...humbly suggest:

typedef ubyte latin1_t = 0;
typedef ushort ucs2_t = 0;
typedef ubyte koi8r...

...a char.

BTW, you can do this:

typedef char mychar = 0;

mychar[] a = new mychar...

...Code example:

  typedef int ft(int);
  //typedef typeof(test) fp; // This alternative typedef also crashes...

...in D?

Now arguably developers could just typedef or alias char[] as string and be...

...is confusing if one also has a typedef named 'as'. Having keywords be distinct, and...

...chance to legalize them.

Exactly!

Consider this
typedef uint color { ubyte red() {....} }
I want to...

...like length(uint newLength),
opIndexAssign, etc.

extended typedef allows you to define
explicitly such const...

...allows for this on the other hand

typedef char[] string
{
	disable opSliceAssign;
	string toLower(){..}
}

If...

...you will define let's say following:

typedef  string char[]
{
    disable opSliceAssign;
    ....
    char[] tolower() { ..... }
}

then...

...There are strong reasons for that.

extended typedef and alias will allow D to have...