[Bug c++/107292] New: no warning for unused std::error_code

[trass3r at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107292

            Bug ID: 107292
           Summary: no warning for unused std::error_code
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trass3r at gmail dot com
  Target Milestone: ---

#include <system_error>
void foo()
{
    std::error_code ec;
}

The code does get optimized away as system_category() is [[gnu::const]] but
there is no -Wunused warning.

https://godbolt.org/z/M68ToY78b