my $buildargs = $class->_generate_BUILDARGS($metaclass);
my $processattrs = $class->_generate_processattrs($metaclass, \@attrs);
- my @compiled_constraints = map { $_->_compiled_type_constraint }
- map { $_->{type_constraint} ? $_->{type_constraint} : () } @attrs;
+ my @compiled_constraints = map { $_ ? $_->_compiled_type_constraint : undef }
+ map { $_->type_constraint } @attrs;
my $code = sprintf("#line %d %s\n", __LINE__, __FILE__).<<"...";
sub {