Re: libstdc++/41975

[Paolo Carlini <paolo dot carlini at oracle dot com>]

Hi,
> Ok to commit in trunk ?
I think the patch can go in. Of course please make sure to be around 
over the next days (in particular ;) just in case something shows up on 
less widespread platforms.

Modulo (but I don't think should block the commit more than, say, 1/2 days):
> Regarding:
>
> +      static_assert(__or_<integral_constant<bool, __cache_hash_code>,
> +		      integral_constant<bool,
> +			noexcept(declval<const _H1&>()(declval<const _Key&>()))>
> +			>::value,
> +      	    "Cache the hash code or qualify your hash functor with noexcept");
>
> I would recommend to wrap the expression test in a wrapper trait combined
> to ensure lazy evaluation. As written, this test is always performed, regardless
> of the value of __cache_hash_code.
Right. Daniel, can you help Francois a bit more concretely, just to make 
sure we don't have to iterate on this?

Thanks again!!!
Paolo.