[Bug c++/106847] New: deprecated class data member makes the class generate diagnostics even when the member is not used

["avi at scylladb dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106847

            Bug ID: 106847
           Summary: deprecated class data member makes the class generate
                    diagnostics even when the member is not used
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: avi at scylladb dot com
  Target Milestone: ---

A class with a deprecated member:

    struct foo {
        [[deprecated]] bool x;
    };

Cannot be used without lots of noise from the compiler:

    foo make_a_foo() {
        foo f;
        return f;
    }

<source>: In function 'foo make_a_foo()':
<source>:10:12: warning: 'f' is used uninitialized [-Wuninitialized]
   10 |     return f;
      |            ^
<source>:9:9: note: 'f' declared here
    9 |     foo f;
      |         ^
Compiler returned: 0


Although I didn't touch x, the compiler thinks I did. IMO synthesized
constructors (and assignment operators) should suppress the warning and only
explicit access by the user should trigger the warning.