From: Jason Merrill <jason@redhat.com>
Date: Tue, 8 Jun 2021 13:19:58 +0000 (-0400)
Subject: c++: braced-list overload resolution [PR100963]
X-Git-Tag: releases/gcc-11.2.0~276
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5af06ce836d4d8d1654db3855db8b86a994faf49;p=thirdparty%2Fgcc.git

c++: braced-list overload resolution [PR100963]

My PR969626 patch made us ignore template candidates when there's a perfect
non-template candidate.  In this case, we were considering B(int) a perfect
match for B({0}), but the brace elision makes it imperfect.

	PR c++/100963

gcc/cp/ChangeLog:

	* call.c (perfect_conversion_p): Check check_narrowing.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/initlist124.C: New test.
---

diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 4c4cb5d04916..4f1565dc68f3 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -5878,6 +5878,9 @@ perfect_conversion_p (conversion *conv)
 			next_conversion (conv)->type))
 	return false;
     }
+  if (conv->check_narrowing)
+    /* Brace elision is imperfect.  */
+    return false;
   return true;
 }
 
diff --git a/gcc/testsuite/g++.dg/cpp0x/initlist124.C b/gcc/testsuite/g++.dg/cpp0x/initlist124.C
new file mode 100644
index 000000000000..45dcbb303e29
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/initlist124.C
@@ -0,0 +1,13 @@
+// PR c++/100963
+// { dg-do compile { target c++11 } }
+
+#include <initializer_list>
+
+struct B {
+  B(int) = delete;
+  template<class T> B(std::initializer_list<T>);
+};
+
+int main() {
+  B({0});
+}