1#!/usr/bin/perl -w
2
3use strict;
4use warnings;
5
6use Test::More 'no_plan';
7
8{
9    package Stuff;
10
11    use Test::More;
12    use Method::Signatures;
13
14    method echo($arg is ro) {
15        return $arg;
16    }
17
18#line 19
19    method naughty($arg is ro) {
20        $arg++
21    }
22
23    is( Stuff->echo(42), 42 );
24    ok !eval { Stuff->naughty(23) };
25    like $@, qr/^Modification of a read-only value attempted at \Q$0\E line 20/;
26}
27