It seems like you're making your life harder than you have to. You would be much better off picking one standard data representation and supplying multiple initialization functions, e.g.: 

package Identity;

sub init_first_last
{
    my ($c, $first, $last) = @_;
    die unless $first =~ /^\S+$/ && $last =~ /^\S+$/;
    bless { first => $first, last => $last }, $c;
}

sub init_fullname
{
    my $c = shift;
    my ($first, $last) = split ' ', shift;
    init_first_last $c, $first, $last;
}

sub fullname
{
    join ' ', @{$_[0]}{qw(first last)};
}

sub first
{
    shift->{first};
}

sub last
{
    shift->{last};
}

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In reply to Re: Idea: Moose Mutal Coercion by educated_foo
in thread Idea: Moose Mutual Coercion by k0st

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