is(ElementType!(char[2]) == dchar - why?

[Denis Feklushkin via Digitalmars-d-learn]

import std.stdio;
import std.range.primitives;

void main()
{
    writeln(
        typeid(ElementType!(char[2]))
    );

    static assert(is(ElementType!(char[2]) == dchar)); // why?
}

?

https://run.dlang.io/is/Q74yHm