Transfer modes for parameters and return values

[David Vandevoorde]

Hello again,

In 3.1.1 and 3.1.4, the ABI specifies that "by value" class type  
parameters and class type return values are passed via the address of  
a reference if the class type has
	(a) a nontrivial destructor, or
	(b) a nontrivial copy constructor.

Should we now also add to that:
	(c) a (nontrivial) move constructor
?

(There is currently no notion of "trivial move constructor", but I  
think there are suggestions to introduce that in the future.)

	Daveed