That's a nice & small answer. It does seem overkill for the gtk example...
use v6;
use GTK::Simple;
with GTK::Simple::App.new(title => 'abc') {
my $app = $_;
my $button;
.set-content:
GTK::Simple::VBox.new(
GTK::Simple::Button.new(label => 'bcd').clicked.tap({
.sensitive = False; $button.sensitive = True; });
$button = GTK::Simple::Button.new(label => 'cde');
$button.clicked.tap({ $app.exit; });
);
.border-width = 20;
.run;
};
