Defined in carb/simplegui/SimpleGuiTypes.h

const WindowFlags carb::simplegui::kWindowFlagUnsavedDocument = 1 << 20

Append ‘*’ to title without affecting the ID, as a convenience to avoid using the ### operator. When used in a tab/docking context, tab is selected on closure and closure is deferred by one frame to allow code to cancel the closure (with a confirmation popup, etc.) without flicker.