From 656c0212909bc91b1025aa12774d981adb531b4c Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Tue, 5 Jul 2022 17:05:47 -0400
Subject: [PATCH] c++: dependent conversion operator lookup [PR106179]

This testcase demonstrates that my assumption that we would only be
interested in a class template lookup if the template-id is followed by ::
was wrong.

	PR c++/106179
	PR c++/106024

gcc/cp/ChangeLog:

	* parser.cc (cp_parser_lookup_name): Remove :: requirement
	for using unqualified lookup result.

gcc/testsuite/ChangeLog:

	* g++.dg/template/operator16.C: New test.
---
 gcc/cp/parser.cc                           | 4 ----
 gcc/testsuite/g++.dg/template/operator16.C | 9 +++++++++
 2 files changed, 9 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/template/operator16.C

diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index df657a3fb2b..5cd6a527d93 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -30738,10 +30738,6 @@ cp_parser_lookup_name (cp_parser *parser, tree name,
 	     looking at a template arg list.  */
 	  if (!cp_parser_skip_entire_template_parameter_list (parser))
 	    decl = NULL_TREE;
-	  /* And only use the unqualified lookup if we're looking at ::.  */
-	  if (decl
-	      && !cp_lexer_next_token_is (parser->lexer, CPP_SCOPE))
-	    decl = NULL_TREE;
 	}
 
       /* If we know we're looking for a type (e.g. A in p->A::x),
diff --git a/gcc/testsuite/g++.dg/template/operator16.C b/gcc/testsuite/g++.dg/template/operator16.C
new file mode 100644
index 00000000000..434a266850c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/operator16.C
@@ -0,0 +1,9 @@
+// PR c++/106179
+
+struct Mat {
+  template <typename> Mat();
+};
+template <typename> struct Mat_;
+template <typename _Tp> Mat::Mat() {
+  _Tp commaInitializer = commaInitializer.operator Mat_<_Tp>;
+}
-- 
2.11.4.GIT