#!/usr/bin/perl

use 5.010;
use strict;
use warnings;

use re 'eval';

sub make_esc_delim {
    my ($delim) = @_;
    return qr{\Q$delim\E[^$delim\\]*+(?>\\.|[^$delim\\]+)*\Q$delim\E}s;
}

my $str_dq = make_esc_delim(q{"});

my %bpairs;
{
    local $" = q{};
    foreach my $d ([qw~< >~], [qw~( )~], [qw~{ }~], [qw~[ ]~]) {
        my @ed = map {quotemeta} @{$d};

         $bpairs{$d->[0]} =
         qr{
            $ed[0]
            (?<content>
                (?>
                    (??{$bpairs{$d->[0]}}) (?{print "After eval!\n"})
                            |
                       (?> $str_dq | [^@ed] )
                )*
            )
            $ed[1]
        }xs;
    }
}

my $x = q~func{{xx|"}"} @{d}end}~;

if($x =~ /$bpairs{'{'}/){
    print "First matched: $&\n";
}

if($x =~ /func$bpairs{'{'}/){       # here is the problem
    print "Second matched: $&\n";
}