Optimize hashtable allocator

[Marc Glisse]

On Wed, 31 Oct 2012, Jonathan Wakely wrote:

> On 31 October 2012 22:14, François Dumont wrote:
>>     Here is the patch I came to. I use the 'universal reference' like you
>> propose but some tests started to fail because I think gcc called it instead
>> of the move constructor.
>
> Ah of course.  The defaulted copy/move constructors you added are the
> right solution for that.

Assuming you never copy a non-const lvalue or a const rvalue. The current 
use seems ok, I just wanted to mention that it is rather fragile.

-- 
Marc Glisse