public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
* [Bug c++/96848] New: Inherited conditionally explicit constructors via using declaration do not enforce explicitness if dependent on template parameter @ 2020-08-30 1:03 northon_patrick3 at yahoo dot ca 2021-08-17 7:06 ` [Bug c++/96848] " pinskia at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: northon_patrick3 at yahoo dot ca @ 2020-08-30 1:03 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96848 Bug ID: 96848 Summary: Inherited conditionally explicit constructors via using declaration do not enforce explicitness if dependent on template parameter Product: gcc Version: 10.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: northon_patrick3 at yahoo dot ca Target Milestone: --- Example: https://godbolt.org/z/4x9r7e ```cpp #include <iostream> #include <type_traits> struct E {}; struct F {}; struct G {}; template <typename From_, typename To_> constexpr bool isValidImplicitConvert = false; template <> constexpr bool isValidImplicitConvert<E, G> = true; template <typename T_> struct A { template <typename OT_> explicit(!isValidImplicitConvert<OT_, T_>) constexpr A(const OT_ &) {} //explicit(isValidImplicitConvert<E, T_>) constexpr A(E) {} //explicit(isValidImplicitConvert<F, T_>) constexpr A(F) {} }; template <typename T_> struct B : public A<T_> { using A<T_>::A; }; int main(int, char **) { std::cout << std::is_convertible_v<E, A<G>> << '\n'; std::cout << std::is_convertible_v<F, A<G>> << '\n'; std::cout << std::is_convertible_v<E, B<G>> << '\n'; std::cout << std::is_convertible_v<F, B<G>> << '\n'; return 0; } ``` Output: ``` 1 0 1 1 ``` Expected output: ``` 1 0 1 0 ``` When inheriting constructors from a base class via a using declaration, if said constructors are conditionally explicit and the condition is dependent on a deduced template parameter, the explicit state is ignored. Clang give the expected output, however I am not sure who is correct. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/96848] Inherited conditionally explicit constructors via using declaration do not enforce explicitness if dependent on template parameter 2020-08-30 1:03 [Bug c++/96848] New: Inherited conditionally explicit constructors via using declaration do not enforce explicitness if dependent on template parameter northon_patrick3 at yahoo dot ca @ 2021-08-17 7:06 ` pinskia at gcc dot gnu.org 2021-08-17 7:09 ` pinskia at gcc dot gnu.org 2023-02-19 20:12 ` oliver.rosten at googlemail dot com 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-08-17 7:06 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96848 --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- ICC, clang and MSVC all agree the output should be 1010. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/96848] Inherited conditionally explicit constructors via using declaration do not enforce explicitness if dependent on template parameter 2020-08-30 1:03 [Bug c++/96848] New: Inherited conditionally explicit constructors via using declaration do not enforce explicitness if dependent on template parameter northon_patrick3 at yahoo dot ca 2021-08-17 7:06 ` [Bug c++/96848] " pinskia at gcc dot gnu.org @ 2021-08-17 7:09 ` pinskia at gcc dot gnu.org 2023-02-19 20:12 ` oliver.rosten at googlemail dot com 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-08-17 7:09 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96848 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2021-08-17 Ever confirmed|0 |1 Depends on| |85251 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Confirmed. I suspect PR 85251 is the underlying issue though, GCC loses explicit even in the unconditional case. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85251 [Bug 85251] Using declaration for base class constructor looses explicit. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/96848] Inherited conditionally explicit constructors via using declaration do not enforce explicitness if dependent on template parameter 2020-08-30 1:03 [Bug c++/96848] New: Inherited conditionally explicit constructors via using declaration do not enforce explicitness if dependent on template parameter northon_patrick3 at yahoo dot ca 2021-08-17 7:06 ` [Bug c++/96848] " pinskia at gcc dot gnu.org 2021-08-17 7:09 ` pinskia at gcc dot gnu.org @ 2023-02-19 20:12 ` oliver.rosten at googlemail dot com 2 siblings, 0 replies; 4+ messages in thread From: oliver.rosten at googlemail dot com @ 2023-02-19 20:12 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96848 Oliver Rosten <oliver.rosten at googlemail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |oliver.rosten at googlemail dot co | |m --- Comment #3 from Oliver Rosten <oliver.rosten at googlemail dot com> --- I just came across an issue which I think has the same underlying cause: https://godbolt.org/z/Ph8xbeM7s ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2023-02-19 20:12 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-08-30 1:03 [Bug c++/96848] New: Inherited conditionally explicit constructors via using declaration do not enforce explicitness if dependent on template parameter northon_patrick3 at yahoo dot ca 2021-08-17 7:06 ` [Bug c++/96848] " pinskia at gcc dot gnu.org 2021-08-17 7:09 ` pinskia at gcc dot gnu.org 2023-02-19 20:12 ` oliver.rosten at googlemail 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).