A template construct like using()

[cc]

On Tuesday, 26 April 2022 at 21:33:43 UTC, Chris Katko wrote:
> I swear I asked something like this before years ago but it 
> doesn't show up in my previous forum posts.
>
> I'm looking for a construct that mimics using(var)/with(var)

```d
void draw_with(bitmap* drawb, void delegate() dg) {
	set_target_bitmap(drawb);
	dg();
	set_target_bitmap(original_target);
}

bitmap* b;
draw_with(b, {
	draw_pixel(red, 16, 16);
});
```

If your draw code doesn't depend on any scoped state you can use 
`function()` instead of `delegate()` to save a GC call.