And by the way: You are not doing numeric addition on a string, you are evaluating "0 but true" in numeric context (to 0) - therefore no warning.

That makes no sense. The correct answer is that "0 but true" is special-cased. 

$ perl -wle'print 0+"0 abc"'
Argument "0 abc" isn't numeric in addition (+) at -e line 1.
0

$ perl -wle'print 0+"0 but true"'
0

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In reply to Re^3: What is true and false in Perl? by ikegami
in thread What is true and false in Perl? by root

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