[v3 patch] Fix friend declaration so it is visible to name lookup

[Paolo Carlini]

Hi,

On 08/21/2015 02:57 PM, Jonathan Wakely wrote:
> On 21/08/15 00:03 +0200, Paolo Carlini wrote:
>> Hi,
>>
>> On 08/20/2015 10:21 PM, Jonathan Wakely wrote:
>>> Jason pointed out this isn't valid, and is going to fail to compile
>>> soon with a fix he's making.
>> I seem to remember that at some point we had the exact same issue 
>> with some member operator<< and operator>> of <random>.
>
> I don't remember that, but hopefully we won't have any more problems
> like this now that Jason is making the front-end diagnose it.
Yes. For your curiosity, I think I had in mind libstdc++/54376, which, 
besides being about operator==, wasn't the same issue because involved 
*template* classes. In any case, the lesson is that inline template 
friends are consistently rather evil ;)

Paolo.