Add nullptr support to scoped_ptr.

base/memory/scoped_ptr_unittest.cc

 // 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.
 
 #include "base/memory/scoped_ptr.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 388 matching lines @@
   }
 
   // Test uncaught Pass() does not leak.
   {
     ConDecLogger* logger = new ConDecLogger(&constructed);
     scoped_ptr<ConDecLogger> scoper(logger);
     EXPECT_EQ(1, constructed);
 
     // Should auto-destruct logger by end of scope.
     scoper.Pass();
+    // This differs from unique_ptr, as Pass() has side effects but std::move()
+    // does not.
     EXPECT_FALSE(scoper.get());
   }
   EXPECT_EQ(0, constructed);
 
   // Test that passing to function which does nothing does not leak.
   {
     ConDecLogger* logger = new ConDecLogger(&constructed);
     scoped_ptr<ConDecLogger> scoper(logger);
     EXPECT_EQ(1, constructed);
 
@@ skipping 176 matching lines @@
   {
     OverloadedNewAndDelete::ResetCounters();
     scoped_ptr<OverloadedNewAndDelete> scoper(new OverloadedNewAndDelete());
     EXPECT_TRUE(scoper.get());
 
     scoped_ptr<OverloadedNewAndDelete> scoper2(scoper.Pass());
   }
   EXPECT_EQ(1, OverloadedNewAndDelete::delete_count());
   EXPECT_EQ(1, OverloadedNewAndDelete::new_count());
 }
+
+scoped_ptr<int> NullIntReturn() {
+  return nullptr;
+}
+
+TEST(ScopedPtrTest, Nullptr) {
+  scoped_ptr<int> scoper1(nullptr);
+  scoped_ptr<int> scoper2(new int);
+  scoper2 = nullptr;
+  scoped_ptr<int> scoper3(NullIntReturn());
+  scoped_ptr<int> scoper4 = NullIntReturn();
+  EXPECT_EQ(nullptr, scoper1.get());
+  EXPECT_EQ(nullptr, scoper2.get());
+  EXPECT_EQ(nullptr, scoper3.get());
+  EXPECT_EQ(nullptr, scoper4.get());
+}
+
+scoped_ptr<int[]> NullIntArrayReturn() {
+  return nullptr;
+}
+
+TEST(ScopedPtrTest, NullptrArray) {
+  scoped_ptr<int[]> scoper1(nullptr);
+  scoped_ptr<int[]> scoper2(new int[3]);

[jamesr, 2014/09/27 20:30:36]

oh, that would explain it!  we do seem to have pretty good coverage above for
preserving deleters, but we might want to add more tests using rvalue semantics
when we get there.

+  scoper2 = nullptr;
+  scoped_ptr<int[]> scoper3(NullIntArrayReturn());
+  scoped_ptr<int[]> scoper4 = NullIntArrayReturn();
+  EXPECT_EQ(nullptr, scoper1.get());
+  EXPECT_EQ(nullptr, scoper2.get());
+  EXPECT_EQ(nullptr, scoper3.get());
+  EXPECT_EQ(nullptr, scoper4.get());
+}
+
+class Super {};
+class Sub : public Super {};
+
+scoped_ptr<Sub> SubClassReturn() {
+  return make_scoped_ptr(new Sub);
+}
+
+TEST(ScopedPtrTest, Conversion) {
+  scoped_ptr<Sub> sub1(new Sub);
+  scoped_ptr<Sub> sub2(new Sub);
+
+  // Upcast with Pass() works.
+  scoped_ptr<Super> super1 = sub1.Pass();
+  super1 = sub2.Pass();
+
+  // Upcast with an rvalue works.
+  scoped_ptr<Super> super2 = SubClassReturn();
+  super2 = SubClassReturn();
+}