bind_internal.h

// This file was GENERATED by command:
//     pump.py bind_internal.h.pump
// DO NOT EDIT BY HAND!!!


// 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.

#ifndef BASE_BIND_INTERNAL_H_
#define BASE_BIND_INTERNAL_H_

#include "base/bind_helpers.h"
#include "base/callback_internal.h"
#include "base/memory/raw_scoped_refptr_mismatch_checker.h"
#include "base/memory/weak_ptr.h"
#include "base/template_util.h"
#include "build/build_config.h"

#if defined(OS_WIN)
#include "base/bind_internal_win.h"
#endif

namespace base {
namespace internal {

// See base/callback.h for user documentation.
//
//
// CONCEPTS:
//  Runnable -- A type (really a type class) that has a single Run() method
//              and a RunType typedef that corresponds to the type of Run().
//              A Runnable can declare that it should treated like a method
//              call by including a typedef named IsMethod.  The value of
//              this typedef is NOT inspected, only the existence.  When a
//              Runnable declares itself a method, Bind() will enforce special
//              refcounting + WeakPtr handling semantics for the first
//              parameter which is expected to be an object.
//  Functor -- A copyable type representing something that should be called.
//             All function pointers, Callback<>, and Runnables are functors
//             even if the invocation syntax differs.
//  RunType -- A function type (as opposed to function _pointer_ type) for
//             a Run() function.  Usually just a convenience typedef.
//  (Bound)ArgsType -- A function type that is being (ab)used to store the
//                     types of set of arguments.  The "return" type is always
//                     void here.  We use this hack so that we do not need
//                     a new type name for each arity of type. (eg.,
//                     BindState1, BindState2).  This makes forward
//                     declarations and friending much much easier.
//
// Types:
//  RunnableAdapter<> -- Wraps the various "function" pointer types into an
//                       object that adheres to the Runnable interface.
//  FunctionTraits<> -- Type traits that unwrap a function signature into a
//                      a set of easier to use typedefs.  Used mainly for
//                      compile time asserts.
//                      There are |ARITY| FunctionTraits types.
//  ForceVoidReturn<> -- Helper class for translating function signatures to
//                       equivalent forms with a "void" return type.
//  FunctorTraits<> -- Type traits used determine the correct RunType and
//                     RunnableType for a Functor.  This is where function
//                     signature adapters are applied.
//  MakeRunnable<> -- Takes a Functor and returns an object in the Runnable
//                    type class that represents the underlying Functor.
//                    There are |O(1)| MakeRunnable types.
//  InvokeHelper<> -- Take a Runnable + arguments and actully invokes it.
// Handle the differing syntaxes needed for WeakPtr<> support,
//                    and for ignoring return values.  This is separate from
//                    Invoker to avoid creating multiple version of Invoker<>
//                    which grows at O(n^2) with the arity.
//  Invoker<> -- Unwraps the curried parameters and executes the Runnable.
//               There are |(ARITY^2 + ARITY)/2| Invoketypes.
//  BindState<> -- Stores the curried parameters, and is the main entry point
//                 into the Bind() system, doing most of the type resolution.
//                 There are ARITY BindState types.

// HasNonConstReferenceParam selects true_type when any of the parameters in
// |Sig| is a non-const reference.
// Implementation note: This non-specialized case handles zero-arity case only.
// Non-zero-arity cases should be handled by the specialization below.
template <typename Sig>
struct HasNonConstReferenceParam : false_type {};

// Implementation note: Select true_type if the first parameter is a non-const
// reference.  Otherwise, skip the first parameter and check rest of parameters
// recursively.
template <typename R, typename T, typename... Args>
struct HasNonConstReferenceParam<R(T, Args...)>
    : SelectType<is_non_const_reference<T>::value,
                 true_type,
                 HasNonConstReferenceParam<R(Args...)>>::Type {};

// HasRefCountedTypeAsRawPtr selects true_type when any of the |Args| is a raw
// pointer to a RefCounted type.
// Implementation note: This non-specialized case handles zero-arity case only.
// Non-zero-arity cases should be handled by the specialization below.
template <typename... Args>
struct HasRefCountedTypeAsRawPtr : false_type {};

// Implementation note: Select true_type if the first parameter is a raw pointer
// to a RefCounted type. Otherwise, skip the first parameter and check rest of
// parameters recursively.
template <typename T, typename... Args>
struct HasRefCountedTypeAsRawPtr<T, Args...>
    : SelectType<NeedsScopedRefptrButGetsRawPtr<T>::value,
                 true_type,
                 HasRefCountedTypeAsRawPtr<Args...>>::Type {};

// BindsArrayToFirstArg selects true_type when |is_method| is true and the first
// item of |Args| is an array type.
// Implementation note: This non-specialized case handles !is_method case and
// zero-arity case only.  Other cases should be handled by the specialization
// below.
template <bool is_method, typename... Args>
struct BindsArrayToFirstArg : false_type {};

template <typename T, typename... Args>
struct BindsArrayToFirstArg<true, T, Args...> : is_array<T> {};

// HasRefCountedParamAsRawPtr is the same to HasRefCountedTypeAsRawPtr except
// when |is_method| is true HasRefCountedParamAsRawPtr skips the first argument.
// Implementation note: This non-specialized case handles !is_method case and
// zero-arity case only.  Other cases should be handled by the specialization
// below.
template <bool is_method, typename... Args>
struct HasRefCountedParamAsRawPtr : HasRefCountedTypeAsRawPtr<Args...> {};

template <typename T, typename... Args>
struct HasRefCountedParamAsRawPtr<true, T, Args...>
    : HasRefCountedTypeAsRawPtr<Args...> {};

// RunnableAdapter<>
//
// The RunnableAdapter<> templates provide a uniform interface for invoking
// a function pointer, method pointer, or const method pointer. The adapter
// exposes a Run() method with an appropriate signature. Using this wrapper
// allows for writing code that supports all three pointer types without
// undue repetition.  Without it, a lot of code would need to be repeated 3
// times.
//
// For method pointers and const method pointers the first argument to Run()
// is considered to be the received of the method.  This is similar to STL's
// mem_fun().
//
// This class also exposes a RunType typedef that is the function type of the
// Run() function.
//
// If and only if the wrapper contains a method or const method pointer, an
// IsMethod typedef is exposed.  The existence of this typedef (NOT the value)
// marks that the wrapper should be considered a method wrapper.

template <typename Functor>
class RunnableAdapter;

// Function.
template <typename R, typename... Args>
class RunnableAdapter<R(*)(Args...)> {
 public:
  typedef R (RunType)(Args...);

  explicit RunnableAdapter(R(*function)(Args...))
      : function_(function) {
  }

  R Run(typename CallbackParamTraits<Args>::ForwardType... args) {
    return function_(CallbackForward(args)...);
  }

 private:
  R (*function_)(Args...);
};

// Method.
template <typename R, typename T, typename... Args>
class RunnableAdapter<R(T::*)(Args...)> {
 public:
  typedef R (RunType)(T*, Args...);
  typedef true_type IsMethod;

  explicit RunnableAdapter(R(T::*method)(Args...))
      : method_(method) {
  }

  R Run(T* object, typename CallbackParamTraits<Args>::ForwardType... args) {
    return (object->*method_)(CallbackForward(args)...);
  }

 private:
  R (T::*method_)(Args...);
};

// Const Method.
template <typename R, typename T, typename... Args>
class RunnableAdapter<R(T::*)(Args...) const> {
 public:
  typedef R (RunType)(const T*, Args...);
  typedef true_type IsMethod;

  explicit RunnableAdapter(R(T::*method)(Args...) const)
      : method_(method) {
  }

  R Run(const T* object,
        typename CallbackParamTraits<Args>::ForwardType... args) {
    return (object->*method_)(CallbackForward(args)...);
  }

 private:
  R (T::*method_)(Args...) const;
};

// TODO(tzik): Remove FunctionTraits after we finish removing bind.pump.
// FunctionTraits<>
//
// Breaks a function signature apart into typedefs for easier introspection.
template <typename Sig>
struct FunctionTraits;

template <typename R>
struct FunctionTraits<R()> {
  typedef R ReturnType;
};

template <typename R, typename A1>
struct FunctionTraits<R(A1)> {
  typedef R ReturnType;
  typedef A1 A1Type;
};

template <typename R, typename A1, typename A2>
struct FunctionTraits<R(A1, A2)> {
  typedef R ReturnType;
  typedef A1 A1Type;
  typedef A2 A2Type;
};

template <typename R, typename A1, typename A2, typename A3>
struct FunctionTraits<R(A1, A2, A3)> {
  typedef R ReturnType;
  typedef A1 A1Type;
  typedef A2 A2Type;
  typedef A3 A3Type;
};

template <typename R, typename A1, typename A2, typename A3, typename A4>
struct FunctionTraits<R(A1, A2, A3, A4)> {
  typedef R ReturnType;
  typedef A1 A1Type;
  typedef A2 A2Type;
  typedef A3 A3Type;
  typedef A4 A4Type;
};

template <typename R, typename A1, typename A2, typename A3, typename A4,
    typename A5>
struct FunctionTraits<R(A1, A2, A3, A4, A5)> {
  typedef R ReturnType;
  typedef A1 A1Type;
  typedef A2 A2Type;
  typedef A3 A3Type;
  typedef A4 A4Type;
  typedef A5 A5Type;
};

template <typename R, typename A1, typename A2, typename A3, typename A4,
    typename A5, typename A6>
struct FunctionTraits<R(A1, A2, A3, A4, A5, A6)> {
  typedef R ReturnType;
  typedef A1 A1Type;
  typedef A2 A2Type;
  typedef A3 A3Type;
  typedef A4 A4Type;
  typedef A5 A5Type;
  typedef A6 A6Type;
};

template <typename R, typename A1, typename A2, typename A3, typename A4,
    typename A5, typename A6, typename A7>
struct FunctionTraits<R(A1, A2, A3, A4, A5, A6, A7)> {
  typedef R ReturnType;
  typedef A1 A1Type;
  typedef A2 A2Type;
  typedef A3 A3Type;
  typedef A4 A4Type;
  typedef A5 A5Type;
  typedef A6 A6Type;
  typedef A7 A7Type;
};


// ForceVoidReturn<>
//
// Set of templates that support forcing the function return type to void.
template <typename Sig>
struct ForceVoidReturn;

template <typename R, typename... Args>
struct ForceVoidReturn<R(Args...)> {
  typedef void(RunType)(Args...);
};


// FunctorTraits<>
//
// See description at top of file.
template <typename T>
struct FunctorTraits {
  typedef RunnableAdapter<T> RunnableType;
  typedef typename RunnableType::RunType RunType;
};

template <typename T>
struct FunctorTraits<IgnoreResultHelper<T> > {
  typedef typename FunctorTraits<T>::RunnableType RunnableType;
  typedef typename ForceVoidReturn<
      typename RunnableType::RunType>::RunType RunType;
};

template <typename T>
struct FunctorTraits<Callback<T> > {
  typedef Callback<T> RunnableType;
  typedef typename Callback<T>::RunType RunType;
};


// MakeRunnable<>
//
// Converts a passed in functor to a RunnableType using type inference.

template <typename T>
typename FunctorTraits<T>::RunnableType MakeRunnable(const T& t) {
  return RunnableAdapter<T>(t);
}

template <typename T>
typename FunctorTraits<T>::RunnableType
MakeRunnable(const IgnoreResultHelper<T>& t) {
  return MakeRunnable(t.functor_);
}

template <typename T>
const typename FunctorTraits<Callback<T> >::RunnableType&
MakeRunnable(const Callback<T>& t) {
  DCHECK(!t.is_null());
  return t;
}


// InvokeHelper<>
//
// There are 3 logical InvokeHelper<> specializations: normal, void-return,
// WeakCalls.
//
// The normal type just calls the underlying runnable.
//
// We need a InvokeHelper to handle void return types in order to support
// IgnoreResult().  Normally, if the Runnable's RunType had a void return,
// the template system would just accept "return functor.Run()" ignoring
// the fact that a void function is being used with return. This piece of
// sugar breaks though when the Runnable's RunType is not void.  Thus, we
// need a partial specialization to change the syntax to drop the "return"
// from the invocation call.
//
// WeakCalls similarly need special syntax that is applied to the first
// argument to check if they should no-op themselves.
template <bool IsWeakCall, typename ReturnType, typename Runnable,
          typename ArgsType>
struct InvokeHelper;

template <typename ReturnType, typename Runnable, typename... Args>
struct InvokeHelper<false, ReturnType, Runnable,
    void(Args...)>  {
  static ReturnType MakeItSo(Runnable runnable, Args... args) {
    return runnable.Run(CallbackForward(args)...);
  }
};

template <typename Runnable, typename... Args>
struct InvokeHelper<false, void, Runnable, void(Args...)>  {
  static void MakeItSo(Runnable runnable, Args... args) {
    runnable.Run(CallbackForward(args)...);
  }
};

template <typename Runnable, typename BoundWeakPtr, typename... Args>
struct InvokeHelper<true, void, Runnable, void(BoundWeakPtr, Args...)>  {
  static void MakeItSo(Runnable runnable, BoundWeakPtr weak_ptr, Args... args) {
    if (!weak_ptr.get()) {
      return;
    }
    runnable.Run(weak_ptr.get(), CallbackForward(args)...);
  }
};

#if !defined(_MSC_VER)

template <typename ReturnType, typename Runnable, typename ArgsType>
struct InvokeHelper<true, ReturnType, Runnable, ArgsType> {
  // WeakCalls are only supported for functions with a void return type.
  // Otherwise, the function result would be undefined if the the WeakPtr<>
  // is invalidated.
  COMPILE_ASSERT(is_void<ReturnType>::value,
                 weak_ptrs_can_only_bind_to_methods_without_return_values);
};

#endif

// Invoker<>
//
// See description at the top of the file.
template <int NumBound, typename Storage, typename RunType>
struct Invoker;

// Arity 0 -> 0.
template <typename StorageType, typename R>
struct Invoker<0, StorageType, R()> {
  typedef R(RunType)(BindStateBase*);

  typedef R(UnboundRunType)();

  static R Run(BindStateBase* base) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.

    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void()>
               ::MakeItSo(storage->runnable_);
  }
};

// Arity 1 -> 1.
template <typename StorageType, typename R,typename X1>
struct Invoker<0, StorageType, R(X1)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X1>::ForwardType);

  typedef R(UnboundRunType)(X1);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X1>::ForwardType x1) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.

    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename CallbackParamTraits<X1>::ForwardType x1)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1));
  }
};

// Arity 1 -> 0.
template <typename StorageType, typename R,typename X1>
struct Invoker<1, StorageType, R(X1)> {
  typedef R(RunType)(BindStateBase*);

  typedef R(UnboundRunType)();

  static R Run(BindStateBase* base) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1));
  }
};

// Arity 2 -> 2.
template <typename StorageType, typename R,typename X1, typename X2>
struct Invoker<0, StorageType, R(X1, X2)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X1>::ForwardType,
      typename CallbackParamTraits<X2>::ForwardType);

  typedef R(UnboundRunType)(X1, X2);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X1>::ForwardType x1,
      typename CallbackParamTraits<X2>::ForwardType x2) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.

    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename CallbackParamTraits<X1>::ForwardType x1,
               typename CallbackParamTraits<X2>::ForwardType x2)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2));
  }
};

// Arity 2 -> 1.
template <typename StorageType, typename R,typename X1, typename X2>
struct Invoker<1, StorageType, R(X1, X2)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X2>::ForwardType);

  typedef R(UnboundRunType)(X2);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X2>::ForwardType x2) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X2>::ForwardType x2)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2));
  }
};

// Arity 2 -> 0.
template <typename StorageType, typename R,typename X1, typename X2>
struct Invoker<2, StorageType, R(X1, X2)> {
  typedef R(RunType)(BindStateBase*);

  typedef R(UnboundRunType)();

  static R Run(BindStateBase* base) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2));
  }
};

// Arity 3 -> 3.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3>
struct Invoker<0, StorageType, R(X1, X2, X3)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X1>::ForwardType,
      typename CallbackParamTraits<X2>::ForwardType,
      typename CallbackParamTraits<X3>::ForwardType);

  typedef R(UnboundRunType)(X1, X2, X3);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X1>::ForwardType x1,
      typename CallbackParamTraits<X2>::ForwardType x2,
      typename CallbackParamTraits<X3>::ForwardType x3) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.

    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename CallbackParamTraits<X1>::ForwardType x1,
               typename CallbackParamTraits<X2>::ForwardType x2,
               typename CallbackParamTraits<X3>::ForwardType x3)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3));
  }
};

// Arity 3 -> 2.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3>
struct Invoker<1, StorageType, R(X1, X2, X3)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X2>::ForwardType,
      typename CallbackParamTraits<X3>::ForwardType);

  typedef R(UnboundRunType)(X2, X3);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X2>::ForwardType x2,
      typename CallbackParamTraits<X3>::ForwardType x3) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X2>::ForwardType x2,
               typename CallbackParamTraits<X3>::ForwardType x3)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3));
  }
};

// Arity 3 -> 1.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3>
struct Invoker<2, StorageType, R(X1, X2, X3)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X3>::ForwardType);

  typedef R(UnboundRunType)(X3);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X3>::ForwardType x3) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X3>::ForwardType x3)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3));
  }
};

// Arity 3 -> 0.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3>
struct Invoker<3, StorageType, R(X1, X2, X3)> {
  typedef R(RunType)(BindStateBase*);

  typedef R(UnboundRunType)();

  static R Run(BindStateBase* base) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3));
  }
};

// Arity 4 -> 4.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4>
struct Invoker<0, StorageType, R(X1, X2, X3, X4)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X1>::ForwardType,
      typename CallbackParamTraits<X2>::ForwardType,
      typename CallbackParamTraits<X3>::ForwardType,
      typename CallbackParamTraits<X4>::ForwardType);

  typedef R(UnboundRunType)(X1, X2, X3, X4);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X1>::ForwardType x1,
      typename CallbackParamTraits<X2>::ForwardType x2,
      typename CallbackParamTraits<X3>::ForwardType x3,
      typename CallbackParamTraits<X4>::ForwardType x4) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.

    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename CallbackParamTraits<X1>::ForwardType x1,
               typename CallbackParamTraits<X2>::ForwardType x2,
               typename CallbackParamTraits<X3>::ForwardType x3,
               typename CallbackParamTraits<X4>::ForwardType x4)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4));
  }
};

// Arity 4 -> 3.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4>
struct Invoker<1, StorageType, R(X1, X2, X3, X4)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X2>::ForwardType,
      typename CallbackParamTraits<X3>::ForwardType,
      typename CallbackParamTraits<X4>::ForwardType);

  typedef R(UnboundRunType)(X2, X3, X4);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X2>::ForwardType x2,
      typename CallbackParamTraits<X3>::ForwardType x3,
      typename CallbackParamTraits<X4>::ForwardType x4) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X2>::ForwardType x2,
               typename CallbackParamTraits<X3>::ForwardType x3,
               typename CallbackParamTraits<X4>::ForwardType x4)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4));
  }
};

// Arity 4 -> 2.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4>
struct Invoker<2, StorageType, R(X1, X2, X3, X4)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X3>::ForwardType,
      typename CallbackParamTraits<X4>::ForwardType);

  typedef R(UnboundRunType)(X3, X4);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X3>::ForwardType x3,
      typename CallbackParamTraits<X4>::ForwardType x4) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X3>::ForwardType x3,
               typename CallbackParamTraits<X4>::ForwardType x4)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4));
  }
};

// Arity 4 -> 1.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4>
struct Invoker<3, StorageType, R(X1, X2, X3, X4)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X4>::ForwardType);

  typedef R(UnboundRunType)(X4);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X4>::ForwardType x4) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X4>::ForwardType x4)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4));
  }
};

// Arity 4 -> 0.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4>
struct Invoker<4, StorageType, R(X1, X2, X3, X4)> {
  typedef R(RunType)(BindStateBase*);

  typedef R(UnboundRunType)();

  static R Run(BindStateBase* base) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;
    typedef typename StorageType::Bound4UnwrapTraits Bound4UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    typename Bound4UnwrapTraits::ForwardType x4 =
        Bound4UnwrapTraits::Unwrap(storage->p4_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename Bound4UnwrapTraits::ForwardType)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4));
  }
};

// Arity 5 -> 5.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5>
struct Invoker<0, StorageType, R(X1, X2, X3, X4, X5)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X1>::ForwardType,
      typename CallbackParamTraits<X2>::ForwardType,
      typename CallbackParamTraits<X3>::ForwardType,
      typename CallbackParamTraits<X4>::ForwardType,
      typename CallbackParamTraits<X5>::ForwardType);

  typedef R(UnboundRunType)(X1, X2, X3, X4, X5);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X1>::ForwardType x1,
      typename CallbackParamTraits<X2>::ForwardType x2,
      typename CallbackParamTraits<X3>::ForwardType x3,
      typename CallbackParamTraits<X4>::ForwardType x4,
      typename CallbackParamTraits<X5>::ForwardType x5) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.

    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename CallbackParamTraits<X1>::ForwardType x1,
               typename CallbackParamTraits<X2>::ForwardType x2,
               typename CallbackParamTraits<X3>::ForwardType x3,
               typename CallbackParamTraits<X4>::ForwardType x4,
               typename CallbackParamTraits<X5>::ForwardType x5)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5));
  }
};

// Arity 5 -> 4.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5>
struct Invoker<1, StorageType, R(X1, X2, X3, X4, X5)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X2>::ForwardType,
      typename CallbackParamTraits<X3>::ForwardType,
      typename CallbackParamTraits<X4>::ForwardType,
      typename CallbackParamTraits<X5>::ForwardType);

  typedef R(UnboundRunType)(X2, X3, X4, X5);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X2>::ForwardType x2,
      typename CallbackParamTraits<X3>::ForwardType x3,
      typename CallbackParamTraits<X4>::ForwardType x4,
      typename CallbackParamTraits<X5>::ForwardType x5) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X2>::ForwardType x2,
               typename CallbackParamTraits<X3>::ForwardType x3,
               typename CallbackParamTraits<X4>::ForwardType x4,
               typename CallbackParamTraits<X5>::ForwardType x5)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5));
  }
};

// Arity 5 -> 3.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5>
struct Invoker<2, StorageType, R(X1, X2, X3, X4, X5)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X3>::ForwardType,
      typename CallbackParamTraits<X4>::ForwardType,
      typename CallbackParamTraits<X5>::ForwardType);

  typedef R(UnboundRunType)(X3, X4, X5);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X3>::ForwardType x3,
      typename CallbackParamTraits<X4>::ForwardType x4,
      typename CallbackParamTraits<X5>::ForwardType x5) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X3>::ForwardType x3,
               typename CallbackParamTraits<X4>::ForwardType x4,
               typename CallbackParamTraits<X5>::ForwardType x5)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5));
  }
};

// Arity 5 -> 2.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5>
struct Invoker<3, StorageType, R(X1, X2, X3, X4, X5)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X4>::ForwardType,
      typename CallbackParamTraits<X5>::ForwardType);

  typedef R(UnboundRunType)(X4, X5);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X4>::ForwardType x4,
      typename CallbackParamTraits<X5>::ForwardType x5) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X4>::ForwardType x4,
               typename CallbackParamTraits<X5>::ForwardType x5)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5));
  }
};

// Arity 5 -> 1.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5>
struct Invoker<4, StorageType, R(X1, X2, X3, X4, X5)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X5>::ForwardType);

  typedef R(UnboundRunType)(X5);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X5>::ForwardType x5) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;
    typedef typename StorageType::Bound4UnwrapTraits Bound4UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    typename Bound4UnwrapTraits::ForwardType x4 =
        Bound4UnwrapTraits::Unwrap(storage->p4_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename Bound4UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X5>::ForwardType x5)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5));
  }
};

// Arity 5 -> 0.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5>
struct Invoker<5, StorageType, R(X1, X2, X3, X4, X5)> {
  typedef R(RunType)(BindStateBase*);

  typedef R(UnboundRunType)();

  static R Run(BindStateBase* base) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;
    typedef typename StorageType::Bound4UnwrapTraits Bound4UnwrapTraits;
    typedef typename StorageType::Bound5UnwrapTraits Bound5UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    typename Bound4UnwrapTraits::ForwardType x4 =
        Bound4UnwrapTraits::Unwrap(storage->p4_);
    typename Bound5UnwrapTraits::ForwardType x5 =
        Bound5UnwrapTraits::Unwrap(storage->p5_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename Bound4UnwrapTraits::ForwardType,
               typename Bound5UnwrapTraits::ForwardType)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5));
  }
};

// Arity 6 -> 6.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6>
struct Invoker<0, StorageType, R(X1, X2, X3, X4, X5, X6)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X1>::ForwardType,
      typename CallbackParamTraits<X2>::ForwardType,
      typename CallbackParamTraits<X3>::ForwardType,
      typename CallbackParamTraits<X4>::ForwardType,
      typename CallbackParamTraits<X5>::ForwardType,
      typename CallbackParamTraits<X6>::ForwardType);

  typedef R(UnboundRunType)(X1, X2, X3, X4, X5, X6);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X1>::ForwardType x1,
      typename CallbackParamTraits<X2>::ForwardType x2,
      typename CallbackParamTraits<X3>::ForwardType x3,
      typename CallbackParamTraits<X4>::ForwardType x4,
      typename CallbackParamTraits<X5>::ForwardType x5,
      typename CallbackParamTraits<X6>::ForwardType x6) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.

    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename CallbackParamTraits<X1>::ForwardType x1,
               typename CallbackParamTraits<X2>::ForwardType x2,
               typename CallbackParamTraits<X3>::ForwardType x3,
               typename CallbackParamTraits<X4>::ForwardType x4,
               typename CallbackParamTraits<X5>::ForwardType x5,
               typename CallbackParamTraits<X6>::ForwardType x6)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6));
  }
};

// Arity 6 -> 5.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6>
struct Invoker<1, StorageType, R(X1, X2, X3, X4, X5, X6)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X2>::ForwardType,
      typename CallbackParamTraits<X3>::ForwardType,
      typename CallbackParamTraits<X4>::ForwardType,
      typename CallbackParamTraits<X5>::ForwardType,
      typename CallbackParamTraits<X6>::ForwardType);

  typedef R(UnboundRunType)(X2, X3, X4, X5, X6);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X2>::ForwardType x2,
      typename CallbackParamTraits<X3>::ForwardType x3,
      typename CallbackParamTraits<X4>::ForwardType x4,
      typename CallbackParamTraits<X5>::ForwardType x5,
      typename CallbackParamTraits<X6>::ForwardType x6) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X2>::ForwardType x2,
               typename CallbackParamTraits<X3>::ForwardType x3,
               typename CallbackParamTraits<X4>::ForwardType x4,
               typename CallbackParamTraits<X5>::ForwardType x5,
               typename CallbackParamTraits<X6>::ForwardType x6)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6));
  }
};

// Arity 6 -> 4.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6>
struct Invoker<2, StorageType, R(X1, X2, X3, X4, X5, X6)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X3>::ForwardType,
      typename CallbackParamTraits<X4>::ForwardType,
      typename CallbackParamTraits<X5>::ForwardType,
      typename CallbackParamTraits<X6>::ForwardType);

  typedef R(UnboundRunType)(X3, X4, X5, X6);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X3>::ForwardType x3,
      typename CallbackParamTraits<X4>::ForwardType x4,
      typename CallbackParamTraits<X5>::ForwardType x5,
      typename CallbackParamTraits<X6>::ForwardType x6) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X3>::ForwardType x3,
               typename CallbackParamTraits<X4>::ForwardType x4,
               typename CallbackParamTraits<X5>::ForwardType x5,
               typename CallbackParamTraits<X6>::ForwardType x6)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6));
  }
};

// Arity 6 -> 3.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6>
struct Invoker<3, StorageType, R(X1, X2, X3, X4, X5, X6)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X4>::ForwardType,
      typename CallbackParamTraits<X5>::ForwardType,
      typename CallbackParamTraits<X6>::ForwardType);

  typedef R(UnboundRunType)(X4, X5, X6);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X4>::ForwardType x4,
      typename CallbackParamTraits<X5>::ForwardType x5,
      typename CallbackParamTraits<X6>::ForwardType x6) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X4>::ForwardType x4,
               typename CallbackParamTraits<X5>::ForwardType x5,
               typename CallbackParamTraits<X6>::ForwardType x6)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6));
  }
};

// Arity 6 -> 2.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6>
struct Invoker<4, StorageType, R(X1, X2, X3, X4, X5, X6)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X5>::ForwardType,
      typename CallbackParamTraits<X6>::ForwardType);

  typedef R(UnboundRunType)(X5, X6);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X5>::ForwardType x5,
      typename CallbackParamTraits<X6>::ForwardType x6) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;
    typedef typename StorageType::Bound4UnwrapTraits Bound4UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    typename Bound4UnwrapTraits::ForwardType x4 =
        Bound4UnwrapTraits::Unwrap(storage->p4_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename Bound4UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X5>::ForwardType x5,
               typename CallbackParamTraits<X6>::ForwardType x6)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6));
  }
};

// Arity 6 -> 1.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6>
struct Invoker<5, StorageType, R(X1, X2, X3, X4, X5, X6)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X6>::ForwardType);

  typedef R(UnboundRunType)(X6);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X6>::ForwardType x6) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;
    typedef typename StorageType::Bound4UnwrapTraits Bound4UnwrapTraits;
    typedef typename StorageType::Bound5UnwrapTraits Bound5UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    typename Bound4UnwrapTraits::ForwardType x4 =
        Bound4UnwrapTraits::Unwrap(storage->p4_);
    typename Bound5UnwrapTraits::ForwardType x5 =
        Bound5UnwrapTraits::Unwrap(storage->p5_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename Bound4UnwrapTraits::ForwardType,
               typename Bound5UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X6>::ForwardType x6)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6));
  }
};

// Arity 6 -> 0.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6>
struct Invoker<6, StorageType, R(X1, X2, X3, X4, X5, X6)> {
  typedef R(RunType)(BindStateBase*);

  typedef R(UnboundRunType)();

  static R Run(BindStateBase* base) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;
    typedef typename StorageType::Bound4UnwrapTraits Bound4UnwrapTraits;
    typedef typename StorageType::Bound5UnwrapTraits Bound5UnwrapTraits;
    typedef typename StorageType::Bound6UnwrapTraits Bound6UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    typename Bound4UnwrapTraits::ForwardType x4 =
        Bound4UnwrapTraits::Unwrap(storage->p4_);
    typename Bound5UnwrapTraits::ForwardType x5 =
        Bound5UnwrapTraits::Unwrap(storage->p5_);
    typename Bound6UnwrapTraits::ForwardType x6 =
        Bound6UnwrapTraits::Unwrap(storage->p6_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename Bound4UnwrapTraits::ForwardType,
               typename Bound5UnwrapTraits::ForwardType,
               typename Bound6UnwrapTraits::ForwardType)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6));
  }
};

// Arity 7 -> 7.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6, typename X7>
struct Invoker<0, StorageType, R(X1, X2, X3, X4, X5, X6, X7)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X1>::ForwardType,
      typename CallbackParamTraits<X2>::ForwardType,
      typename CallbackParamTraits<X3>::ForwardType,
      typename CallbackParamTraits<X4>::ForwardType,
      typename CallbackParamTraits<X5>::ForwardType,
      typename CallbackParamTraits<X6>::ForwardType,
      typename CallbackParamTraits<X7>::ForwardType);

  typedef R(UnboundRunType)(X1, X2, X3, X4, X5, X6, X7);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X1>::ForwardType x1,
      typename CallbackParamTraits<X2>::ForwardType x2,
      typename CallbackParamTraits<X3>::ForwardType x3,
      typename CallbackParamTraits<X4>::ForwardType x4,
      typename CallbackParamTraits<X5>::ForwardType x5,
      typename CallbackParamTraits<X6>::ForwardType x6,
      typename CallbackParamTraits<X7>::ForwardType x7) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.

    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename CallbackParamTraits<X1>::ForwardType x1,
               typename CallbackParamTraits<X2>::ForwardType x2,
               typename CallbackParamTraits<X3>::ForwardType x3,
               typename CallbackParamTraits<X4>::ForwardType x4,
               typename CallbackParamTraits<X5>::ForwardType x5,
               typename CallbackParamTraits<X6>::ForwardType x6,
               typename CallbackParamTraits<X7>::ForwardType x7)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6), CallbackForward(x7));
  }
};

// Arity 7 -> 6.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6, typename X7>
struct Invoker<1, StorageType, R(X1, X2, X3, X4, X5, X6, X7)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X2>::ForwardType,
      typename CallbackParamTraits<X3>::ForwardType,
      typename CallbackParamTraits<X4>::ForwardType,
      typename CallbackParamTraits<X5>::ForwardType,
      typename CallbackParamTraits<X6>::ForwardType,
      typename CallbackParamTraits<X7>::ForwardType);

  typedef R(UnboundRunType)(X2, X3, X4, X5, X6, X7);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X2>::ForwardType x2,
      typename CallbackParamTraits<X3>::ForwardType x3,
      typename CallbackParamTraits<X4>::ForwardType x4,
      typename CallbackParamTraits<X5>::ForwardType x5,
      typename CallbackParamTraits<X6>::ForwardType x6,
      typename CallbackParamTraits<X7>::ForwardType x7) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X2>::ForwardType x2,
               typename CallbackParamTraits<X3>::ForwardType x3,
               typename CallbackParamTraits<X4>::ForwardType x4,
               typename CallbackParamTraits<X5>::ForwardType x5,
               typename CallbackParamTraits<X6>::ForwardType x6,
               typename CallbackParamTraits<X7>::ForwardType x7)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6), CallbackForward(x7));
  }
};

// Arity 7 -> 5.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6, typename X7>
struct Invoker<2, StorageType, R(X1, X2, X3, X4, X5, X6, X7)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X3>::ForwardType,
      typename CallbackParamTraits<X4>::ForwardType,
      typename CallbackParamTraits<X5>::ForwardType,
      typename CallbackParamTraits<X6>::ForwardType,
      typename CallbackParamTraits<X7>::ForwardType);

  typedef R(UnboundRunType)(X3, X4, X5, X6, X7);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X3>::ForwardType x3,
      typename CallbackParamTraits<X4>::ForwardType x4,
      typename CallbackParamTraits<X5>::ForwardType x5,
      typename CallbackParamTraits<X6>::ForwardType x6,
      typename CallbackParamTraits<X7>::ForwardType x7) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X3>::ForwardType x3,
               typename CallbackParamTraits<X4>::ForwardType x4,
               typename CallbackParamTraits<X5>::ForwardType x5,
               typename CallbackParamTraits<X6>::ForwardType x6,
               typename CallbackParamTraits<X7>::ForwardType x7)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6), CallbackForward(x7));
  }
};

// Arity 7 -> 4.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6, typename X7>
struct Invoker<3, StorageType, R(X1, X2, X3, X4, X5, X6, X7)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X4>::ForwardType,
      typename CallbackParamTraits<X5>::ForwardType,
      typename CallbackParamTraits<X6>::ForwardType,
      typename CallbackParamTraits<X7>::ForwardType);

  typedef R(UnboundRunType)(X4, X5, X6, X7);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X4>::ForwardType x4,
      typename CallbackParamTraits<X5>::ForwardType x5,
      typename CallbackParamTraits<X6>::ForwardType x6,
      typename CallbackParamTraits<X7>::ForwardType x7) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X4>::ForwardType x4,
               typename CallbackParamTraits<X5>::ForwardType x5,
               typename CallbackParamTraits<X6>::ForwardType x6,
               typename CallbackParamTraits<X7>::ForwardType x7)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6), CallbackForward(x7));
  }
};

// Arity 7 -> 3.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6, typename X7>
struct Invoker<4, StorageType, R(X1, X2, X3, X4, X5, X6, X7)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X5>::ForwardType,
      typename CallbackParamTraits<X6>::ForwardType,
      typename CallbackParamTraits<X7>::ForwardType);

  typedef R(UnboundRunType)(X5, X6, X7);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X5>::ForwardType x5,
      typename CallbackParamTraits<X6>::ForwardType x6,
      typename CallbackParamTraits<X7>::ForwardType x7) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;
    typedef typename StorageType::Bound4UnwrapTraits Bound4UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    typename Bound4UnwrapTraits::ForwardType x4 =
        Bound4UnwrapTraits::Unwrap(storage->p4_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename Bound4UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X5>::ForwardType x5,
               typename CallbackParamTraits<X6>::ForwardType x6,
               typename CallbackParamTraits<X7>::ForwardType x7)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6), CallbackForward(x7));
  }
};

// Arity 7 -> 2.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6, typename X7>
struct Invoker<5, StorageType, R(X1, X2, X3, X4, X5, X6, X7)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X6>::ForwardType,
      typename CallbackParamTraits<X7>::ForwardType);

  typedef R(UnboundRunType)(X6, X7);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X6>::ForwardType x6,
      typename CallbackParamTraits<X7>::ForwardType x7) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;
    typedef typename StorageType::Bound4UnwrapTraits Bound4UnwrapTraits;
    typedef typename StorageType::Bound5UnwrapTraits Bound5UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    typename Bound4UnwrapTraits::ForwardType x4 =
        Bound4UnwrapTraits::Unwrap(storage->p4_);
    typename Bound5UnwrapTraits::ForwardType x5 =
        Bound5UnwrapTraits::Unwrap(storage->p5_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename Bound4UnwrapTraits::ForwardType,
               typename Bound5UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X6>::ForwardType x6,
               typename CallbackParamTraits<X7>::ForwardType x7)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6), CallbackForward(x7));
  }
};

// Arity 7 -> 1.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6, typename X7>
struct Invoker<6, StorageType, R(X1, X2, X3, X4, X5, X6, X7)> {
  typedef R(RunType)(BindStateBase*,
      typename CallbackParamTraits<X7>::ForwardType);

  typedef R(UnboundRunType)(X7);

  static R Run(BindStateBase* base,
      typename CallbackParamTraits<X7>::ForwardType x7) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;
    typedef typename StorageType::Bound4UnwrapTraits Bound4UnwrapTraits;
    typedef typename StorageType::Bound5UnwrapTraits Bound5UnwrapTraits;
    typedef typename StorageType::Bound6UnwrapTraits Bound6UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    typename Bound4UnwrapTraits::ForwardType x4 =
        Bound4UnwrapTraits::Unwrap(storage->p4_);
    typename Bound5UnwrapTraits::ForwardType x5 =
        Bound5UnwrapTraits::Unwrap(storage->p5_);
    typename Bound6UnwrapTraits::ForwardType x6 =
        Bound6UnwrapTraits::Unwrap(storage->p6_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename Bound4UnwrapTraits::ForwardType,
               typename Bound5UnwrapTraits::ForwardType,
               typename Bound6UnwrapTraits::ForwardType,
               typename CallbackParamTraits<X7>::ForwardType x7)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6), CallbackForward(x7));
  }
};

// Arity 7 -> 0.
template <typename StorageType, typename R,typename X1, typename X2,
    typename X3, typename X4, typename X5, typename X6, typename X7>
struct Invoker<7, StorageType, R(X1, X2, X3, X4, X5, X6, X7)> {
  typedef R(RunType)(BindStateBase*);

  typedef R(UnboundRunType)();

  static R Run(BindStateBase* base) {
    StorageType* storage = static_cast<StorageType*>(base);

    // Local references to make debugger stepping easier. If in a debugger,
    // you really want to warp ahead and step through the
    // InvokeHelper<>::MakeItSo() call below.
    typedef typename StorageType::Bound1UnwrapTraits Bound1UnwrapTraits;
    typedef typename StorageType::Bound2UnwrapTraits Bound2UnwrapTraits;
    typedef typename StorageType::Bound3UnwrapTraits Bound3UnwrapTraits;
    typedef typename StorageType::Bound4UnwrapTraits Bound4UnwrapTraits;
    typedef typename StorageType::Bound5UnwrapTraits Bound5UnwrapTraits;
    typedef typename StorageType::Bound6UnwrapTraits Bound6UnwrapTraits;
    typedef typename StorageType::Bound7UnwrapTraits Bound7UnwrapTraits;

    typename Bound1UnwrapTraits::ForwardType x1 =
        Bound1UnwrapTraits::Unwrap(storage->p1_);
    typename Bound2UnwrapTraits::ForwardType x2 =
        Bound2UnwrapTraits::Unwrap(storage->p2_);
    typename Bound3UnwrapTraits::ForwardType x3 =
        Bound3UnwrapTraits::Unwrap(storage->p3_);
    typename Bound4UnwrapTraits::ForwardType x4 =
        Bound4UnwrapTraits::Unwrap(storage->p4_);
    typename Bound5UnwrapTraits::ForwardType x5 =
        Bound5UnwrapTraits::Unwrap(storage->p5_);
    typename Bound6UnwrapTraits::ForwardType x6 =
        Bound6UnwrapTraits::Unwrap(storage->p6_);
    typename Bound7UnwrapTraits::ForwardType x7 =
        Bound7UnwrapTraits::Unwrap(storage->p7_);
    return InvokeHelper<StorageType::IsWeakCall::value, R,
           typename StorageType::RunnableType,
           void(typename Bound1UnwrapTraits::ForwardType,
               typename Bound2UnwrapTraits::ForwardType,
               typename Bound3UnwrapTraits::ForwardType,
               typename Bound4UnwrapTraits::ForwardType,
               typename Bound5UnwrapTraits::ForwardType,
               typename Bound6UnwrapTraits::ForwardType,
               typename Bound7UnwrapTraits::ForwardType)>
               ::MakeItSo(storage->runnable_, CallbackForward(x1),
                   CallbackForward(x2), CallbackForward(x3),
                   CallbackForward(x4), CallbackForward(x5),
                   CallbackForward(x6), CallbackForward(x7));
  }
};


// BindState<>
//
// This stores all the state passed into Bind() and is also where most
// of the template resolution magic occurs.
//
// Runnable is the functor we are binding arguments to.
// RunType is type of the Run() function that the Invoker<> should use.
// Normally, this is the same as the RunType of the Runnable, but it can
// be different if an adapter like IgnoreResult() has been used.
//
// BoundArgsType contains the storage type for all the bound arguments by
// (ab)using a function type.
template <typename Runnable, typename RunType, typename BoundArgsType>
struct BindState;

template <typename Runnable, typename RunType>
struct BindState<Runnable, RunType, void()> : public BindStateBase {
  typedef Runnable RunnableType;
  typedef false_type IsWeakCall;
  typedef Invoker<0, BindState, RunType> InvokerType;
  typedef typename InvokerType::UnboundRunType UnboundRunType;
  explicit BindState(const Runnable& runnable)
      : runnable_(runnable) {
  }

  RunnableType runnable_;

 private:
  ~BindState() override {  }

};

template <typename Runnable, typename RunType, typename P1>
struct BindState<Runnable, RunType, void(P1)> : public BindStateBase {
  typedef Runnable RunnableType;
  typedef IsWeakMethod<HasIsMethodTag<Runnable>::value, P1> IsWeakCall;
  typedef Invoker<1, BindState, RunType> InvokerType;
  typedef typename InvokerType::UnboundRunType UnboundRunType;

  // Convenience typedefs for bound argument types.
  typedef UnwrapTraits<P1> Bound1UnwrapTraits;

  BindState(const Runnable& runnable, const P1& p1)
      : runnable_(runnable),
        p1_(p1) {
    MaybeRefcount<HasIsMethodTag<Runnable>::value, P1>::AddRef(p1_);
  }

  RunnableType runnable_;
  P1 p1_;

 private:
  ~BindState() override {    MaybeRefcount<HasIsMethodTag<Runnable>::value,
      P1>::Release(p1_);  }

};

template <typename Runnable, typename RunType, typename P1, typename P2>
struct BindState<Runnable, RunType, void(P1, P2)> : public BindStateBase {
  typedef Runnable RunnableType;
  typedef IsWeakMethod<HasIsMethodTag<Runnable>::value, P1> IsWeakCall;
  typedef Invoker<2, BindState, RunType> InvokerType;
  typedef typename InvokerType::UnboundRunType UnboundRunType;

  // Convenience typedefs for bound argument types.
  typedef UnwrapTraits<P1> Bound1UnwrapTraits;
  typedef UnwrapTraits<P2> Bound2UnwrapTraits;

  BindState(const Runnable& runnable, const P1& p1, const P2& p2)
      : runnable_(runnable),
        p1_(p1),
        p2_(p2) {
    MaybeRefcount<HasIsMethodTag<Runnable>::value, P1>::AddRef(p1_);
  }

  RunnableType runnable_;
  P1 p1_;
  P2 p2_;

 private:
  ~BindState() override {    MaybeRefcount<HasIsMethodTag<Runnable>::value,
      P1>::Release(p1_);  }

};

template <typename Runnable, typename RunType, typename P1, typename P2,
    typename P3>
struct BindState<Runnable, RunType, void(P1, P2, P3)> : public BindStateBase {
  typedef Runnable RunnableType;
  typedef IsWeakMethod<HasIsMethodTag<Runnable>::value, P1> IsWeakCall;
  typedef Invoker<3, BindState, RunType> InvokerType;
  typedef typename InvokerType::UnboundRunType UnboundRunType;

  // Convenience typedefs for bound argument types.
  typedef UnwrapTraits<P1> Bound1UnwrapTraits;
  typedef UnwrapTraits<P2> Bound2UnwrapTraits;
  typedef UnwrapTraits<P3> Bound3UnwrapTraits;

  BindState(const Runnable& runnable, const P1& p1, const P2& p2, const P3& p3)
      : runnable_(runnable),
        p1_(p1),
        p2_(p2),
        p3_(p3) {
    MaybeRefcount<HasIsMethodTag<Runnable>::value, P1>::AddRef(p1_);
  }

  RunnableType runnable_;
  P1 p1_;
  P2 p2_;
  P3 p3_;

 private:
  ~BindState() override {    MaybeRefcount<HasIsMethodTag<Runnable>::value,
      P1>::Release(p1_);  }

};

template <typename Runnable, typename RunType, typename P1, typename P2,
    typename P3, typename P4>
struct BindState<Runnable, RunType, void(P1, P2, P3,
    P4)> : public BindStateBase {
  typedef Runnable RunnableType;
  typedef IsWeakMethod<HasIsMethodTag<Runnable>::value, P1> IsWeakCall;
  typedef Invoker<4, BindState, RunType> InvokerType;
  typedef typename InvokerType::UnboundRunType UnboundRunType;

  // Convenience typedefs for bound argument types.
  typedef UnwrapTraits<P1> Bound1UnwrapTraits;
  typedef UnwrapTraits<P2> Bound2UnwrapTraits;
  typedef UnwrapTraits<P3> Bound3UnwrapTraits;
  typedef UnwrapTraits<P4> Bound4UnwrapTraits;

  BindState(const Runnable& runnable, const P1& p1, const P2& p2, const P3& p3,
      const P4& p4)
      : runnable_(runnable),
        p1_(p1),
        p2_(p2),
        p3_(p3),
        p4_(p4) {
    MaybeRefcount<HasIsMethodTag<Runnable>::value, P1>::AddRef(p1_);
  }

  RunnableType runnable_;
  P1 p1_;
  P2 p2_;
  P3 p3_;
  P4 p4_;

 private:
  ~BindState() override {    MaybeRefcount<HasIsMethodTag<Runnable>::value,
      P1>::Release(p1_);  }

};

template <typename Runnable, typename RunType, typename P1, typename P2,
    typename P3, typename P4, typename P5>
struct BindState<Runnable, RunType, void(P1, P2, P3, P4,
    P5)> : public BindStateBase {
  typedef Runnable RunnableType;
  typedef IsWeakMethod<HasIsMethodTag<Runnable>::value, P1> IsWeakCall;
  typedef Invoker<5, BindState, RunType> InvokerType;
  typedef typename InvokerType::UnboundRunType UnboundRunType;

  // Convenience typedefs for bound argument types.
  typedef UnwrapTraits<P1> Bound1UnwrapTraits;
  typedef UnwrapTraits<P2> Bound2UnwrapTraits;
  typedef UnwrapTraits<P3> Bound3UnwrapTraits;
  typedef UnwrapTraits<P4> Bound4UnwrapTraits;
  typedef UnwrapTraits<P5> Bound5UnwrapTraits;

  BindState(const Runnable& runnable, const P1& p1, const P2& p2, const P3& p3,
      const P4& p4, const P5& p5)
      : runnable_(runnable),
        p1_(p1),
        p2_(p2),
        p3_(p3),
        p4_(p4),
        p5_(p5) {
    MaybeRefcount<HasIsMethodTag<Runnable>::value, P1>::AddRef(p1_);
  }

  RunnableType runnable_;
  P1 p1_;
  P2 p2_;
  P3 p3_;
  P4 p4_;
  P5 p5_;

 private:
  ~BindState() override {    MaybeRefcount<HasIsMethodTag<Runnable>::value,
      P1>::Release(p1_);  }

};

template <typename Runnable, typename RunType, typename P1, typename P2,
    typename P3, typename P4, typename P5, typename P6>
struct BindState<Runnable, RunType, void(P1, P2, P3, P4, P5,
    P6)> : public BindStateBase {
  typedef Runnable RunnableType;
  typedef IsWeakMethod<HasIsMethodTag<Runnable>::value, P1> IsWeakCall;
  typedef Invoker<6, BindState, RunType> InvokerType;
  typedef typename InvokerType::UnboundRunType UnboundRunType;

  // Convenience typedefs for bound argument types.
  typedef UnwrapTraits<P1> Bound1UnwrapTraits;
  typedef UnwrapTraits<P2> Bound2UnwrapTraits;
  typedef UnwrapTraits<P3> Bound3UnwrapTraits;
  typedef UnwrapTraits<P4> Bound4UnwrapTraits;
  typedef UnwrapTraits<P5> Bound5UnwrapTraits;
  typedef UnwrapTraits<P6> Bound6UnwrapTraits;

  BindState(const Runnable& runnable, const P1& p1, const P2& p2, const P3& p3,
      const P4& p4, const P5& p5, const P6& p6)
      : runnable_(runnable),
        p1_(p1),
        p2_(p2),
        p3_(p3),
        p4_(p4),
        p5_(p5),
        p6_(p6) {
    MaybeRefcount<HasIsMethodTag<Runnable>::value, P1>::AddRef(p1_);
  }

  RunnableType runnable_;
  P1 p1_;
  P2 p2_;
  P3 p3_;
  P4 p4_;
  P5 p5_;
  P6 p6_;

 private:
  ~BindState() override {    MaybeRefcount<HasIsMethodTag<Runnable>::value,
      P1>::Release(p1_);  }

};

template <typename Runnable, typename RunType, typename P1, typename P2,
    typename P3, typename P4, typename P5, typename P6, typename P7>
struct BindState<Runnable, RunType, void(P1, P2, P3, P4, P5, P6,
    P7)> : public BindStateBase {
  typedef Runnable RunnableType;
  typedef IsWeakMethod<HasIsMethodTag<Runnable>::value, P1> IsWeakCall;
  typedef Invoker<7, BindState, RunType> InvokerType;
  typedef typename InvokerType::UnboundRunType UnboundRunType;

  // Convenience typedefs for bound argument types.
  typedef UnwrapTraits<P1> Bound1UnwrapTraits;
  typedef UnwrapTraits<P2> Bound2UnwrapTraits;
  typedef UnwrapTraits<P3> Bound3UnwrapTraits;
  typedef UnwrapTraits<P4> Bound4UnwrapTraits;
  typedef UnwrapTraits<P5> Bound5UnwrapTraits;
  typedef UnwrapTraits<P6> Bound6UnwrapTraits;
  typedef UnwrapTraits<P7> Bound7UnwrapTraits;

  BindState(const Runnable& runnable, const P1& p1, const P2& p2, const P3& p3,
      const P4& p4, const P5& p5, const P6& p6, const P7& p7)
      : runnable_(runnable),
        p1_(p1),
        p2_(p2),
        p3_(p3),
        p4_(p4),
        p5_(p5),
        p6_(p6),
        p7_(p7) {
    MaybeRefcount<HasIsMethodTag<Runnable>::value, P1>::AddRef(p1_);
  }

  RunnableType runnable_;
  P1 p1_;
  P2 p2_;
  P3 p3_;
  P4 p4_;
  P5 p5_;
  P6 p6_;
  P7 p7_;

 private:
  ~BindState() override {    MaybeRefcount<HasIsMethodTag<Runnable>::value,
      P1>::Release(p1_);  }

};

}  // namespace internal
}  // namespace base

#endif  // BASE_BIND_INTERNAL_H_