There is only one edge case that springs to mind - where there are pragma that effect how the regexp works. Certain pragma like use re '/u' will affect the stringification of the regexp reference, so you don't need to worry about them. But others, like re::engine::Lua effect the behaviour of the regexp without effecting the stringification.

If you can wrap the regexp in a coderef, then you can use B::Deparse to get a string of Perl code, and that will preserve pragmata...

sub regexp2code (&) {
    require B::Deparse;
    my $re = shift;
    '(do ' . B::Deparse->new->coderef2text($re) . ')';
}

LUA_STYLE: {
    use re::engine::Lua;
    CORE::say regexp2code { qr(%a) };
}

PERL_STYLE: {
    CORE::say regexp2code { qr(%a) };
}
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