Assume you have an overloaded function (let's say "void func(int a)" and "void func(double a)"). When typing a function call and reaching this point: "func(", then auto completion will tell you something like "1 of 2, void func(int a)", with some arrows implying you can step through the possibilities via arrow keys or using your mouse, especially because the arrows are being highlighted when hovering over them (see screen shot; there this function freefunc2 is overloaded three times; unfortunately my screen shot program does not show the mouse pointer even though I told it to do so but you'll see what I mean). But when you actually click on them, the tool tip disappears. At least for me that was unexpected. So either an implementation of mouse usage would be nice or you could make it a bit more obvious that mouse usage is not possible.