#!/usr/bin/perl -w
use strict;
use warnings;
use Test::More 'no_plan';
{
package Stuff;
use Test::More;
use Method::Signatures;
method echo($arg is ro) {
return $arg;
}
#line 19
method naughty($arg is ro) {
$arg++
}
is( Stuff->echo(42), 42 );
ok !eval { Stuff->naughty(23) };
like $@, qr/^Modification of a read-only value attempted at \Q$0\E line 20/;
}