I finally have a semi-finished example showing the use of GUI Buttons, Layovers and Text:
//Create a function object for member function for this instance
function<void()> myOnClickFnc = bind( &MyClass::FunctionName, this );
//Then Set the OnClickFunction for my GuiElement
button->SetOnClickEvent( myOnClickFnc );
//Create a function object for static class function
function<void()> myOnClickFnc = &MyStaticClass::FunctionName;
//Create a function object for function
function<void()> myOnClickFnc = &functionName;
//Then Set the OnClickFunction for my GuiElement
button->SetOnClickEvent( myOnClickFnc );
This project is really coming along and I am now looking to tidy up some bits and really design how the "Engine" will be exposed to the user.
Keep coding :)