Why std.algorithm.sort can't be applied to char[]?

[John Colvin via Digitalmars-d-learn]

On Monday, 12 May 2014 at 14:56:46 UTC, John Colvin wrote:
> On Monday, 12 May 2014 at 14:49:53 UTC, hane wrote:
>> and is there any way to sort char array with algorithm.sort?
>> ---
>> import std.algorithm;
>> import std.range;
>>
>> void main()
>> {
>>  int[] arr = [5, 3, 7];
>>  sort(arr); // OK
>>
>>  char[] arr2 = ['z', 'g', 'c'];
>>  sort(arr2); // error
>>  sort!q{ a[0] > b[0] }(zip(arr, arr2)); // error
>> }
>> ---
>> I don't know what's difference between int[] and char[] in D, 
>> but it's very unnatural.
>
> char[] is a rather special type of array: the language has 
> unicode support and iterates over it by code-point (i.e. not 
> guaranteed to be a single char per iteration).
>
> If you want to sort chars and are assuming ASCII, you can just 
> use std.string.representation to work with them as integer 
> types:
>
> import std.algorithm;
> import std.range;
> import std.string;
>
> void main()
> {
>   int[] arr = [5, 3, 7];
>   sort(arr); // OK
>
>   char[] arr2 = ['z', 'g', 'c'];
>   sort(arr2.representation); // error
>   sort!q{ a[0] > b[0] }(zip(arr, arr2.representation)); // error
> }

woops, should have deleted the // error comments