public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
* [Bug libstdc++/97561] New: coroutine_handle doesn't have inheritance @ 2020-10-24 14:29 stinkingmadgod at gmail dot com 2020-10-26 12:31 ` [Bug libstdc++/97561] " redi at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: stinkingmadgod at gmail dot com @ 2020-10-24 14:29 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97561 Bug ID: 97561 Summary: coroutine_handle doesn't have inheritance Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libstdc++ Assignee: unassigned at gcc dot gnu.org Reporter: stinkingmadgod at gmail dot com Target Milestone: --- std::coroutine_handle<promise_type> doesn't inherit from std::coroutine_handle<void>. [coroutine.handle.general] template<class Promise> struct coroutine_handle : coroutine_handle<> #include<coroutine> struct task { struct promise_type { task get_return_object() { return {}; } std::suspend_never initial_suspend() { return {}; } std::suspend_never final_suspend() { return {}; } void return_void() {} void unhandled_exception() {} }; }; int main() { std::coroutine_handle<task::promise_type> c; std::coroutine_handle<>& c2 = c; // fails } ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug libstdc++/97561] coroutine_handle doesn't have inheritance 2020-10-24 14:29 [Bug libstdc++/97561] New: coroutine_handle doesn't have inheritance stinkingmadgod at gmail dot com @ 2020-10-26 12:31 ` redi at gcc dot gnu.org 2020-10-26 12:33 ` redi at gcc dot gnu.org 2020-10-26 17:15 ` stinkingmadgod at gmail dot com 2 siblings, 0 replies; 4+ messages in thread From: redi at gcc dot gnu.org @ 2020-10-26 12:31 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97561 Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> --- This is intentional, see https://wg21.link/lwg3460 which is expected to be voted into the draft in a few weeks. The inheritance requires unimplementable and nonsensical behaviour. You can still do this: std::coroutine_handle<task::promise_type> c; std::coroutine_handle<> c2 = c; You just can't bind a coroutine_handle<> reference to a coroutine_handle<P> directly. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug libstdc++/97561] coroutine_handle doesn't have inheritance 2020-10-24 14:29 [Bug libstdc++/97561] New: coroutine_handle doesn't have inheritance stinkingmadgod at gmail dot com 2020-10-26 12:31 ` [Bug libstdc++/97561] " redi at gcc dot gnu.org @ 2020-10-26 12:33 ` redi at gcc dot gnu.org 2020-10-26 17:15 ` stinkingmadgod at gmail dot com 2 siblings, 0 replies; 4+ messages in thread From: redi at gcc dot gnu.org @ 2020-10-26 12:33 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97561 --- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- Do you have a real world use case where the inheritance is actually required? ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug libstdc++/97561] coroutine_handle doesn't have inheritance 2020-10-24 14:29 [Bug libstdc++/97561] New: coroutine_handle doesn't have inheritance stinkingmadgod at gmail dot com 2020-10-26 12:31 ` [Bug libstdc++/97561] " redi at gcc dot gnu.org 2020-10-26 12:33 ` redi at gcc dot gnu.org @ 2020-10-26 17:15 ` stinkingmadgod at gmail dot com 2 siblings, 0 replies; 4+ messages in thread From: stinkingmadgod at gmail dot com @ 2020-10-26 17:15 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97561 --- Comment #3 from stinkingmadgod at gmail dot com --- Thanks for the link. I was attempting to create a type-erased task type where the handles in one case was be passed in as a std::coroutine_handle<>& to avoid using std::function and the like. It was experimental and unlikely to be motivating, but I initially thought the inheritance situation was a bug. ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-10-26 17:15 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-10-24 14:29 [Bug libstdc++/97561] New: coroutine_handle doesn't have inheritance stinkingmadgod at gmail dot com 2020-10-26 12:31 ` [Bug libstdc++/97561] " redi at gcc dot gnu.org 2020-10-26 12:33 ` redi at gcc dot gnu.org 2020-10-26 17:15 ` stinkingmadgod at gmail dot com
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).