Shorn of its obfuscation, that code is equivalent to 
'' =~ '(?{eval"print\"hello world\\n\""})';

[download]
Note that the pattern is within a string literal ('') rather than a pattern literal (//). The 5.17.x changes make it so that code blocks which don't need a 'use re eval' can appear only within pattern literals.

Dave.

In reply to Re: Perl 5.17 change to use re 'eval' breaks Acme::EyeDrops by dave_the_m
in thread Perl 5.17 change to use re 'eval' breaks Acme::EyeDrops by eyepopslikeamosquito

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