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// Author: wan@google.com (Zhanyong Wan)

// Google Mock - a framework for writing C++ mock classes.
//
// This file implements some commonly used argument matchers.  More
// matchers can be defined by the user implementing the
// MatcherInterface<T> interface if necessary.

#ifndef GMOCK_INCLUDE_GMOCK_GMOCK_MATCHERS_H_
#define GMOCK_INCLUDE_GMOCK_GMOCK_MATCHERS_H_

#include <algorithm>
#include <limits>
#include <ostream>  // NOLINT
#include <sstream>
#include <string>
#include <utility>
#include <vector>

#include "gmock/internal/gmock-internal-utils.h"
#include "gmock/internal/gmock-port.h"
#include "gtest/gtest.h"

namespace testing {

// To implement a matcher Foo for type T, define:
//   1. a class FooMatcherImpl that implements the
//      MatcherInterface<T> interface, and
//   2. a factory function that creates a Matcher<T> object from a
//      FooMatcherImpl*.
//
// The two-level delegation design makes it possible to allow a user
// to write "v" instead of "Eq(v)" where a Matcher is expected, which
// is impossible if we pass matchers by pointers.  It also eases
// ownership management as Matcher objects can now be copied like
// plain values.

// MatchResultListener is an abstract class.  Its << operator can be
// used by a matcher to explain why a value matches or doesn't match.
//
// TODO(wan@google.com): add method
//   bool InterestedInWhy(bool result) const;
// to indicate whether the listener is interested in why the match
// result is 'result'.
class MatchResultListener {
 public:
  // Creates a listener object with the given underlying ostream.  The
  // listener does not own the ostream.
  explicit MatchResultListener(::std::ostream* os) : stream_(os) {}
  virtual ~MatchResultListener() = 0;  // Makes this class abstract.

  // Streams x to the underlying ostream; does nothing if the ostream
  // is NULL.
  template <typename T>
  MatchResultListener& operator<<(const T& x) {
    if (stream_ != NULL)
      *stream_ << x;
    return *this;
  }

  // Returns the underlying ostream.
  ::std::ostream* stream() { return stream_; }

  // Returns true iff the listener is interested in an explanation of
  // the match result.  A matcher's MatchAndExplain() method can use
  // this information to avoid generating the explanation when no one
  // intends to hear it.
  bool IsInterested() const { return stream_ != NULL; }

 private:
  ::std::ostream* const stream_;

  GTEST_DISALLOW_COPY_AND_ASSIGN_(MatchResultListener);
};

inline MatchResultListener::~MatchResultListener() {
}

// The implementation of a matcher.
template <typename T>
class MatcherInterface {
 public:
  virtual ~MatcherInterface() {}

  // Returns true iff the matcher matches x; also explains the match
  // result to 'listener', in the form of a non-restrictive relative
  // clause ("which ...", "whose ...", etc) that describes x.  For
  // example, the MatchAndExplain() method of the Pointee(...) matcher
  // should generate an explanation like "which points to ...".
  //
  // You should override this method when defining a new matcher.
  //
  // It's the responsibility of the caller (Google Mock) to guarantee
  // that 'listener' is not NULL.  This helps to simplify a matcher's
  // implementation when it doesn't care about the performance, as it
  // can talk to 'listener' without checking its validity first.
  // However, in order to implement dummy listeners efficiently,
  // listener->stream() may be NULL.
  virtual bool MatchAndExplain(T x, MatchResultListener* listener) const = 0;

  // Describes this matcher to an ostream.  The function should print
  // a verb phrase that describes the property a value matching this
  // matcher should have.  The subject of the verb phrase is the value
  // being matched.  For example, the DescribeTo() method of the Gt(7)
  // matcher prints "is greater than 7".
  virtual void DescribeTo(::std::ostream* os) const = 0;

  // Describes the negation of this matcher to an ostream.  For
  // example, if the description of this matcher is "is greater than
  // 7", the negated description could be "is not greater than 7".
  // You are not required to override this when implementing
  // MatcherInterface, but it is highly advised so that your matcher
  // can produce good error messages.
  virtual void DescribeNegationTo(::std::ostream* os) const {
    *os << "not (";
    DescribeTo(os);
    *os << ")";
  }
};

namespace internal {

// A match result listener that ignores the explanation.
class DummyMatchResultListener : public MatchResultListener {
 public:
  DummyMatchResultListener() : MatchResultListener(NULL) {}

 private:
  GTEST_DISALLOW_COPY_AND_ASSIGN_(DummyMatchResultListener);
};

// A match result listener that forwards the explanation to a given
// ostream.  The difference between this and MatchResultListener is
// that the former is concrete.
class StreamMatchResultListener : public MatchResultListener {
 public:
  explicit StreamMatchResultListener(::std::ostream* os)
      : MatchResultListener(os) {}

 private:
  GTEST_DISALLOW_COPY_AND_ASSIGN_(StreamMatchResultListener);
};

// A match result listener that stores the explanation in a string.
class StringMatchResultListener : public MatchResultListener {
 public:
  StringMatchResultListener() : MatchResultListener(&ss_) {}

  // Returns the explanation heard so far.
  internal::string str() const { return ss_.str(); }

 private:
  ::std::stringstream ss_;

  GTEST_DISALLOW_COPY_AND_ASSIGN_(StringMatchResultListener);
};

// An internal class for implementing Matcher<T>, which will derive
// from it.  We put functionalities common to all Matcher<T>
// specializations here to avoid code duplication.
template <typename T>
class MatcherBase {
 public:
  // Returns true iff the matcher matches x; also explains the match
  // result to 'listener'.
  bool MatchAndExplain(T x, MatchResultListener* listener) const {
    return impl_->MatchAndExplain(x, listener);
  }

  // Returns true iff this matcher matches x.
  bool Matches(T x) const {
    DummyMatchResultListener dummy;
    return MatchAndExplain(x, &dummy);
  }

  // Describes this matcher to an ostream.
  void DescribeTo(::std::ostream* os) const { impl_->DescribeTo(os); }

  // Describes the negation of this matcher to an ostream.
  void DescribeNegationTo(::std::ostream* os) const {
    impl_->DescribeNegationTo(os);
  }

  // Explains why x matches, or doesn't match, the matcher.
  void ExplainMatchResultTo(T x, ::std::ostream* os) const {
    StreamMatchResultListener listener(os);
    MatchAndExplain(x, &listener);
  }

 protected:
  MatcherBase() {}

  // Constructs a matcher from its implementation.
  explicit MatcherBase(const MatcherInterface<T>* impl)
      : impl_(impl) {}

  virtual ~MatcherBase() {}

 private:
  // shared_ptr (util/gtl/shared_ptr.h) and linked_ptr have similar
  // interfaces.  The former dynamically allocates a chunk of memory
  // to hold the reference count, while the latter tracks all
  // references using a circular linked list without allocating
  // memory.  It has been observed that linked_ptr performs better in
  // typical scenarios.  However, shared_ptr can out-perform
  // linked_ptr when there are many more uses of the copy constructor
  // than the default constructor.
  //
  // If performance becomes a problem, we should see if using
  // shared_ptr helps.
  ::testing::internal::linked_ptr<const MatcherInterface<T> > impl_;
};

}  // namespace internal

// A Matcher<T> is a copyable and IMMUTABLE (except by assignment)
// object that can check whether a value of type T matches.  The
// implementation of Matcher<T> is just a linked_ptr to const
// MatcherInterface<T>, so copying is fairly cheap.  Don't inherit
// from Matcher!
template <typename T>
class Matcher : public internal::MatcherBase<T> {
 public:
  // Constructs a null matcher.  Needed for storing Matcher objects in STL
  // containers.  A default-constructed matcher is not yet initialized.  You
  // cannot use it until a valid value has been assigned to it.
  Matcher() {}

  // Constructs a matcher from its implementation.
  explicit Matcher(const MatcherInterface<T>* impl)
      : internal::MatcherBase<T>(impl) {}

  // Implicit constructor here allows people to write
  // EXPECT_CALL(foo, Bar(5)) instead of EXPECT_CALL(foo, Bar(Eq(5))) sometimes
  Matcher(T value);  // NOLINT
};

// The following two specializations allow the user to write str
// instead of Eq(str) and "foo" instead of Eq("foo") when a string
// matcher is expected.
template <>
class Matcher<const internal::string&>
    : public internal::MatcherBase<const internal::string&> {
 public:
  Matcher() {}

  explicit Matcher(const MatcherInterface<const internal::string&>* impl)
      : internal::MatcherBase<const internal::string&>(impl) {}

  // Allows the user to write str instead of Eq(str) sometimes, where
  // str is a string object.
  Matcher(const internal::string& s);  // NOLINT

  // Allows the user to write "foo" instead of Eq("foo") sometimes.
  Matcher(const char* s);  // NOLINT
};

template <>
class Matcher<internal::string>
    : public internal::MatcherBase<internal::string> {
 public:
  Matcher() {}

  explicit Matcher(const MatcherInterface<internal::string>* impl)
      : internal::MatcherBase<internal::string>(impl) {}

  // Allows the user to write str instead of Eq(str) sometimes, where
  // str is a string object.
  Matcher(const internal::string& s);  // NOLINT

  // Allows the user to write "foo" instead of Eq("foo") sometimes.
  Matcher(const char* s);  // NOLINT
};

// The PolymorphicMatcher class template makes it easy to implement a
// polymorphic matcher (i.e. a matcher that can match values of more
// than one type, e.g. Eq(n) and NotNull()).
//
// To define a polymorphic matcher, a user should provide an Impl
// class that has a DescribeTo() method and a DescribeNegationTo()
// method, and define a member function (or member function template)
//
//   bool MatchAndExplain(const Value& value,
//                        MatchResultListener* listener) const;
//
// See the definition of NotNull() for a complete example.
template <class Impl>
class PolymorphicMatcher {
 public:
  explicit PolymorphicMatcher(const Impl& an_impl) : impl_(an_impl) {}

  // Returns a mutable reference to the underlying matcher
  // implementation object.
  Impl& mutable_impl() { return impl_; }

  // Returns an immutable reference to the underlying matcher
  // implementation object.
  const Impl& impl() const { return impl_; }

  template <typename T>
  operator Matcher<T>() const {
    return Matcher<T>(new MonomorphicImpl<T>(impl_));
  }

 private:
  template <typename T>
  class MonomorphicImpl : public MatcherInterface<T> {
   public:
    explicit MonomorphicImpl(const Impl& impl) : impl_(impl) {}

    virtual void DescribeTo(::std::ostream* os) const {
      impl_.DescribeTo(os);
    }

    virtual void DescribeNegationTo(::std::ostream* os) const {
      impl_.DescribeNegationTo(os);
    }

    virtual bool MatchAndExplain(T x, MatchResultListener* listener) const {
      return impl_.MatchAndExplain(x, listener);
    }

   private:
    const Impl impl_;

    GTEST_DISALLOW_ASSIGN_(MonomorphicImpl);
  };

  Impl impl_;

  GTEST_DISALLOW_ASSIGN_(PolymorphicMatcher);
};

// Creates a matcher from its implementation.  This is easier to use
// than the Matcher<T> constructor as it doesn't require you to
// explicitly write the template argument, e.g.
//
//   MakeMatcher(foo);
// vs
//   Matcher<const string&>(foo);
template <typename T>
inline Matcher<T> MakeMatcher(const MatcherInterface<T>* impl) {
  return Matcher<T>(impl);
};

// Creates a polymorphic matcher from its implementation.  This is
// easier to use than the PolymorphicMatcher<Impl> constructor as it
// doesn't require you to explicitly write the template argument, e.g.
//
//   MakePolymorphicMatcher(foo);
// vs
//   PolymorphicMatcher<TypeOfFoo>(foo);
template <class Impl>
inline PolymorphicMatcher<Impl> MakePolymorphicMatcher(const Impl& impl) {
  return PolymorphicMatcher<Impl>(impl);
}

// In order to be safe and clear, casting between different matcher
// types is done explicitly via MatcherCast<T>(m), which takes a
// matcher m and returns a Matcher<T>.  It compiles only when T can be
// statically converted to the argument type of m.
template <typename T, typename M>
Matcher<T> MatcherCast(M m);

// Implements SafeMatcherCast().
//
// We use an intermediate class to do the actual safe casting as Nokia's
// Symbian compiler cannot decide between
// template <T, M> ... (M) and
// template <T, U> ... (const Matcher<U>&)
// for function templates but can for member function templates.
template <typename T>
class SafeMatcherCastImpl {
 public:
  // This overload handles polymorphic matchers only since monomorphic
  // matchers are handled by the next one.
  template <typename M>
  static inline Matcher<T> Cast(M polymorphic_matcher) {
    return Matcher<T>(polymorphic_matcher);
  }

  // This overload handles monomorphic matchers.
  //
  // In general, if type T can be implicitly converted to type U, we can
  // safely convert a Matcher<U> to a Matcher<T> (i.e. Matcher is
  // contravariant): just keep a copy of the original Matcher<U>, convert the
  // argument from type T to U, and then pass it to the underlying Matcher<U>.
  // The only exception is when U is a reference and T is not, as the
  // underlying Matcher<U> may be interested in the argument's address, which
  // is not preserved in the conversion from T to U.
  template <typename U>
  static inline Matcher<T> Cast(const Matcher<U>& matcher) {
    // Enforce that T can be implicitly converted to U.
    GTEST_COMPILE_ASSERT_((internal::ImplicitlyConvertible<T, U>::value),
                          T_must_be_implicitly_convertible_to_U);
    // Enforce that we are not converting a non-reference type T to a reference
    // type U.
    GTEST_COMPILE_ASSERT_(
        internal::is_reference<T>::value || !internal::is_reference<U>::value,
        cannot_convert_non_referentce_arg_to_reference);
    // In case both T and U are arithmetic types, enforce that the
    // conversion is not lossy.
    typedef GTEST_REMOVE_REFERENCE_AND_CONST_(T) RawT;
    typedef GTEST_REMOVE_REFERENCE_AND_CONST_(U) RawU;
    const bool kTIsOther = GMOCK_KIND_OF_(RawT) == internal::kOther;
    const bool kUIsOther = GMOCK_KIND_OF_(RawU) == internal::kOther;
    GTEST_COMPILE_ASSERT_(
        kTIsOther || kUIsOther ||
        (internal::LosslessArithmeticConvertible<RawT, RawU>::value),
        conversion_of_arithmetic_types_must_be_lossless);
    return MatcherCast<T>(matcher);
  }
};

template <typename T, typename M>
inline Matcher<T> SafeMatcherCast(const M& polymorphic_matcher) {
  return SafeMatcherCastImpl<T>::Cast(polymorphic_matcher);
}

// A<T>() returns a matcher that matches any value of type T.
template <typename T>
Matcher<T> A();

// Anything inside the 'internal' namespace IS INTERNAL IMPLEMENTATION
// and MUST NOT BE USED IN USER CODE!!!
namespace internal {

// If the explanation is not empty, prints it to the ostream.
inline void PrintIfNotEmpty(const internal::string& explanation,
                            std::ostream* os) {
  if (explanation != "" && os != NULL) {
    *os << ", " << explanation;
  }
}

// Returns true if the given type name is easy to read by a human.
// This is used to decide whether printing the type of a value might
// be helpful.
inline bool IsReadableTypeName(const string& type_name) {
  // We consider a type name readable if it's short or doesn't contain
  // a template or function type.
  return (type_name.length() <= 20 ||
          type_name.find_first_of("<(") == string::npos);
}

// Matches the value against the given matcher, prints the value and explains
// the match result to the listener. Returns the match result.
// 'listener' must not be NULL.
// Value cannot be passed by const reference, because some matchers take a
// non-const argument.
template <typename Value, typename T>
bool MatchPrintAndExplain(Value& value, const Matcher<T>& matcher,
                          MatchResultListener* listener) {
  if (!listener->IsInterested()) {
    // If the listener is not interested, we do not need to construct the
    // inner explanation.
    return matcher.Matches(value);
  }

  StringMatchResultListener inner_listener;
  const bool match = matcher.MatchAndExplain(value, &inner_listener);

  UniversalPrint(value, listener->stream());
#if GTEST_HAS_RTTI
  const string& type_name = GetTypeName<Value>();
  if (IsReadableTypeName(type_name))
    *listener->stream() << " (of type " << type_name << ")";
#endif
  PrintIfNotEmpty(inner_listener.str(), listener->stream());

  return match;
}

// An internal helper class for doing compile-time loop on a tuple's
// fields.
template <size_t N>
class TuplePrefix {
 public:
  // TuplePrefix<N>::Matches(matcher_tuple, value_tuple) returns true
  // iff the first N fields of matcher_tuple matches the first N
  // fields of value_tuple, respectively.
  template <typename MatcherTuple, typename ValueTuple>
  static bool Matches(const MatcherTuple& matcher_tuple,
                      const ValueTuple& value_tuple) {
    using ::std::tr1::get;
    return TuplePrefix<N - 1>::Matches(matcher_tuple, value_tuple)
        && get<N - 1>(matcher_tuple).Matches(get<N - 1>(value_tuple));
  }

  // TuplePrefix<N>::ExplainMatchFailuresTo(matchers, values, os)
  // describes failures in matching the first N fields of matchers
  // against the first N fields of values.  If there is no failure,
  // nothing will be streamed to os.
  template <typename MatcherTuple, typename ValueTuple>
  static void ExplainMatchFailuresTo(const MatcherTuple& matchers,
                                     const ValueTuple& values,
                                     ::std::ostream* os) {
    using ::std::tr1::tuple_element;
    using ::std::tr1::get;

    // First, describes failures in the first N - 1 fields.
    TuplePrefix<N - 1>::ExplainMatchFailuresTo(matchers, values, os);

    // Then describes the failure (if any) in the (N - 1)-th (0-based)
    // field.
    typename tuple_element<N - 1, MatcherTuple>::type matcher =
        get<N - 1>(matchers);
    typedef typename tuple_element<N - 1, ValueTuple>::type Value;
    Value value = get<N - 1>(values);
    StringMatchResultListener listener;
    if (!matcher.MatchAndExplain(value, &listener)) {
      // TODO(wan): include in the message the name of the parameter
      // as used in MOCK_METHOD*() when possible.
      *os << "  Expected arg #" << N - 1 << ": ";
      get<N - 1>(matchers).DescribeTo(os);
      *os << "\n           Actual: ";
      // We remove the reference in type Value to prevent the
      // universal printer from printing the address of value, which
      // isn't interesting to the user most of the time.  The
      // matcher's MatchAndExplain() method handles the case when
      // the address is interesting.
      internal::UniversalPrint(value, os);
      PrintIfNotEmpty(listener.str(), os);
      *os << "\n";
    }
  }
};

// The base case.
template <>
class TuplePrefix<0> {
 public:
  template <typename MatcherTuple, typename ValueTuple>
  static bool Matches(const MatcherTuple& /* matcher_tuple */,
                      const ValueTuple& /* value_tuple */) {
    return true;
  }

  template <typename MatcherTuple, typename ValueTuple>
  static void ExplainMatchFailuresTo(const MatcherTuple& /* matchers */,
                                     const ValueTuple& /* values */,
                                     ::std::ostream* /* os */) {}
};

// TupleMatches(matcher_tuple, value_tuple) returns true iff all
// matchers in matcher_tuple match the corresponding fields in
// value_tuple.  It is a compiler error if matcher_tuple and
// value_tuple have different number of fields or incompatible field
// types.
template <typename MatcherTuple, typename ValueTuple>
bool TupleMatches(const MatcherTuple& matcher_tuple,
                  const ValueTuple& value_tuple) {
  using ::std::tr1::tuple_size;
  // Makes sure that matcher_tuple and value_tuple have the same
  // number of fields.
  GTEST_COMPILE_ASSERT_(tuple_size<MatcherTuple>::value ==
                        tuple_size<ValueTuple>::value,
                        matcher_and_value_have_different_numbers_of_fields);
  return TuplePrefix<tuple_size<ValueTuple>::value>::
      Matches(matcher_tuple, value_tuple);
}

// Describes failures in matching matchers against values.  If there
// is no failure, nothing will be streamed to os.
template <typename MatcherTuple, typename ValueTuple>
void ExplainMatchFailureTupleTo(const MatcherTuple& matchers,
                                const ValueTuple& values,
                                ::std::ostream* os) {
  using ::std::tr1::tuple_size;
  TuplePrefix<tuple_size<MatcherTuple>::value>::ExplainMatchFailuresTo(
      matchers, values, os);
}

// The MatcherCastImpl class template is a helper for implementing
// MatcherCast().  We need this helper in order to partially
// specialize the implementation of MatcherCast() (C++ allows
// class/struct templates to be partially specialized, but not
// function templates.).

// This general version is used when MatcherCast()'s argument is a
// polymorphic matcher (i.e. something that can be converted to a
// Matcher but is not one yet; for example, Eq(value)).
template <typename T, typename M>
class MatcherCastImpl {
 public:
  static Matcher<T> Cast(M polymorphic_matcher) {
    return Matcher<T>(polymorphic_matcher);
  }
};

// This more specialized version is used when MatcherCast()'s argument
// is already a Matcher.  This only compiles when type T can be
// statically converted to type U.
template <typename T, typename U>
class MatcherCastImpl<T, Matcher<U> > {
 public:
  static Matcher<T> Cast(const Matcher<U>& source_matcher) {
    return Matcher<T>(new Impl(source_matcher));
  }

 private:
  class Impl : public MatcherInterface<T> {
   public:
    explicit Impl(const Matcher<U>& source_matcher)
        : source_matcher_(source_matcher) {}

    // We delegate the matching logic to the source matcher.
    virtual bool MatchAndExplain(T x, MatchResultListener* listener) const {
      return source_matcher_.MatchAndExplain(static_cast<U>(x), listener);
    }

    virtual void DescribeTo(::std::ostream* os) const {
      source_matcher_.DescribeTo(os);
    }

    virtual void DescribeNegationTo(::std::ostream* os) const {
      source_matcher_.DescribeNegationTo(os);
    }

   private:
    const Matcher<U> source_matcher_;

    GTEST_DISALLOW_ASSIGN_(Impl);
  };
};

// This even more specialized version is used for efficiently casting
// a matcher to its own type.
template <typename T>
class MatcherCastImpl<T, Matcher<T> > {
 public:
  static Matcher<T> Cast(const Matcher<T>& matcher) { return matcher; }
};

// Implements A<T>().
template <typename T>
class AnyMatcherImpl : public MatcherInterface<T> {
 public:
  virtual bool MatchAndExplain(
      T /* x */, MatchResultListener* /* listener */) const { return true; }
  virtual void DescribeTo(::std::ostream* os) const { *os << "is anything"; }
  virtual void DescribeNegationTo(::std::ostream* os) const {
    // This is mostly for completeness' safe, as it's not very useful
    // to write Not(A<bool>()).  However we cannot completely rule out
    // such a possibility, and it doesn't hurt to be prepared.
    *os << "never matches";
  }
};

// Implements _, a matcher that matches any value of any
// type.  This is a polymorphic matcher, so we need a template type
// conversion operator to make it appearing as a Matcher<T> for any
// type T.
class AnythingMatcher {
 public:
  template <typename T>
  operator Matcher<T>() const { return A<T>(); }
};

// Implements a matcher that compares a given value with a
// pre-supplied value using one of the ==, <=, <, etc, operators.  The
// two values being compared don't have to have the same type.
//
// The matcher defined here is polymorphic (for example, Eq(5) can be
// used to match an int, a short, a double, etc).  Therefore we use
// a template type conversion operator in the implementation.
//
// We define this as a macro in order to eliminate duplicated source
// code.
//
// The following template definition assumes that the Rhs parameter is
// a "bare" type (i.e. neither 'const T' nor 'T&').
#define GMOCK_IMPLEMENT_COMPARISON_MATCHER_( \
    name, op, relation, negated_relation) \
  template <typename Rhs> class name##Matcher { \
   public: \
    explicit name##Matcher(const Rhs& rhs) : rhs_(rhs) {} \
    template <typename Lhs> \
    operator Matcher<Lhs>() const { \
      return MakeMatcher(new Impl<Lhs>(rhs_)); \
    } \
   private: \
    template <typename Lhs> \
    class Impl : public MatcherInterface<Lhs> { \
     public: \
      explicit Impl(const Rhs& rhs) : rhs_(rhs) {} \
      virtual bool MatchAndExplain(\
          Lhs lhs, MatchResultListener* /* listener */) const { \
        return lhs op rhs_; \
      } \
      virtual void DescribeTo(::std::ostream* os) const { \
        *os << relation  " "; \
        UniversalPrint(rhs_, os); \
      } \
      virtual void DescribeNegationTo(::std::ostream* os) const { \
        *os << negated_relation  " "; \
        UniversalPrint(rhs_, os); \
      } \
     private: \
      Rhs rhs_; \
      GTEST_DISALLOW_ASSIGN_(Impl); \
    }; \
    Rhs rhs_; \
    GTEST_DISALLOW_ASSIGN_(name##Matcher); \
  }

// Implements Eq(v), Ge(v), Gt(v), Le(v), Lt(v), and Ne(v)
// respectively.
GMOCK_IMPLEMENT_COMPARISON_MATCHER_(Eq, ==, "is equal to", "isn't equal to");
GMOCK_IMPLEMENT_COMPARISON_MATCHER_(Ge, >=, "is >=", "isn't >=");
GMOCK_IMPLEMENT_COMPARISON_MATCHER_(Gt, >, "is >", "isn't >");
GMOCK_IMPLEMENT_COMPARISON_MATCHER_(Le, <=, "is <=", "isn't <=");
GMOCK_IMPLEMENT_COMPARISON_MATCHER_(Lt, <, "is <", "isn't <");
GMOCK_IMPLEMENT_COMPARISON_MATCHER_(Ne, !=, "isn't equal to", "is equal to");

#undef GMOCK_IMPLEMENT_COMPARISON_MATCHER_

// Implements the polymorphic IsNull() matcher, which matches any raw or smart
// pointer that is NULL.
class IsNullMatcher {
 public:
  template <typename Pointer>
  bool MatchAndExplain(const Pointer& p,
                       MatchResultListener* /* listener */) const {
    return GetRawPointer(p) == NULL;
  }

  void DescribeTo(::std::ostream* os) const { *os << "is NULL"; }
  void DescribeNegationTo(::std::ostream* os) const {
    *os << "isn't NULL";
  }
};

// Implements the polymorphic NotNull() matcher, which matches any raw or smart
// pointer that is not NULL.
class NotNullMatcher {
 public:
  template <typename Pointer>
  bool MatchAndExplain(const Pointer& p,
                       MatchResultListener* /* listener */) const {
    return GetRawPointer(p) != NULL;
  }

  void DescribeTo(::std::ostream* os) const { *os << "isn't NULL"; }
  void DescribeNegationTo(::std::ostream* os) const {
    *os << "is NULL";
  }
};

// Ref(variable) matches any argument that is a reference to
// 'variable'.  This matcher is polymorphic as it can match any
// super type of the type of 'variable'.
//
// The RefMatcher template class implements Ref(variable).  It can
// only be instantiated with a reference type.  This prevents a user
// from mistakenly using Ref(x) to match a non-reference function
// argument.  For example, the following will righteously cause a
// compiler error:
//
//   int n;
//   Matcher<int> m1 = Ref(n);   // This won't compile.
//   Matcher<int&> m2 = Ref(n);  // This will compile.
template <typename T>
class RefMatcher;

template <typename T>
class RefMatcher<T&> {
  // Google Mock is a generic framework and thus needs to support
  // mocking any function types, including those that take non-const
  // reference arguments.  Therefore the template parameter T (and
  // Super below) can be instantiated to either a const type or a
  // non-const type.
 public:
  // RefMatcher() takes a T& instead of const T&, as we want the
  // compiler to catch using Ref(const_value) as a matcher for a
  // non-const reference.
  explicit RefMatcher(T& x) : object_(x) {}  // NOLINT

  template <typename Super>
  operator Matcher<Super&>() const {
    // By passing object_ (type T&) to Impl(), which expects a Super&,
    // we make sure that Super is a super type of T.  In particular,
    // this catches using Ref(const_value) as a matcher for a
    // non-const reference, as you cannot implicitly convert a const
    // reference to a non-const reference.
    return MakeMatcher(new Impl<Super>(object_));
  }

 private:
  template <typename Super>
  class Impl : public MatcherInterface<Super&> {
   public:
    explicit Impl(Super& x) : object_(x) {}  // NOLINT

    // MatchAndExplain() takes a Super& (as opposed to const Super&)
    // in order to match the interface MatcherInterface<Super&>.
    virtual bool MatchAndExplain(
        Super& x, MatchResultListener* listener) const {
      *listener << "which is located @" << static_cast<const void*>(&x);
      return &x == &object_;
    }

    virtual void DescribeTo(::std::ostream* os) const {
      *os << "references the variable ";
      UniversalPrinter<Super&>::Print(object_, os);
    }

    virtual void DescribeNegationTo(::std::ostream* os) const {
      *os << "does not reference the variable ";
      UniversalPrinter<Super&>::Print(object_, os);
    }

   private:
    const Super& object_;

    GTEST_DISALLOW_ASSIGN_(Impl);
  };

  T& object_;

  GTEST_DISALLOW_ASSIGN_(RefMatcher);
};

// Polymorphic helper functions for narrow and wide string matchers.
inline bool CaseInsensitiveCStringEquals(const char* lhs, const char* rhs) {
  return String::CaseInsensitiveCStringEquals(lhs, rhs);
}

inline bool CaseInsensitiveCStringEquals(const wchar_t* lhs,
                                         const wchar_t* rhs) {
  return String::CaseInsensitiveWideCStringEquals(lhs, rhs);
}

// String comparison for narrow or wide strings that can have embedded NUL
// characters.
template <typename StringType>
bool CaseInsensitiveStringEquals(const StringType& s1,
                                 const StringType& s2) {
  // Are the heads equal?
  if (!CaseInsensitiveCStringEquals(s1.c_str(), s2.c_str())) {
    return false;
  }

  // Skip the equal heads.
  const typename StringType::value_type nul = 0;
  const size_t i1 = s1.find(nul), i2 = s2.find(nul);

  // Are we at the end of either s1 or s2?
  if (i1 == StringType::npos || i2 == StringType::npos) {
    return i1 == i2;
  }

  // Are the tails equal?
  return CaseInsensitiveStringEquals(s1.substr(i1 + 1), s2.substr(i2 + 1));
}

// String matchers.

// Implements equality-based string matchers like StrEq, StrCaseNe, and etc.
template <typename StringType>
class StrEqualityMatcher {
 public:
  typedef typename StringType::const_pointer ConstCharPointer;

  StrEqualityMatcher(const StringType& str, bool expect_eq,
                     bool case_sensitive)
      : string_(str), expect_eq_(expect_eq), case_sensitive_(case_sensitive) {}

  // When expect_eq_ is true, returns true iff s is equal to string_;
  // otherwise returns true iff s is not equal to string_.
  bool MatchAndExplain(ConstCharPointer s,
                       MatchResultListener* listener) const {
    if (s == NULL) {
      return !expect_eq_;
    }
    return MatchAndExplain(StringType(s), listener);
  }

  bool MatchAndExplain(const StringType& s,
                       MatchResultListener* /* listener */) const {
    const bool eq = case_sensitive_ ? s == string_ :
        CaseInsensitiveStringEquals(s, string_);
    return expect_eq_ == eq;
  }

  void DescribeTo(::std::ostream* os) const {
    DescribeToHelper(expect_eq_, os);
  }

  void DescribeNegationTo(::std::ostream* os) const {
    DescribeToHelper(!expect_eq_, os);
  }

 private:
  void DescribeToHelper(bool expect_eq, ::std::ostream* os) const {
    *os << (expect_eq ? "is " : "isn't ");
    *os << "equal to ";
    if (!case_sensitive_) {
      *os << "(ignoring case) ";
    }
    UniversalPrint(string_, os);
  }

  const StringType string_;
  const bool expect_eq_;
  const bool case_sensitive_;

  GTEST_DISALLOW_ASSIGN_(StrEqualityMatcher);
};

// Implements the polymorphic HasSubstr(substring) matcher, which
// can be used as a Matcher<T> as long as T can be converted to a
// string.
template <typename StringType>
class HasSubstrMatcher {
 public:
  typedef typename StringType::const_pointer ConstCharPointer;

  explicit HasSubstrMatcher(const StringType& substring)
      : substring_(substring) {}

  // These overloaded methods allow HasSubstr(substring) to be used as a
  // Matcher<T> as long as T can be converted to string.  Returns true
  // iff s contains substring_ as a substring.
  bool MatchAndExplain(ConstCharPointer s,
                       MatchResultListener* listener) const {
    return s != NULL && MatchAndExplain(StringType(s), listener);
  }

  bool MatchAndExplain(const StringType& s,
                       MatchResultListener* /* listener */) const {
    return s.find(substring_) != StringType::npos;
  }

  // Describes what this matcher matches.
  void DescribeTo(::std::ostream* os) const {
    *os << "has substring ";
    UniversalPrint(substring_, os);
  }

  void DescribeNegationTo(::std::ostream* os) const {
    *os << "has no substring ";
    UniversalPrint(substring_, os);
  }

 private:
  const StringType substring_;

  GTEST_DISALLOW_ASSIGN_(HasSubstrMatcher);
};

// Implements the polymorphic StartsWith(substring) matcher, which
// can be used as a Matcher<T> as long as T can be converted to a
// string.
template <typename StringType>
class StartsWithMatcher {
 public:
  typedef typename StringType::const_pointer ConstCharPointer;

  explicit StartsWithMatcher(const StringType& prefix) : prefix_(prefix) {
  }

  // These overloaded methods allow StartsWith(prefix) to be used as a
  // Matcher<T> as long as T can be converted to string.  Returns true
  // iff s starts with prefix_.
  bool MatchAndExplain(ConstCharPointer s,
                       MatchResultListener* listener) const {
    return s != NULL && MatchAndExplain(StringType(s), listener);
  }

  bool MatchAndExplain(const StringType& s,
                       MatchResultListener* /* listener */) const {
    return s.length() >= prefix_.length() &&
        s.substr(0, prefix_.length()) == prefix_;
  }

  void DescribeTo(::std::ostream* os) const {
    *os << "starts with ";
    UniversalPrint(prefix_, os);
  }

  void DescribeNegationTo(::std::ostream* os) const {
    *os << "doesn't start with ";
    UniversalPrint(prefix_, os);
  }

 private:
  const StringType prefix_;

  GTEST_DISALLOW_ASSIGN_(StartsWithMatcher);
};

// Implements the polymorphic EndsWith(substring) matcher, which
// can be used as a Matcher<T> as long as T can be converted to a
// string.
template <typename StringType>
class EndsWithMatcher {
 public:
  typedef typename StringType::const_pointer ConstCharPointer;

  explicit EndsWithMatcher(const StringType& suffix) : suffix_(suffix) {}

  // These overloaded methods allow EndsWith(suffix) to be used as a
  // Matcher<T> as long as T can be converted to string.  Returns true
  // iff s ends with suffix_.
  bool MatchAndExplain(ConstCharPointer s,
                       MatchResultListener* listener) const {
    return s != NULL && MatchAndExplain(StringType(s), listener);
  }

  bool MatchAndExplain(const StringType& s,
                       MatchResultListener* /* listener */) const {
    return s.length() >= suffix_.length() &&
        s.substr(s.length() - suffix_.length()) == suffix_;
  }

  void DescribeTo(::std::ostream* os) const {
    *os << "ends with ";
    UniversalPrint(suffix_, os);
  }

  void DescribeNegationTo(::std::ostream* os) const {
    *os << "doesn't end with ";
    UniversalPrint(suffix_, os);
  }

 private:
  const StringType suffix_;

  GTEST_DISALLOW_ASSIGN_(EndsWithMatcher);
};

// Implements polymorphic matchers MatchesRegex(regex) and
// ContainsRegex(regex), which can be used as a Matcher<T> as long as
// T can be converted to a string.
class MatchesRegexMatcher {
 public:
  MatchesRegexMatcher(const RE* regex, bool full_match)
      : regex_(regex), full_match_(full_match) {}

  // These overloaded methods allow MatchesRegex(regex) to be used as
  // a Matcher<T> as long as T can be converted to string.  Returns
  // true iff s matches regular expression regex.  When full_match_ is
  // true, a full match is done; otherwise a partial match is done.
  bool MatchAndExplain(const char* s,
                       MatchResultListener* listener) const {
    return s != NULL && MatchAndExplain(internal::string(s), listener);
  }

  bool MatchAndExplain(const internal::string& s,
                       MatchResultListener* /* listener */) const {
    return full_match_ ? RE::FullMatch(s, *regex_) :
        RE::PartialMatch(s, *regex_);
  }

  void DescribeTo(::std::ostream* os) const {
    *os << (full_match_ ? "matches" : "contains")
        << " regular expression ";
    UniversalPrinter<internal::string>::Print(regex_->pattern(), os);
  }

  void DescribeNegationTo(::std::ostream* os) const {
    *os << "doesn't " << (full_match_ ? "match" : "contain")
        << " regular expression ";
    UniversalPrinter<internal::string>::Print(regex_->pattern(), os);
  }

 private:
  const internal::linked_ptr<const RE> regex_;
  const bool full_match_;

  GTEST_DISALLOW_ASSIGN_(MatchesRegexMatcher);
};

// Implements a matcher that compares the two fields of a 2-tuple
// using one of the ==, <=, <, etc, operators.  The two fields being
// compared don't have to have the same type.
//
// The matcher defined here is polymorphic (for example, Eq() can be
// used to match a tuple<int, short>, a tuple<const long&, double>,
// etc).  Therefore we use a template type conversion operator in the
// implementation.
//
// We define this as a macro in order to eliminate duplicated source
// code.
#define GMOCK_IMPLEMENT_COMPARISON2_MATCHER_(name, op, relation) \
  class name##2Matcher { \
   public: \
    template <typename T1, typename T2> \
    operator Matcher< ::std::tr1::tuple<T1, T2> >() const { \
      return MakeMatcher(new Impl< ::std::tr1::tuple<T1, T2> >); \
    } \
    template <typename T1, typename T2> \
    operator Matcher<const ::std::tr1::tuple<T1, T2>&>() const { \
      return MakeMatcher(new Impl<const ::std::tr1::tuple<T1, T2>&>); \
    } \
   private: \
    template <typename Tuple> \
    class Impl : public MatcherInterface<Tuple> { \
     public: \
      virtual bool MatchAndExplain( \
          Tuple args, \
          MatchResultListener* /* listener */) const { \
        return ::std::tr1::get<0>(args) op ::std::tr1::get<1>(args); \
      } \
      virtual void DescribeTo(::std::ostream* os) const { \
        *os << "are " relation;                                 \
      } \
      virtual void DescribeNegationTo(::std::ostream* os) const { \
        *os << "aren't " relation; \
      } \
    }; \
  }

// Implements Eq(), Ge(), Gt(), Le(), Lt(), and Ne() respectively.
GMOCK_IMPLEMENT_COMPARISON2_MATCHER_(Eq, ==, "an equal pair");
GMOCK_IMPLEMENT_COMPARISON2_MATCHER_(
    Ge, >=, "a pair where the first >= the second");
GMOCK_IMPLEMENT_COMPARISON2_MATCHER_(
    Gt, >, "a pair where the first > the second");
GMOCK_IMPLEMENT_COMPARISON2_MATCHER_(
    Le, <=, "a pair where the first <= the second");
GMOCK_IMPLEMENT_COMPARISON2_MATCHER_(
    Lt, <, "a pair where the first < the second");
GMOCK_IMPLEMENT_COMPARISON2_MATCHER_(Ne, !=, "an unequal pair");

#undef GMOCK_IMPLEMENT_COMPARISON2_MATCHER_

// Implements the Not(...) matcher for a particular argument type T.
// We do not nest it inside the NotMatcher class template, as that
// will prevent different instantiations of NotMatcher from sharing
// the same NotMatcherImpl<T> class.
template <typename T>
class NotMatcherImpl : public MatcherInterface<T> {
 public:
  explicit NotMatcherImpl(const Matcher<T>& matcher)
      : matcher_(matcher) {}

  virtual bool MatchAndExplain(T x, MatchResultListener* listener) const {
    return !matcher_.MatchAndExplain(x, listener);
  }

  virtual void DescribeTo(::std::ostream* os) const {
    matcher_.DescribeNegationTo(os);
  }

  virtual void DescribeNegationTo(::std::ostream* os) const {
    matcher_.DescribeTo(os);
  }

 private:
  const Matcher<T> matcher_;

  GTEST_DISALLOW_ASSIGN_(NotMatcherImpl);
};

// Implements the Not(m) matcher, which matches a value that doesn't
// match matcher m.
template <typename InnerMatcher>
class NotMatcher {
 public:
  explicit NotMatcher(InnerMatcher matcher) : matcher_(matcher) {}

  // This template type conversion operator allows Not(m) to be used
  // to match any type m can match.
  template <typename T>
  operator Matcher<T>() const {
    return Matcher<T>(new NotMatcherImpl<T>(SafeMatcherCast<T>(matcher_)));
  }

 private:
  InnerMatcher matcher_;

  GTEST_DISALLOW_ASSIGN_(NotMatcher);
};

// Implements the AllOf(m1, m2) matcher for a particular argument type
// T. We do not nest it inside the BothOfMatcher class template, as
// that will prevent different instantiations of BothOfMatcher from
// sharing the same BothOfMatcherImpl<T> class.
template <typename T>
class BothOfMatcherImpl : public MatcherInterface<T> {
 public:
  BothOfMatcherImpl(const Matcher<T>& matcher1, const Matcher<T>& matcher2)
      : matcher1_(matcher1), matcher2_(matcher2) {}

  virtual void DescribeTo(::std::ostream* os) const {
    *os << "(";
    matcher1_.DescribeTo(os);
    *os << ") and (";
    matcher2_.DescribeTo(os);
    *os << ")";
  }

  virtual void DescribeNegationTo(::std::ostream* os) const {
    *os << "(";
    matcher1_.DescribeNegationTo(os);
    *os << ") or (";
    matcher2_.DescribeNegationTo(os);
    *os << ")";
  }

  virtual bool MatchAndExplain(T x, MatchResultListener* listener) const {
    // If either matcher1_ or matcher2_ doesn't match x, we only need
    // to explain why one of them fails.
    StringMatchResultListener listener1;
    if (!matcher1_.MatchAndExplain(x, &listener1)) {
      *listener << listener1.str();
      return false;
    }

    StringMatchResultListener listener2;
    if (!matcher2_.MatchAndExplain(x, &listener2)) {
      *listener << listener2.str();
      return false;
    }

    // Otherwise we need to explain why *both* of them match.
    const internal::string s1 = listener1.str();
    const internal::string s2 = listener2.str();

    if (s1 == "") {
      *listener << s2;
    } else {
      *listener << s1;
      if (s2 != "") {
        *listener << ", and " << s2;
      }
    }
    return true;
  }

 private:
  const Matcher<T> matcher1_;
  const Matcher<T> matcher2_;

  GTEST_DISALLOW_ASSIGN_(BothOfMatcherImpl);
};

// Used for implementing the AllOf(m_1, ..., m_n) matcher, which
// matches a value that matches all of the matchers m_1, ..., and m_n.
template <typename Matcher1, typename Matcher2>
class BothOfMatcher {
 public:
  BothOfMatcher(Matcher1 matcher1, Matcher2 matcher2)
      : matcher1_(matcher1), matcher2_(matcher2) {}

  // This template type conversion operator allows a
  // BothOfMatcher<Matcher1, Matcher2> object to match any type that
  // both Matcher1 and Matcher2 can match.
  template <typename T>
  operator Matcher<T>() const {
    return Matcher<T>(new BothOfMatcherImpl<T>(SafeMatcherCast<T>(matcher1_),
                                               SafeMatcherCast<T>(matcher2_)));
  }

 private:
  Matcher1 matcher1_;
  Matcher2 matcher2_;

  GTEST_DISALLOW_ASSIGN_(BothOfMatcher);
};

// Implements the AnyOf(m1, m2) matcher for a particular argument type
// T.  We do not nest it inside the AnyOfMatcher class template, as
// that will prevent different instantiations of AnyOfMatcher from
// sharing the same EitherOfMatcherImpl<T> class.
template <typename T>
class EitherOfMatcherImpl : public MatcherInterface<T> {
 public:
  EitherOfMatcherImpl(const Matcher<T>& matcher1, const Matcher<T>& matcher2)
      : matcher1_(matcher1), matcher2_(matcher2) {}

  virtual void DescribeTo(::std::ostream* os) const {
    *os << "(";
    matcher1_.DescribeTo(os);
    *os << ") or (";
    matcher2_.DescribeTo(os);
    *os << ")";
  }

  virtual void DescribeNegationTo(::std::ostream* os) const {
    *os << "(";
    matcher1_.DescribeNegationTo(os);
    *os << ") and (";
    matcher2_.DescribeNegationTo(os);
    *os << ")";
  }

  virtual bool MatchAndExplain(T x, MatchResultListener* listener) const {
    // If either matcher1_ or matcher2_ matches x, we just need to
    // explain why *one* of them matches.
    StringMatchResultListener listener1;
    if (matcher1_.MatchAndExplain(x, &listener1)) {
      *listener << listener1.str();
      return true;
    }

    StringMatchResultListener listener2;
    if (matcher2_.MatchAndExplain(x, &listener2)) {
      *listener << listener2.str();
      return true;
    }

    // Otherwise we need to explain why *both* of them fail.
    const internal::string s1 = listener1.str();
    const internal::string s2 = listener2.str();

    if (s1 == "") {
      *listener << s2;
    } else {
      *listener << s1;
      if (s2 != "") {
        *listener << ", and " << s2;
      }
    }
    return false;
  }

 private:
  const Matcher<T> matcher1_;
  const Matcher<T> matcher2_;

  GTEST_DISALLOW_ASSIGN_(EitherOfMatcherImpl);
};

// Used for implementing the AnyOf(m_1, ..., m_n) matcher, which
// matches a value that matches at least one of the matchers m_1, ...,
// and m_n.
template <typename Matcher1, typename Matcher2>
class EitherOfMatcher {
 public:
  EitherOfMatcher(Matcher1 matcher1, Matcher2 matcher2)
      : matcher1_(matcher1), matcher2_(matcher2) {}

  // This template type conversion operator allows a
  // EitherOfMatcher<Matcher1, Matcher2> object to match any type that
  // both Matcher1 and Matcher2 can match.
  template <typename T>
  operator Matcher<T>() const {
    return Matcher<T>(new EitherOfMatcherImpl<T>(
        SafeMatcherCast<T>(matcher1_), SafeMatcherCast<T>(matcher2_)));
  }

 private:
  Matcher1 matcher1_;
  Matcher2 matcher2_;

  GTEST_DISALLOW_ASSIGN_(EitherOfMatcher);
};

// Used for implementing Truly(pred), which turns a predicate into a
// matcher.
template <typename Predicate>
class TrulyMatcher {
 public:
  explicit TrulyMatcher(Predicate pred) : predicate_(pred) {}

  // This method template allows Truly(pred) to be used as a matcher
  // for type T where T is the argument type of predicate 'pred'.  The
  // argument is passed by reference as the predicate may be
  // interested in the address of the argument.
  template <typename T>
  bool MatchAndExplain(T& x,  // NOLINT
                       MatchResultListener* /* listener */) const {
    // Without the if-statement, MSVC sometimes warns about converting
    // a value to bool (warning 4800).
    //
    // We cannot write 'return !!predicate_(x);' as that doesn't work
    // when predicate_(x) returns a class convertible to bool but
    // having no operator!().
    if (predicate_(x))
      return true;
    return false;
  }

  void DescribeTo(::std::ostream* os) const {
    *os << "satisfies the given predicate";
  }

  void DescribeNegationTo(::std::ostream* os) const {
    *os << "doesn't satisfy the given predicate";
  }

 private:
  Predicate predicate_;

  GTEST_DISALLOW_ASSIGN_(TrulyMatcher);
};

// Used for implementing Matches(matcher), which turns a matcher into
// a predicate.
template <typename M>
class MatcherAsPredicate {
 public:
  explicit MatcherAsPredicate(M matcher) : matcher_(matcher) {}

  // This template operator() allows Matches(m) to be used as a
  // predicate on type T where m is a matcher on type T.
  //
  // The argument x is passed by reference instead of by value, as
  // some matcher may be interested in its address (e.g. as in
  // Matches(Ref(n))(x)).
  template <typename T>
  bool operator()(const T& x) const {
    // We let matcher_ commit to a particular type here instead of
    // when the MatcherAsPredicate object was constructed.  This
    // allows us to write Matches(m) where m is a polymorphic matcher
    // (e.g. Eq(5)).
    //
    // If we write Matcher<T>(matcher_).Matches(x) here, it won't
    // compile when matcher_ has type Matcher<const T&>; if we write
    // Matcher<const T&>(matcher_).Matches(x) here, it won't compile
    // when matcher_ h…