Thanks for the excellent explanation.

I now see the problem with multiple inheritance. If my FragileDancer class has use base qw( Fragile Dancer ); then a call to break() produces damage; but if the class has use base qw( Dancer Fragile ); then break() produces dancing. And no warning that a method name conflict has been encountered.

So, I can see how roles could be useful here. But my experiments with Role::Tiny have so far been less than encouraging. :-( My first thought was:

package FragileDancer
{
    use Role::Tiny::With;
    with "Fragile";
    with "Dancer";
    ...
[download]

but that turns out to be a documented way to resolve the conflict — it silently gives Fragile behaviour to break() because the Fragile role is listed first. So, it’s no different to the scenario with multiple inheritance. To get an exception, it seems I have to write:

package FragileDancer
{
    use Role::Tiny::With;
    with 'Fragile', 'Dancer';
    ...
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which produces:

Due to a method name conflict between roles 'Dancer and Fragile', the 
+method 'break' must be implemented by 'FragileDancer' at C:\Perl\lib\
+perl5/Role/Tiny.pm line 183.
[download]

So far, so good. But when I implement that FragileDancer::break method as required, it makes no difference: the exception is generated exactly as before.

#! perl
use strict;
use warnings;

package Fragile
{
    use Role::Tiny;
    sub break { print shift->{name}, " is being damaged!\n"; }
}

package Dancer
{
    use Role::Tiny;
    sub break { print shift->{name}, " is break dancing!\n"; }
}

package FragileDancer
{
    use Role::Tiny::With;
    with 'Fragile', 'Dancer';

    sub break { print 'For ', shift->{name}, " FragileDancer::break\n"
+; }

    sub new
    {
        my ($class, $name) = @_;
        my  $self = { name => $name };
        return bless $self, $class;
    }
}

my $fg = FragileDancer->new('Nina');
   $fg->break();
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23:44 >perl 655_SoPW.pl
Due to a method name conflict between roles 'Dancer and Fragile', the 
+method 'break' must be implemented by 'FragileDancer' at C:\Perl\lib\
+perl5/Role/Tiny.pm line 183.

23:44 >
[download]

What am I missing here?