Delegates can be a pain, as they often have results different
from what one would intuitively expect. This can easily result in
bugs.
Here's a line that caused a bug that took me awhile to find:
```
foreach(card; unitCards) card.submitted = delegate() =>
selectUnit(card.unit);
```
Each `UnitInfoCard` object (which `card` is a member of) contains
a `Unit` object called `unit`. The intention of this line was
that each object in `unitCards` would call `selectUnit` with it's
own `unit` every time it calls `submitted`. Instead, every card
calls `submitted` with the *last* value of `card`.
This is because the delegate assignment causes the local `card`
variable to remain alive. The delegate that's assigned is linked
to this variable itself, not the value at the time that the
delegate is assigned.
Is there a way I can dereference a variable when placing it in a
delegate, so that it's current value is used, rather than the
variable itself?
