how to get the \uxxxx unicode code from a char

[Brad Anderson via Digitalmars-d-learn]

On Tuesday, 14 October 2014 at 20:08:03 UTC, Brad Anderson wrote:
> On Tuesday, 14 October 2014 at 20:05:07 UTC, Brad Anderson 
> wrote:
>> https://github.com/D-Programming-Language/phobos/blob/master/std/json.d#L579
>
> Oops. Linked the the parser section. I actually don't see any 
> unicode escape encoder in here. Perhaps he meant the upcoming 
> JSON module.

Here we go.

https://github.com/s-ludwig/std_data_json/blob/4ecb90626055269f4897902404741f1173fb5e8e/source/stdx/data/json/generator.d#L451

Sönke's is pretty sophisticated. You could probably just use the 
non-surrogate supporting simple branch.