michael@0: // This file was GENERATED by command:
michael@0: //     pump.py callback.h.pump
michael@0: // DO NOT EDIT BY HAND!!!
michael@0: 
michael@0: 
michael@0: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef BASE_CALLBACK_H_
michael@0: #define BASE_CALLBACK_H_
michael@0: 
michael@0: #include "base/callback_forward.h"
michael@0: #include "base/callback_internal.h"
michael@0: #include "base/template_util.h"
michael@0: 
michael@0: // NOTE: Header files that do not require the full definition of Callback or
michael@0: // Closure should #include "base/callback_forward.h" instead of this file.
michael@0: 
michael@0: // -----------------------------------------------------------------------------
michael@0: // Introduction
michael@0: // -----------------------------------------------------------------------------
michael@0: //
michael@0: // The templated Callback class is a generalized function object. Together
michael@0: // with the Bind() function in bind.h, they provide a type-safe method for
michael@0: // performing partial application of functions.
michael@0: //
michael@0: // Partial application (or "currying") is the process of binding a subset of
michael@0: // a function's arguments to produce another function that takes fewer
michael@0: // arguments. This can be used to pass around a unit of delayed execution,
michael@0: // much like lexical closures are used in other languages. For example, it
michael@0: // is used in Chromium code to schedule tasks on different MessageLoops.
michael@0: //
michael@0: // A callback with no unbound input parameters (base::Callback<void(void)>)
michael@0: // is called a base::Closure. Note that this is NOT the same as what other
michael@0: // languages refer to as a closure -- it does not retain a reference to its
michael@0: // enclosing environment.
michael@0: //
michael@0: // MEMORY MANAGEMENT AND PASSING
michael@0: //
michael@0: // The Callback objects themselves should be passed by const-reference, and
michael@0: // stored by copy. They internally store their state via a refcounted class
michael@0: // and thus do not need to be deleted.
michael@0: //
michael@0: // The reason to pass via a const-reference is to avoid unnecessary
michael@0: // AddRef/Release pairs to the internal state.
michael@0: //
michael@0: //
michael@0: // -----------------------------------------------------------------------------
michael@0: // Quick reference for basic stuff
michael@0: // -----------------------------------------------------------------------------
michael@0: //
michael@0: // BINDING A BARE FUNCTION
michael@0: //
michael@0: //   int Return5() { return 5; }
michael@0: //   base::Callback<int(void)> func_cb = base::Bind(&Return5);
michael@0: //   LOG(INFO) << func_cb.Run();  // Prints 5.
michael@0: //
michael@0: // BINDING A CLASS METHOD
michael@0: //
michael@0: //   The first argument to bind is the member function to call, the second is
michael@0: //   the object on which to call it.
michael@0: //
michael@0: //   class Ref : public base::RefCountedThreadSafe<Ref> {
michael@0: //    public:
michael@0: //     int Foo() { return 3; }
michael@0: //     void PrintBye() { LOG(INFO) << "bye."; }
michael@0: //   };
michael@0: //   scoped_refptr<Ref> ref = new Ref();
michael@0: //   base::Callback<void(void)> ref_cb = base::Bind(&Ref::Foo, ref);
michael@0: //   LOG(INFO) << ref_cb.Run();  // Prints out 3.
michael@0: //
michael@0: //   By default the object must support RefCounted or you will get a compiler
michael@0: //   error. If you're passing between threads, be sure it's
michael@0: //   RefCountedThreadSafe! See "Advanced binding of member functions" below if
michael@0: //   you don't want to use reference counting.
michael@0: //
michael@0: // RUNNING A CALLBACK
michael@0: //
michael@0: //   Callbacks can be run with their "Run" method, which has the same
michael@0: //   signature as the template argument to the callback.
michael@0: //
michael@0: //   void DoSomething(const base::Callback<void(int, std::string)>& callback) {
michael@0: //     callback.Run(5, "hello");
michael@0: //   }
michael@0: //
michael@0: //   Callbacks can be run more than once (they don't get deleted or marked when
michael@0: //   run). However, this precludes using base::Passed (see below).
michael@0: //
michael@0: //   void DoSomething(const base::Callback<double(double)>& callback) {
michael@0: //     double myresult = callback.Run(3.14159);
michael@0: //     myresult += callback.Run(2.71828);
michael@0: //   }
michael@0: //
michael@0: // PASSING UNBOUND INPUT PARAMETERS
michael@0: //
michael@0: //   Unbound parameters are specified at the time a callback is Run(). They are
michael@0: //   specified in the Callback template type:
michael@0: //
michael@0: //   void MyFunc(int i, const std::string& str) {}
michael@0: //   base::Callback<void(int, const std::string&)> cb = base::Bind(&MyFunc);
michael@0: //   cb.Run(23, "hello, world");
michael@0: //
michael@0: // PASSING BOUND INPUT PARAMETERS
michael@0: //
michael@0: //   Bound parameters are specified when you create thee callback as arguments
michael@0: //   to Bind(). They will be passed to the function and the Run()ner of the
michael@0: //   callback doesn't see those values or even know that the function it's
michael@0: //   calling.
michael@0: //
michael@0: //   void MyFunc(int i, const std::string& str) {}
michael@0: //   base::Callback<void(void)> cb = base::Bind(&MyFunc, 23, "hello world");
michael@0: //   cb.Run();
michael@0: //
michael@0: //   A callback with no unbound input parameters (base::Callback<void(void)>)
michael@0: //   is called a base::Closure. So we could have also written:
michael@0: //
michael@0: //   base::Closure cb = base::Bind(&MyFunc, 23, "hello world");
michael@0: //
michael@0: //   When calling member functions, bound parameters just go after the object
michael@0: //   pointer.
michael@0: //
michael@0: //   base::Closure cb = base::Bind(&MyClass::MyFunc, this, 23, "hello world");
michael@0: //
michael@0: // PARTIAL BINDING OF PARAMETERS
michael@0: //
michael@0: //   You can specify some parameters when you create the callback, and specify
michael@0: //   the rest when you execute the callback.
michael@0: //
michael@0: //   void MyFunc(int i, const std::string& str) {}
michael@0: //   base::Callback<void(const std::string&)> cb = base::Bind(&MyFunc, 23);
michael@0: //   cb.Run("hello world");
michael@0: //
michael@0: //   When calling a function bound parameters are first, followed by unbound
michael@0: //   parameters.
michael@0: //
michael@0: //
michael@0: // -----------------------------------------------------------------------------
michael@0: // Quick reference for advanced binding
michael@0: // -----------------------------------------------------------------------------
michael@0: //
michael@0: // BINDING A CLASS METHOD WITH WEAK POINTERS
michael@0: //
michael@0: //   base::Bind(&MyClass::Foo, GetWeakPtr());
michael@0: //
michael@0: //   The callback will not be issued if the object is destroyed at the time
michael@0: //   it's issued. DANGER: weak pointers are not threadsafe, so don't use this
michael@0: //   when passing between threads!
michael@0: //
michael@0: // BINDING A CLASS METHOD WITH MANUAL LIFETIME MANAGEMENT
michael@0: //
michael@0: //   base::Bind(&MyClass::Foo, base::Unretained(this));
michael@0: //
michael@0: //   This disables all lifetime management on the object. You're responsible
michael@0: //   for making sure the object is alive at the time of the call. You break it,
michael@0: //   you own it!
michael@0: //
michael@0: // BINDING A CLASS METHOD AND HAVING THE CALLBACK OWN THE CLASS
michael@0: //
michael@0: //   MyClass* myclass = new MyClass;
michael@0: //   base::Bind(&MyClass::Foo, base::Owned(myclass));
michael@0: //
michael@0: //   The object will be deleted when the callback is destroyed, even if it's
michael@0: //   not run (like if you post a task during shutdown). Potentially useful for
michael@0: //   "fire and forget" cases.
michael@0: //
michael@0: // IGNORING RETURN VALUES
michael@0: //
michael@0: //   Sometimes you want to call a function that returns a value in a callback
michael@0: //   that doesn't expect a return value.
michael@0: //
michael@0: //   int DoSomething(int arg) { cout << arg << endl; }
michael@0: //   base::Callback<void<int>) cb =
michael@0: //       base::Bind(base::IgnoreResult(&DoSomething));
michael@0: //
michael@0: //
michael@0: // -----------------------------------------------------------------------------
michael@0: // Quick reference for binding parameters to Bind()
michael@0: // -----------------------------------------------------------------------------
michael@0: //
michael@0: // Bound parameters are specified as arguments to Bind() and are passed to the
michael@0: // function. A callback with no parameters or no unbound parameters is called a
michael@0: // Closure (base::Callback<void(void)> and base::Closure are the same thing).
michael@0: //
michael@0: // PASSING PARAMETERS OWNED BY THE CALLBACK
michael@0: //
michael@0: //   void Foo(int* arg) { cout << *arg << endl; }
michael@0: //   int* pn = new int(1);
michael@0: //   base::Closure foo_callback = base::Bind(&foo, base::Owned(pn));
michael@0: //
michael@0: //   The parameter will be deleted when the callback is destroyed, even if it's
michael@0: //   not run (like if you post a task during shutdown).
michael@0: //
michael@0: // PASSING PARAMETERS AS A scoped_ptr
michael@0: //
michael@0: //   void TakesOwnership(scoped_ptr<Foo> arg) {}
michael@0: //   scoped_ptr<Foo> f(new Foo);
michael@0: //   // f becomes null during the following call.
michael@0: //   base::Closure cb = base::Bind(&TakesOwnership, base::Passed(&f));
michael@0: //
michael@0: //   Ownership of the parameter will be with the callback until the it is run,
michael@0: //   when ownership is passed to the callback function. This means the callback
michael@0: //   can only be run once. If the callback is never run, it will delete the
michael@0: //   object when it's destroyed.
michael@0: //
michael@0: // PASSING PARAMETERS AS A scoped_refptr
michael@0: //
michael@0: //   void TakesOneRef(scoped_refptr<Foo> arg) {}
michael@0: //   scoped_refptr<Foo> f(new Foo)
michael@0: //   base::Closure cb = base::Bind(&TakesOneRef, f);
michael@0: //
michael@0: //   This should "just work." The closure will take a reference as long as it
michael@0: //   is alive, and another reference will be taken for the called function.
michael@0: //
michael@0: // PASSING PARAMETERS BY REFERENCE
michael@0: //
michael@0: //   void foo(int arg) { cout << arg << endl }
michael@0: //   int n = 1;
michael@0: //   base::Closure has_ref = base::Bind(&foo, base::ConstRef(n));
michael@0: //   n = 2;
michael@0: //   has_ref.Run();  // Prints "2"
michael@0: //
michael@0: //   Normally parameters are copied in the closure. DANGER: ConstRef stores a
michael@0: //   const reference instead, referencing the original parameter. This means
michael@0: //   that you must ensure the object outlives the callback!
michael@0: //
michael@0: //
michael@0: // -----------------------------------------------------------------------------
michael@0: // Implementation notes
michael@0: // -----------------------------------------------------------------------------
michael@0: //
michael@0: // WHERE IS THIS DESIGN FROM:
michael@0: //
michael@0: // The design Callback and Bind is heavily influenced by C++'s
michael@0: // tr1::function/tr1::bind, and by the "Google Callback" system used inside
michael@0: // Google.
michael@0: //
michael@0: //
michael@0: // HOW THE IMPLEMENTATION WORKS:
michael@0: //
michael@0: // There are three main components to the system:
michael@0: //   1) The Callback classes.
michael@0: //   2) The Bind() functions.
michael@0: //   3) The arguments wrappers (e.g., Unretained() and ConstRef()).
michael@0: //
michael@0: // The Callback classes represent a generic function pointer. Internally,
michael@0: // it stores a refcounted piece of state that represents the target function
michael@0: // and all its bound parameters.  Each Callback specialization has a templated
michael@0: // constructor that takes an BindState<>*.  In the context of the constructor,
michael@0: // the static type of this BindState<> pointer uniquely identifies the
michael@0: // function it is representing, all its bound parameters, and a Run() method
michael@0: // that is capable of invoking the target.
michael@0: //
michael@0: // Callback's constructor takes the BindState<>* that has the full static type
michael@0: // and erases the target function type as well as the types of the bound
michael@0: // parameters.  It does this by storing a pointer to the specific Run()
michael@0: // function, and upcasting the state of BindState<>* to a
michael@0: // BindStateBase*. This is safe as long as this BindStateBase pointer
michael@0: // is only used with the stored Run() pointer.
michael@0: //
michael@0: // To BindState<> objects are created inside the Bind() functions.
michael@0: // These functions, along with a set of internal templates, are responsible for
michael@0: //
michael@0: //  - Unwrapping the function signature into return type, and parameters
michael@0: //  - Determining the number of parameters that are bound
michael@0: //  - Creating the BindState storing the bound parameters
michael@0: //  - Performing compile-time asserts to avoid error-prone behavior
michael@0: //  - Returning an Callback<> with an arity matching the number of unbound
michael@0: //    parameters and that knows the correct refcounting semantics for the
michael@0: //    target object if we are binding a method.
michael@0: //
michael@0: // The Bind functions do the above using type-inference, and template
michael@0: // specializations.
michael@0: //
michael@0: // By default Bind() will store copies of all bound parameters, and attempt
michael@0: // to refcount a target object if the function being bound is a class method.
michael@0: // These copies are created even if the function takes parameters as const
michael@0: // references. (Binding to non-const references is forbidden, see bind.h.)
michael@0: //
michael@0: // To change this behavior, we introduce a set of argument wrappers
michael@0: // (e.g., Unretained(), and ConstRef()).  These are simple container templates
michael@0: // that are passed by value, and wrap a pointer to argument.  See the
michael@0: // file-level comment in base/bind_helpers.h for more info.
michael@0: //
michael@0: // These types are passed to the Unwrap() functions, and the MaybeRefcount()
michael@0: // functions respectively to modify the behavior of Bind().  The Unwrap()
michael@0: // and MaybeRefcount() functions change behavior by doing partial
michael@0: // specialization based on whether or not a parameter is a wrapper type.
michael@0: //
michael@0: // ConstRef() is similar to tr1::cref.  Unretained() is specific to Chromium.
michael@0: //
michael@0: //
michael@0: // WHY NOT TR1 FUNCTION/BIND?
michael@0: //
michael@0: // Direct use of tr1::function and tr1::bind was considered, but ultimately
michael@0: // rejected because of the number of copy constructors invocations involved
michael@0: // in the binding of arguments during construction, and the forwarding of
michael@0: // arguments during invocation.  These copies will no longer be an issue in
michael@0: // C++0x because C++0x will support rvalue reference allowing for the compiler
michael@0: // to avoid these copies.  However, waiting for C++0x is not an option.
michael@0: //
michael@0: // Measured with valgrind on gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5), the
michael@0: // tr1::bind call itself will invoke a non-trivial copy constructor three times
michael@0: // for each bound parameter.  Also, each when passing a tr1::function, each
michael@0: // bound argument will be copied again.
michael@0: //
michael@0: // In addition to the copies taken at binding and invocation, copying a
michael@0: // tr1::function causes a copy to be made of all the bound parameters and
michael@0: // state.
michael@0: //
michael@0: // Furthermore, in Chromium, it is desirable for the Callback to take a
michael@0: // reference on a target object when representing a class method call.  This
michael@0: // is not supported by tr1.
michael@0: //
michael@0: // Lastly, tr1::function and tr1::bind has a more general and flexible API.
michael@0: // This includes things like argument reordering by use of
michael@0: // tr1::bind::placeholder, support for non-const reference parameters, and some
michael@0: // limited amount of subtyping of the tr1::function object (e.g.,
michael@0: // tr1::function<int(int)> is convertible to tr1::function<void(int)>).
michael@0: //
michael@0: // These are not features that are required in Chromium. Some of them, such as
michael@0: // allowing for reference parameters, and subtyping of functions, may actually
michael@0: // become a source of errors. Removing support for these features actually
michael@0: // allows for a simpler implementation, and a terser Currying API.
michael@0: //
michael@0: //
michael@0: // WHY NOT GOOGLE CALLBACKS?
michael@0: //
michael@0: // The Google callback system also does not support refcounting.  Furthermore,
michael@0: // its implementation has a number of strange edge cases with respect to type
michael@0: // conversion of its arguments.  In particular, the argument's constness must
michael@0: // at times match exactly the function signature, or the type-inference might
michael@0: // break.  Given the above, writing a custom solution was easier.
michael@0: //
michael@0: //
michael@0: // MISSING FUNCTIONALITY
michael@0: //  - Invoking the return of Bind.  Bind(&foo).Run() does not work;
michael@0: //  - Binding arrays to functions that take a non-const pointer.
michael@0: //    Example:
michael@0: //      void Foo(const char* ptr);
michael@0: //      void Bar(char* ptr);
michael@0: //      Bind(&Foo, "test");
michael@0: //      Bind(&Bar, "test");  // This fails because ptr is not const.
michael@0: 
michael@0: namespace base {
michael@0: 
michael@0: // First, we forward declare the Callback class template. This informs the
michael@0: // compiler that the template only has 1 type parameter which is the function
michael@0: // signature that the Callback is representing.
michael@0: //
michael@0: // After this, create template specializations for 0-7 parameters. Note that
michael@0: // even though the template typelist grows, the specialization still
michael@0: // only has one type: the function signature.
michael@0: //
michael@0: // If you are thinking of forward declaring Callback in your own header file,
michael@0: // please include "base/callback_forward.h" instead.
michael@0: template <typename Sig>
michael@0: class Callback;
michael@0: 
michael@0: namespace internal {
michael@0: template <typename Runnable, typename RunType, typename BoundArgsType>
michael@0: struct BindState;
michael@0: }  // namespace internal
michael@0: 
michael@0: template <typename R>
michael@0: class Callback<R(void)> : public internal::CallbackBase {
michael@0:  public:
michael@0:   typedef R(RunType)();
michael@0: 
michael@0:   Callback() : CallbackBase(NULL) { }
michael@0: 
michael@0:   // Note that this constructor CANNOT be explicit, and that Bind() CANNOT
michael@0:   // return the exact Callback<> type.  See base/bind.h for details.
michael@0:   template <typename Runnable, typename BindRunType, typename BoundArgsType>
michael@0:   Callback(internal::BindState<Runnable, BindRunType,
michael@0:            BoundArgsType>* bind_state)
michael@0:       : CallbackBase(bind_state) {
michael@0: 
michael@0:     // Force the assignment to a local variable of PolymorphicInvoke
michael@0:     // so the compiler will typecheck that the passed in Run() method has
michael@0:     // the correct type.
michael@0:     PolymorphicInvoke invoke_func =
michael@0:         &internal::BindState<Runnable, BindRunType, BoundArgsType>
michael@0:             ::InvokerType::Run;
michael@0:     polymorphic_invoke_ = reinterpret_cast<InvokeFuncStorage>(invoke_func);
michael@0:   }
michael@0: 
michael@0:   bool Equals(const Callback& other) const {
michael@0:     return CallbackBase::Equals(other);
michael@0:   }
michael@0: 
michael@0:   R Run() const {
michael@0:     PolymorphicInvoke f =
michael@0:         reinterpret_cast<PolymorphicInvoke>(polymorphic_invoke_);
michael@0: 
michael@0:     return f(bind_state_.get());
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   typedef R(*PolymorphicInvoke)(
michael@0:       internal::BindStateBase*);
michael@0: 
michael@0: };
michael@0: 
michael@0: template <typename R, typename A1>
michael@0: class Callback<R(A1)> : public internal::CallbackBase {
michael@0:  public:
michael@0:   typedef R(RunType)(A1);
michael@0: 
michael@0:   Callback() : CallbackBase(NULL) { }
michael@0: 
michael@0:   // Note that this constructor CANNOT be explicit, and that Bind() CANNOT
michael@0:   // return the exact Callback<> type.  See base/bind.h for details.
michael@0:   template <typename Runnable, typename BindRunType, typename BoundArgsType>
michael@0:   Callback(internal::BindState<Runnable, BindRunType,
michael@0:            BoundArgsType>* bind_state)
michael@0:       : CallbackBase(bind_state) {
michael@0: 
michael@0:     // Force the assignment to a local variable of PolymorphicInvoke
michael@0:     // so the compiler will typecheck that the passed in Run() method has
michael@0:     // the correct type.
michael@0:     PolymorphicInvoke invoke_func =
michael@0:         &internal::BindState<Runnable, BindRunType, BoundArgsType>
michael@0:             ::InvokerType::Run;
michael@0:     polymorphic_invoke_ = reinterpret_cast<InvokeFuncStorage>(invoke_func);
michael@0:   }
michael@0: 
michael@0:   bool Equals(const Callback& other) const {
michael@0:     return CallbackBase::Equals(other);
michael@0:   }
michael@0: 
michael@0:   R Run(typename internal::CallbackParamTraits<A1>::ForwardType a1) const {
michael@0:     PolymorphicInvoke f =
michael@0:         reinterpret_cast<PolymorphicInvoke>(polymorphic_invoke_);
michael@0: 
michael@0:     return f(bind_state_.get(), internal::CallbackForward(a1));
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   typedef R(*PolymorphicInvoke)(
michael@0:       internal::BindStateBase*,
michael@0:           typename internal::CallbackParamTraits<A1>::ForwardType);
michael@0: 
michael@0: };
michael@0: 
michael@0: template <typename R, typename A1, typename A2>
michael@0: class Callback<R(A1, A2)> : public internal::CallbackBase {
michael@0:  public:
michael@0:   typedef R(RunType)(A1, A2);
michael@0: 
michael@0:   Callback() : CallbackBase(NULL) { }
michael@0: 
michael@0:   // Note that this constructor CANNOT be explicit, and that Bind() CANNOT
michael@0:   // return the exact Callback<> type.  See base/bind.h for details.
michael@0:   template <typename Runnable, typename BindRunType, typename BoundArgsType>
michael@0:   Callback(internal::BindState<Runnable, BindRunType,
michael@0:            BoundArgsType>* bind_state)
michael@0:       : CallbackBase(bind_state) {
michael@0: 
michael@0:     // Force the assignment to a local variable of PolymorphicInvoke
michael@0:     // so the compiler will typecheck that the passed in Run() method has
michael@0:     // the correct type.
michael@0:     PolymorphicInvoke invoke_func =
michael@0:         &internal::BindState<Runnable, BindRunType, BoundArgsType>
michael@0:             ::InvokerType::Run;
michael@0:     polymorphic_invoke_ = reinterpret_cast<InvokeFuncStorage>(invoke_func);
michael@0:   }
michael@0: 
michael@0:   bool Equals(const Callback& other) const {
michael@0:     return CallbackBase::Equals(other);
michael@0:   }
michael@0: 
michael@0:   R Run(typename internal::CallbackParamTraits<A1>::ForwardType a1,
michael@0:         typename internal::CallbackParamTraits<A2>::ForwardType a2) const {
michael@0:     PolymorphicInvoke f =
michael@0:         reinterpret_cast<PolymorphicInvoke>(polymorphic_invoke_);
michael@0: 
michael@0:     return f(bind_state_.get(), internal::CallbackForward(a1),
michael@0:              internal::CallbackForward(a2));
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   typedef R(*PolymorphicInvoke)(
michael@0:       internal::BindStateBase*,
michael@0:           typename internal::CallbackParamTraits<A1>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A2>::ForwardType);
michael@0: 
michael@0: };
michael@0: 
michael@0: template <typename R, typename A1, typename A2, typename A3>
michael@0: class Callback<R(A1, A2, A3)> : public internal::CallbackBase {
michael@0:  public:
michael@0:   typedef R(RunType)(A1, A2, A3);
michael@0: 
michael@0:   Callback() : CallbackBase(NULL) { }
michael@0: 
michael@0:   // Note that this constructor CANNOT be explicit, and that Bind() CANNOT
michael@0:   // return the exact Callback<> type.  See base/bind.h for details.
michael@0:   template <typename Runnable, typename BindRunType, typename BoundArgsType>
michael@0:   Callback(internal::BindState<Runnable, BindRunType,
michael@0:            BoundArgsType>* bind_state)
michael@0:       : CallbackBase(bind_state) {
michael@0: 
michael@0:     // Force the assignment to a local variable of PolymorphicInvoke
michael@0:     // so the compiler will typecheck that the passed in Run() method has
michael@0:     // the correct type.
michael@0:     PolymorphicInvoke invoke_func =
michael@0:         &internal::BindState<Runnable, BindRunType, BoundArgsType>
michael@0:             ::InvokerType::Run;
michael@0:     polymorphic_invoke_ = reinterpret_cast<InvokeFuncStorage>(invoke_func);
michael@0:   }
michael@0: 
michael@0:   bool Equals(const Callback& other) const {
michael@0:     return CallbackBase::Equals(other);
michael@0:   }
michael@0: 
michael@0:   R Run(typename internal::CallbackParamTraits<A1>::ForwardType a1,
michael@0:         typename internal::CallbackParamTraits<A2>::ForwardType a2,
michael@0:         typename internal::CallbackParamTraits<A3>::ForwardType a3) const {
michael@0:     PolymorphicInvoke f =
michael@0:         reinterpret_cast<PolymorphicInvoke>(polymorphic_invoke_);
michael@0: 
michael@0:     return f(bind_state_.get(), internal::CallbackForward(a1),
michael@0:              internal::CallbackForward(a2),
michael@0:              internal::CallbackForward(a3));
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   typedef R(*PolymorphicInvoke)(
michael@0:       internal::BindStateBase*,
michael@0:           typename internal::CallbackParamTraits<A1>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A2>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A3>::ForwardType);
michael@0: 
michael@0: };
michael@0: 
michael@0: template <typename R, typename A1, typename A2, typename A3, typename A4>
michael@0: class Callback<R(A1, A2, A3, A4)> : public internal::CallbackBase {
michael@0:  public:
michael@0:   typedef R(RunType)(A1, A2, A3, A4);
michael@0: 
michael@0:   Callback() : CallbackBase(NULL) { }
michael@0: 
michael@0:   // Note that this constructor CANNOT be explicit, and that Bind() CANNOT
michael@0:   // return the exact Callback<> type.  See base/bind.h for details.
michael@0:   template <typename Runnable, typename BindRunType, typename BoundArgsType>
michael@0:   Callback(internal::BindState<Runnable, BindRunType,
michael@0:            BoundArgsType>* bind_state)
michael@0:       : CallbackBase(bind_state) {
michael@0: 
michael@0:     // Force the assignment to a local variable of PolymorphicInvoke
michael@0:     // so the compiler will typecheck that the passed in Run() method has
michael@0:     // the correct type.
michael@0:     PolymorphicInvoke invoke_func =
michael@0:         &internal::BindState<Runnable, BindRunType, BoundArgsType>
michael@0:             ::InvokerType::Run;
michael@0:     polymorphic_invoke_ = reinterpret_cast<InvokeFuncStorage>(invoke_func);
michael@0:   }
michael@0: 
michael@0:   bool Equals(const Callback& other) const {
michael@0:     return CallbackBase::Equals(other);
michael@0:   }
michael@0: 
michael@0:   R Run(typename internal::CallbackParamTraits<A1>::ForwardType a1,
michael@0:         typename internal::CallbackParamTraits<A2>::ForwardType a2,
michael@0:         typename internal::CallbackParamTraits<A3>::ForwardType a3,
michael@0:         typename internal::CallbackParamTraits<A4>::ForwardType a4) const {
michael@0:     PolymorphicInvoke f =
michael@0:         reinterpret_cast<PolymorphicInvoke>(polymorphic_invoke_);
michael@0: 
michael@0:     return f(bind_state_.get(), internal::CallbackForward(a1),
michael@0:              internal::CallbackForward(a2),
michael@0:              internal::CallbackForward(a3),
michael@0:              internal::CallbackForward(a4));
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   typedef R(*PolymorphicInvoke)(
michael@0:       internal::BindStateBase*,
michael@0:           typename internal::CallbackParamTraits<A1>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A2>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A3>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A4>::ForwardType);
michael@0: 
michael@0: };
michael@0: 
michael@0: template <typename R, typename A1, typename A2, typename A3, typename A4,
michael@0:     typename A5>
michael@0: class Callback<R(A1, A2, A3, A4, A5)> : public internal::CallbackBase {
michael@0:  public:
michael@0:   typedef R(RunType)(A1, A2, A3, A4, A5);
michael@0: 
michael@0:   Callback() : CallbackBase(NULL) { }
michael@0: 
michael@0:   // Note that this constructor CANNOT be explicit, and that Bind() CANNOT
michael@0:   // return the exact Callback<> type.  See base/bind.h for details.
michael@0:   template <typename Runnable, typename BindRunType, typename BoundArgsType>
michael@0:   Callback(internal::BindState<Runnable, BindRunType,
michael@0:            BoundArgsType>* bind_state)
michael@0:       : CallbackBase(bind_state) {
michael@0: 
michael@0:     // Force the assignment to a local variable of PolymorphicInvoke
michael@0:     // so the compiler will typecheck that the passed in Run() method has
michael@0:     // the correct type.
michael@0:     PolymorphicInvoke invoke_func =
michael@0:         &internal::BindState<Runnable, BindRunType, BoundArgsType>
michael@0:             ::InvokerType::Run;
michael@0:     polymorphic_invoke_ = reinterpret_cast<InvokeFuncStorage>(invoke_func);
michael@0:   }
michael@0: 
michael@0:   bool Equals(const Callback& other) const {
michael@0:     return CallbackBase::Equals(other);
michael@0:   }
michael@0: 
michael@0:   R Run(typename internal::CallbackParamTraits<A1>::ForwardType a1,
michael@0:         typename internal::CallbackParamTraits<A2>::ForwardType a2,
michael@0:         typename internal::CallbackParamTraits<A3>::ForwardType a3,
michael@0:         typename internal::CallbackParamTraits<A4>::ForwardType a4,
michael@0:         typename internal::CallbackParamTraits<A5>::ForwardType a5) const {
michael@0:     PolymorphicInvoke f =
michael@0:         reinterpret_cast<PolymorphicInvoke>(polymorphic_invoke_);
michael@0: 
michael@0:     return f(bind_state_.get(), internal::CallbackForward(a1),
michael@0:              internal::CallbackForward(a2),
michael@0:              internal::CallbackForward(a3),
michael@0:              internal::CallbackForward(a4),
michael@0:              internal::CallbackForward(a5));
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   typedef R(*PolymorphicInvoke)(
michael@0:       internal::BindStateBase*,
michael@0:           typename internal::CallbackParamTraits<A1>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A2>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A3>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A4>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A5>::ForwardType);
michael@0: 
michael@0: };
michael@0: 
michael@0: template <typename R, typename A1, typename A2, typename A3, typename A4,
michael@0:     typename A5, typename A6>
michael@0: class Callback<R(A1, A2, A3, A4, A5, A6)> : public internal::CallbackBase {
michael@0:  public:
michael@0:   typedef R(RunType)(A1, A2, A3, A4, A5, A6);
michael@0: 
michael@0:   Callback() : CallbackBase(NULL) { }
michael@0: 
michael@0:   // Note that this constructor CANNOT be explicit, and that Bind() CANNOT
michael@0:   // return the exact Callback<> type.  See base/bind.h for details.
michael@0:   template <typename Runnable, typename BindRunType, typename BoundArgsType>
michael@0:   Callback(internal::BindState<Runnable, BindRunType,
michael@0:            BoundArgsType>* bind_state)
michael@0:       : CallbackBase(bind_state) {
michael@0: 
michael@0:     // Force the assignment to a local variable of PolymorphicInvoke
michael@0:     // so the compiler will typecheck that the passed in Run() method has
michael@0:     // the correct type.
michael@0:     PolymorphicInvoke invoke_func =
michael@0:         &internal::BindState<Runnable, BindRunType, BoundArgsType>
michael@0:             ::InvokerType::Run;
michael@0:     polymorphic_invoke_ = reinterpret_cast<InvokeFuncStorage>(invoke_func);
michael@0:   }
michael@0: 
michael@0:   bool Equals(const Callback& other) const {
michael@0:     return CallbackBase::Equals(other);
michael@0:   }
michael@0: 
michael@0:   R Run(typename internal::CallbackParamTraits<A1>::ForwardType a1,
michael@0:         typename internal::CallbackParamTraits<A2>::ForwardType a2,
michael@0:         typename internal::CallbackParamTraits<A3>::ForwardType a3,
michael@0:         typename internal::CallbackParamTraits<A4>::ForwardType a4,
michael@0:         typename internal::CallbackParamTraits<A5>::ForwardType a5,
michael@0:         typename internal::CallbackParamTraits<A6>::ForwardType a6) const {
michael@0:     PolymorphicInvoke f =
michael@0:         reinterpret_cast<PolymorphicInvoke>(polymorphic_invoke_);
michael@0: 
michael@0:     return f(bind_state_.get(), internal::CallbackForward(a1),
michael@0:              internal::CallbackForward(a2),
michael@0:              internal::CallbackForward(a3),
michael@0:              internal::CallbackForward(a4),
michael@0:              internal::CallbackForward(a5),
michael@0:              internal::CallbackForward(a6));
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   typedef R(*PolymorphicInvoke)(
michael@0:       internal::BindStateBase*,
michael@0:           typename internal::CallbackParamTraits<A1>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A2>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A3>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A4>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A5>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A6>::ForwardType);
michael@0: 
michael@0: };
michael@0: 
michael@0: template <typename R, typename A1, typename A2, typename A3, typename A4,
michael@0:     typename A5, typename A6, typename A7>
michael@0: class Callback<R(A1, A2, A3, A4, A5, A6, A7)> : public internal::CallbackBase {
michael@0:  public:
michael@0:   typedef R(RunType)(A1, A2, A3, A4, A5, A6, A7);
michael@0: 
michael@0:   Callback() : CallbackBase(NULL) { }
michael@0: 
michael@0:   // Note that this constructor CANNOT be explicit, and that Bind() CANNOT
michael@0:   // return the exact Callback<> type.  See base/bind.h for details.
michael@0:   template <typename Runnable, typename BindRunType, typename BoundArgsType>
michael@0:   Callback(internal::BindState<Runnable, BindRunType,
michael@0:            BoundArgsType>* bind_state)
michael@0:       : CallbackBase(bind_state) {
michael@0: 
michael@0:     // Force the assignment to a local variable of PolymorphicInvoke
michael@0:     // so the compiler will typecheck that the passed in Run() method has
michael@0:     // the correct type.
michael@0:     PolymorphicInvoke invoke_func =
michael@0:         &internal::BindState<Runnable, BindRunType, BoundArgsType>
michael@0:             ::InvokerType::Run;
michael@0:     polymorphic_invoke_ = reinterpret_cast<InvokeFuncStorage>(invoke_func);
michael@0:   }
michael@0: 
michael@0:   bool Equals(const Callback& other) const {
michael@0:     return CallbackBase::Equals(other);
michael@0:   }
michael@0: 
michael@0:   R Run(typename internal::CallbackParamTraits<A1>::ForwardType a1,
michael@0:         typename internal::CallbackParamTraits<A2>::ForwardType a2,
michael@0:         typename internal::CallbackParamTraits<A3>::ForwardType a3,
michael@0:         typename internal::CallbackParamTraits<A4>::ForwardType a4,
michael@0:         typename internal::CallbackParamTraits<A5>::ForwardType a5,
michael@0:         typename internal::CallbackParamTraits<A6>::ForwardType a6,
michael@0:         typename internal::CallbackParamTraits<A7>::ForwardType a7) const {
michael@0:     PolymorphicInvoke f =
michael@0:         reinterpret_cast<PolymorphicInvoke>(polymorphic_invoke_);
michael@0: 
michael@0:     return f(bind_state_.get(), internal::CallbackForward(a1),
michael@0:              internal::CallbackForward(a2),
michael@0:              internal::CallbackForward(a3),
michael@0:              internal::CallbackForward(a4),
michael@0:              internal::CallbackForward(a5),
michael@0:              internal::CallbackForward(a6),
michael@0:              internal::CallbackForward(a7));
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   typedef R(*PolymorphicInvoke)(
michael@0:       internal::BindStateBase*,
michael@0:           typename internal::CallbackParamTraits<A1>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A2>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A3>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A4>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A5>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A6>::ForwardType,
michael@0:           typename internal::CallbackParamTraits<A7>::ForwardType);
michael@0: 
michael@0: };
michael@0: 
michael@0: 
michael@0: // Syntactic sugar to make Callbacks<void(void)> easier to declare since it
michael@0: // will be used in a lot of APIs with delayed execution.
michael@0: typedef Callback<void(void)> Closure;
michael@0: 
michael@0: }  // namespace base
michael@0: 
michael@0: #endif  // BASE_CALLBACK_H