCH}, it behaves as expected. Thank you for any hints!

In reply to ${^MATCH} sometimes fails in target of substitution? by raygun

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