[Bug]: FieldsAre cannot support struct type

[Kevin-WongCHN]

Describe the issue

the documentation about FieldsAre wrote:

struct MyStruct {
  int value = 42;
  std::string greeting = "aloha";
};
MyStruct s;
EXPECT_THAT(s, FieldsAre(42, "aloha"));

however, when I run this:

struct MyStruct {
  int value = 42;
  std::string greeting = "aloha";
};
TEST(MyTestSuite, FieldsAreMatcherTest) {
    MyStruct s;
    EXPECT_THAT(s, FieldsAre(42, "aloha"));
}

g++ cannot compile:
note: types 'std::pair<_Tp1, _Tp2>' and 'const MyStruct' have incompatible cv-qualifiers

Steps to reproduce the problem

wrote the above code and run googletest

What version of GoogleTest are you using?

1.15.2

What operating system and version are you using?

windows10

What compiler and version are you using?

gcc (tdm64-1) 9.2.0

What build system are you using?

cmake version 3.22.2

Additional context

No response