[PATCH] Add explicit default constructors where required by the standard

[Jonathan Wakely]

On 14 May 2013 10:45, Evgeniy Stepanov wrote:
> This must have fallen through the cracks.

It's still in my Git branch at home. I've been too busy to push any
commits recently, but I haven't forgotten it.


> I realized we also need it in the 4_7 branch. Could you backport the
> change there, too, if it is not too much trouble?

Yes, for such a small, safe change I'm happy to apply it to the 4.7 branch too.