Remove BindStateHolder and have Bind() return a Callback<> object directly.

base/callback_unittest.cc

 // Copyright (c) 2011 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/callback.h"
 #include "base/callback_internal.h"
 #include "base/callback_old.h"
 #include "base/memory/scoped_ptr.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
+
 namespace {
 
 class HelperObject {
  public:
   HelperObject() : next_number_(0) { }
   int GetNextNumber() { return ++next_number_; }
   void GetNextNumberArg(int* number) { *number = GetNextNumber(); }
 
  private:
   int next_number_;
 };
 
 struct FakeInvoker {
   typedef void(RunType)(internal::BindStateBase*);
   static void Run(internal::BindStateBase*) {
   }
 };
+}  // namespace
+
+namespace internal {
+template <typename Runnable, typename RunType, typename BoundArgsType>
+struct BindState;
 
 // White-box testpoints to inject into a Callback<> object for checking
-// comparators and emptiness APIs.
-class FakeBindState1 : public internal::BindStateBase {
+// comparators and emptiness APIs.  Use a BindState that is specialized
+// based on a type we declared in this anonymous namespace to remove any chance

[akalin, 2011/12/02 18:54:45]

this anonymous namespace -> the anonymous namespace above

[awong, 2011/12/06 00:21:12]

Done.

+// of colliding with another instantiation and breaking the one-definition-rule.
+template <>
+struct internal::BindState<void(void), void(void), void(FakeInvoker)>
+    : public internal::BindStateBase {
  public:
   typedef FakeInvoker InvokerType;
 };
 
-class FakeBindState2 : public internal::BindStateBase {
+template <>
+struct internal::BindState<void(void), void(void),
+                           void(FakeInvoker, FakeInvoker)>
+    : public internal::BindStateBase {
  public:
   typedef FakeInvoker InvokerType;
 };
+}  // namespace internal
+
+namespace {
+
+typedef internal::BindState<void(void), void(void), void(FakeInvoker)>
+    FakeBindState1;
+typedef internal::BindState<void(void), void(void),
+                            void(FakeInvoker, FakeInvoker)>
+   FakeBindState2;
 
 TEST(CallbackOld, OneArg) {
   HelperObject obj;
   scoped_ptr<Callback1<int*>::Type> callback(
       NewCallback(&obj, &HelperObject::GetNextNumberArg));
 
   int number = 0;
   callback->Run(&number);
   EXPECT_EQ(number, 1);
 }
 
 TEST(CallbackOld, ReturnValue) {
   HelperObject obj;
   scoped_ptr<CallbackWithReturnValue<int>::Type> callback(
       NewCallbackWithReturnValue(&obj, &HelperObject::GetNextNumber));
 
   EXPECT_EQ(callback->Run(), 1);
 }
 
 class CallbackTest : public ::testing::Test {
  public:
   CallbackTest()
-      : callback_a_(MakeBindStateHolder(new FakeBindState1())),
-        callback_b_(MakeBindStateHolder(new FakeBindState2())) {
+      : callback_a_(new FakeBindState1()),
+        callback_b_(new FakeBindState2()) {
   }
 
   virtual ~CallbackTest() {
   }
 
  protected:
   Callback<void(void)> callback_a_;
   const Callback<void(void)> callback_b_;  // Ensure APIs work with const.
   Callback<void(void)> null_callback_;
 };
@@ skipping 23 matching lines @@
   EXPECT_FALSE(callback_a_.is_null());
   EXPECT_FALSE(callback_b_.is_null());
 }
 
 TEST_F(CallbackTest, Equals) {
   EXPECT_TRUE(callback_a_.Equals(callback_a_));
   EXPECT_FALSE(callback_a_.Equals(callback_b_));
   EXPECT_FALSE(callback_b_.Equals(callback_a_));
 
   // We should compare based on instance, not type.
-  Callback<void(void)> callback_c(
-      MakeBindStateHolder(new FakeBindState1()));
+  Callback<void(void)> callback_c(new FakeBindState1());
   Callback<void(void)> callback_a2 = callback_a_;
   EXPECT_TRUE(callback_a_.Equals(callback_a2));
   EXPECT_FALSE(callback_a_.Equals(callback_c));
 
   // Empty, however, is always equal to empty.
   Callback<void(void)> empty2;
   EXPECT_TRUE(null_callback_.Equals(empty2));
 }
 
 TEST_F(CallbackTest, Reset) {
   // Resetting should bring us back to empty.
   ASSERT_FALSE(callback_a_.is_null());
   ASSERT_FALSE(callback_a_.Equals(null_callback_));
 
   callback_a_.Reset();
 
   EXPECT_TRUE(callback_a_.is_null());
   EXPECT_TRUE(callback_a_.Equals(null_callback_));
 }
 
 }  // namespace
 }  // namespace base