Re: [PATCH 2/2] Add gdb::string_view

[Simon Marchi <simon dot marchi at polymtl dot ca>]

On 2018-03-19 08:21, Pedro Alves wrote:
> > Hmm, when building with older g++ (such as the aarch64 builders on the 
> > buildbot,
> > which have g++ 4.8), it trips on:
> >
> >   using __idt = std::common_type_t<_Tp>;
> >
> > It looks like that release of g++ didn't have std::common_type_t.  I 
> > guess it
> > would be possible to avoid using it, and change these:
>
> It has std::common_type though.  C++14 std::foo_t types are usually 
> just a
> helper/convenience alias template, like:
>
>   /// Alias template for common_type
>   template<typename... _Tp>
>     using common_type_t = typename common_type<_Tp...>::type;
>
> So it sounds like we can just use the C++11 / ::type form directly, or
> add gdb::common_type_t somewhere, like common/traits.h or to our
> copy of string_view.

Ok thanks I think I got it to work now.

> >     operator==(basic_string_view<_CharT, _Traits> __x,
> >                __detail::__idt<basic_string_view<_CharT, _Traits>> 
> > __y) noexcept
> >
> > for
> >
> >     operator==(basic_string_view<_CharT, _Traits> __x,
> >                basic_string_view<_CharT, _Traits> __y) noexcept
> >
> > but I am not aware of what consequences it would have.
>
> Would it be possible to import some of the libstdc++'s relevant
> testscases into our unit tests framework, like was done for
> gdb::optional [1]?
>
> [1] https://sourceware.org/ml/gdb-patches/2017-04/msg00239.html

Good idea, I did it and it caught a few important compilation issues!

I just need to clean up the patches and I'll send a v2.

Thanks,

Simon