Googletest export

Create implementation macroses for matchers to move variadic parameters to the
end of parameters list.

To save backward compatibility, old macroses will be still taking `description`
parameter as the last one. But they will use INTERNAL macro that takes
`description` as the second parameter.

PiperOrigin-RevId: 291724469

3 files changed, 257 insertions, 441 deletions

diff --git a/googlemock/include/gmock/gmock-generated-matchers.h b/googlemock/include/gmock/gmock-generated-matchers.h
index 4234b267..346b145e 100644
--- a/googlemock/include/gmock/gmock-generated-matchers.h
+++ b/googlemock/include/gmock/gmock-generated-matchers.h
@@ -47,220 +47,7 @@
 #include <vector>
 #include "gmock/gmock-matchers.h"
 
-// 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_P10 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/master/googlemock/docs/cook_book.md
-
-#define MATCHER(name, description)\
+#define GMOCK_INTERNAL_MATCHER(name, description)\
   class name##Matcher : public \
       ::testing::internal::MatcherBaseImpl<name##Matcher> {\
     using __internal_base_type = \
@@ -304,7 +91,7 @@
       ::testing::MatchResultListener* result_listener GTEST_ATTRIBUTE_UNUSED_)\
           const
 
-#define MATCHER_P(name, p0, description)\
+#define GMOCK_INTERNAL_MATCHER_P(name, description, p0)\
   template <typename p0##_type>\
   class name##MatcherP : public \
       ::testing::internal::MatcherBaseImpl<name##MatcherP<p0##_type>> {\
@@ -352,7 +139,7 @@
       ::testing::MatchResultListener* result_listener GTEST_ATTRIBUTE_UNUSED_)\
           const
 
-#define MATCHER_P2(name, p0, p1, description)\
+#define GMOCK_INTERNAL_MATCHER_P2(name, description, p0, p1)\
   template <typename p0##_type, typename p1##_type>\
   class name##MatcherP2 : public \
       ::testing::internal::MatcherBaseImpl<name##MatcherP2<p0##_type, \
@@ -404,7 +191,7 @@
       ::testing::MatchResultListener* result_listener GTEST_ATTRIBUTE_UNUSED_)\
           const
 
-#define MATCHER_P3(name, p0, p1, p2, description)\
+#define GMOCK_INTERNAL_MATCHER_P3(name, description, p0, p1, p2)\
   template <typename p0##_type, typename p1##_type, typename p2##_type>\
   class name##MatcherP3 : public \
       ::testing::internal::MatcherBaseImpl<name##MatcherP3<p0##_type, \
@@ -458,7 +245,7 @@
       ::testing::MatchResultListener* result_listener GTEST_ATTRIBUTE_UNUSED_)\
           const
 
-#define MATCHER_P4(name, p0, p1, p2, p3, description)\
+#define GMOCK_INTERNAL_MATCHER_P4(name, description, p0, p1, p2, p3)\
   template <typename p0##_type, typename p1##_type, typename p2##_type, \
       typename p3##_type>\
   class name##MatcherP4 : public \
@@ -520,7 +307,7 @@
       ::testing::MatchResultListener* result_listener GTEST_ATTRIBUTE_UNUSED_)\
           const
 
-#define MATCHER_P5(name, p0, p1, p2, p3, p4, description)\
+#define GMOCK_INTERNAL_MATCHER_P5(name, description, p0, p1, p2, p3, p4)\
   template <typename p0##_type, typename p1##_type, typename p2##_type, \
       typename p3##_type, typename p4##_type>\
   class name##MatcherP5 : public \
@@ -584,7 +371,7 @@
       ::testing::MatchResultListener* result_listener GTEST_ATTRIBUTE_UNUSED_)\
           const
 
-#define MATCHER_P6(name, p0, p1, p2, p3, p4, p5, description)\
+#define GMOCK_INTERNAL_MATCHER_P6(name, description, p0, p1, p2, p3, p4, p5)\
   template <typename p0##_type, typename p1##_type, typename p2##_type, \
       typename p3##_type, typename p4##_type, typename p5##_type>\
   class name##MatcherP6 : public \
@@ -649,7 +436,8 @@
       ::testing::MatchResultListener* result_listener GTEST_ATTRIBUTE_UNUSED_)\
           const
 
-#define MATCHER_P7(name, p0, p1, p2, p3, p4, p5, p6, description)\
+#define GMOCK_INTERNAL_MATCHER_P7(name, description, p0, p1, p2, p3, p4, p5, \
+    p6)\
   template <typename p0##_type, typename p1##_type, typename p2##_type, \
       typename p3##_type, typename p4##_type, typename p5##_type, \
       typename p6##_type>\
@@ -722,7 +510,8 @@
       ::testing::MatchResultListener* result_listener GTEST_ATTRIBUTE_UNUSED_)\
           const
 
-#define MATCHER_P8(name, p0, p1, p2, p3, p4, p5, p6, p7, description)\
+#define GMOCK_INTERNAL_MATCHER_P8(name, description, p0, p1, p2, p3, p4, p5, \
+    p6, p7)\
   template <typename p0##_type, typename p1##_type, typename p2##_type, \
       typename p3##_type, typename p4##_type, typename p5##_type, \
       typename p6##_type, typename p7##_type>\
@@ -799,7 +588,8 @@
       ::testing::MatchResultListener* result_listener GTEST_ATTRIBUTE_UNUSED_)\
           const
 
-#define MATCHER_P9(name, p0, p1, p2, p3, p4, p5, p6, p7, p8, description)\
+#define GMOCK_INTERNAL_MATCHER_P9(name, description, p0, p1, p2, p3, p4, p5, \
+    p6, p7, p8)\
   template <typename p0##_type, typename p1##_type, typename p2##_type, \
       typename p3##_type, typename p4##_type, typename p5##_type, \
       typename p6##_type, typename p7##_type, typename p8##_type>\
@@ -879,7 +669,8 @@
       ::testing::MatchResultListener* result_listener GTEST_ATTRIBUTE_UNUSED_)\
           const
 
-#define MATCHER_P10(name, p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, description)\
+#define GMOCK_INTERNAL_MATCHER_P10(name, description, p0, p1, p2, p3, p4, p5, \
+    p6, p7, p8, p9)\
   template <typename p0##_type, typename p1##_type, typename p2##_type, \
       typename p3##_type, typename p4##_type, typename p5##_type, \
       typename p6##_type, typename p7##_type, typename p8##_type, \
diff --git a/googlemock/include/gmock/gmock-generated-matchers.h.pump b/googlemock/include/gmock/gmock-generated-matchers.h.pump
index 54e3ca31..fc0ffdcf 100644
--- a/googlemock/include/gmock/gmock-generated-matchers.h.pump
+++ b/googlemock/include/gmock/gmock-generated-matchers.h.pump
@@ -49,225 +49,12 @@ $$ }} This line fixes auto-indentation of the following code in Emacs.
 #include <vector>
 #include "gmock/gmock-matchers.h"
 
-// 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/master/googlemock/docs/cook_book.md
-
 $range i 0..n
 $for i
 
 [[
-$var macro_name = [[$if i==0 [[MATCHER]] $elif i==1 [[MATCHER_P]]
-                                         $else [[MATCHER_P$i]]]]
+$var macro_name = [[$if i==0 [[GMOCK_INTERNAL_MATCHER]] $elif i==1 [[GMOCK_INTERNAL_MATCHER_P]]
+                                         $else [[GMOCK_INTERNAL_MATCHER_P$i]]]]
 $var class_name = [[name##Matcher[[$if i==0 [[]] $elif i==1 [[P]]
                                                  $else [[P$i]]]]]]
 $range j 0..i-1
@@ -291,7 +78,7 @@ $var param_field_decls2 = [[$for j
     p$j##_type const p$j;\
 ]]]]
 
-#define $macro_name(name$for j [[, p$j]], description)\$template
+#define $macro_name(name, description$for j [[, p$j]])\$template
   class $class_name : public ::testing::internal::MatcherBaseImpl<$class_name$param_types> {\
     using __internal_base_type = ::testing::internal::MatcherBaseImpl<$class_name>;\
    public:\
diff --git a/googlemock/include/gmock/gmock-matchers.h b/googlemock/include/gmock/gmock-matchers.h
index f1805dbb..22211210 100644
--- a/googlemock/include/gmock/gmock-matchers.h
+++ b/googlemock/include/gmock/gmock-matchers.h
@@ -30,7 +30,220 @@
 
 // Google Mock - a framework for writing C++ mock classes.
 //
-// This file implements some commonly used argument matchers.  More
+// 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/master/googlemock/docs/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.
 //
@@ -4607,6 +4820,31 @@ PolymorphicMatcher<internal::variant_matcher::VariantMatcher<T> > VariantWith(
 #define EXPECT_THAT(value, matcher) EXPECT_PRED_FORMAT1(\
     ::testing::internal::MakePredicateFormatterFromMatcher(matcher), value)
 
+// MATCHER* macroses itself are listed below.
+#define MATCHER(name, description) GMOCK_INTERNAL_MATCHER(name, description)
+#define MATCHER_P(name, p0, description) \
+  GMOCK_INTERNAL_MATCHER_P(name, description, p0)
+#define MATCHER_P2(name, p0, p1, description) \
+  GMOCK_INTERNAL_MATCHER_P2(name, description, p0, p1)
+#define MATCHER_P3(name, p0, p1, p2, description) \
+  GMOCK_INTERNAL_MATCHER_P3(name, description, p0, p1, p2)
+#define MATCHER_P4(name, p0, p1, p2, p3, description) \
+  GMOCK_INTERNAL_MATCHER_P4(name, description, p0, p1, p2, p3)
+#define MATCHER_P5(name, p0, p1, p2, p3, p4, description) \
+  GMOCK_INTERNAL_MATCHER_P5(name, description, p0, p1, p2, p3, p4)
+#define MATCHER_P6(name, p0, p1, p2, p3, p4, p5, description) \
+  GMOCK_INTERNAL_MATCHER_P6(name, description, p0, p1, p2, p3, p4, p5)
+#define MATCHER_P7(name, p0, p1, p2, p3, p4, p5, p6, description) \
+  GMOCK_INTERNAL_MATCHER_P7(name, description, p0, p1, p2, p3, p4, p5, p6)
+#define MATCHER_P8(name, p0, p1, p2, p3, p4, p5, p6, p7, description) \
+  GMOCK_INTERNAL_MATCHER_P8(name, description, p0, p1, p2, p3, p4, p5, p6, p7)
+#define MATCHER_P9(name, p0, p1, p2, p3, p4, p5, p6, p7, p8, description)      \
+  GMOCK_INTERNAL_MATCHER_P9(name, description, p0, p1, p2, p3, p4, p5, p6, p7, \
+                            p8)
+#define MATCHER_P10(name, p0, p1, p2, p3, p4, p5, p6, p7, p8, p9, description) \
+  GMOCK_INTERNAL_MATCHER_P10(name, description, p0, p1, p2, p3, p4, p5, p6,    \
+                             p7, p8, p9)
+
 }  // namespace testing
 
 GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251 5046