about std.string.representation

[bioinfornatics]

works as expected

import std.traits   : isSomeChar;
import std.range    : ElementEncodingType;
import std.stdio;

@safe pure nothrow
template CharEncodingType(Char)
{
     alias ET = ElementEncodingType!Char;

     static if (is (ET == char)) {
         alias CharEncodingType = ubyte;

     } else static if (is (ET == wchar)) {
         alias CharEncodingType = ushort;

     } else static if (is (ET == dchar)) {
         alias CharEncodingType = uint;

     } else {
         alias CharEncodingType = ET;
     }
}

void main()
{
     string  t  = "test";
     char[]  c  = "test".dup;
     dchar[] dc = "test"d.dup;
     wchar[] wc = "test"w.dup;

     alias T  = CharEncodingType!(typeof(t));
     alias C  = CharEncodingType!(typeof(c));
     alias DC = CharEncodingType!(typeof(dc));
     alias WC = CharEncodingType!(typeof(wc));

     writeln( typeid(T), ' ', typeid(C), ' ', typeid(DC), ' ', 
typeid(WC) );

}


Result
immutable(char) ubyte uint ushort



thanks all