Follwing code should compile:

struct S
{
  void opAssign(T)(auto ref T rhs)
    if (!__traits(isRef, rhs))
  {}
}
static assert(hasElaborateAssign!S);

Because hasElaborateAssign!T checks is(typeof(T.init.opAssign(T.init))),
but T.init is always lvalue, so S cannot pass its test.