How to hand in a closure variable

[Dicebot]

On Monday, 24 March 2014 at 16:40:55 UTC, Bienlein wrote:
> Now I want the closure (aka delegate) to have a closure 
> variable:
>
> int a = 7;
> int delegate(int) dg = { value => return value + a + 3; };
> auto result = dg(123);
>
> Unhappily, the code above doesn't compile. Tried various 
> things, looked for samples on the D hompepage and in the book 
> by Çehreli, but had no luck.
>
> Some hints appreciated.
> Thanks, Bienlein

auto dg = (int value) { return value + a + 3; };

or short-hand form:

auto dg = (int value) => value + a + 3;