how to get the \uxxxx unicode code from a char

[jicman via Digitalmars-d-learn]

On Tuesday, 14 October 2014 at 19:49:16 UTC, Sean Kelly wrote:
> On Tuesday, 14 October 2014 at 19:47:00 UTC, jicman wrote:
>>
>> Greetings.
>>
>> Imagine this code,
>>
>> char[] s = "ABCabc";
>> foreach (char c; s)
>> {
>>  // how do I convert c to something an Unicode code? ie. 
>> \u9999.
>>
>> }
>
> I'd look at the JSON string encoder.

JSON?  What does JSON has to do with my basic D? :-) No thanks. 
:-)