Forwarding constructor arguments to super

[pillsy]

Is there a good way to forward constructor arguments to a superclass 
constructor? I.e., if I have
something like this

class Foo {
  int _x;

  this (int x) { _x = x; }
}

class Bar : Foo {}

I'd like to able to have this just work:

auto bar = new Bar(3);

However, doing this means that DMD complains that Bar.this isn't callable with 
an int argument. The
next thing I tried was

class Bar : Foo
{
  this (Args) (Args... args) { super(args): }
}

at which point DMD complains that constructor Bar.this conflicts with template 
Bar.__ctor(Args...). I'm
using DMD 2.046, if it matters.

Thank you,
Pillsy