...it is persistent auto win = new DrawableWindow(width, height);

// still use an image the same...

...Image!(255, 255);

    foreach(a; 0..image.width)
    foreach(b; 0..image.height)
        image.fast...

...improved to window.title = "Find"; w=window.width; Etc, etc.

The use of properties, delegates...

...are handles in JS, or what the "width" and "height" attributes refer to.

I just...

...Box(T, size_t width, size_t height){
>
> alias width width_;
> alias height height_;
>
> //do...

...Box(T, size_t width, size_t height){

alias width width_;
alias height height_;

//do...

...lastValue; // the first dollar should resolve to "width", the second to "height"

Now speaking of...

...much more generally useful and the fixed width one would mostly add clutter.

BTW, does...

...you're doing with regard to overflow, you could used fixed width as an optimization.

...possibly overflows in the case of fixed width integers) for the denominator in this case?