defaulting to blitting when overloading opAssign

[Steven Schveighoffer]

With D1, if I define an opAssign for a struct, I can still access the 
blitting version by just assigning to another instance of the same struct.

i.e.:

struct S
{
   int x;
   S opAssign(int n) {x = n; return *this;}
}

void foo(S s)
{
   S s2;
   s2 = s; // ok, just does a bitcopy
}

However, in D2.019 (not sure when this was added), I now get a compile error 
for the assignment statement:

function testit.S.opAssign (int n) does not match parameter types (S)
Error: cannot implicitly convert expression (s) of type S to int

I have to define opAssign(S s).  The docs still say it's not allowed, but 
apparently it is necessary.

Is there any way to call the default bitcopy from this overloaded opAssign, 
or flag that a struct should just be bitcopied when being assigned?

-Steve