use v5.36;
no builtins;
plan tests => 8;
ok !defined eval 'is_bool(true)' => 'is_bool(true)';
ok $@ =~ /^\QBareword "true" not allowed/ => '...with correct error message';
ok !defined eval 'is_bool(false)' => 'is_bool(false)';
ok $@ =~ /^\QBareword "false" not allowed/ => '...with correct error message';
ok !defined eval 'true()' => 'true()';
ok $@ =~ /^\QUndefined subroutine &main::true/ => '...with correct error message';
ok !defined eval '!false()' => '!false()';
ok $@ =~ /^\QUndefined subroutine &main::false/ => '...with correct error message';
done_testing();