llvm/third-party/unittest/googlemock/include/gmock/gmock-matchers.h

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// Google Mock - a framework for writing C++ mock classes.
//
// The MATCHER* family of macros can be used in a namespace scope to
// define custom matchers easily.
//
// Basic Usage
// ===========
//
// The syntax
//
//   MATCHER(name, description_string) { statements; }
//
// defines a matcher with the given name that executes the statements,
// which must return a bool to indicate if the match succeeds.  Inside
// the statements, you can refer to the value being matched by 'arg',
// and refer to its type by 'arg_type'.
//
// The description string documents what the matcher does, and is used
// to generate the failure message when the match fails.  Since a
// MATCHER() is usually defined in a header file shared by multiple
// C++ source files, we require the description to be a C-string
// literal to avoid possible side effects.  It can be empty, in which
// case we'll use the sequence of words in the matcher name as the
// description.
//
// For example:
//
//   MATCHER(IsEven, "") { return (arg % 2) == 0; }
//
// allows you to write
//
//   // Expects mock_foo.Bar(n) to be called where n is even.
//   EXPECT_CALL(mock_foo, Bar(IsEven()));
//
// or,
//
//   // Verifies that the value of some_expression is even.
//   EXPECT_THAT(some_expression, IsEven());
//
// If the above assertion fails, it will print something like:
//
//   Value of: some_expression
//   Expected: is even
//     Actual: 7
//
// where the description "is even" is automatically calculated from the
// matcher name IsEven.
//
// Argument Type
// =============
//
// Note that the type of the value being matched (arg_type) is
// determined by the context in which you use the matcher and is
// supplied to you by the compiler, so you don't need to worry about
// declaring it (nor can you).  This allows the matcher to be
// polymorphic.  For example, IsEven() can be used to match any type
// where the value of "(arg % 2) == 0" can be implicitly converted to
// a bool.  In the "Bar(IsEven())" example above, if method Bar()
// takes an int, 'arg_type' will be int; if it takes an unsigned long,
// 'arg_type' will be unsigned long; and so on.
//
// Parameterizing Matchers
// =======================
//
// Sometimes you'll want to parameterize the matcher.  For that you
// can use another macro:
//
//   MATCHER_P(name, param_name, description_string) { statements; }
//
// For example:
//
//   MATCHER_P(HasAbsoluteValue, value, "") { return abs(arg) == value; }
//
// will allow you to write:
//
//   EXPECT_THAT(Blah("a"), HasAbsoluteValue(n));
//
// which may lead to this message (assuming n is 10):
//
//   Value of: Blah("a")
//   Expected: has absolute value 10
//     Actual: -9
//
// Note that both the matcher description and its parameter are
// printed, making the message human-friendly.
//
// In the matcher definition body, you can write 'foo_type' to
// reference the type of a parameter named 'foo'.  For example, in the
// body of MATCHER_P(HasAbsoluteValue, value) above, you can write
// 'value_type' to refer to the type of 'value'.
//
// We also provide MATCHER_P2, MATCHER_P3, ..., up to MATCHER_P$n to
// support multi-parameter matchers.
//
// Describing Parameterized Matchers
// =================================
//
// The last argument to MATCHER*() is a string-typed expression.  The
// expression can reference all of the matcher's parameters and a
// special bool-typed variable named 'negation'.  When 'negation' is
// false, the expression should evaluate to the matcher's description;
// otherwise it should evaluate to the description of the negation of
// the matcher.  For example,
//
//   using testing::PrintToString;
//
//   MATCHER_P2(InClosedRange, low, hi,
//       std::string(negation ? "is not" : "is") + " in range [" +
//       PrintToString(low) + ", " + PrintToString(hi) + "]") {
//     return low <= arg && arg <= hi;
//   }
//   ...
//   EXPECT_THAT(3, InClosedRange(4, 6));
//   EXPECT_THAT(3, Not(InClosedRange(2, 4)));
//
// would generate two failures that contain the text:
//
//   Expected: is in range [4, 6]
//   ...
//   Expected: is not in range [2, 4]
//
// If you specify "" as the description, the failure message will
// contain the sequence of words in the matcher name followed by the
// parameter values printed as a tuple.  For example,
//
//   MATCHER_P2(InClosedRange, low, hi, "") { ... }
//   ...
//   EXPECT_THAT(3, InClosedRange(4, 6));
//   EXPECT_THAT(3, Not(InClosedRange(2, 4)));
//
// would generate two failures that contain the text:
//
//   Expected: in closed range (4, 6)
//   ...
//   Expected: not (in closed range (2, 4))
//
// Types of Matcher Parameters
// ===========================
//
// For the purpose of typing, you can view
//
//   MATCHER_Pk(Foo, p1, ..., pk, description_string) { ... }
//
// as shorthand for
//
//   template <typename p1_type, ..., typename pk_type>
//   FooMatcherPk<p1_type, ..., pk_type>
//   Foo(p1_type p1, ..., pk_type pk) { ... }
//
// When you write Foo(v1, ..., vk), the compiler infers the types of
// the parameters v1, ..., and vk for you.  If you are not happy with
// the result of the type inference, you can specify the types by
// explicitly instantiating the template, as in Foo<long, bool>(5,
// false).  As said earlier, you don't get to (or need to) specify
// 'arg_type' as that's determined by the context in which the matcher
// is used.  You can assign the result of expression Foo(p1, ..., pk)
// to a variable of type FooMatcherPk<p1_type, ..., pk_type>.  This
// can be useful when composing matchers.
//
// While you can instantiate a matcher template with reference types,
// passing the parameters by pointer usually makes your code more
// readable.  If, however, you still want to pass a parameter by
// reference, be aware that in the failure message generated by the
// matcher you will see the value of the referenced object but not its
// address.
//
// Explaining Match Results
// ========================
//
// Sometimes the matcher description alone isn't enough to explain why
// the match has failed or succeeded.  For example, when expecting a
// long string, it can be very helpful to also print the diff between
// the expected string and the actual one.  To achieve that, you can
// optionally stream additional information to a special variable
// named result_listener, whose type is a pointer to class
// MatchResultListener:
//
//   MATCHER_P(EqualsLongString, str, "") {
//     if (arg == str) return true;
//
//     *result_listener << "the difference: "
///                     << DiffStrings(str, arg);
//     return false;
//   }
//
// Overloading Matchers
// ====================
//
// You can overload matchers with different numbers of parameters:
//
//   MATCHER_P(Blah, a, description_string1) { ... }
//   MATCHER_P2(Blah, a, b, description_string2) { ... }
//
// Caveats
// =======
//
// When defining a new matcher, you should also consider implementing
// MatcherInterface or using MakePolymorphicMatcher().  These
// approaches require more work than the MATCHER* macros, but also
// give you more control on the types of the value being matched and
// the matcher parameters, which may leads to better compiler error
// messages when the matcher is used wrong.  They also allow
// overloading matchers based on parameter types (as opposed to just
// based on the number of parameters).
//
// MATCHER*() can only be used in a namespace scope as templates cannot be
// declared inside of a local class.
//
// More Information
// ================
//
// To learn more about using these macros, please search for 'MATCHER'
// on
// https://github.com/google/googletest/blob/main/docs/gmock_cook_book.md
//
// This file also implements some commonly used argument matchers.  More
// matchers can be defined by the user implementing the
// MatcherInterface<T> interface if necessary.
//
// See googletest/include/gtest/gtest-matchers.h for the definition of class
// Matcher, class MatcherInterface, and others.

// IWYU pragma: private, include "gmock/gmock.h"
// IWYU pragma: friend gmock/.*

#ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MATCHERS_H_
#define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MATCHERS_H_

#include <algorithm>
#include <cmath>
#include <exception>
#include <functional>
#include <initializer_list>
#include <ios>
#include <iterator>
#include <limits>
#include <memory>
#include <ostream>  // NOLINT
#include <sstream>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>

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

// MSVC warning C5046 is new as of VS2017 version 15.8.
#if defined(_MSC_VER) && _MSC_VER >= 1915
#define GMOCK_MAYBE_5046_ …
#else
#define GMOCK_MAYBE_5046_
#endif

GTEST_DISABLE_MSC_WARNINGS_PUSH_(…)

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.

// A match result listener that stores the explanation in a string.
class StringMatchResultListener : public MatchResultListener { … };

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

// 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)) or a value (for
// example, "hello").
template <typename T, typename M>
class MatcherCastImpl { … };

// 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.
MatcherCastImpl<T, Matcher<U>>;

// This even more specialized version is used for efficiently casting
// a matcher to its own type.
MatcherCastImpl<T, Matcher<T>>;

// Template specialization for parameterless Matcher.
template <typename Derived>
class MatcherBaseImpl { … };

// Template specialization for Matcher with parameters.
MatcherBaseImpl<Derived<Ts...>>;

}  // namespace internal

// 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>
inline Matcher<T> MatcherCast(const M& matcher) { … }

// This overload handles polymorphic matchers and values only since
// monomorphic matchers are handled by the next one.
template <typename T, typename M>
inline Matcher<T> SafeMatcherCast(const M& polymorphic_matcher_or_value) { … }

// 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 T, typename U>
inline Matcher<T> SafeMatcherCast(const Matcher<U>& 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 std::string& explanation,
                            ::std::ostream* os) { … }

// 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 std::string& type_name) { … }

// 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) { … }

// An internal helper class for doing compile-time loop on a tuple's
// fields.
template <size_t N>
class TuplePrefix { … };

// The base case.
template <>
class TuplePrefix<0> { … };

// TupleMatches(matcher_tuple, value_tuple) returns true if and only if
// 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) { … }

// 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) { … }

// TransformTupleValues and its helper.
//
// TransformTupleValuesHelper hides the internal machinery that
// TransformTupleValues uses to implement a tuple traversal.
template <typename Tuple, typename Func, typename OutIter>
class TransformTupleValuesHelper { … };

// Successively invokes 'f(element)' on each element of the tuple 't',
// appending each result to the 'out' iterator. Returns the final value
// of 'out'.
template <typename Tuple, typename Func, typename OutIter>
OutIter TransformTupleValues(Func f, const Tuple& t, OutIter out) { … }

// 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 { … };

// Implements the polymorphic IsNull() matcher, which matches any raw or smart
// pointer that is NULL.
class IsNullMatcher { … };

// Implements the polymorphic NotNull() matcher, which matches any raw or smart
// pointer that is not NULL.
class NotNullMatcher { … };

// 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;

RefMatcher<T &>;

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

inline bool CaseInsensitiveCStringEquals(const wchar_t* lhs,
                                         const wchar_t* 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) { … }

// String matchers.

// Implements equality-based string matchers like StrEq, StrCaseNe, and etc.
template <typename StringType>
class 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 { … };

// 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 { … };

// 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 { … };

// Implements the polymorphic WhenBase64Unescaped(matcher) matcher, which can be
// used as a Matcher<T> as long as T can be converted to a string.
class WhenBase64UnescapedMatcher { … };

// 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 std::tuple<int, short>, a std::tuple<const long&, double>,
// etc).  Therefore we use a template type conversion operator in the
// implementation.
template <typename D, typename Op>
class PairMatchBase { … };

class Eq2Matcher : public PairMatchBase<Eq2Matcher, std::equal_to<>> { … };
class Ne2Matcher : public PairMatchBase<Ne2Matcher, std::not_equal_to<>> { … };
class Lt2Matcher : public PairMatchBase<Lt2Matcher, std::less<>> { … };
class Gt2Matcher : public PairMatchBase<Gt2Matcher, std::greater<>> { … };
class Le2Matcher : public PairMatchBase<Le2Matcher, std::less_equal<>> { … };
class Ge2Matcher : public PairMatchBase<Ge2Matcher, std::greater_equal<>> { … };

// 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<const T&> { … };

// Implements the Not(m) matcher, which matches a value that doesn't
// match matcher m.
template <typename InnerMatcher>
class 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 AllOfMatcherImpl : public MatcherInterface<const T&> { … };

// VariadicMatcher is used for the variadic implementation of
// AllOf(m_1, m_2, ...) and AnyOf(m_1, m_2, ...).
// CombiningMatcher<T> is used to recursively combine the provided matchers
// (of type Args...).
template <template <typename T> class CombiningMatcher, typename... Args>
class VariadicMatcher { … };

AllOfMatcher;

// 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 AnyOfMatcherImpl : public MatcherInterface<const T&> { … };

// AnyOfMatcher is used for the variadic implementation of AnyOf(m_1, m_2, ...).
AnyOfMatcher;

// ConditionalMatcher is the implementation of Conditional(cond, m1, m2)
template <typename MatcherTrue, typename MatcherFalse>
class ConditionalMatcher { … };

// Wrapper for implementation of Any/AllOfArray().
template <template <class> class MatcherImpl, typename T>
class SomeOfArrayMatcher { … };

AllOfArrayMatcher;

AnyOfArrayMatcher;

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

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

// For implementing ASSERT_THAT() and EXPECT_THAT().  The template
// argument M must be a type that can be converted to a matcher.
template <typename M>
class PredicateFormatterFromMatcher { … };

// A helper function for converting a matcher to a predicate-formatter
// without the user needing to explicitly write the type.  This is
// used for implementing ASSERT_THAT() and EXPECT_THAT().
// Implementation detail: 'matcher' is received by-value to force decaying.
template <typename M>
inline PredicateFormatterFromMatcher<M> MakePredicateFormatterFromMatcher(
    M matcher) { … }

// Implements the polymorphic IsNan() matcher, which matches any floating type
// value that is Nan.
class IsNanMatcher { … };

// Implements the polymorphic floating point equality matcher, which matches
// two float values using ULP-based approximation or, optionally, a
// user-specified epsilon.  The template is meant to be instantiated with
// FloatType being either float or double.
template <typename FloatType>
class FloatingEqMatcher { … };

// A 2-tuple ("binary") wrapper around FloatingEqMatcher:
// FloatingEq2Matcher() matches (x, y) by matching FloatingEqMatcher(x, false)
// against y, and FloatingEq2Matcher(e) matches FloatingEqMatcher(x, false, e)
// against y. The former implements "Eq", the latter "Near". At present, there
// is no version that compares NaNs as equal.
template <typename FloatType>
class FloatingEq2Matcher { … };

// Implements the Pointee(m) matcher for matching a pointer whose
// pointee matches matcher m.  The pointer can be either raw or smart.
template <typename InnerMatcher>
class PointeeMatcher { … };

// Implements the Pointer(m) matcher
// Implements the Pointer(m) matcher for matching a pointer that matches matcher
// m.  The pointer can be either raw or smart, and will match `m` against the
// raw pointer.
template <typename InnerMatcher>
class PointerMatcher { … };

#if GTEST_HAS_RTTI
// Implements the WhenDynamicCastTo<T>(m) matcher that matches a pointer or
// reference that matches inner_matcher when dynamic_cast<T> is applied.
// The result of dynamic_cast<To> is forwarded to the inner matcher.
// If To is a pointer and the cast fails, the inner matcher will receive NULL.
// If To is a reference and the cast fails, this matcher returns false
// immediately.
template <typename To>
class WhenDynamicCastToMatcherBase {
 public:
  explicit WhenDynamicCastToMatcherBase(const Matcher<To>& matcher)
      : matcher_(matcher) {}

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

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

 protected:
  const Matcher<To> matcher_;

  static std::string GetToName() { return GetTypeName<To>(); }

 private:
  static void GetCastTypeDescription(::std::ostream* os) {
    *os << "when dynamic_cast to " << GetToName() << ", ";
  }
};

// Primary template.
// To is a pointer. Cast and forward the result.
template <typename To>
class WhenDynamicCastToMatcher : public WhenDynamicCastToMatcherBase<To> {
 public:
  explicit WhenDynamicCastToMatcher(const Matcher<To>& matcher)
      : WhenDynamicCastToMatcherBase<To>(matcher) {}

  template <typename From>
  bool MatchAndExplain(From from, MatchResultListener* listener) const {
    To to = dynamic_cast<To>(from);
    return MatchPrintAndExplain(to, this->matcher_, listener);
  }
};

// Specialize for references.
// In this case we return false if the dynamic_cast fails.
template <typename To>
class WhenDynamicCastToMatcher<To&> : public WhenDynamicCastToMatcherBase<To&> {
 public:
  explicit WhenDynamicCastToMatcher(const Matcher<To&>& matcher)
      : WhenDynamicCastToMatcherBase<To&>(matcher) {}

  template <typename From>
  bool MatchAndExplain(From& from, MatchResultListener* listener) const {
    // We don't want an std::bad_cast here, so do the cast with pointers.
    To* to = dynamic_cast<To*>(&from);
    if (to == nullptr) {
      *listener << "which cannot be dynamic_cast to " << this->GetToName();
      return false;
    }
    return MatchPrintAndExplain(*to, this->matcher_, listener);
  }
};
#endif  // GTEST_HAS_RTTI

// Implements the Field() matcher for matching a field (i.e. member
// variable) of an object.
template <typename Class, typename FieldType>
class FieldMatcher { … };

// Implements the Property() matcher for matching a property
// (i.e. return value of a getter method) of an object.
//
// Property is a const-qualified member function of Class returning
// PropertyType.
template <typename Class, typename PropertyType, typename Property>
class PropertyMatcher { … };

// Type traits specifying various features of different functors for ResultOf.
// The default template specifies features for functor objects.
template <typename Functor>
struct CallableTraits { … };

// Specialization for function pointers.
CallableTraits<ResType (*)(ArgType)>;

// Implements the ResultOf() matcher for matching a return value of a
// unary function of an object.
template <typename Callable, typename InnerMatcher>
class ResultOfMatcher { … };

// Implements a matcher that checks the size of an STL-style container.
template <typename SizeMatcher>
class SizeIsMatcher { … };

// Implements a matcher that checks the begin()..end() distance of an STL-style
// container.
template <typename DistanceMatcher>
class BeginEndDistanceIsMatcher { … };

// Implements an equality matcher for any STL-style container whose elements
// support ==. This matcher is like Eq(), but its failure explanations provide
// more detailed information that is useful when the container is used as a set.
// The failure message reports elements that are in one of the operands but not
// the other. The failure messages do not report duplicate or out-of-order
// elements in the containers (which don't properly matter to sets, but can
// occur if the containers are vectors or lists, for example).
//
// Uses the container's const_iterator, value_type, operator ==,
// begin(), and end().
template <typename Container>
class ContainerEqMatcher { … };

// A comparator functor that uses the < operator to compare two values.
struct LessComparator { … };

// Implements WhenSortedBy(comparator, container_matcher).
template <typename Comparator, typename ContainerMatcher>
class WhenSortedByMatcher { … };

// Implements Pointwise(tuple_matcher, rhs_container).  tuple_matcher
// must be able to be safely cast to Matcher<std::tuple<const T1&, const
// T2&> >, where T1 and T2 are the types of elements in the LHS
// container and the RHS container respectively.
template <typename TupleMatcher, typename RhsContainer>
class PointwiseMatcher { … };

// Holds the logic common to ContainsMatcherImpl and EachMatcherImpl.
template <typename Container>
class QuantifierMatcherImpl : public MatcherInterface<Container> { … };

// Implements Contains(element_matcher) for the given argument type Container.
// Symmetric to EachMatcherImpl.
template <typename Container>
class ContainsMatcherImpl : public QuantifierMatcherImpl<Container> { … };

// Implements Each(element_matcher) for the given argument type Container.
// Symmetric to ContainsMatcherImpl.
template <typename Container>
class EachMatcherImpl : public QuantifierMatcherImpl<Container> { … };

// Implements Contains(element_matcher).Times(n) for the given argument type
// Container.
template <typename Container>
class ContainsTimesMatcherImpl : public QuantifierMatcherImpl<Container> { … };

// Implements polymorphic Contains(element_matcher).Times(n).
template <typename M>
class ContainsTimesMatcher { … };

// Implements polymorphic Contains(element_matcher).
template <typename M>
class ContainsMatcher { … };

// Implements polymorphic Each(element_matcher).
template <typename M>
class EachMatcher { … };

struct Rank1 { … };
struct Rank0 : Rank1 { … };

namespace pair_getters {
get;
template <typename T>
auto First(T& x, Rank1) -> decltype(get<0>(x)) { … }
template <typename T>
auto First(T& x, Rank0) -> decltype((x.first)) { … }

template <typename T>
auto Second(T& x, Rank1) -> decltype(get<1>(x)) { … }
template <typename T>
auto Second(T& x, Rank0) -> decltype((x.second)) { … }
}  // namespace pair_getters

// Implements Key(inner_matcher) for the given argument pair type.
// Key(inner_matcher) matches an std::pair whose 'first' field matches
// inner_matcher.  For example, Contains(Key(Ge(5))) can be used to match an
// std::map that contains at least one element whose key is >= 5.
template <typename PairType>
class KeyMatcherImpl : public MatcherInterface<PairType> { … };

// Implements polymorphic Key(matcher_for_key).
template <typename M>
class KeyMatcher { … };

// Implements polymorphic Address(matcher_for_address).
template <typename InnerMatcher>
class AddressMatcher { … };

// Implements Pair(first_matcher, second_matcher) for the given argument pair
// type with its two matchers. See Pair() function below.
template <typename PairType>
class PairMatcherImpl : public MatcherInterface<PairType> { … };

// Implements polymorphic Pair(first_matcher, second_matcher).
template <typename FirstMatcher, typename SecondMatcher>
class PairMatcher { … };

template <typename T, size_t... I>
auto UnpackStructImpl(const T& t, IndexSequence<I...>, int)
    -> decltype(std::tie(get<I>(t)...)) { … }

#if defined(__cpp_structured_bindings) && __cpp_structured_bindings >= 201606
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<1>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<2>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<3>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<4>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<5>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<6>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<7>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<8>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<9>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<10>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<11>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<12>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<13>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<14>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<15>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<16>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<17>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<18>, char) { … }
template <typename T>
auto UnpackStructImpl(const T& t, MakeIndexSequence<19>, char) { … }
#endif  // defined(__cpp_structured_bindings)

template <size_t I, typename T>
auto UnpackStruct(const T& t)
    -> decltype((UnpackStructImpl)(t, MakeIndexSequence<I>{ … }

// Helper function to do comma folding in C++11.
// The array ensures left-to-right order of evaluation.
// Usage: VariadicExpand({expr...});
template <typename T, size_t N>
void VariadicExpand(const T (&)[N]) { … }

template <typename Struct, typename StructSize>
class FieldsAreMatcherImpl;

FieldsAreMatcherImpl<Struct, IndexSequence<I...>>;

template <typename... Inner>
class FieldsAreMatcher { … };

// Implements ElementsAre() and ElementsAreArray().
template <typename Container>
class ElementsAreMatcherImpl : public MatcherInterface<Container> { … };

// Connectivity matrix of (elements X matchers), in element-major order.
// Initially, there are no edges.
// Use NextGraph() to iterate over all possible edge configurations.
// Use Randomize() to generate a random edge configuration.
class GTEST_API_ MatchMatrix { … };

ElementMatcherPair;
ElementMatcherPairs;

// Returns a maximum bipartite matching for the specified graph 'g'.
// The matching is represented as a vector of {element, matcher} pairs.
GTEST_API_ ElementMatcherPairs FindMaxBipartiteMatching(const MatchMatrix& g);

struct UnorderedMatcherRequire { … };

// Untyped base class for implementing UnorderedElementsAre.  By
// putting logic that's not specific to the element type here, we
// reduce binary bloat and increase compilation speed.
class GTEST_API_ UnorderedElementsAreMatcherImplBase { … };

// Implements UnorderedElementsAre, UnorderedElementsAreArray, IsSubsetOf, and
// IsSupersetOf.
template <typename Container>
class UnorderedElementsAreMatcherImpl
    : public MatcherInterface<Container>,
      public UnorderedElementsAreMatcherImplBase { … };

// Functor for use in TransformTuple.
// Performs MatcherCast<Target> on an input argument of any type.
template <typename Target>
struct CastAndAppendTransform { … };

// Implements UnorderedElementsAre.
template <typename MatcherTuple>
class UnorderedElementsAreMatcher { … };

// Implements ElementsAre.
template <typename MatcherTuple>
class ElementsAreMatcher { … };

// Implements UnorderedElementsAreArray(), IsSubsetOf(), and IsSupersetOf().
template <typename T>
class UnorderedElementsAreArrayMatcher { … };

// Implements ElementsAreArray().
template <typename T>
class ElementsAreArrayMatcher { … };

// Given a 2-tuple matcher tm of type Tuple2Matcher and a value second
// of type Second, BoundSecondMatcher<Tuple2Matcher, Second>(tm,
// second) is a polymorphic matcher that matches a value x if and only if
// tm matches tuple (x, second).  Useful for implementing
// UnorderedPointwise() in terms of UnorderedElementsAreArray().
//
// BoundSecondMatcher is copyable and assignable, as we need to put
// instances of this class in a vector when implementing
// UnorderedPointwise().
template <typename Tuple2Matcher, typename Second>
class BoundSecondMatcher { … };

// Given a 2-tuple matcher tm and a value second,
// MatcherBindSecond(tm, second) returns a matcher that matches a
// value x if and only if tm matches tuple (x, second).  Useful for
// implementing UnorderedPointwise() in terms of UnorderedElementsAreArray().
template <typename Tuple2Matcher, typename Second>
BoundSecondMatcher<Tuple2Matcher, Second> MatcherBindSecond(
    const Tuple2Matcher& tm, const Second& second) { … }

// Returns the description for a matcher defined using the MATCHER*()
// macro where the user-supplied description string is "", if
// 'negation' is false; otherwise returns the description of the
// negation of the matcher.  'param_values' contains a list of strings
// that are the print-out of the matcher's parameters.
GTEST_API_ std::string FormatMatcherDescription(
    bool negation, const char* matcher_name,
    const std::vector<const char*>& param_names, const Strings& param_values);

// Implements a matcher that checks the value of a optional<> type variable.
template <typename ValueMatcher>
class OptionalMatcher { … };

namespace variant_matcher {
// Overloads to allow VariantMatcher to do proper ADL lookup.
template <typename T>
void holds_alternative() { … }
template <typename T>
void get() { … }

// Implements a matcher that checks the value of a variant<> type variable.
template <typename T>
class VariantMatcher { … };

}  // namespace variant_matcher

namespace any_cast_matcher {

// Overloads to allow AnyCastMatcher to do proper ADL lookup.
template <typename T>
void any_cast() { … }

// Implements a matcher that any_casts the value.
template <typename T>
class AnyCastMatcher { … };

}  // namespace any_cast_matcher

// Implements the Args() matcher.
template <class ArgsTuple, size_t... k>
class ArgsMatcherImpl : public MatcherInterface<ArgsTuple> { … };

template <class InnerMatcher, size_t... k>
class ArgsMatcher { … };

}  // namespace internal

// ElementsAreArray(iterator_first, iterator_last)
// ElementsAreArray(pointer, count)
// ElementsAreArray(array)
// ElementsAreArray(container)
// ElementsAreArray({ e1, e2, ..., en })
//
// The ElementsAreArray() functions are like ElementsAre(...), except
// that they are given a homogeneous sequence rather than taking each
// element as a function argument. The sequence can be specified as an
// array, a pointer and count, a vector, an initializer list, or an
// STL iterator range. In each of these cases, the underlying sequence
// can be either a sequence of values or a sequence of matchers.
//
// All forms of ElementsAreArray() make a copy of the input matcher sequence.

template <typename Iter>
inline internal::ElementsAreArrayMatcher<
    typename ::std::iterator_traits<Iter>::value_type>
ElementsAreArray(Iter first, Iter last) { … }

template <typename T>
inline auto ElementsAreArray(const T* pointer, size_t count)
    -> decltype(ElementsAreArray(pointer, pointer + count)) { … }

template <typename T, size_t N>
inline auto ElementsAreArray(const T (&array)[N])
    -> decltype(ElementsAreArray(array, N)) { … }

template <typename Container>
inline auto ElementsAreArray(const Container& container)
    -> decltype(ElementsAreArray(container.begin(), container.end())) { … }

template <typename T>
inline auto ElementsAreArray(::std::initializer_list<T> xs)
    -> decltype(ElementsAreArray(xs.begin(), xs.end())) { … }

// UnorderedElementsAreArray(iterator_first, iterator_last)
// UnorderedElementsAreArray(pointer, count)
// UnorderedElementsAreArray(array)
// UnorderedElementsAreArray(container)
// UnorderedElementsAreArray({ e1, e2, ..., en })
//
// UnorderedElementsAreArray() verifies that a bijective mapping onto a
// collection of matchers exists.
//
// The matchers can be specified as an array, a pointer and count, a container,
// an initializer list, or an STL iterator range. In each of these cases, the
// underlying matchers can be either values or matchers.

template <typename Iter>
inline internal::UnorderedElementsAreArrayMatcher<
    typename ::std::iterator_traits<Iter>::value_type>
UnorderedElementsAreArray(Iter first, Iter last) { … }

template <typename T>
inline internal::UnorderedElementsAreArrayMatcher<T> UnorderedElementsAreArray(
    const T* pointer, size_t count) { … }

template <typename T, size_t N>
inline internal::UnorderedElementsAreArrayMatcher<T> UnorderedElementsAreArray(
    const T (&array)[N]) { … }

template <typename Container>
inline internal::UnorderedElementsAreArrayMatcher<
    typename Container::value_type>
UnorderedElementsAreArray(const Container& container) { … }

template <typename T>
inline internal::UnorderedElementsAreArrayMatcher<T> UnorderedElementsAreArray(
    ::std::initializer_list<T> xs) { … }

// _ is a matcher that matches anything of any type.
//
// This definition is fine as:
//
//   1. The C++ standard permits using the name _ in a namespace that
//      is not the global namespace or ::std.
//   2. The AnythingMatcher class has no data member or constructor,
//      so it's OK to create global variables of this type.
//   3. c-style has approved of using _ in this case.
const internal::AnythingMatcher _ = …;
// Creates a matcher that matches any value of the given type T.
template <typename T>
inline Matcher<T> A() { … }

// Creates a matcher that matches any value of the given type T.
template <typename T>
inline Matcher<T> An() { … }

template <typename T, typename M>
Matcher<T> internal::MatcherCastImpl<T, M>::CastImpl(
    const M& value, std::false_type /* convertible_to_matcher */,
    std::false_type /* convertible_to_T */) { … }

// Creates a polymorphic matcher that matches any NULL pointer.
inline PolymorphicMatcher<internal::IsNullMatcher> IsNull() { … }

// Creates a polymorphic matcher that matches any non-NULL pointer.
// This is convenient as Not(NULL) doesn't compile (the compiler
// thinks that that expression is comparing a pointer with an integer).
inline PolymorphicMatcher<internal::NotNullMatcher> NotNull() { … }

// Creates a polymorphic matcher that matches any argument that
// references variable x.
template <typename T>
inline internal::RefMatcher<T&> Ref(T& x) { … }

// Creates a polymorphic matcher that matches any NaN floating point.
inline PolymorphicMatcher<internal::IsNanMatcher> IsNan() { … }

// Creates a matcher that matches any double argument approximately
// equal to rhs, where two NANs are considered unequal.
inline internal::FloatingEqMatcher<double> DoubleEq(double rhs) { … }

// Creates a matcher that matches any double argument approximately
// equal to rhs, including NaN values when rhs is NaN.
inline internal::FloatingEqMatcher<double> NanSensitiveDoubleEq(double rhs) { … }

// Creates a matcher that matches any double argument approximately equal to
// rhs, up to the specified max absolute error bound, where two NANs are
// considered unequal.  The max absolute error bound must be non-negative.
inline internal::FloatingEqMatcher<double> DoubleNear(double rhs,
                                                      double max_abs_error) { … }

// Creates a matcher that matches any double argument approximately equal to
// rhs, up to the specified max absolute error bound, including NaN values when
// rhs is NaN.  The max absolute error bound must be non-negative.
inline internal::FloatingEqMatcher<double> NanSensitiveDoubleNear(
    double rhs, double max_abs_error) { … }

// Creates a matcher that matches any float argument approximately
// equal to rhs, where two NANs are considered unequal.
inline internal::FloatingEqMatcher<float> FloatEq(float rhs) { … }

// Creates a matcher that matches any float argument approximately
// equal to rhs, including NaN values when rhs is NaN.
inline internal::FloatingEqMatcher<float> NanSensitiveFloatEq(float rhs) { … }

// Creates a matcher that matches any float argument approximately equal to
// rhs, up to the specified max absolute error bound, where two NANs are
// considered unequal.  The max absolute error bound must be non-negative.
inline internal::FloatingEqMatcher<float> FloatNear(float rhs,
                                                    float max_abs_error) { … }

// Creates a matcher that matches any float argument approximately equal to
// rhs, up to the specified max absolute error bound, including NaN values when
// rhs is NaN.  The max absolute error bound must be non-negative.
inline internal::FloatingEqMatcher<float> NanSensitiveFloatNear(
    float rhs, float max_abs_error) { … }

// Creates a matcher that matches a pointer (raw or smart) that points
// to a value that matches inner_matcher.
template <typename InnerMatcher>
inline internal::PointeeMatcher<InnerMatcher> Pointee(
    const InnerMatcher& inner_matcher) { … }

#if GTEST_HAS_RTTI
// Creates a matcher that matches a pointer or reference that matches
// inner_matcher when dynamic_cast<To> is applied.
// The result of dynamic_cast<To> is forwarded to the inner matcher.
// If To is a pointer and the cast fails, the inner matcher will receive NULL.
// If To is a reference and the cast fails, this matcher returns false
// immediately.
template <typename To>
inline PolymorphicMatcher<internal::WhenDynamicCastToMatcher<To>>
WhenDynamicCastTo(const Matcher<To>& inner_matcher) {
  return MakePolymorphicMatcher(
      internal::WhenDynamicCastToMatcher<To>(inner_matcher));
}
#endif  // GTEST_HAS_RTTI

// Creates a matcher that matches an object whose given field matches
// 'matcher'.  For example,
//   Field(&Foo::number, Ge(5))
// matches a Foo object x if and only if x.number >= 5.
template <typename Class, typename FieldType, typename FieldMatcher>
inline PolymorphicMatcher<internal::FieldMatcher<Class, FieldType>> Field(
    FieldType Class::*field, const FieldMatcher& matcher) { … }

// Same as Field() but also takes the name of the field to provide better error
// messages.
template <typename Class, typename FieldType, typename FieldMatcher>
inline PolymorphicMatcher<internal::FieldMatcher<Class, FieldType>> Field(
    const std::string& field_name, FieldType Class::*field,
    const FieldMatcher& matcher) { … }

// Creates a matcher that matches an object whose given property
// matches 'matcher'.  For example,
//   Property(&Foo::str, StartsWith("hi"))
// matches a Foo object x if and only if x.str() starts with "hi".
template <typename Class, typename PropertyType, typename PropertyMatcher>
inline PolymorphicMatcher<internal::PropertyMatcher<
    Class, PropertyType, PropertyType (Class::*)() const>>
Property(PropertyType (Class::*property)() const,
         const PropertyMatcher& matcher) { … }

// Same as Property() above, but also takes the name of the property to provide
// better error messages.
template <typename Class, typename PropertyType, typename PropertyMatcher>
inline PolymorphicMatcher<internal::PropertyMatcher<
    Class, PropertyType, PropertyType (Class::*)() const>>
Property(const std::string& property_name,
         PropertyType (Class::*property)() const,
         const PropertyMatcher& matcher) { … }

// The same as above but for reference-qualified member functions.
template <typename Class, typename PropertyType, typename PropertyMatcher>
inline PolymorphicMatcher<internal::PropertyMatcher<
    Class, PropertyType, PropertyType (Class::*)() const&>>
Property(PropertyType (Class::*property)() const&,
         const PropertyMatcher& matcher) { … }

// Three-argument form for reference-qualified member functions.
template <typename Class, typename PropertyType, typename PropertyMatcher>
inline PolymorphicMatcher<internal::PropertyMatcher<
    Class, PropertyType, PropertyType (Class::*)() const&>>
Property(const std::string& property_name,
         PropertyType (Class::*property)() const&,
         const PropertyMatcher& matcher) { … }

// Creates a matcher that matches an object if and only if the result of
// applying a callable to x matches 'matcher'. For example,
//   ResultOf(f, StartsWith("hi"))
// matches a Foo object x if and only if f(x) starts with "hi".
// `callable` parameter can be a function, function pointer, or a functor. It is
// required to keep no state affecting the results of the calls on it and make
// no assumptions about how many calls will be made. Any state it keeps must be
// protected from the concurrent access.
template <typename Callable, typename InnerMatcher>
internal::ResultOfMatcher<Callable, InnerMatcher> ResultOf(
    Callable callable, InnerMatcher matcher) { … }

// Same as ResultOf() above, but also takes a description of the `callable`
// result to provide better error messages.
template <typename Callable, typename InnerMatcher>
internal::ResultOfMatcher<Callable, InnerMatcher> ResultOf(
    const std::string& result_description, Callable callable,
    InnerMatcher matcher) { … }

// String matchers.

// Matches a string equal to str.
template <typename T = std::string>
PolymorphicMatcher<internal::StrEqualityMatcher<std::string>> StrEq(
    const internal::StringLike<T>& str) { … }

// Matches a string not equal to str.
template <typename T = std::string>
PolymorphicMatcher<internal::StrEqualityMatcher<std::string>> StrNe(
    const internal::StringLike<T>& str) { … }

// Matches a string equal to str, ignoring case.
template <typename T = std::string>
PolymorphicMatcher<internal::StrEqualityMatcher<std::string>> StrCaseEq(
    const internal::StringLike<T>& str) { … }

// Matches a string not equal to str, ignoring case.
template <typename T = std::string>
PolymorphicMatcher<internal::StrEqualityMatcher<std::string>> StrCaseNe(
    const internal::StringLike<T>& str) { … }

// Creates a matcher that matches any string, std::string, or C string
// that contains the given substring.
template <typename T = std::string>
PolymorphicMatcher<internal::HasSubstrMatcher<std::string>> HasSubstr(
    const internal::StringLike<T>& substring) { … }

// Matches a string that starts with 'prefix' (case-sensitive).
template <typename T = std::string>
PolymorphicMatcher<internal::StartsWithMatcher<std::string>> StartsWith(
    const internal::StringLike<T>& prefix) { … }

// Matches a string that ends with 'suffix' (case-sensitive).
template <typename T = std::string>
PolymorphicMatcher<internal::EndsWithMatcher<std::string>> EndsWith(
    const internal::StringLike<T>& suffix) { … }

#if GTEST_HAS_STD_WSTRING
// Wide string matchers.

// Matches a string equal to str.
inline PolymorphicMatcher<internal::StrEqualityMatcher<std::wstring>> StrEq(
    const std::wstring& str) { … }

// Matches a string not equal to str.
inline PolymorphicMatcher<internal::StrEqualityMatcher<std::wstring>> StrNe(
    const std::wstring& str) { … }

// Matches a string equal to str, ignoring case.
inline PolymorphicMatcher<internal::StrEqualityMatcher<std::wstring>> StrCaseEq(
    const std::wstring& str) { … }

// Matches a string not equal to str, ignoring case.
inline PolymorphicMatcher<internal::StrEqualityMatcher<std::wstring>> StrCaseNe(
    const std::wstring& str) { … }

// Creates a matcher that matches any ::wstring, std::wstring, or C wide string
// that contains the given substring.
inline PolymorphicMatcher<internal::HasSubstrMatcher<std::wstring>> HasSubstr(
    const std::wstring& substring) { … }

// Matches a string that starts with 'prefix' (case-sensitive).
inline PolymorphicMatcher<internal::StartsWithMatcher<std::wstring>> StartsWith(
    const std::wstring& prefix) { … }

// Matches a string that ends with 'suffix' (case-sensitive).
inline PolymorphicMatcher<internal::EndsWithMatcher<std::wstring>> EndsWith(
    const std::wstring& suffix) { … }

#endif  // GTEST_HAS_STD_WSTRING

// Creates a polymorphic matcher that matches a 2-tuple where the
// first field == the second field.
inline internal::Eq2Matcher Eq() { … }

// Creates a polymorphic matcher that matches a 2-tuple where the
// first field >= the second field.
inline internal::Ge2Matcher Ge() { … }

// Creates a polymorphic matcher that matches a 2-tuple where the
// first field > the second field.
inline internal::Gt2Matcher Gt() { … }

// Creates a polymorphic matcher that matches a 2-tuple where the
// first field <= the second field.
inline internal::Le2Matcher Le() { … }

// Creates a polymorphic matcher that matches a 2-tuple where the
// first field < the second field.
inline internal::Lt2Matcher Lt() { … }

// Creates a polymorphic matcher that matches a 2-tuple where the
// first field != the second field.
inline internal::Ne2Matcher Ne() { … }

// Creates a polymorphic matcher that matches a 2-tuple where
// FloatEq(first field) matches the second field.
inline internal::FloatingEq2Matcher<float> FloatEq() { … }

// Creates a polymorphic matcher that matches a 2-tuple where
// DoubleEq(first field) matches the second field.
inline internal::FloatingEq2Matcher<double> DoubleEq() { … }

// Creates a polymorphic matcher that matches a 2-tuple where
// FloatEq(first field) matches the second field with NaN equality.
inline internal::FloatingEq2Matcher<float> NanSensitiveFloatEq() { … }

// Creates a polymorphic matcher that matches a 2-tuple where
// DoubleEq(first field) matches the second field with NaN equality.
inline internal::FloatingEq2Matcher<double> NanSensitiveDoubleEq() { … }

// Creates a polymorphic matcher that matches a 2-tuple where
// FloatNear(first field, max_abs_error) matches the second field.
inline internal::FloatingEq2Matcher<float> FloatNear(float max_abs_error) { … }

// Creates a polymorphic matcher that matches a 2-tuple where
// DoubleNear(first field, max_abs_error) matches the second field.
inline internal::FloatingEq2Matcher<double> DoubleNear(double max_abs_error) { … }

// Creates a polymorphic matcher that matches a 2-tuple where
// FloatNear(first field, max_abs_error) matches the second field with NaN
// equality.
inline internal::FloatingEq2Matcher<float> NanSensitiveFloatNear(
    float max_abs_error) { … }

// Creates a polymorphic matcher that matches a 2-tuple where
// DoubleNear(first field, max_abs_error) matches the second field with NaN
// equality.
inline internal::FloatingEq2Matcher<double> NanSensitiveDoubleNear(
    double max_abs_error) { … }

// Creates a matcher that matches any value of type T that m doesn't
// match.
template <typename InnerMatcher>
inline internal::NotMatcher<InnerMatcher> Not(InnerMatcher m) { … }

// Returns a matcher that matches anything that satisfies the given
// predicate.  The predicate can be any unary function or functor
// whose return type can be implicitly converted to bool.
template <typename Predicate>
inline PolymorphicMatcher<internal::TrulyMatcher<Predicate>> Truly(
    Predicate pred) { … }

// Returns a matcher that matches the container size. The container must
// support both size() and size_type which all STL-like containers provide.
// Note that the parameter 'size' can be a value of type size_type as well as
// matcher. For instance:
//   EXPECT_THAT(container, SizeIs(2));     // Checks container has 2 elements.
//   EXPECT_THAT(container, SizeIs(Le(2));  // Checks container has at most 2.
template <typename SizeMatcher>
inline internal::SizeIsMatcher<SizeMatcher> SizeIs(
    const SizeMatcher& size_matcher) { … }

// Returns a matcher that matches the distance between the container's begin()
// iterator and its end() iterator, i.e. the size of the container. This matcher
// can be used instead of SizeIs with containers such as std::forward_list which
// do not implement size(). The container must provide const_iterator (with
// valid iterator_traits), begin() and end().
template <typename DistanceMatcher>
inline internal::BeginEndDistanceIsMatcher<DistanceMatcher> BeginEndDistanceIs(
    const DistanceMatcher& distance_matcher) { … }

// Returns a matcher that matches an equal container.
// This matcher behaves like Eq(), but in the event of mismatch lists the
// values that are included in one container but not the other. (Duplicate
// values and order differences are not explained.)
template <typename Container>
inline PolymorphicMatcher<
    internal::ContainerEqMatcher<typename std::remove_const<Container>::type>>
ContainerEq(const Container& rhs) { … }

// Returns a matcher that matches a container that, when sorted using
// the given comparator, matches container_matcher.
template <typename Comparator, typename ContainerMatcher>
inline internal::WhenSortedByMatcher<Comparator, ContainerMatcher> WhenSortedBy(
    const Comparator& comparator, const ContainerMatcher& container_matcher) { … }

// Returns a matcher that matches a container that, when sorted using
// the < operator, matches container_matcher.
template <typename ContainerMatcher>
inline internal::WhenSortedByMatcher<internal::LessComparator, ContainerMatcher>
WhenSorted(const ContainerMatcher& container_matcher) { … }

// Matches an STL-style container or a native array that contains the
// same number of elements as in rhs, where its i-th element and rhs's
// i-th element (as a pair) satisfy the given pair matcher, for all i.
// TupleMatcher must be able to be safely cast to Matcher<std::tuple<const
// T1&, const T2&> >, where T1 and T2 are the types of elements in the
// LHS container and the RHS container respectively.
template <typename TupleMatcher, typename Container>
inline internal::PointwiseMatcher<TupleMatcher,
                                  typename std::remove_const<Container>::type>
Pointwise(const TupleMatcher& tuple_matcher, const Container& rhs) { … }

// Supports the Pointwise(m, {a, b, c}) syntax.
template <typename TupleMatcher, typename T>
inline internal::PointwiseMatcher<TupleMatcher, std::vector<T>> Pointwise(
    const TupleMatcher& tuple_matcher, std::initializer_list<T> rhs) { … }

// UnorderedPointwise(pair_matcher, rhs) matches an STL-style
// container or a native array that contains the same number of
// elements as in rhs, where in some permutation of the container, its
// i-th element and rhs's i-th element (as a pair) satisfy the given
// pair matcher, for all i.  Tuple2Matcher must be able to be safely
// cast to Matcher<std::tuple<const T1&, const T2&> >, where T1 and T2 are
// the types of elements in the LHS container and the RHS container
// respectively.
//
// This is like Pointwise(pair_matcher, rhs), except that the element
// order doesn't matter.
template <typename Tuple2Matcher, typename RhsContainer>
inline internal::UnorderedElementsAreArrayMatcher<
    typename internal::BoundSecondMatcher<
        Tuple2Matcher,
        typename internal::StlContainerView<
            typename std::remove_const<RhsContainer>::type>::type::value_type>>
UnorderedPointwise(const Tuple2Matcher& tuple2_matcher,
                   const RhsContainer& rhs_container) { … }

// Supports the UnorderedPointwise(m, {a, b, c}) syntax.
template <typename Tuple2Matcher, typename T>
inline internal::UnorderedElementsAreArrayMatcher<
    typename internal::BoundSecondMatcher<Tuple2Matcher, T>>
UnorderedPointwise(const Tuple2Matcher& tuple2_matcher,
                   std::initializer_list<T> rhs) { … }

// Matches an STL-style container or a native array that contains at
// least one element matching the given value or matcher.
//
// Examples:
//   ::std::set<int> page_ids;
//   page_ids.insert(3);
//   page_ids.insert(1);
//   EXPECT_THAT(page_ids, Contains(1));
//   EXPECT_THAT(page_ids, Contains(Gt(2)));
//   EXPECT_THAT(page_ids, Not(Contains(4)));  // See below for Times(0)
//
//   ::std::map<int, size_t> page_lengths;
//   page_lengths[1] = 100;
//   EXPECT_THAT(page_lengths,
//               Contains(::std::pair<const int, size_t>(1, 100)));
//
//   const char* user_ids[] = { "joe", "mike", "tom" };
//   EXPECT_THAT(user_ids, Contains(Eq(::std::string("tom"))));
//
// The matcher supports a modifier `Times` that allows to check for arbitrary
// occurrences including testing for absence with Times(0).
//
// Examples:
//   ::std::vector<int> ids;
//   ids.insert(1);
//   ids.insert(1);
//   ids.insert(3);
//   EXPECT_THAT(ids, Contains(1).Times(2));      // 1 occurs 2 times
//   EXPECT_THAT(ids, Contains(2).Times(0));      // 2 is not present
//   EXPECT_THAT(ids, Contains(3).Times(Ge(1)));  // 3 occurs at least once

template <typename M>
inline internal::ContainsMatcher<M> Contains(M matcher) { … }

// IsSupersetOf(iterator_first, iterator_last)
// IsSupersetOf(pointer, count)
// IsSupersetOf(array)
// IsSupersetOf(container)
// IsSupersetOf({e1, e2, ..., en})
//
// IsSupersetOf() verifies that a surjective partial mapping onto a collection
// of matchers exists. In other words, a container matches
// IsSupersetOf({e1, ..., en}) if and only if there is a permutation
// {y1, ..., yn} of some of the container's elements where y1 matches e1,
// ..., and yn matches en. Obviously, the size of the container must be >= n
// in order to have a match. Examples:
//
// - {1, 2, 3} matches IsSupersetOf({Ge(3), Ne(0)}), as 3 matches Ge(3) and
//   1 matches Ne(0).
// - {1, 2} doesn't match IsSupersetOf({Eq(1), Lt(2)}), even though 1 matches
//   both Eq(1) and Lt(2). The reason is that different matchers must be used
//   for elements in different slots of the container.
// - {1, 1, 2} matches IsSupersetOf({Eq(1), Lt(2)}), as (the first) 1 matches
//   Eq(1) and (the second) 1 matches Lt(2).
// - {1, 2, 3} matches IsSupersetOf(Gt(1), Gt(1)), as 2 matches (the first)
//   Gt(1) and 3 matches (the second) Gt(1).
//
// The matchers can be specified as an array, a pointer and count, a container,
// an initializer list, or an STL iterator range. In each of these cases, the
// underlying matchers can be either values or matchers.

template <typename Iter>
inline internal::UnorderedElementsAreArrayMatcher<
    typename ::std::iterator_traits<Iter>::value_type>
IsSupersetOf(Iter first, Iter last) { … }

template <typename T>
inline internal::UnorderedElementsAreArrayMatcher<T> IsSupersetOf(
    const T* pointer, size_t count) { … }

template <typename T, size_t N>
inline internal::UnorderedElementsAreArrayMatcher<T> IsSupersetOf(
    const T (&array)[N]) { … }

template <typename Container>
inline internal::UnorderedElementsAreArrayMatcher<
    typename Container::value_type>
IsSupersetOf(const Container& container) { … }

template <typename T>
inline internal::UnorderedElementsAreArrayMatcher<T> IsSupersetOf(
    ::std::initializer_list<T> xs) { … }

// IsSubsetOf(iterator_first, iterator_last)
// IsSubsetOf(pointer, count)
// IsSubsetOf(array)
// IsSubsetOf(container)
// IsSubsetOf({e1, e2, ..., en})
//
// IsSubsetOf() verifies that an injective mapping onto a collection of matchers
// exists.  In other words, a container matches IsSubsetOf({e1, ..., en}) if and
// only if there is a subset of matchers {m1, ..., mk} which would match the
// container using UnorderedElementsAre.  Obviously, the size of the container
// must be <= n in order to have a match. Examples:
//
// - {1} matches IsSubsetOf({Gt(0), Lt(0)}), as 1 matches Gt(0).
// - {1, -1} matches IsSubsetOf({Lt(0), Gt(0)}), as 1 matches Gt(0) and -1
//   matches Lt(0).
// - {1, 2} doesn't matches IsSubsetOf({Gt(0), Lt(0)}), even though 1 and 2 both
//   match Gt(0). The reason is that different matchers must be used for
//   elements in different slots of the container.
//
// The matchers can be specified as an array, a pointer and count, a container,
// an initializer list, or an STL iterator range. In each of these cases, the
// underlying matchers can be either values or matchers.

template <typename Iter>
inline internal::UnorderedElementsAreArrayMatcher<
    typename ::std::iterator_traits<Iter>::value_type>
IsSubsetOf(Iter first, Iter last) { … }

template <typename T>
inline internal::UnorderedElementsAreArrayMatcher<T> IsSubsetOf(
    const T* pointer, size_t count) { … }

template <typename T, size_t N>
inline internal::UnorderedElementsAreArrayMatcher<T> IsSubsetOf(
    const T (&array)[N]) { … }

template <typename Container>
inline internal::UnorderedElementsAreArrayMatcher<
    typename Container::value_type>
IsSubsetOf(const Container& container) { … }

template <typename T>
inline internal::UnorderedElementsAreArrayMatcher<T> IsSubsetOf(
    ::std::initializer_list<T> xs) { … }

// Matches an STL-style container or a native array that contains only
// elements matching the given value or matcher.
//
// Each(m) is semantically equivalent to `Not(Contains(Not(m)))`. Only
// the messages are different.
//
// Examples:
//   ::std::set<int> page_ids;
//   // Each(m) matches an empty container, regardless of what m is.
//   EXPECT_THAT(page_ids, Each(Eq(1)));
//   EXPECT_THAT(page_ids, Each(Eq(77)));
//
//   page_ids.insert(3);
//   EXPECT_THAT(page_ids, Each(Gt(0)));
//   EXPECT_THAT(page_ids, Not(Each(Gt(4))));
//   page_ids.insert(1);
//   EXPECT_THAT(page_ids, Not(Each(Lt(2))));
//
//   ::std::map<int, size_t> page_lengths;
//   page_lengths[1] = 100;
//   page_lengths[2] = 200;
//   page_lengths[3] = 300;
//   EXPECT_THAT(page_lengths, Not(Each(Pair(1, 100))));
//   EXPECT_THAT(page_lengths, Each(Key(Le(3))));
//
//   const char* user_ids[] = { "joe", "mike", "tom" };
//   EXPECT_THAT(user_ids, Not(Each(Eq(::std::string("tom")))));
template <typename M>
inline internal::EachMatcher<M> Each(M matcher) { … }

// Key(inner_matcher) matches an std::pair whose 'first' field matches
// inner_matcher.  For example, Contains(Key(Ge(5))) can be used to match an
// std::map that contains at least one element whose key is >= 5.
template <typename M>
inline internal::KeyMatcher<M> Key(M inner_matcher) { … }

// Pair(first_matcher, second_matcher) matches a std::pair whose 'first' field
// matches first_matcher and whose 'second' field matches second_matcher.  For
// example, EXPECT_THAT(map_type, ElementsAre(Pair(Ge(5), "foo"))) can be used
// to match a std::map<int, string> that contains exactly one element whose key
// is >= 5 and whose value equals "foo".
template <typename FirstMatcher, typename SecondMatcher>
inline internal::PairMatcher<FirstMatcher, SecondMatcher> Pair(
    FirstMatcher first_matcher, SecondMatcher second_matcher) { … }

namespace no_adl {
// Conditional() creates a matcher that conditionally uses either the first or
// second matcher provided. For example, we could create an `equal if, and only
// if' matcher using the Conditional wrapper as follows:
//
//   EXPECT_THAT(result, Conditional(condition, Eq(expected), Ne(expected)));
template <typename MatcherTrue, typename MatcherFalse>
internal::ConditionalMatcher<MatcherTrue, MatcherFalse> Conditional(
    bool condition, MatcherTrue matcher_true, MatcherFalse matcher_false) { … }

// FieldsAre(matchers...) matches piecewise the fields of compatible structs.
// These include those that support `get<I>(obj)`, and when structured bindings
// are enabled any class that supports them.
// In particular, `std::tuple`, `std::pair`, `std::array` and aggregate types.
template <typename... M>
internal::FieldsAreMatcher<typename std::decay<M>::type...> FieldsAre(
    M&&... matchers) { … }

// Creates a matcher that matches a pointer (raw or smart) that matches
// inner_matcher.
template <typename InnerMatcher>
inline internal::PointerMatcher<InnerMatcher> Pointer(
    const InnerMatcher& inner_matcher) { … }

// Creates a matcher that matches an object that has an address that matches
// inner_matcher.
template <typename InnerMatcher>
inline internal::AddressMatcher<InnerMatcher> Address(
    const InnerMatcher& inner_matcher) { … }

// Matches a base64 escaped string, when the unescaped string matches the
// internal matcher.
template <typename MatcherType>
internal::WhenBase64UnescapedMatcher WhenBase64Unescaped(
    const MatcherType& internal_matcher) { … }
}  // namespace no_adl

// Returns a predicate that is satisfied by anything that matches the
// given matcher.
template <typename M>
inline internal::MatcherAsPredicate<M> Matches(M matcher) { … }

// Returns true if and only if the value matches the matcher.
template <typename T, typename M>
inline bool Value(const T& value, M matcher) { … }

// Matches the value against the given matcher and explains the match
// result to listener.
template <typename T, typename M>
inline bool ExplainMatchResult(M matcher, const T& value,
                               MatchResultListener* listener) { … }

// Returns a string representation of the given matcher.  Useful for description
// strings of matchers defined using MATCHER_P* macros that accept matchers as
// their arguments.  For example:
//
// MATCHER_P(XAndYThat, matcher,
//           "X that " + DescribeMatcher<int>(matcher, negation) +
//               (negation ? " or" : " and") + " Y that " +
//               DescribeMatcher<double>(matcher, negation)) {
//   return ExplainMatchResult(matcher, arg.x(), result_listener) &&
//          ExplainMatchResult(matcher, arg.y(), result_listener);
// }
template <typename T, typename M>
std::string DescribeMatcher(const M& matcher, bool negation = false) { … }

template <typename... Args>
internal::ElementsAreMatcher<
    std::tuple<typename std::decay<const Args&>::type...>>
ElementsAre(const Args&... matchers) { … }

template <typename... Args>
internal::UnorderedElementsAreMatcher<
    std::tuple<typename std::decay<const Args&>::type...>>
UnorderedElementsAre(const Args&... matchers) { … }

// Define variadic matcher versions.
template <typename... Args>
internal::AllOfMatcher<typename std::decay<const Args&>::type...> AllOf(
    const Args&... matchers) { … }

template <typename... Args>
internal::AnyOfMatcher<typename std::decay<const Args&>::type...> AnyOf(
    const Args&... matchers) { … }

// AnyOfArray(array)
// AnyOfArray(pointer, count)
// AnyOfArray(container)
// AnyOfArray({ e1, e2, ..., en })
// AnyOfArray(iterator_first, iterator_last)
//
// AnyOfArray() verifies whether a given value matches any member of a
// collection of matchers.
//
// AllOfArray(array)
// AllOfArray(pointer, count)
// AllOfArray(container)
// AllOfArray({ e1, e2, ..., en })
// AllOfArray(iterator_first, iterator_last)
//
// AllOfArray() verifies whether a given value matches all members of a
// collection of matchers.
//
// The matchers can be specified as an array, a pointer and count, a container,
// an initializer list, or an STL iterator range. In each of these cases, the
// underlying matchers can be either values or matchers.

template <typename Iter>
inline internal::AnyOfArrayMatcher<
    typename ::std::iterator_traits<Iter>::value_type>
AnyOfArray(Iter first, Iter last) { … }

template <typename Iter>
inline internal::AllOfArrayMatcher<
    typename ::std::iterator_traits<Iter>::value_type>
AllOfArray(Iter first, Iter last) { … }

template <typename T>
inline internal::AnyOfArrayMatcher<T> AnyOfArray(const T* ptr, size_t count) { … }

template <typename T>
inline internal::AllOfArrayMatcher<T> AllOfArray(const T* ptr, size_t count) { … }

template <typename T, size_t N>
inline internal::AnyOfArrayMatcher<T> AnyOfArray(const T (&array)[N]) { … }

template <typename T, size_t N>
inline internal::AllOfArrayMatcher<T> AllOfArray(const T (&array)[N]) { … }

template <typename Container>
inline internal::AnyOfArrayMatcher<typename Container::value_type> AnyOfArray(
    const Container& container) { … }

template <typename Container>
inline internal::AllOfArrayMatcher<typename Container::value_type> AllOfArray(
    const Container& container) { … }

template <typename T>
inline internal::AnyOfArrayMatcher<T> AnyOfArray(
    ::std::initializer_list<T> xs) { … }

template <typename T>
inline internal::AllOfArrayMatcher<T> AllOfArray(
    ::std::initializer_list<T> xs) { … }

// Args<N1, N2, ..., Nk>(a_matcher) matches a tuple if the selected
// fields of it matches a_matcher.  C++ doesn't support default
// arguments for function templates, so we have to overload it.
template <size_t... k, typename InnerMatcher>
internal::ArgsMatcher<typename std::decay<InnerMatcher>::type, k...> Args(
    InnerMatcher&& matcher) { … }

// AllArgs(m) is a synonym of m.  This is useful in
//
//   EXPECT_CALL(foo, Bar(_, _)).With(AllArgs(Eq()));
//
// which is easier to read than
//
//   EXPECT_CALL(foo, Bar(_, _)).With(Eq());
template <typename InnerMatcher>
inline InnerMatcher AllArgs(const InnerMatcher& matcher) { … }

// Returns a matcher that matches the value of an optional<> type variable.
// The matcher implementation only uses '!arg' and requires that the optional<>
// type has a 'value_type' member type and that '*arg' is of type 'value_type'
// and is printable using 'PrintToString'. It is compatible with
// std::optional/std::experimental::optional.
// Note that to compare an optional type variable against nullopt you should
// use Eq(nullopt) and not Eq(Optional(nullopt)). The latter implies that the
// optional value contains an optional itself.
template <typename ValueMatcher>
inline internal::OptionalMatcher<ValueMatcher> Optional(
    const ValueMatcher& value_matcher) { … }

// Returns a matcher that matches the value of a absl::any type variable.
template <typename T>
PolymorphicMatcher<internal::any_cast_matcher::AnyCastMatcher<T>> AnyWith(
    const Matcher<const T&>& matcher) { … }

// Returns a matcher that matches the value of a variant<> type variable.
// The matcher implementation uses ADL to find the holds_alternative and get
// functions.
// It is compatible with std::variant.
template <typename T>
PolymorphicMatcher<internal::variant_matcher::VariantMatcher<T>> VariantWith(
    const Matcher<const T&>& matcher) { … }

#if GTEST_HAS_EXCEPTIONS

// Anything inside the `internal` namespace is internal to the implementation
// and must not be used in user code!
namespace internal {

class WithWhatMatcherImpl {
 public:
  WithWhatMatcherImpl(Matcher<std::string> matcher)
      : matcher_(std::move(matcher)) {}

  void DescribeTo(std::ostream* os) const {
    *os << "contains .what() that ";
    matcher_.DescribeTo(os);
  }

  void DescribeNegationTo(std::ostream* os) const {
    *os << "contains .what() that does not ";
    matcher_.DescribeTo(os);
  }

  template <typename Err>
  bool MatchAndExplain(const Err& err, MatchResultListener* listener) const {
    *listener << "which contains .what() (of value = " << err.what()
              << ") that ";
    return matcher_.MatchAndExplain(err.what(), listener);
  }

 private:
  const Matcher<std::string> matcher_;
};

inline PolymorphicMatcher<WithWhatMatcherImpl> WithWhat(
    Matcher<std::string> m) {
  return MakePolymorphicMatcher(WithWhatMatcherImpl(std::move(m)));
}

template <typename Err>
class ExceptionMatcherImpl {
  class NeverThrown {
   public:
    const char* what() const noexcept {
      return "this exception should never be thrown";
    }
  };

  // If the matchee raises an exception of a wrong type, we'd like to
  // catch it and print its message and type. To do that, we add an additional
  // catch clause:
  //
  //     try { ... }
  //     catch (const Err&) { /* an expected exception */ }
  //     catch (const std::exception&) { /* exception of a wrong type */ }
  //
  // However, if the `Err` itself is `std::exception`, we'd end up with two
  // identical `catch` clauses:
  //
  //     try { ... }
  //     catch (const std::exception&) { /* an expected exception */ }
  //     catch (const std::exception&) { /* exception of a wrong type */ }
  //
  // This can cause a warning or an error in some compilers. To resolve
  // the issue, we use a fake error type whenever `Err` is `std::exception`:
  //
  //     try { ... }
  //     catch (const std::exception&) { /* an expected exception */ }
  //     catch (const NeverThrown&) { /* exception of a wrong type */ }
  using DefaultExceptionType = typename std::conditional<
      std::is_same<typename std::remove_cv<
                       typename std::remove_reference<Err>::type>::type,
                   std::exception>::value,
      const NeverThrown&, const std::exception&>::type;

 public:
  ExceptionMatcherImpl(Matcher<const Err&> matcher)
      : matcher_(std::move(matcher)) {}

  void DescribeTo(std::ostream* os) const {
    *os << "throws an exception which is a " << GetTypeName<Err>();
    *os << " which ";
    matcher_.DescribeTo(os);
  }

  void DescribeNegationTo(std::ostream* os) const {
    *os << "throws an exception which is not a " << GetTypeName<Err>();
    *os << " which ";
    matcher_.DescribeNegationTo(os);
  }

  template <typename T>
  bool MatchAndExplain(T&& x, MatchResultListener* listener) const {
    try {
      (void)(std::forward<T>(x)());
    } catch (const Err& err) {
      *listener << "throws an exception which is a " << GetTypeName<Err>();
      *listener << " ";
      return matcher_.MatchAndExplain(err, listener);
    } catch (DefaultExceptionType err) {
#if GTEST_HAS_RTTI
      *listener << "throws an exception of type " << GetTypeName(typeid(err));
      *listener << " ";
#else
      *listener << "throws an std::exception-derived type ";
#endif
      *listener << "with description \"" << err.what() << "\"";
      return false;
    } catch (...) {
      *listener << "throws an exception of an unknown type";
      return false;
    }

    *listener << "does not throw any exception";
    return false;
  }

 private:
  const Matcher<const Err&> matcher_;
};

}  // namespace internal

// Throws()
// Throws(exceptionMatcher)
// ThrowsMessage(messageMatcher)
//
// This matcher accepts a callable and verifies that when invoked, it throws
// an exception with the given type and properties.
//
// Examples:
//
//   EXPECT_THAT(
//       []() { throw std::runtime_error("message"); },
//       Throws<std::runtime_error>());
//
//   EXPECT_THAT(
//       []() { throw std::runtime_error("message"); },
//       ThrowsMessage<std::runtime_error>(HasSubstr("message")));
//
//   EXPECT_THAT(
//       []() { throw std::runtime_error("message"); },
//       Throws<std::runtime_error>(
//           Property(&std::runtime_error::what, HasSubstr("message"))));

template <typename Err>
PolymorphicMatcher<internal::ExceptionMatcherImpl<Err>> Throws() {
  return MakePolymorphicMatcher(
      internal::ExceptionMatcherImpl<Err>(A<const Err&>()));
}

template <typename Err, typename ExceptionMatcher>
PolymorphicMatcher<internal::ExceptionMatcherImpl<Err>> Throws(
    const ExceptionMatcher& exception_matcher) {
  // Using matcher cast allows users to pass a matcher of a more broad type.
  // For example user may want to pass Matcher<std::exception>
  // to Throws<std::runtime_error>, or Matcher<int64> to Throws<int32>.
  return MakePolymorphicMatcher(internal::ExceptionMatcherImpl<Err>(
      SafeMatcherCast<const Err&>(exception_matcher)));
}

template <typename Err, typename MessageMatcher>
PolymorphicMatcher<internal::ExceptionMatcherImpl<Err>> ThrowsMessage(
    MessageMatcher&& message_matcher) {
  static_assert(std::is_base_of<std::exception, Err>::value,
                "expected an std::exception-derived type");
  return Throws<Err>(internal::WithWhat(
      MatcherCast<std::string>(std::forward<MessageMatcher>(message_matcher))));
}

#endif  // GTEST_HAS_EXCEPTIONS

// These macros allow using matchers to check values in Google Test
// tests.  ASSERT_THAT(value, matcher) and EXPECT_THAT(value, matcher)
// succeed if and only if the value matches the matcher.  If the assertion
// fails, the value and the description of the matcher will be printed.
#define ASSERT_THAT(value, matcher) …
#define EXPECT_THAT(value, matcher) …

// MATCHER* macros itself are listed below.
#define MATCHER(name, description) …

#define MATCHER_P(name, p0, description) …
#define MATCHER_P2(name, p0, p1, description) …
#define MATCHER_P3(name, p0, p1, p2, description) …
#define MATCHER_P4(name, p0, p1, p2, p3, description) …
#define MATCHER_P5(name, p0, p1, p2, p3, p4, description) …
#define MATCHER_P6(name, p0, p1, p2, p3, p4, p5, description) …
#define MATCHER_P7(name, p0, p1, p2, p3, p4, p5, p6, description) …
#define MATCHER_P8(name, p0, p1, p2, p3, p4, p5, p6, p7, description) …
#define MATCHER_P9(name, p0, p1, p2, p3, p4, p5, p6, p7, p8, description) …
#define MATCHER_P10(name, p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, description) …

#define GMOCK_INTERNAL_MATCHER(name, full_name, description, arg_names, args) …

#define GMOCK_INTERNAL_MATCHER_TEMPLATE_PARAMS(args) …
#define GMOCK_INTERNAL_MATCHER_TEMPLATE_PARAM(i_unused, data_unused, arg) …

#define GMOCK_INTERNAL_MATCHER_TYPE_PARAMS(args) …
#define GMOCK_INTERNAL_MATCHER_TYPE_PARAM(i_unused, data_unused, arg) …

#define GMOCK_INTERNAL_MATCHER_FUNCTION_ARGS(args) …
#define GMOCK_INTERNAL_MATCHER_FUNCTION_ARG(i, data_unused, arg) …

#define GMOCK_INTERNAL_MATCHER_FORWARD_ARGS(args) …
#define GMOCK_INTERNAL_MATCHER_FORWARD_ARG(i, data_unused, arg) …

#define GMOCK_INTERNAL_MATCHER_MEMBERS(args) …
#define GMOCK_INTERNAL_MATCHER_MEMBER(i_unused, data_unused, arg) …

#define GMOCK_INTERNAL_MATCHER_MEMBERS_USAGE(args) …
#define GMOCK_INTERNAL_MATCHER_MEMBER_USAGE(i_unused, data_unused, arg) …

#define GMOCK_INTERNAL_MATCHER_ARGS_USAGE(args) …
#define GMOCK_INTERNAL_MATCHER_ARG_USAGE(i, data_unused, arg_unused) …

// To prevent ADL on certain functions we put them on a separate namespace.
usingnamespaceno_adl;  // NOLINT

}  // namespace testing

GTEST_DISABLE_MSC_WARNINGS_POP_(…)  //  4251 5046

// Include any custom callback matchers added by the local installation.
// We must include this header at the end to make sure it can use the
// declarations from this file.
#include "gmock/internal/custom/gmock-matchers.h"

#endif  // GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MATCHERS_H_