From 5b93c0eede070f8f3a6ce4a394937311c33df550 Mon Sep 17 00:00:00 2001
From: Paolo Carlini <paolo.carlini@oracle.com>
Date: Wed, 4 Oct 2017 21:25:20 +0000
Subject: [PATCH] re PR c++/80471 ((gcc extension) Forwarding-reference `auto`
 function parameters do not follow the same rules as template functions or
 generic lambdas)

2017-10-04  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/80471
	* g++.dg/cpp1y/pr80471.C: New.

From-SVN: r253432
---
 gcc/testsuite/ChangeLog              |  5 +++++
 gcc/testsuite/g++.dg/cpp1y/pr80471.C | 23 +++++++++++++++++++++++
 2 files changed, 28 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/cpp1y/pr80471.C

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b1e3edcb828..bd4133b70ad 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-10-04  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/80471
+	* g++.dg/cpp1y/pr80471.C: New.
+
 2017-10-04  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/78131
diff --git a/gcc/testsuite/g++.dg/cpp1y/pr80471.C b/gcc/testsuite/g++.dg/cpp1y/pr80471.C
new file mode 100644
index 00000000000..bca4022cf57
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/pr80471.C
@@ -0,0 +1,23 @@
+// PR c++/80471
+// { dg-do compile { target c++14 } }
+// { dg-options "" }
+
+template <class, class>
+constexpr bool is_same = false;
+template <class T>
+constexpr bool is_same<T, T> = true;
+
+template<class T>
+decltype(auto) f(T&& a){return a;}
+
+decltype(auto) g(auto&& a){return a;}
+
+auto z = [](auto&& a) -> decltype(auto) { return a; };
+
+int main()
+{
+  int i;
+  static_assert(is_same< decltype(f(i)), int& >, "");
+  static_assert(is_same< decltype(g(i)), int  >, "");
+  static_assert(is_same< decltype(z(i)), int& >, "");
+}
-- 
2.30.2