How can I initialize the base class without default constructor?

[shelllet]

idl

[default_interface]
unsealed runtimeclass ActionControl : Microsoft.UI.Xaml.Controls.ContentControl
{
	ActionControl(String key);
}

[default_interface]
runtimeclass Xaml_StartProcess : ActionControl
{
	Xaml_StartProcess(String key);
}

projection class

struct Xaml_StartProcess : Xaml_StartProcessT<Xaml_StartProcess>
{
	Xaml_StartProcess(hstring const & key) : implements_type(key){}
};

i try to add implements_type, but
compile error: illegal member initialization: 'implements_type' is not a base or member

[btueffers]

Hi @shelllet is there any additional information about your question that is specific to XAML? If not, the Microsoft Q & A would be a better place to have this discussion.

[shelllet]

thx, may be cppwinrt is a better place.