Well, if you want constant folding, then you'll have to deal with the warning being generated. It's a mandatory warning.

Of course, just because the warning will be generated; doesn't mean it has to be displayed. $SIG{__WARN__} can catch and hide it.

Of course, just because the warning will be generated; doesn't mean it has to be displayed. $SIG{__WARN__} can catch and hide it.

Really? What am I doing wrong then?

C:\test>perl -wE"$SIG{__WARN__}=sub{}; sub f(){1}; say f; sub f(){2}; 
+say f;"
Constant subroutine f redefined at -e line 1.
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With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

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The definition of the constants happens at compile time. The assignment to $SIG{__WARN__} happens at run time. You want it in a BEGIN block.

perl -wE'BEGIN{$SIG{__WARN__}=sub{}}; sub f(){1}; say f; sub f(){2}; s
+ay f;'
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perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'

$ perl -wE"BEGIN{$SIG{__WARN__}=sub{};} sub f(){1}; say f; sub f(){2};
+ say f;"
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