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* [Bug c++/112594] New: Non-type template parameter created with converting constructor sometimes has original type @ 2023-11-17 17:36 mital at mitalashok dot co.uk 2023-11-20 5:05 ` [Bug c++/112594] " pinskia at gcc dot gnu.org ` (3 more replies) 0 siblings, 4 replies; 5+ messages in thread From: mital at mitalashok dot co.uk @ 2023-11-17 17:36 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112594 Bug ID: 112594 Summary: Non-type template parameter created with converting constructor sometimes has original type Product: gcc Version: 14.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: mital at mitalashok dot co.uk Target Milestone: --- The following code complains that `N` (which was declared `n N`) is `3` (of type `int`) instead of `n(3)`: <https://godbolt.org/z/rv3777Ycv> template<typename T> concept C = true; struct n { constexpr n(int) {} static int i; }; template<n N> using get_n_i_type = decltype(N.i); template<int X> int f() { using iii = get_n_i_type<X>; #if 1 // Change to 0 and this compiles static_assert(C<iii>); #endif return iii{}; } template int f<3>(); Compiler error given: <source>: In instantiation of 'int f() [with int X = 3]': <source>:21:19: required from here 21 | template int f<3>(); | ^ <source>:10:33: error: request for member 'i' in '3', which is of non-class type 'int' 10 | using get_n_i_type = decltype(N.i); | ~~^ This compiles fine if Clang and MSVC or if you remove the static_assert or change `template<int X>` to `template<auto X>`. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/112594] Non-type template parameter created with converting constructor sometimes has original type 2023-11-17 17:36 [Bug c++/112594] New: Non-type template parameter created with converting constructor sometimes has original type mital at mitalashok dot co.uk @ 2023-11-20 5:05 ` pinskia at gcc dot gnu.org 2023-11-20 5:09 ` pinskia at gcc dot gnu.org ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-11-20 5:05 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112594 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever confirmed|0 |1 Last reconfirmed| |2023-11-20 --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Confirmed. This fails in a similar way so it is not related to i being static here: ``` template<typename T> concept C = true; struct n { constexpr n(int a) : i(a) {} int i; }; template<n N> using get_n_i_type = decltype(N.i); template<int X> int f() { using iii = get_n_i_type<X>; #if 1 // Change to 0 and this compiles static_assert(C<iii>); #endif return iii{}; } template int f<3>(); ``` I will file another related bug seperately which seems like a regression on the trunk. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/112594] Non-type template parameter created with converting constructor sometimes has original type 2023-11-17 17:36 [Bug c++/112594] New: Non-type template parameter created with converting constructor sometimes has original type mital at mitalashok dot co.uk 2023-11-20 5:05 ` [Bug c++/112594] " pinskia at gcc dot gnu.org @ 2023-11-20 5:09 ` pinskia at gcc dot gnu.org 2024-01-19 18:35 ` cvs-commit at gcc dot gnu.org 2024-01-19 18:37 ` jason at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-11-20 5:09 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112594 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |rejects-valid --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #1) > > I will file another related bug seperately which seems like a regression on > the trunk. Filed PR 112632 for that case, basically using `inline constexpr` rather than `conccept` used to work in GCC 13 but fails on the trunk ... ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/112594] Non-type template parameter created with converting constructor sometimes has original type 2023-11-17 17:36 [Bug c++/112594] New: Non-type template parameter created with converting constructor sometimes has original type mital at mitalashok dot co.uk 2023-11-20 5:05 ` [Bug c++/112594] " pinskia at gcc dot gnu.org 2023-11-20 5:09 ` pinskia at gcc dot gnu.org @ 2024-01-19 18:35 ` cvs-commit at gcc dot gnu.org 2024-01-19 18:37 ` jason at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: cvs-commit at gcc dot gnu.org @ 2024-01-19 18:35 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112594 --- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Jason Merrill <jason@gcc.gnu.org>: https://gcc.gnu.org/g:f1e5bf0d83ee4da81b6317c6d7f1278fe7eaa5a0 commit r14-8291-gf1e5bf0d83ee4da81b6317c6d7f1278fe7eaa5a0 Author: Jason Merrill <jason@redhat.com> Date: Wed Jan 17 17:29:33 2024 -0500 c++: alias template argument conversion [PR112632] We've had a problem with lost conversions to template parameter types for a while now; looking at this PR, it occurred to me that the problem is really with alias (and concept) templates, since we do substitution of dependent arguments into them in a way that we don't for other templates. And fixing that specific problem is a lot simpler than adding IMPLICIT_CONV_EXPR around all dependent template arguments the way I gave up on for 111357. The other part of the fix was changing tsubst_expr to actually call convert_nontype_argument instead of assuming it will eventually happen. I waffled about stripping the forced conversion when !force_conv vs. skipping them in iterative_hash_template_arg and template_args_equal (like we already do for some other conversions) and decided to go with the former, but that isn't a strong preference if it turns out to be somehow problematic. PR c++/112632 PR c++/112594 PR c++/111357 PR c++/104594 PR c++/67898 gcc/cp/ChangeLog: * cp-tree.h (IMPLICIT_CONV_EXPR_FORCED): New. * pt.cc (expand_integer_pack): Remove 111357 workaround. (maybe_convert_nontype_argument): Add force parm. (convert_template_argument): Handle alias template args specially. (tsubst_expr): Don't ignore IMPLICIT_CONV_EXPR_NONTYPE_ARG. * error.cc (dump_expr) [CASE_CONVERT]: Handle null optype. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/alias-decl-nontype1.C: New test. * g++.dg/cpp2a/concepts-narrowing1.C: New test. * g++.dg/cpp2a/nontype-class63.C: New test. * g++.dg/cpp2a/nontype-class63a.C: New test. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/112594] Non-type template parameter created with converting constructor sometimes has original type 2023-11-17 17:36 [Bug c++/112594] New: Non-type template parameter created with converting constructor sometimes has original type mital at mitalashok dot co.uk ` (2 preceding siblings ...) 2024-01-19 18:35 ` cvs-commit at gcc dot gnu.org @ 2024-01-19 18:37 ` jason at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: jason at gcc dot gnu.org @ 2024-01-19 18:37 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112594 Jason Merrill <jason at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |FIXED CC| |jason at gcc dot gnu.org Target Milestone|--- |14.0 --- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> --- Fixed for GCC 14. ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2024-01-19 18:37 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-11-17 17:36 [Bug c++/112594] New: Non-type template parameter created with converting constructor sometimes has original type mital at mitalashok dot co.uk 2023-11-20 5:05 ` [Bug c++/112594] " pinskia at gcc dot gnu.org 2023-11-20 5:09 ` pinskia at gcc dot gnu.org 2024-01-19 18:35 ` cvs-commit at gcc dot gnu.org 2024-01-19 18:37 ` jason at gcc dot gnu.org
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