module theaterlights; import std.stdio : writeln; import std.conv : to; class TheaterLights { private string description; this(string description) { this.description = description; } void on() { writeln(description ~ " on"); } void off() { writeln(description ~ " off"); } void dim(int level) { writeln(description ~ " dimming to " ~ level.to!string ~ "%"); } override string toString() const { return description; } }