[Bug c++/97438] New: [accepts-invalid] coroutines accepts prmomise type with both return_value() and return_void()

[avi--- via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97438

            Bug ID: 97438
           Summary: [accepts-invalid] coroutines accepts prmomise type
                    with both return_value() and return_void()
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: a...@cloudius-systems.com
  Target Milestone: ---

The standard says:

[dcl.fct.def.coroutine]

6. The unqualified-ids return_­void and return_­value are looked up in the
scope of the promise type. If both are found, the program is ill-formed.


But gcc accepts such a promise type. Clang rejects it.