use strict;
use warnings;
use Test::More tests => 2;

my $pattern     = '\Aabc\/';
my $replacement = '123\/';
my $flags       = 'i';

my $value    = 'ABC/def';
my $expected = '123/def';


my $command = "\$value =~ s/$pattern/$replacement/$flags";
diag $command;
eval $command;
ok( $value eq $expected, 'use eval directly' );

$value    = 'ABC/def';
my $re = new Regexp($pattern);
$value = $re->substitute( $value, $replacement, $flags );
ok( $value eq $expected, 'use eval in class' );




package Regexp;

sub new {
    my ( $class, $pattern ) = @_;
    my $new_object = bless \$pattern, $class;
    return $new_object;
}

sub substitute {
    my ( $self, $value, $replacement, $flags ) = @_;
    my $pattern = $$self;
    my $command = "\$value =~ s/$pattern/$replacement/$flags";
    main::diag $command;
    eval $command;
    return $value;
}
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OUTPUT:

1..2
# $value =~ s/\Aabc\//123\//i
ok 1 - use eval directly
# $value =~ s/\Aabc\//123\//i
ok 2 - use eval in class
[download]