From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1888) id D241F3858C50; Fri, 22 Jul 2022 22:43:53 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D241F3858C50 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Patrick Palka To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-1805] c++: CTAD from initializer list [PR106366] X-Act-Checkin: gcc X-Git-Author: Patrick Palka X-Git-Refname: refs/heads/master X-Git-Oldrev: b585af38a12bd6b64dbbb8c645e8e2b83b7ba012 X-Git-Newrev: f77bbc8f86900b21abdec457b4153b30512e192d Message-Id: <20220722224353.D241F3858C50@sourceware.org> Date: Fri, 22 Jul 2022 22:43:53 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 22 Jul 2022 22:43:53 -0000 https://gcc.gnu.org/g:f77bbc8f86900b21abdec457b4153b30512e192d commit r13-1805-gf77bbc8f86900b21abdec457b4153b30512e192d Author: Patrick Palka Date: Fri Jul 22 18:42:02 2022 -0400 c++: CTAD from initializer list [PR106366] During CTAD, we currently perform the first phase of overload resolution from [over.match.list] only if the class template has a list constructor. But according to [over.match.class.deduct]/4 it should be enough to just have a guide that looks like a list constructor (which is a more general criterion in light of user-defined guides). PR c++/106366 gcc/cp/ChangeLog: * pt.cc (do_class_deduction): Don't consider TYPE_HAS_LIST_CTOR when setting try_list_ctor. Reset args even when try_list_ctor is true and there are no list candidates. Call resolve_args on the reset args. Rename try_list_ctor to try_list_cand. gcc/testsuite/ChangeLog: * g++.dg/cpp1z/class-deduction112.C: New test. Diff: --- gcc/cp/pt.cc | 31 ++++++++++++------------- gcc/testsuite/g++.dg/cpp1z/class-deduction112.C | 14 +++++++++++ 2 files changed, 29 insertions(+), 16 deletions(-) diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 718dfa5bfa8..c415db304c9 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -30240,7 +30240,7 @@ do_class_deduction (tree ptype, tree tmpl, tree init, tree type = TREE_TYPE (tmpl); - bool try_list_ctor = false; + bool try_list_cand = false; bool list_init_p = false; releasing_vec rv_args = NULL; @@ -30250,8 +30250,8 @@ do_class_deduction (tree ptype, tree tmpl, tree init, else if (BRACE_ENCLOSED_INITIALIZER_P (init)) { list_init_p = true; - try_list_ctor = TYPE_HAS_LIST_CTOR (type); - if (try_list_ctor && CONSTRUCTOR_NELTS (init) == 1 + try_list_cand = true; + if (CONSTRUCTOR_NELTS (init) == 1 && !CONSTRUCTOR_IS_DESIGNATED_INIT (init)) { /* As an exception, the first phase in 16.3.1.7 (considering the @@ -30261,9 +30261,9 @@ do_class_deduction (tree ptype, tree tmpl, tree init, specialization of C. */ tree elt = CONSTRUCTOR_ELT (init, 0)->value; if (is_spec_or_derived (TREE_TYPE (elt), tmpl)) - try_list_ctor = false; + try_list_cand = false; } - if (try_list_ctor || is_std_init_list (type)) + if (try_list_cand || is_std_init_list (type)) args = make_tree_vector_single (init); else args = make_tree_vector_from_ctor (init); @@ -30310,26 +30310,25 @@ do_class_deduction (tree ptype, tree tmpl, tree init, tree fndecl = error_mark_node; - /* If this is list-initialization and the class has a list constructor, first + /* If this is list-initialization and the class has a list guide, first try deducing from the list as a single argument, as [over.match.list]. */ - tree list_cands = NULL_TREE; - if (try_list_ctor && cands) - for (lkp_iterator iter (cands); iter; ++iter) - { - tree dg = *iter; + if (try_list_cand) + { + tree list_cands = NULL_TREE; + for (tree dg : lkp_range (cands)) if (is_list_ctor (dg)) list_cands = lookup_add (dg, list_cands); - } - if (list_cands) - { - fndecl = perform_dguide_overload_resolution (list_cands, args, tf_none); - + if (list_cands) + fndecl = perform_dguide_overload_resolution (list_cands, args, tf_none); if (fndecl == error_mark_node) { /* That didn't work, now try treating the list as a sequence of arguments. */ release_tree_vector (args); args = make_tree_vector_from_ctor (init); + args = resolve_args (args, complain); + if (args == NULL) + return error_mark_node; } } diff --git a/gcc/testsuite/g++.dg/cpp1z/class-deduction112.C b/gcc/testsuite/g++.dg/cpp1z/class-deduction112.C new file mode 100644 index 00000000000..8da5868ff98 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1z/class-deduction112.C @@ -0,0 +1,14 @@ +// PR c++/106366 +// { dg-do compile { target c++17 } } + +#include + +template +struct A { A(...); }; + +template +A(std::initializer_list) -> A; + +A a{1,2,3}; +using type = decltype(a); +using type = A;