On Mon, 7 Jul 2025 at 07:53, Tomasz Kaminski <tkami...@redhat.com> wrote: > > Thanks. > I am not sure if template is necessary here, as I believe this is type-only > context, but I never understood the rules around this.
Same here. I remain unconvinced that relaxing the rules in the standard was a good idea. "You always need it" was a lot easier to understand than "you sometimes need it and even most members of the standard committee aren't sure when you need it, probably safer to just use it anyway". > > On Sat, Jul 5, 2025 at 1:15 AM Jonathan Wakely <jwak...@redhat.com> wrote: >> >> Clang wants this change: >> >> --- a/libstdc++-v3/include/std/mdspan >> +++ b/libstdc++-v3/include/std/mdspan >> @@ -509,7 +509,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION >> >> template<typename _Layout, typename _Mapping> >> concept __mapping_of = >> - is_same_v<typename _Layout::mapping<typename _Mapping::extents_type>, >> + is_same_v<typename _Layout::template mapping<typename >> _Mapping::extents_type>, >> _Mapping>; >> >> template<typename _Mapping> >> >> to fix: >> >> /home/jwakely/gcc/latest/lib/gcc/x86_64-pc-linux-gnu/16.0.0/../../../../include/c++/16.0.0/mdspan:512:30: >> error: use 'template' keyword to treat 'mapping' a >> s a dependent template name >> 512 | is_same_v<typename _Layout::mapping<typename >> _Mapping::extents_type>, >> | ^ >> >> >> I'll push that on Monday. >>
