Add std::get_deleter overload with correct signature

* include/bits/shared_ptr.h (get_deleter): Add overload matching
	standard signature.
	* include/bits/shared_ptr_base.h (__shared_ptr): Declare new
	get_deleter overload as a friend.
	* testsuite/20_util/shared_ptr/misc/get_deleter.cc: New.

From-SVN: r249267

libstdc++-v3/ChangeLog

@@ -1,3 +1,11 @@
+2017-06-16  Jonathan Wakely  <jwakely@redhat.com>
+
+	* include/bits/shared_ptr.h (get_deleter): Add overload matching
+	standard signature.
+	* include/bits/shared_ptr_base.h (__shared_ptr): Declare new
+	get_deleter overload as a friend.
+	* testsuite/20_util/shared_ptr/misc/get_deleter.cc: New.
+
 2017-06-16  Jakub Jelinek  <jakub@redhat.com>
 
 	PR libstdc++/81092

libstdc++-v3/include/bits/shared_ptr.h

@@ -70,7 +70,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       return __os;
     }
 
-  /// 20.7.2.2.10 shared_ptr get_deleter
   template<typename _Del, typename _Tp, _Lock_policy _Lp>
     inline _Del*
     get_deleter(const __shared_ptr<_Tp, _Lp>& __p) noexcept
@@ -82,6 +81,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 #endif
     }
 
+  /// 20.7.2.2.10 shared_ptr get_deleter
+  template<typename _Del, typename _Tp>
+    inline _Del*
+    get_deleter(const shared_ptr<_Tp>& __p) noexcept
+    {
+#if __cpp_rtti
+      return static_cast<_Del*>(__p._M_get_deleter(typeid(_Del)));
+#else
+      return 0;
+#endif
+    }
 
   /**
    *  @brief  A smart pointer with reference-counted copy semantics.

libstdc++-v3/include/bits/shared_ptr_base.h

@@ -1402,6 +1402,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       template<typename _Del, typename _Tp1, _Lock_policy _Lp1>
 	friend _Del* get_deleter(const __shared_ptr<_Tp1, _Lp1>&) noexcept;
 
+      template<typename _Del, typename _Tp1>
+	friend _Del* get_deleter(const shared_ptr<_Tp1>&) noexcept;
+
       element_type*	   _M_ptr;         // Contained pointer.
       __shared_count<_Lp>  _M_refcount;    // Reference counter.
     };

libstdc++-v3/testsuite/20_util/shared_ptr/misc/get_deleter.cc

@@ -0,0 +1,44 @@
+// Copyright (C) 2017 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/>.
+
+// { dg-do run { target c++11 } }
+
+#include <memory>
+#include <testsuite_hooks.h>
+
+struct Del {
+  template<typename T> void operator()(T* p) const noexcept { delete p; }
+};
+
+Del* (*f1)(const std::shared_ptr<int>&) = std::get_deleter<Del, int>;
+
+void
+test01()
+{
+  std::shared_ptr<int> p;
+  VERIFY( std::get_deleter<Del>(p) == nullptr );
+  p = std::shared_ptr<int>(new int, Del());
+  VERIFY( std::get_deleter<Del>(p) != nullptr );
+  p = std::shared_ptr<int>(new int);
+  VERIFY( std::get_deleter<Del>(p) == nullptr );
+}
+
+int
+main()
+{
+  test01();
+}