yaml-cpp

gmock-actions.h (39706B)

---

 // Copyright 2007, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
 // Google Mock - a framework for writing C++ mock classes.
 //
 // This file implements some commonly used actions.
 
 // GOOGLETEST_CM0002 DO NOT DELETE
 
 #ifndef GMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_
 #define GMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_
 
 #ifndef _WIN32_WCE
 # include <errno.h>
 #endif
 
 #include <algorithm>
 #include <functional>
 #include <memory>
 #include <string>
 #include <type_traits>
 #include <utility>
 
 #include "gmock/internal/gmock-internal-utils.h"
 #include "gmock/internal/gmock-port.h"
 
 #ifdef _MSC_VER
 # pragma warning(push)
 # pragma warning(disable:4100)
 #endif
 
 namespace testing {
 
 // To implement an action Foo, define:
 //   1. a class FooAction that implements the ActionInterface interface, and
 //   2. a factory function that creates an Action object from a
 //      const FooAction*.
 //
 // The two-level delegation design follows that of Matcher, providing
 // consistency for extension developers.  It also eases ownership
 // management as Action objects can now be copied like plain values.
 
 namespace internal {
 
 // BuiltInDefaultValueGetter<T, true>::Get() returns a
 // default-constructed T value.  BuiltInDefaultValueGetter<T,
 // false>::Get() crashes with an error.
 //
 // This primary template is used when kDefaultConstructible is true.
 template <typename T, bool kDefaultConstructible>
 struct BuiltInDefaultValueGetter {
   static T Get() { return T(); }
 };
 template <typename T>
 struct BuiltInDefaultValueGetter<T, false> {
   static T Get() {
     Assert(false, __FILE__, __LINE__,
            "Default action undefined for the function return type.");
     return internal::Invalid<T>();
     // The above statement will never be reached, but is required in
     // order for this function to compile.
   }
 };
 
 // BuiltInDefaultValue<T>::Get() returns the "built-in" default value
 // for type T, which is NULL when T is a raw pointer type, 0 when T is
 // a numeric type, false when T is bool, or "" when T is string or
 // std::string.  In addition, in C++11 and above, it turns a
 // default-constructed T value if T is default constructible.  For any
 // other type T, the built-in default T value is undefined, and the
 // function will abort the process.
 template <typename T>
 class BuiltInDefaultValue {
  public:
   // This function returns true if and only if type T has a built-in default
   // value.
   static bool Exists() {
     return ::std::is_default_constructible<T>::value;
   }
 
   static T Get() {
     return BuiltInDefaultValueGetter<
         T, ::std::is_default_constructible<T>::value>::Get();
   }
 };
 
 // This partial specialization says that we use the same built-in
 // default value for T and const T.
 template <typename T>
 class BuiltInDefaultValue<const T> {
  public:
   static bool Exists() { return BuiltInDefaultValue<T>::Exists(); }
   static T Get() { return BuiltInDefaultValue<T>::Get(); }
 };
 
 // This partial specialization defines the default values for pointer
 // types.
 template <typename T>
 class BuiltInDefaultValue<T*> {
  public:
   static bool Exists() { return true; }
   static T* Get() { return nullptr; }
 };
 
 // The following specializations define the default values for
 // specific types we care about.
 #define GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(type, value) \
   template <> \
   class BuiltInDefaultValue<type> { \
    public: \
     static bool Exists() { return true; } \
     static type Get() { return value; } \
   }
 
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(void, );  // NOLINT
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(::std::string, "");
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(bool, false);
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned char, '\0');
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed char, '\0');
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(char, '\0');
 
 // There's no need for a default action for signed wchar_t, as that
 // type is the same as wchar_t for gcc, and invalid for MSVC.
 //
 // There's also no need for a default action for unsigned wchar_t, as
 // that type is the same as unsigned int for gcc, and invalid for
 // MSVC.
 #if GMOCK_WCHAR_T_IS_NATIVE_
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(wchar_t, 0U);  // NOLINT
 #endif
 
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned short, 0U);  // NOLINT
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed short, 0);     // NOLINT
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned int, 0U);
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed int, 0);
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned long, 0UL);  // NOLINT
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed long, 0L);     // NOLINT
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(UInt64, 0);
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(Int64, 0);
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(float, 0);
 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(double, 0);
 
 #undef GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_
 
 }  // namespace internal
 
 // When an unexpected function call is encountered, Google Mock will
 // let it return a default value if the user has specified one for its
 // return type, or if the return type has a built-in default value;
 // otherwise Google Mock won't know what value to return and will have
 // to abort the process.
 //
 // The DefaultValue<T> class allows a user to specify the
 // default value for a type T that is both copyable and publicly
 // destructible (i.e. anything that can be used as a function return
 // type).  The usage is:
 //
 //   // Sets the default value for type T to be foo.
 //   DefaultValue<T>::Set(foo);
 template <typename T>
 class DefaultValue {
  public:
   // Sets the default value for type T; requires T to be
   // copy-constructable and have a public destructor.
   static void Set(T x) {
     delete producer_;
     producer_ = new FixedValueProducer(x);
   }
 
   // Provides a factory function to be called to generate the default value.
   // This method can be used even if T is only move-constructible, but it is not
   // limited to that case.
   typedef T (*FactoryFunction)();
   static void SetFactory(FactoryFunction factory) {
     delete producer_;
     producer_ = new FactoryValueProducer(factory);
   }
 
   // Unsets the default value for type T.
   static void Clear() {
     delete producer_;
     producer_ = nullptr;
   }
 
   // Returns true if and only if the user has set the default value for type T.
   static bool IsSet() { return producer_ != nullptr; }
 
   // Returns true if T has a default return value set by the user or there
   // exists a built-in default value.
   static bool Exists() {
     return IsSet() || internal::BuiltInDefaultValue<T>::Exists();
   }
 
   // Returns the default value for type T if the user has set one;
   // otherwise returns the built-in default value. Requires that Exists()
   // is true, which ensures that the return value is well-defined.
   static T Get() {
     return producer_ == nullptr ? internal::BuiltInDefaultValue<T>::Get()
                                 : producer_->Produce();
   }
 
  private:
   class ValueProducer {
    public:
     virtual ~ValueProducer() {}
     virtual T Produce() = 0;
   };
 
   class FixedValueProducer : public ValueProducer {
    public:
     explicit FixedValueProducer(T value) : value_(value) {}
     T Produce() override { return value_; }
 
    private:
     const T value_;
     GTEST_DISALLOW_COPY_AND_ASSIGN_(FixedValueProducer);
   };
 
   class FactoryValueProducer : public ValueProducer {
    public:
     explicit FactoryValueProducer(FactoryFunction factory)
         : factory_(factory) {}
     T Produce() override { return factory_(); }
 
    private:
     const FactoryFunction factory_;
     GTEST_DISALLOW_COPY_AND_ASSIGN_(FactoryValueProducer);
   };
 
   static ValueProducer* producer_;
 };
 
 // This partial specialization allows a user to set default values for
 // reference types.
 template <typename T>
 class DefaultValue<T&> {
  public:
   // Sets the default value for type T&.
   static void Set(T& x) {  // NOLINT
     address_ = &x;
   }
 
   // Unsets the default value for type T&.
   static void Clear() { address_ = nullptr; }
 
   // Returns true if and only if the user has set the default value for type T&.
   static bool IsSet() { return address_ != nullptr; }
 
   // Returns true if T has a default return value set by the user or there
   // exists a built-in default value.
   static bool Exists() {
     return IsSet() || internal::BuiltInDefaultValue<T&>::Exists();
   }
 
   // Returns the default value for type T& if the user has set one;
   // otherwise returns the built-in default value if there is one;
   // otherwise aborts the process.
   static T& Get() {
     return address_ == nullptr ? internal::BuiltInDefaultValue<T&>::Get()
                                : *address_;
   }
 
  private:
   static T* address_;
 };
 
 // This specialization allows DefaultValue<void>::Get() to
 // compile.
 template <>
 class DefaultValue<void> {
  public:
   static bool Exists() { return true; }
   static void Get() {}
 };
 
 // Points to the user-set default value for type T.
 template <typename T>
 typename DefaultValue<T>::ValueProducer* DefaultValue<T>::producer_ = nullptr;
 
 // Points to the user-set default value for type T&.
 template <typename T>
 T* DefaultValue<T&>::address_ = nullptr;
 
 // Implement this interface to define an action for function type F.
 template <typename F>
 class ActionInterface {
  public:
   typedef typename internal::Function<F>::Result Result;
   typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
 
   ActionInterface() {}
   virtual ~ActionInterface() {}
 
   // Performs the action.  This method is not const, as in general an
   // action can have side effects and be stateful.  For example, a
   // get-the-next-element-from-the-collection action will need to
   // remember the current element.
   virtual Result Perform(const ArgumentTuple& args) = 0;
 
  private:
   GTEST_DISALLOW_COPY_AND_ASSIGN_(ActionInterface);
 };
 
 // An Action<F> is a copyable and IMMUTABLE (except by assignment)
 // object that represents an action to be taken when a mock function
 // of type F is called.  The implementation of Action<T> is just a
 // std::shared_ptr to const ActionInterface<T>. Don't inherit from Action!
 // You can view an object implementing ActionInterface<F> as a
 // concrete action (including its current state), and an Action<F>
 // object as a handle to it.
 template <typename F>
 class Action {
   // Adapter class to allow constructing Action from a legacy ActionInterface.
   // New code should create Actions from functors instead.
   struct ActionAdapter {
     // Adapter must be copyable to satisfy std::function requirements.
     ::std::shared_ptr<ActionInterface<F>> impl_;
 
     template <typename... Args>
     typename internal::Function<F>::Result operator()(Args&&... args) {
       return impl_->Perform(
           ::std::forward_as_tuple(::std::forward<Args>(args)...));
     }
   };
 
  public:
   typedef typename internal::Function<F>::Result Result;
   typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
 
   // Constructs a null Action.  Needed for storing Action objects in
   // STL containers.
   Action() {}
 
   // Construct an Action from a specified callable.
   // This cannot take std::function directly, because then Action would not be
   // directly constructible from lambda (it would require two conversions).
   template <typename G,
             typename = typename ::std::enable_if<
                 ::std::is_constructible<::std::function<F>, G>::value>::type>
   Action(G&& fun) : fun_(::std::forward<G>(fun)) {}  // NOLINT
 
   // Constructs an Action from its implementation.
   explicit Action(ActionInterface<F>* impl)
       : fun_(ActionAdapter{::std::shared_ptr<ActionInterface<F>>(impl)}) {}
 
   // This constructor allows us to turn an Action<Func> object into an
   // Action<F>, as long as F's arguments can be implicitly converted
   // to Func's and Func's return type can be implicitly converted to F's.
   template <typename Func>
   explicit Action(const Action<Func>& action) : fun_(action.fun_) {}
 
   // Returns true if and only if this is the DoDefault() action.
   bool IsDoDefault() const { return fun_ == nullptr; }
 
   // Performs the action.  Note that this method is const even though
   // the corresponding method in ActionInterface is not.  The reason
   // is that a const Action<F> means that it cannot be re-bound to
   // another concrete action, not that the concrete action it binds to
   // cannot change state.  (Think of the difference between a const
   // pointer and a pointer to const.)
   Result Perform(ArgumentTuple args) const {
     if (IsDoDefault()) {
       internal::IllegalDoDefault(__FILE__, __LINE__);
     }
     return internal::Apply(fun_, ::std::move(args));
   }
 
  private:
   template <typename G>
   friend class Action;
 
   // fun_ is an empty function if and only if this is the DoDefault() action.
   ::std::function<F> fun_;
 };
 
 // The PolymorphicAction class template makes it easy to implement a
 // polymorphic action (i.e. an action that can be used in mock
 // functions of than one type, e.g. Return()).
 //
 // To define a polymorphic action, a user first provides a COPYABLE
 // implementation class that has a Perform() method template:
 //
 //   class FooAction {
 //    public:
 //     template <typename Result, typename ArgumentTuple>
 //     Result Perform(const ArgumentTuple& args) const {
 //       // Processes the arguments and returns a result, using
 //       // std::get<N>(args) to get the N-th (0-based) argument in the tuple.
 //     }
 //     ...
 //   };
 //
 // Then the user creates the polymorphic action using
 // MakePolymorphicAction(object) where object has type FooAction.  See
 // the definition of Return(void) and SetArgumentPointee<N>(value) for
 // complete examples.
 template <typename Impl>
 class PolymorphicAction {
  public:
   explicit PolymorphicAction(const Impl& impl) : impl_(impl) {}
 
   template <typename F>
   operator Action<F>() const {
     return Action<F>(new MonomorphicImpl<F>(impl_));
   }
 
  private:
   template <typename F>
   class MonomorphicImpl : public ActionInterface<F> {
    public:
     typedef typename internal::Function<F>::Result Result;
     typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
 
     explicit MonomorphicImpl(const Impl& impl) : impl_(impl) {}
 
     Result Perform(const ArgumentTuple& args) override {
       return impl_.template Perform<Result>(args);
     }
 
    private:
     Impl impl_;
 
     GTEST_DISALLOW_ASSIGN_(MonomorphicImpl);
   };
 
   Impl impl_;
 
   GTEST_DISALLOW_ASSIGN_(PolymorphicAction);
 };
 
 // Creates an Action from its implementation and returns it.  The
 // created Action object owns the implementation.
 template <typename F>
 Action<F> MakeAction(ActionInterface<F>* impl) {
   return Action<F>(impl);
 }
 
 // Creates a polymorphic action from its implementation.  This is
 // easier to use than the PolymorphicAction<Impl> constructor as it
 // doesn't require you to explicitly write the template argument, e.g.
 //
 //   MakePolymorphicAction(foo);
 // vs
 //   PolymorphicAction<TypeOfFoo>(foo);
 template <typename Impl>
 inline PolymorphicAction<Impl> MakePolymorphicAction(const Impl& impl) {
   return PolymorphicAction<Impl>(impl);
 }
 
 namespace internal {
 
 // Helper struct to specialize ReturnAction to execute a move instead of a copy
 // on return. Useful for move-only types, but could be used on any type.
 template <typename T>
 struct ByMoveWrapper {
   explicit ByMoveWrapper(T value) : payload(std::move(value)) {}
   T payload;
 };
 
 // Implements the polymorphic Return(x) action, which can be used in
 // any function that returns the type of x, regardless of the argument
 // types.
 //
 // Note: The value passed into Return must be converted into
 // Function<F>::Result when this action is cast to Action<F> rather than
 // when that action is performed. This is important in scenarios like
 //
 // MOCK_METHOD1(Method, T(U));
 // ...
 // {
 //   Foo foo;
 //   X x(&foo);
 //   EXPECT_CALL(mock, Method(_)).WillOnce(Return(x));
 // }
 //
 // In the example above the variable x holds reference to foo which leaves
 // scope and gets destroyed.  If copying X just copies a reference to foo,
 // that copy will be left with a hanging reference.  If conversion to T
 // makes a copy of foo, the above code is safe. To support that scenario, we
 // need to make sure that the type conversion happens inside the EXPECT_CALL
 // statement, and conversion of the result of Return to Action<T(U)> is a
 // good place for that.
 //
 // The real life example of the above scenario happens when an invocation
 // of gtl::Container() is passed into Return.
 //
 template <typename R>
 class ReturnAction {
  public:
   // Constructs a ReturnAction object from the value to be returned.
   // 'value' is passed by value instead of by const reference in order
   // to allow Return("string literal") to compile.
   explicit ReturnAction(R value) : value_(new R(std::move(value))) {}
 
   // This template type conversion operator allows Return(x) to be
   // used in ANY function that returns x's type.
   template <typename F>
   operator Action<F>() const {  // NOLINT
     // Assert statement belongs here because this is the best place to verify
     // conditions on F. It produces the clearest error messages
     // in most compilers.
     // Impl really belongs in this scope as a local class but can't
     // because MSVC produces duplicate symbols in different translation units
     // in this case. Until MS fixes that bug we put Impl into the class scope
     // and put the typedef both here (for use in assert statement) and
     // in the Impl class. But both definitions must be the same.
     typedef typename Function<F>::Result Result;
     GTEST_COMPILE_ASSERT_(
         !std::is_reference<Result>::value,
         use_ReturnRef_instead_of_Return_to_return_a_reference);
     static_assert(!std::is_void<Result>::value,
                   "Can't use Return() on an action expected to return `void`.");
     return Action<F>(new Impl<R, F>(value_));
   }
 
  private:
   // Implements the Return(x) action for a particular function type F.
   template <typename R_, typename F>
   class Impl : public ActionInterface<F> {
    public:
     typedef typename Function<F>::Result Result;
     typedef typename Function<F>::ArgumentTuple ArgumentTuple;
 
     // The implicit cast is necessary when Result has more than one
     // single-argument constructor (e.g. Result is std::vector<int>) and R
     // has a type conversion operator template.  In that case, value_(value)
     // won't compile as the compiler doesn't known which constructor of
     // Result to call.  ImplicitCast_ forces the compiler to convert R to
     // Result without considering explicit constructors, thus resolving the
     // ambiguity. value_ is then initialized using its copy constructor.
     explicit Impl(const std::shared_ptr<R>& value)
         : value_before_cast_(*value),
           value_(ImplicitCast_<Result>(value_before_cast_)) {}
 
     Result Perform(const ArgumentTuple&) override { return value_; }
 
    private:
     GTEST_COMPILE_ASSERT_(!std::is_reference<Result>::value,
                           Result_cannot_be_a_reference_type);
     // We save the value before casting just in case it is being cast to a
     // wrapper type.
     R value_before_cast_;
     Result value_;
 
     GTEST_DISALLOW_COPY_AND_ASSIGN_(Impl);
   };
 
   // Partially specialize for ByMoveWrapper. This version of ReturnAction will
   // move its contents instead.
   template <typename R_, typename F>
   class Impl<ByMoveWrapper<R_>, F> : public ActionInterface<F> {
    public:
     typedef typename Function<F>::Result Result;
     typedef typename Function<F>::ArgumentTuple ArgumentTuple;
 
     explicit Impl(const std::shared_ptr<R>& wrapper)
         : performed_(false), wrapper_(wrapper) {}
 
     Result Perform(const ArgumentTuple&) override {
       GTEST_CHECK_(!performed_)
           << "A ByMove() action should only be performed once.";
       performed_ = true;
       return std::move(wrapper_->payload);
     }
 
    private:
     bool performed_;
     const std::shared_ptr<R> wrapper_;
 
     GTEST_DISALLOW_ASSIGN_(Impl);
   };
 
   const std::shared_ptr<R> value_;
 
   GTEST_DISALLOW_ASSIGN_(ReturnAction);
 };
 
 // Implements the ReturnNull() action.
 class ReturnNullAction {
  public:
   // Allows ReturnNull() to be used in any pointer-returning function. In C++11
   // this is enforced by returning nullptr, and in non-C++11 by asserting a
   // pointer type on compile time.
   template <typename Result, typename ArgumentTuple>
   static Result Perform(const ArgumentTuple&) {
     return nullptr;
   }
 };
 
 // Implements the Return() action.
 class ReturnVoidAction {
  public:
   // Allows Return() to be used in any void-returning function.
   template <typename Result, typename ArgumentTuple>
   static void Perform(const ArgumentTuple&) {
     static_assert(std::is_void<Result>::value, "Result should be void.");
   }
 };
 
 // Implements the polymorphic ReturnRef(x) action, which can be used
 // in any function that returns a reference to the type of x,
 // regardless of the argument types.
 template <typename T>
 class ReturnRefAction {
  public:
   // Constructs a ReturnRefAction object from the reference to be returned.
   explicit ReturnRefAction(T& ref) : ref_(ref) {}  // NOLINT
 
   // This template type conversion operator allows ReturnRef(x) to be
   // used in ANY function that returns a reference to x's type.
   template <typename F>
   operator Action<F>() const {
     typedef typename Function<F>::Result Result;
     // Asserts that the function return type is a reference.  This
     // catches the user error of using ReturnRef(x) when Return(x)
     // should be used, and generates some helpful error message.
     GTEST_COMPILE_ASSERT_(std::is_reference<Result>::value,
                           use_Return_instead_of_ReturnRef_to_return_a_value);
     return Action<F>(new Impl<F>(ref_));
   }
 
  private:
   // Implements the ReturnRef(x) action for a particular function type F.
   template <typename F>
   class Impl : public ActionInterface<F> {
    public:
     typedef typename Function<F>::Result Result;
     typedef typename Function<F>::ArgumentTuple ArgumentTuple;
 
     explicit Impl(T& ref) : ref_(ref) {}  // NOLINT
 
     Result Perform(const ArgumentTuple&) override { return ref_; }
 
    private:
     T& ref_;
 
     GTEST_DISALLOW_ASSIGN_(Impl);
   };
 
   T& ref_;
 
   GTEST_DISALLOW_ASSIGN_(ReturnRefAction);
 };
 
 // Implements the polymorphic ReturnRefOfCopy(x) action, which can be
 // used in any function that returns a reference to the type of x,
 // regardless of the argument types.
 template <typename T>
 class ReturnRefOfCopyAction {
  public:
   // Constructs a ReturnRefOfCopyAction object from the reference to
   // be returned.
   explicit ReturnRefOfCopyAction(const T& value) : value_(value) {}  // NOLINT
 
   // This template type conversion operator allows ReturnRefOfCopy(x) to be
   // used in ANY function that returns a reference to x's type.
   template <typename F>
   operator Action<F>() const {
     typedef typename Function<F>::Result Result;
     // Asserts that the function return type is a reference.  This
     // catches the user error of using ReturnRefOfCopy(x) when Return(x)
     // should be used, and generates some helpful error message.
     GTEST_COMPILE_ASSERT_(
         std::is_reference<Result>::value,
         use_Return_instead_of_ReturnRefOfCopy_to_return_a_value);
     return Action<F>(new Impl<F>(value_));
   }
 
  private:
   // Implements the ReturnRefOfCopy(x) action for a particular function type F.
   template <typename F>
   class Impl : public ActionInterface<F> {
    public:
     typedef typename Function<F>::Result Result;
     typedef typename Function<F>::ArgumentTuple ArgumentTuple;
 
     explicit Impl(const T& value) : value_(value) {}  // NOLINT
 
     Result Perform(const ArgumentTuple&) override { return value_; }
 
    private:
     T value_;
 
     GTEST_DISALLOW_ASSIGN_(Impl);
   };
 
   const T value_;
 
   GTEST_DISALLOW_ASSIGN_(ReturnRefOfCopyAction);
 };
 
 // Implements the polymorphic DoDefault() action.
 class DoDefaultAction {
  public:
   // This template type conversion operator allows DoDefault() to be
   // used in any function.
   template <typename F>
   operator Action<F>() const { return Action<F>(); }  // NOLINT
 };
 
 // Implements the Assign action to set a given pointer referent to a
 // particular value.
 template <typename T1, typename T2>
 class AssignAction {
  public:
   AssignAction(T1* ptr, T2 value) : ptr_(ptr), value_(value) {}
 
   template <typename Result, typename ArgumentTuple>
   void Perform(const ArgumentTuple& /* args */) const {
     *ptr_ = value_;
   }
 
  private:
   T1* const ptr_;
   const T2 value_;
 
   GTEST_DISALLOW_ASSIGN_(AssignAction);
 };
 
 #if !GTEST_OS_WINDOWS_MOBILE
 
 // Implements the SetErrnoAndReturn action to simulate return from
 // various system calls and libc functions.
 template <typename T>
 class SetErrnoAndReturnAction {
  public:
   SetErrnoAndReturnAction(int errno_value, T result)
       : errno_(errno_value),
         result_(result) {}
   template <typename Result, typename ArgumentTuple>
   Result Perform(const ArgumentTuple& /* args */) const {
     errno = errno_;
     return result_;
   }
 
  private:
   const int errno_;
   const T result_;
 
   GTEST_DISALLOW_ASSIGN_(SetErrnoAndReturnAction);
 };
 
 #endif  // !GTEST_OS_WINDOWS_MOBILE
 
 // Implements the SetArgumentPointee<N>(x) action for any function
 // whose N-th argument (0-based) is a pointer to x's type.
 template <size_t N, typename A, typename = void>
 struct SetArgumentPointeeAction {
   A value;
 
   template <typename... Args>
   void operator()(const Args&... args) const {
     *::std::get<N>(std::tie(args...)) = value;
   }
 };
 
 // Implements the Invoke(object_ptr, &Class::Method) action.
 template <class Class, typename MethodPtr>
 struct InvokeMethodAction {
   Class* const obj_ptr;
   const MethodPtr method_ptr;
 
   template <typename... Args>
   auto operator()(Args&&... args) const
       -> decltype((obj_ptr->*method_ptr)(std::forward<Args>(args)...)) {
     return (obj_ptr->*method_ptr)(std::forward<Args>(args)...);
   }
 };
 
 // Implements the InvokeWithoutArgs(f) action.  The template argument
 // FunctionImpl is the implementation type of f, which can be either a
 // function pointer or a functor.  InvokeWithoutArgs(f) can be used as an
 // Action<F> as long as f's type is compatible with F.
 template <typename FunctionImpl>
 struct InvokeWithoutArgsAction {
   FunctionImpl function_impl;
 
   // Allows InvokeWithoutArgs(f) to be used as any action whose type is
   // compatible with f.
   template <typename... Args>
   auto operator()(const Args&...) -> decltype(function_impl()) {
     return function_impl();
   }
 };
 
 // Implements the InvokeWithoutArgs(object_ptr, &Class::Method) action.
 template <class Class, typename MethodPtr>
 struct InvokeMethodWithoutArgsAction {
   Class* const obj_ptr;
   const MethodPtr method_ptr;
 
   using ReturnType = typename std::result_of<MethodPtr(Class*)>::type;
 
   template <typename... Args>
   ReturnType operator()(const Args&...) const {
     return (obj_ptr->*method_ptr)();
   }
 };
 
 // Implements the IgnoreResult(action) action.
 template <typename A>
 class IgnoreResultAction {
  public:
   explicit IgnoreResultAction(const A& action) : action_(action) {}
 
   template <typename F>
   operator Action<F>() const {
     // Assert statement belongs here because this is the best place to verify
     // conditions on F. It produces the clearest error messages
     // in most compilers.
     // Impl really belongs in this scope as a local class but can't
     // because MSVC produces duplicate symbols in different translation units
     // in this case. Until MS fixes that bug we put Impl into the class scope
     // and put the typedef both here (for use in assert statement) and
     // in the Impl class. But both definitions must be the same.
     typedef typename internal::Function<F>::Result Result;
 
     // Asserts at compile time that F returns void.
     static_assert(std::is_void<Result>::value, "Result type should be void.");
 
     return Action<F>(new Impl<F>(action_));
   }
 
  private:
   template <typename F>
   class Impl : public ActionInterface<F> {
    public:
     typedef typename internal::Function<F>::Result Result;
     typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
 
     explicit Impl(const A& action) : action_(action) {}
 
     void Perform(const ArgumentTuple& args) override {
       // Performs the action and ignores its result.
       action_.Perform(args);
     }
 
    private:
     // Type OriginalFunction is the same as F except that its return
     // type is IgnoredValue.
     typedef typename internal::Function<F>::MakeResultIgnoredValue
         OriginalFunction;
 
     const Action<OriginalFunction> action_;
 
     GTEST_DISALLOW_ASSIGN_(Impl);
   };
 
   const A action_;
 
   GTEST_DISALLOW_ASSIGN_(IgnoreResultAction);
 };
 
 template <typename InnerAction, size_t... I>
 struct WithArgsAction {
   InnerAction action;
 
   // The inner action could be anything convertible to Action<X>.
   // We use the conversion operator to detect the signature of the inner Action.
   template <typename R, typename... Args>
   operator Action<R(Args...)>() const {  // NOLINT
     Action<R(typename std::tuple_element<I, std::tuple<Args...>>::type...)>
         converted(action);
 
     return [converted](Args... args) -> R {
       return converted.Perform(std::forward_as_tuple(
         std::get<I>(std::forward_as_tuple(std::forward<Args>(args)...))...));
     };
   }
 };
 
 template <typename... Actions>
 struct DoAllAction {
  private:
   template <typename... Args, size_t... I>
   std::vector<Action<void(Args...)>> Convert(IndexSequence<I...>) const {
     return {std::get<I>(actions)...};
   }
 
  public:
   std::tuple<Actions...> actions;
 
   template <typename R, typename... Args>
   operator Action<R(Args...)>() const {  // NOLINT
     struct Op {
       std::vector<Action<void(Args...)>> converted;
       Action<R(Args...)> last;
       R operator()(Args... args) const {
         auto tuple_args = std::forward_as_tuple(std::forward<Args>(args)...);
         for (auto& a : converted) {
           a.Perform(tuple_args);
         }
         return last.Perform(tuple_args);
       }
     };
     return Op{Convert<Args...>(MakeIndexSequence<sizeof...(Actions) - 1>()),
               std::get<sizeof...(Actions) - 1>(actions)};
   }
 };
 
 }  // namespace internal
 
 // An Unused object can be implicitly constructed from ANY value.
 // This is handy when defining actions that ignore some or all of the
 // mock function arguments.  For example, given
 //
 //   MOCK_METHOD3(Foo, double(const string& label, double x, double y));
 //   MOCK_METHOD3(Bar, double(int index, double x, double y));
 //
 // instead of
 //
 //   double DistanceToOriginWithLabel(const string& label, double x, double y) {
 //     return sqrt(x*x + y*y);
 //   }
 //   double DistanceToOriginWithIndex(int index, double x, double y) {
 //     return sqrt(x*x + y*y);
 //   }
 //   ...
 //   EXPECT_CALL(mock, Foo("abc", _, _))
 //       .WillOnce(Invoke(DistanceToOriginWithLabel));
 //   EXPECT_CALL(mock, Bar(5, _, _))
 //       .WillOnce(Invoke(DistanceToOriginWithIndex));
 //
 // you could write
 //
 //   // We can declare any uninteresting argument as Unused.
 //   double DistanceToOrigin(Unused, double x, double y) {
 //     return sqrt(x*x + y*y);
 //   }
 //   ...
 //   EXPECT_CALL(mock, Foo("abc", _, _)).WillOnce(Invoke(DistanceToOrigin));
 //   EXPECT_CALL(mock, Bar(5, _, _)).WillOnce(Invoke(DistanceToOrigin));
 typedef internal::IgnoredValue Unused;
 
 // Creates an action that does actions a1, a2, ..., sequentially in
 // each invocation.
 template <typename... Action>
 internal::DoAllAction<typename std::decay<Action>::type...> DoAll(
     Action&&... action) {
   return {std::forward_as_tuple(std::forward<Action>(action)...)};
 }
 
 // WithArg<k>(an_action) creates an action that passes the k-th
 // (0-based) argument of the mock function to an_action and performs
 // it.  It adapts an action accepting one argument to one that accepts
 // multiple arguments.  For convenience, we also provide
 // WithArgs<k>(an_action) (defined below) as a synonym.
 template <size_t k, typename InnerAction>
 internal::WithArgsAction<typename std::decay<InnerAction>::type, k>
 WithArg(InnerAction&& action) {
   return {std::forward<InnerAction>(action)};
 }
 
 // WithArgs<N1, N2, ..., Nk>(an_action) creates an action that passes
 // the selected arguments of the mock function to an_action and
 // performs it.  It serves as an adaptor between actions with
 // different argument lists.
 template <size_t k, size_t... ks, typename InnerAction>
 internal::WithArgsAction<typename std::decay<InnerAction>::type, k, ks...>
 WithArgs(InnerAction&& action) {
   return {std::forward<InnerAction>(action)};
 }
 
 // WithoutArgs(inner_action) can be used in a mock function with a
 // non-empty argument list to perform inner_action, which takes no
 // argument.  In other words, it adapts an action accepting no
 // argument to one that accepts (and ignores) arguments.
 template <typename InnerAction>
 internal::WithArgsAction<typename std::decay<InnerAction>::type>
 WithoutArgs(InnerAction&& action) {
   return {std::forward<InnerAction>(action)};
 }
 
 // Creates an action that returns 'value'.  'value' is passed by value
 // instead of const reference - otherwise Return("string literal")
 // will trigger a compiler error about using array as initializer.
 template <typename R>
 internal::ReturnAction<R> Return(R value) {
   return internal::ReturnAction<R>(std::move(value));
 }
 
 // Creates an action that returns NULL.
 inline PolymorphicAction<internal::ReturnNullAction> ReturnNull() {
   return MakePolymorphicAction(internal::ReturnNullAction());
 }
 
 // Creates an action that returns from a void function.
 inline PolymorphicAction<internal::ReturnVoidAction> Return() {
   return MakePolymorphicAction(internal::ReturnVoidAction());
 }
 
 // Creates an action that returns the reference to a variable.
 template <typename R>
 inline internal::ReturnRefAction<R> ReturnRef(R& x) {  // NOLINT
   return internal::ReturnRefAction<R>(x);
 }
 
 // Creates an action that returns the reference to a copy of the
 // argument.  The copy is created when the action is constructed and
 // lives as long as the action.
 template <typename R>
 inline internal::ReturnRefOfCopyAction<R> ReturnRefOfCopy(const R& x) {
   return internal::ReturnRefOfCopyAction<R>(x);
 }
 
 // Modifies the parent action (a Return() action) to perform a move of the
 // argument instead of a copy.
 // Return(ByMove()) actions can only be executed once and will assert this
 // invariant.
 template <typename R>
 internal::ByMoveWrapper<R> ByMove(R x) {
   return internal::ByMoveWrapper<R>(std::move(x));
 }
 
 // Creates an action that does the default action for the give mock function.
 inline internal::DoDefaultAction DoDefault() {
   return internal::DoDefaultAction();
 }
 
 // Creates an action that sets the variable pointed by the N-th
 // (0-based) function argument to 'value'.
 template <size_t N, typename T>
 internal::SetArgumentPointeeAction<N, T> SetArgPointee(T x) {
   return {std::move(x)};
 }
 
 // The following version is DEPRECATED.
 template <size_t N, typename T>
 internal::SetArgumentPointeeAction<N, T> SetArgumentPointee(T x) {
   return {std::move(x)};
 }
 
 // Creates an action that sets a pointer referent to a given value.
 template <typename T1, typename T2>
 PolymorphicAction<internal::AssignAction<T1, T2> > Assign(T1* ptr, T2 val) {
   return MakePolymorphicAction(internal::AssignAction<T1, T2>(ptr, val));
 }
 
 #if !GTEST_OS_WINDOWS_MOBILE
 
 // Creates an action that sets errno and returns the appropriate error.
 template <typename T>
 PolymorphicAction<internal::SetErrnoAndReturnAction<T> >
 SetErrnoAndReturn(int errval, T result) {
   return MakePolymorphicAction(
       internal::SetErrnoAndReturnAction<T>(errval, result));
 }
 
 #endif  // !GTEST_OS_WINDOWS_MOBILE
 
 // Various overloads for Invoke().
 
 // Legacy function.
 // Actions can now be implicitly constructed from callables. No need to create
 // wrapper objects.
 // This function exists for backwards compatibility.
 template <typename FunctionImpl>
 typename std::decay<FunctionImpl>::type Invoke(FunctionImpl&& function_impl) {
   return std::forward<FunctionImpl>(function_impl);
 }
 
 // Creates an action that invokes the given method on the given object
 // with the mock function's arguments.
 template <class Class, typename MethodPtr>
 internal::InvokeMethodAction<Class, MethodPtr> Invoke(Class* obj_ptr,
                                                       MethodPtr method_ptr) {
   return {obj_ptr, method_ptr};
 }
 
 // Creates an action that invokes 'function_impl' with no argument.
 template <typename FunctionImpl>
 internal::InvokeWithoutArgsAction<typename std::decay<FunctionImpl>::type>
 InvokeWithoutArgs(FunctionImpl function_impl) {
   return {std::move(function_impl)};
 }
 
 // Creates an action that invokes the given method on the given object
 // with no argument.
 template <class Class, typename MethodPtr>
 internal::InvokeMethodWithoutArgsAction<Class, MethodPtr> InvokeWithoutArgs(
     Class* obj_ptr, MethodPtr method_ptr) {
   return {obj_ptr, method_ptr};
 }
 
 // Creates an action that performs an_action and throws away its
 // result.  In other words, it changes the return type of an_action to
 // void.  an_action MUST NOT return void, or the code won't compile.
 template <typename A>
 inline internal::IgnoreResultAction<A> IgnoreResult(const A& an_action) {
   return internal::IgnoreResultAction<A>(an_action);
 }
 
 // Creates a reference wrapper for the given L-value.  If necessary,
 // you can explicitly specify the type of the reference.  For example,
 // suppose 'derived' is an object of type Derived, ByRef(derived)
 // would wrap a Derived&.  If you want to wrap a const Base& instead,
 // where Base is a base class of Derived, just write:
 //
 //   ByRef<const Base>(derived)
 //
 // N.B. ByRef is redundant with std::ref, std::cref and std::reference_wrapper.
 // However, it may still be used for consistency with ByMove().
 template <typename T>
 inline ::std::reference_wrapper<T> ByRef(T& l_value) {  // NOLINT
   return ::std::reference_wrapper<T>(l_value);
 }
 
 }  // namespace testing
 
 #ifdef _MSC_VER
 # pragma warning(pop)
 #endif
 
 
 #endif  // GMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_