Rename MOVE_ONLY_TYPE_WITH_MOVE_CONSTRUCTOR_FOR_CPP_03

base/move.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.
 
 #ifndef BASE_MOVE_H_
 #define BASE_MOVE_H_
 
 #include <utility>
 
 #include "base/compiler_specific.h"
 
-// Macro with the boilerplate that makes a type move-only in C++11.
+// DEPRECATED: Use DISALLOW_COPY_AND_ASSIGN instead, or if your type will
+// be used in Callbacks, use DISALLOW_COPY_AND_ASSIGN_WITH_MOVE_FOR_BIND.

[Nico, 2015/12/04 22:13:58]

we should probably have a tracking bug for doing this for all instances and then
removing this macro

[danakj, 2015/12/04 22:28:34]

yaa I was thinking the same.. let me create and TODO it.

+#define MOVE_ONLY_TYPE_FOR_CPP_03(type) \
+  DISALLOW_COPY_AND_ASSIGN_WITH_MOVE_FOR_BIND(type)
+
+// A macro to disallow the copy constructor and copy assignment functions.
+// This should be used in the private: declarations for a class.
 //
-// USAGE
+// Use this macro instead of DISALLOW_COPY_AND_ASSIGN if you want to pass
+// ownership of the type through a base::Callback without heap-allocating it
+// into a scoped_ptr.  The class must define a move constructor and move
+// assignment operator to make this work.
 //
-// This macro should be used instead of DISALLOW_COPY_AND_ASSIGN to create
-// a "move-only" type.  Unlike DISALLOW_COPY_AND_ASSIGN, this macro should be
-// the first line in a class declaration.
-//
-// A class using this macro must call .Pass() (or somehow be an r-value already)
-// before it can be:
-//
-//   * Passed as a function argument
-//   * Used as the right-hand side of an assignment
-//   * Returned from a function
-//
-// Each class will still need to define their own move constructor and move
-// operator= to make this useful.  Here's an example of the macro, the move
-// constructor, and the move operator= from a hypothetical scoped_ptr class:
-//
-//  template <typename T>
-//  class scoped_ptr {
-//    MOVE_ONLY_TYPE_WITH_MOVE_CONSTRUCTOR_FOR_CPP_03(type);
-//   public:
-//    scoped_ptr(scoped_ptr&& other) : ptr_(other.release()) { }
-//    scoped_ptr& operator=(scoped_ptr&& other) {
-//      reset(other.release());
-//      return *this;
-//    }
-//  };
-//
-//
-// WHY HAVE typedef void MoveOnlyTypeForCPP03
-//
-// Callback<>/Bind() needs to understand movable-but-not-copyable semantics
-// to call .Pass() appropriately when it is expected to transfer the value.
-// The cryptic typedef MoveOnlyTypeForCPP03 is added to make this check
-// easy and automatic in helper templates for Callback<>/Bind().
+// This version of the macro adds a Pass() function and a cryptic
+// MoveOnlyTypeForCPP03 typedef for the base::Callback implementation to use.
 // See IsMoveOnlyType template and its usage in base/callback_internal.h
 // for more details.
-
-#define MOVE_ONLY_TYPE_FOR_CPP_03(type) \
-  MOVE_ONLY_TYPE_WITH_MOVE_CONSTRUCTOR_FOR_CPP_03(type)
-
-#define MOVE_ONLY_TYPE_WITH_MOVE_CONSTRUCTOR_FOR_CPP_03(type)   \
+#define DISALLOW_COPY_AND_ASSIGN_WITH_MOVE_FOR_BIND(type)       \
  private:                                                       \
   type(const type&) = delete;                                   \
   void operator=(const type&) = delete;                         \
                                                                 \
  public:                                                        \
   type&& Pass() WARN_UNUSED_RESULT { return std::move(*this); } \
   typedef void MoveOnlyTypeForCPP03;                            \

[Nico, 2015/12/04 22:13:58]

We probably want to call this MoveOnlTypeForCallback or something and possibly
add a "TODO: Remove once $link_to_callback_move_bug is done"

[danakj, 2015/12/04 22:28:34]

Ya. I'll put a TODO to remove this whole macro for now pointing to the bug.

I was going to TODO to rename this, but TODO comments inside macros is awkward.

                                                                 \
  private:
 
 #endif  // BASE_MOVE_H_