use v6-alpha; use Test; plan 2; my $value_from_BUILD; class Foo { submethod BUILD (Str :$value) { $value_from_BUILD = $value; } } my $obj = Foo.new( value => 'bar' ); is( $value_from_BUILD, 'bar', 'BUILD arg declared as named and invoked with literal pair should' ~ ' contain only the pair value' ); is( $value_from_BUILD.WHAT, 'Str', 'same arg should be of declared type' );