[Bug c++/98569] New: concept error message does not report the file location

[nico at josuttis dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98569

            Bug ID: 98569
           Summary: concept error message does not report the file
                    location
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: nico at josuttis dot de
  Target Milestone: ---

Look here:
 https://wandbox.org/permlink/6Di4rLNS5H9TNL2R

Here is what is wrong in the error message:

> prog.cc: In function 'int main()':
> prog.cc:18:14: error: no matching function for call to 'add(std::vector<std::atomic<int> >&, std::atomic<int>&)'
>    18 | add(aiVec, ai);     // ERROR: cannot copy/move atomics
>       |              ^
> prog.cc:9:6: note: candidate: 'template<class Coll, class T>  requires  convertible_to<T, typename Coll::value_type> void add(Coll&, const T&)'
>     9 | void add(Coll& coll, const T& val)
>       |      ^~~
> prog.cc:9:6: note:   template argument deduction/substitution failed:
> prog.cc:9:6: note: constraints not satisfied
> In file included from /opt/wandbox/gcc-head/include/c++/11.0.0/compare:39,
>                  from /opt/wandbox/gcc-head/include/c++/11.0.0/bits/stl_pair.h:65,
>                  from /opt/wandbox/gcc-head/include/c++/11.0.0/bits/stl_algobase.h:64,
>                  from /opt/wandbox/gcc-head/include/c++/11.0.0/bits/char_traits.h:39,
>                  from /opt/wandbox/gcc-head/include/c++/11.0.0/ios:40,
>                  from /opt/wandbox/gcc-head/include/c++/11.0.0/ostream:38,
>                  from /opt/wandbox/gcc-head/include/c++/11.0.0/iostream:39,
>                  from prog.cc:1:
> /opt/wandbox/gcc-head/include/c++/11.0.0/concepts: In substitution of 'template<class Coll, class T>  requires  convertible_to<T, typename Coll::value_type> void add(Coll&, const T&) [with Coll = std::vector<std::atomic<int> >; T = std::atomic<int>]':

^^^^^ HERE ^^^^

I assume that this has to be something like
 prog.cc:9:6: In substitution ...

instead of:
 /opt/wandbox/gcc-head/include/c++/11.0.0/concepts: In substitution ...

because it refers to my code not to any code in any header file.


> prog.cc:18:14:   required from here
> /opt/wandbox/gcc-head/include/c++/11.0.0/concepts:72:13:   required for the satisfaction of 'convertible_to<T, typename Coll::value_type>' [with T = std::atomic<int>; Coll = std::vector<std::atomic<int>, std::allocator<std::atomic<int> > >]
> /opt/wandbox/gcc-head/include/c++/11.0.0/concepts:72:30: note: the expression 'is_convertible_v<_From, _To> [with _From = std::atomic<int>; _To = std::atomic<int>]' evaluated to 'false'
>    72 |     concept convertible_to = is_convertible_v<_From, _To>
>       |                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~