Is std.demangle usable?

[Andrej Mitrovic]

import std.stdio;
import std.demangle;
import std.traits;

void main()
{   
    void test()
    {
    }
    
    auto mystr = mangledName!(test); // ----------- demangle4mainFAAyaZv4testMFZv
    writeln(demangle(mystr));        // writes back demangle4mainFAAyaZv4testMFZv
}

Also, the example code is broken in http://www.digitalmars.com/d/2.0/phobos/std_demangle.html