Source expression passed to a lazy parameter

[Per Nordlöw via Digitalmars-d-learn]

Is it possible to get the source expression sent to a lazy 
function?

So that I can implement something like
show(Arg)(lazy Arg arg)
{
    writeln(arg.sourceof, arg);
}

used as

    show(1+2+3);

will print

    1+2+3:6