DO NOT COMMIT: NullPtr support

base/memory/scoped_ptr.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Scopers help you manage ownership of a pointer, helping you easily manage the
 // a pointer within a scope, and automatically destroying the pointer at the
 // end of a scope.  There are two main classes you will use, which correspond
 // to the operators new/delete and new[]/delete[].
 //
 // Example usage (scoped_ptr):
@@ skipping 77 matching lines @@
 #define BASE_MEMORY_SCOPED_PTR_H_
 
 // This is an implementation designed to match the anticipated future TR2
 // implementation of the scoped_ptr class, and its closely-related brethren,
 // scoped_array, scoped_ptr_malloc.
 
 #include <assert.h>
 #include <stddef.h>
 #include <stdlib.h>
 
+#include <type_traits>
+
+
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/move.h"
+#include "base/nullptr.h"
 #include "base/template_util.h"
 
 namespace base {
 
 namespace subtle {
 class RefCountedBase;
 class RefCountedThreadSafeBase;
 }  // namespace subtle
 
 namespace internal {
@@ skipping 23 matching lines @@
   MOVE_ONLY_TYPE_FOR_CPP_03(scoped_ptr, RValue)
 
   COMPILE_ASSERT(base::internal::IsNotRefCounted<C>::value,
                  C_is_refcounted_type_and_needs_scoped_refptr);
 
  public:
 
   // The element type
   typedef C element_type;
 
+  scoped_ptr() : ptr_(NULL) {}
+  scoped_ptr(base::nullptr_t) : ptr_(NULL) {}
+
   // Constructor.  Defaults to initializing with NULL.
   // There is no way to create an uninitialized scoped_ptr.
   // The input parameter must be allocated with new.
-  explicit scoped_ptr(C* p = NULL) : ptr_(p) { }
+  template <typename V>
+  scoped_ptr(V p, typename std::enable_if<!std::is_integral<V>::value &&
+                                          std::is_convertible<V, C*>::value, int>::type = 0) : ptr_(p) { }
 
   // Constructor.  Allows construction from a scoped_ptr rvalue for a
   // convertible type.
   template <typename U>
   scoped_ptr(scoped_ptr<U> other) : ptr_(other.release()) { }
 
   // Constructor.  Move constructor for C++03 move emulation of this type.
   scoped_ptr(RValue rvalue)
       : ptr_(rvalue.object->release()) {
   }
@@ skipping 357 matching lines @@
 
 // A function to convert T* into scoped_ptr<T>
 // Doing e.g. make_scoped_ptr(new FooBarBaz<type>(arg)) is a shorter notation
 // for scoped_ptr<FooBarBaz<type> >(new FooBarBaz<type>(arg))
 template <typename T>
 scoped_ptr<T> make_scoped_ptr(T* ptr) {
   return scoped_ptr<T>(ptr);
 }
 
 #endif  // BASE_MEMORY_SCOPED_PTR_H_