[PATCH] PR libstdc++/79162 ambiguity in string assignment due to string_view overload (LWG 2946)

[Daniel Krügler]

2017-07-28 22:25 GMT+02:00 Tim Song <t.canens.cpp@gmail.com>:
> On Fri, Jul 28, 2017 at 4:10 PM, Daniel Krügler
> <daniel.kruegler@gmail.com> wrote:
>> +      // Performs an implicit conversion from _Tp to __sv_type.
>> +      template<typename _Tp>
>> +        static __sv_type _S_to_string_view(const _Tp& __svt)
>> +        {
>> +          return __svt;
>> +        }
>
> I might have gone for
>
> +        static __sv_type _S_to_string_view(__sv_type __svt) noexcept
> +        {
> +          return __svt;
> +        }
>
> With that, we can also use noexcept(_S_to_string_view(__t)) to make up
> for the absence of is_nothrow_convertible (basically the same thing I
> did in LWG 2993's PR).

Agreed, that makes very much sense. I will adjust the P/R, but before
I resubmit I would like to get feedback whether the other two compare
functions also should become conditionally noexcept.

Thanks,

- Daniel