There's nothing built-in, but you can create a subclass of MooseX::ClassCompositor that does the job in about a dozen lines of code...

{
    package MooseX::ClassCompositor::OnAcid;
    use Moose;
    extends qw( MooseX::ClassCompositor );    
    around class_for => sub {
        my $orig = shift;
        my $self = shift;
        my @roles = map {
            ref($_) eq q(HASH) ? 'Moose::Meta::Role'->create_anon_role
+(methods => $_) : $_
        } @_;
        $self->$orig(@roles);
    };
}

{
    package Foo;
    use Moose::Role;
    requires '_build_bar';
}

my %methods = (
    _build_bar => sub {"foo"},
);

my $class = MooseX::ClassCompositor::OnAcid->new( 
    { class_basename => 'Test' }
)->class_for('Foo', \%methods);

print $class->new->dump;
[download]