* include/std/functional (_Mem_fn): Constrain function call operators

	to avoid ambiguities. Use perfect forwarding.
	* testsuite/20_util/function_objects/mem_fn/55463.cc: Additional
	tests.
	* testsuite/20_util/function_objects/mem_fn/forward.cc: New.
	* testsuite/20_util/bind/ref_neg.cc: Adjust dg-error line numbers.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@193879 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 98 insertions, 6 deletions

diff --git a/libstdc++-v3/testsuite/20_util/function_objects/mem_fn/55463.cc b/libstdc++-v3/testsuite/20_util/function_objects/mem_fn/55463.cc
index 5adce1b7cca..ac11852bc0b 100644
--- a/libstdc++-v3/testsuite/20_util/function_objects/mem_fn/55463.cc
+++ b/libstdc++-v3/testsuite/20_util/function_objects/mem_fn/55463.cc
@@ -32,7 +32,12 @@ struct X
   int data;
 };
 
+struct Y : X { };
+
 using CX = const X;
+using CY = const Y;
+
+using X_ptr = X*;
 
 struct smart_ptr
 {
@@ -41,38 +46,63 @@ struct smart_ptr
 
 std::reference_wrapper<X> ref();
 std::reference_wrapper<const X> cref();
+std::reference_wrapper<Y> yref();
 
 void test01()
 {
   int& i1 = std::mem_fn( &X::func )( X() );
-  int& i2 = std::mem_fn( &X::func )( smart_ptr() );
+  int& i2 = std::mem_fn( &X::func )( Y() );
   int& i3 = std::mem_fn( &X::func )( ref() );
+  int& i4 = std::mem_fn( &X::func )( yref() );
+  int& i5 = std::mem_fn( &X::func )( X_ptr() );
+  int& i6 = std::mem_fn( &X::func )( smart_ptr() );
 
   char& c1 = std::mem_fn( &X::func_c )( X() );
   char& c2 = std::mem_fn( &X::func_c )( CX() );
-  char& c3 = std::mem_fn( &X::func_c )( smart_ptr() );
+  char& c3 = std::mem_fn( &X::func_c )( Y() );
   char& c4 = std::mem_fn( &X::func_c )( ref() );
   char& c5 = std::mem_fn( &X::func_c )( cref() );
+  char& c6 = std::mem_fn( &X::func_c )( yref() );
+  char& c7 = std::mem_fn( &X::func_c )( X_ptr() );
+  char& c8 = std::mem_fn( &X::func_c )( smart_ptr() );
 
   short& s1 = std::mem_fn( &X::func_v )( X() );
-  short& s2 = std::mem_fn( &X::func_v )( smart_ptr() );
+  short& s2 = std::mem_fn( &X::func_v )( Y() );
   short& s3 = std::mem_fn( &X::func_v )( ref() );
+  short& s4 = std::mem_fn( &X::func_v )( yref() );
+  short& s5 = std::mem_fn( &X::func_v )( X_ptr() );
+  short& s6 = std::mem_fn( &X::func_v )( smart_ptr() );
 
   double& d1 = std::mem_fn( &X::func_cv )( X() );
   double& d2 = std::mem_fn( &X::func_cv )( CX() );
-  double& d3 = std::mem_fn( &X::func_cv )( smart_ptr() );
+  double& d3 = std::mem_fn( &X::func_cv )( Y() );
   double& d4 = std::mem_fn( &X::func_cv )( ref() );
   double& d5 = std::mem_fn( &X::func_cv )( cref() );
+  double& d6 = std::mem_fn( &X::func_cv )( yref() );
+  double& d7 = std::mem_fn( &X::func_cv )( X_ptr() );
+  double& d8 = std::mem_fn( &X::func_cv )( smart_ptr() );
 
   // [expr.mptr.oper]
   // The result of a .* expression whose second operand is a pointer to a
   // data member is of the same value category (3.10) as its first operand.
   int&& rval = std::mem_fn( &X::data )( X() );
   const int&& crval = std::mem_fn( &X::data )( CX() );
-
-  int& sval = std::mem_fn( &X::data )( smart_ptr() );
+  int&& yrval = std::mem_fn( &X::data )( Y() );
+  const int&& ycrval = std::mem_fn( &X::data )( CY() );
 
   int& val = std::mem_fn( &X::data )( ref() );
   const int& cval = std::mem_fn( &X::data )( cref() );
+  int& yval = std::mem_fn( &X::data )( yref() );
+
+  int& pval = std::mem_fn( &X::data )( X_ptr() );
+  int& sval = std::mem_fn( &X::data )( smart_ptr() );
 }
 
+void test02()
+{
+  std::reference_wrapper<X> r = ref();
+  X& x1 = std::mem_fn( &std::reference_wrapper<X>::get )( r );
+  const std::reference_wrapper<X> cr = ref();
+  const X& x3 = std::mem_fn( &std::reference_wrapper<X>::get )( cr );
+  X& x2 = std::mem_fn( &std::reference_wrapper<X>::get )( ref() );
+}
diff --git a/libstdc++-v3/testsuite/20_util/function_objects/mem_fn/forward.cc b/libstdc++-v3/testsuite/20_util/function_objects/mem_fn/forward.cc
new file mode 100644
index 00000000000..a231bf6858c
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/function_objects/mem_fn/forward.cc
@@ -0,0 +1,62 @@
+// { dg-options "-std=gnu++11" }
+
+// Copyright (C) 2012 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <functional>
+#include <testsuite_hooks.h>
+
+struct Counter
+{
+  Counter() = default;
+  Counter(const Counter&) { ++count; }
+
+  static int count;
+};
+
+int Counter::count = 0;
+
+struct X
+{
+  int func(Counter, int i) { return i; }
+  char func_c(Counter, char c) const { return c; }
+  short func_v(Counter, short s) volatile { return s; }
+  double func_cv(Counter, double d) const volatile { return d; }
+};
+
+void test01()
+{
+  Counter c;
+  X x;
+
+  std::mem_fn( &X::func )( x, c, 0 );
+  VERIFY( Counter::count == 1 );
+
+  std::mem_fn( &X::func_c )( x, c, 0 );
+  VERIFY( Counter::count == 2 );
+
+  std::mem_fn( &X::func_v )( x, c, 0 );
+  VERIFY( Counter::count == 3 );
+
+  std::mem_fn( &X::func_cv )( x, c, 0 );
+  VERIFY( Counter::count == 4 );
+}
+
+int main()
+{
+  test01();
+}