From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id C6F503858407; Tue, 14 Sep 2021 20:00:03 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C6F503858407 From: "redi at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/48396] std::type_info is implicitly declared Date: Tue, 14 Sep 2021 20:00:03 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c++ X-Bugzilla-Version: 4.7.0 X-Bugzilla-Keywords: accepts-invalid, rejects-valid X-Bugzilla-Severity: normal X-Bugzilla-Who: redi at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cf_reconfirmed_on keywords Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Sep 2021 20:00:03 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D48396 Jonathan Wakely changed: What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed|2021-03-05 00:00:00 |2021-9-14 Keywords| |rejects-valid --- Comment #2 from Jonathan Wakely --- This breaks modules, and makes it very difficult to export a 'std' module, = as proposed by https://wg21.link/p2412r0 export module std; // define it namespace std { class type_info; } // exports export namespace std { }; namespace std { export class type_info; } g++ -fmodules-ts -fmodule-only std.cc std.cc:6:9: error: cannot declare 'struct std::type_info' in a different mo= dule 6 | class type_info; | ^~~~~~~~~ : note: declared here std.cc:14:16: error: cannot declare 'struct std::type_info' in a different module 14 | export class type_info; | ^~~~~~~~~ : note: declared here std.cc:1:8: warning: not writing module 'std' due to errors 1 | export module std; | ^~~~~~ As a stop-gap, could we maybe suppress the implicit definition when -fmodules-ts is in use? Otherwise I am unable to prototype the proposal.=