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* [Bug c++/100779] New: Partial specialization with non-deducible template parameters accepted @ 2021-05-26 19:08 ppalka at gcc dot gnu.org 2021-05-26 19:15 ` [Bug c++/100779] " ppalka at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: ppalka at gcc dot gnu.org @ 2021-05-26 19:08 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100779 Bug ID: 100779 Summary: Partial specialization with non-deducible template parameters accepted Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: ppalka at gcc dot gnu.org Target Milestone: --- template <int> struct A; template <class> struct B; template <class T> struct B<A<sizeof(T)>> { }; This partial specialization should be rejected because its template parameter T is not deducible. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/100779] Partial specialization with non-deducible template parameters accepted 2021-05-26 19:08 [Bug c++/100779] New: Partial specialization with non-deducible template parameters accepted ppalka at gcc dot gnu.org @ 2021-05-26 19:15 ` ppalka at gcc dot gnu.org 2021-05-26 23:49 ` ppalka at gcc dot gnu.org 2021-05-27 16:37 ` cvs-commit at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: ppalka at gcc dot gnu.org @ 2021-05-26 19:15 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100779 --- Comment #1 from Patrick Palka <ppalka at gcc dot gnu.org> --- Another accepts-invalid example: template <int> struct A; template <class> struct B; template <int N> struct B<A<N+0>> { }; ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/100779] Partial specialization with non-deducible template parameters accepted 2021-05-26 19:08 [Bug c++/100779] New: Partial specialization with non-deducible template parameters accepted ppalka at gcc dot gnu.org 2021-05-26 19:15 ` [Bug c++/100779] " ppalka at gcc dot gnu.org @ 2021-05-26 23:49 ` ppalka at gcc dot gnu.org 2021-05-27 16:37 ` cvs-commit at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: ppalka at gcc dot gnu.org @ 2021-05-26 23:49 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100779 --- Comment #2 from Patrick Palka <ppalka at gcc dot gnu.org> --- The problem is ultimately that for_each_template_parm doesn't honor included_nondeduced_p correctly. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/100779] Partial specialization with non-deducible template parameters accepted 2021-05-26 19:08 [Bug c++/100779] New: Partial specialization with non-deducible template parameters accepted ppalka at gcc dot gnu.org 2021-05-26 19:15 ` [Bug c++/100779] " ppalka at gcc dot gnu.org 2021-05-26 23:49 ` ppalka at gcc dot gnu.org @ 2021-05-27 16:37 ` cvs-commit at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: cvs-commit at gcc dot gnu.org @ 2021-05-27 16:37 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100779 --- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Patrick Palka <ppalka@gcc.gnu.org>: https://gcc.gnu.org/g:9b94785dedb08b006419bec1a402614d9241317a commit r12-1093-g9b94785dedb08b006419bec1a402614d9241317a Author: Patrick Palka <ppalka@redhat.com> Date: Thu May 27 12:36:39 2021 -0400 c++: Relax rule for non-type arguments in partial specs [CWG1315] This implements the wording changes of CWG 1315, which permits non-type template arguments in a partial specialization to use template parameters more freely. Delightfully, it seems the only change needed is to remove a single check from process_partial_specialization (amidst a bunch of whitespace changes). But that change alone revealed a latent problem with for_each_template_parm: it ends up looking into some non-deduced contexts even when include_nondeduced_p is false. This causes us to silently accept some partial specializations within the testsuite that contain non-deducible non-type template parameters (and that were previously rejected due to the rule that CWG 1315 relaxed). For now this patch makes a minimal amount of changes to for_each_template_parm_r so that we continue to reject existing ill-formed partial specializations within the testsuite. I opened PR c++/100779 to track this issue. DR 1315 PR c++/67593 PR c++/96555 gcc/cp/ChangeLog: * pt.c (process_partial_specialization): Don't error on a non-simple non-type template argument that involves template parameters. (for_each_template_parm_r): Don't walk TRAIT_EXPR, PLUS_EXPR, MULT_EXPR, or SCOPE_REF when include_nondeduced_p is false. gcc/testsuite/ChangeLog: * g++.dg/template/partial16.C: New test. * g++.dg/template/partial17.C: New test. * g++.dg/template/partial18.C: New test. * g++.dg/template/partial19.C: New test. * g++.dg/cpp0x/pr68724.C: Adjust expected diagnostic for ill-formed partial specialization. * g++.dg/cpp0x/variadic38.C: Likewise. * g++.dg/cpp1z/pr81016.C: Likewise. * g++.dg/template/partial5.C: Likewise. * g++.old-deja/g++.pt/spec21.C: Likewise. ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-05-27 16:37 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-05-26 19:08 [Bug c++/100779] New: Partial specialization with non-deducible template parameters accepted ppalka at gcc dot gnu.org 2021-05-26 19:15 ` [Bug c++/100779] " ppalka at gcc dot gnu.org 2021-05-26 23:49 ` ppalka at gcc dot gnu.org 2021-05-27 16:37 ` cvs-commit at gcc dot gnu.org
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