Here is what I am doing at the moment: 
    $replacement =~ s/\\/\\\\/g;
    eval "\$res =~ s/$pattern/$replacement/$flags";

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It's working, and crucially supports back-references — unlike the $res =~ s/(?$flags:$pattern)/$replacement/ solution.

Of course, the use of eval gives me the heebie-jeebies; but I'm not going to lose too much sleep as we already need to trust the people who write the configuration files that will contain the values used in the eval.

In reply to Re: Regexp substitution using variables by MikeTaylor
in thread Regexp substitution using variables by MikeTaylor

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