qmltc: Enforce required properties

In the attached project, MySquare.qml is compiled with qmltc:

// MySquare.qml
import QtQuick

Rectangle {
    required color
    width: 100
    height: 100
}

 
If we create an instance of MySquare without specifying a value for color...

• ...the instance created in QML produces the error, "Component is missing required property color from Rectangle [required]"
• ...the instance created in C++ silently uses the default value, "#ffffff"

Note: There is no way to "atomically" set the initial properties from C++. They must currently be set after creation has completed.

Suggestion

qmltc-compiled classes should provide a way to specify initial property values (QTBUG-120700) and enforce them for required properties.