Based on gmock, can mock global function, member function, class static function without change source code.

Here is the document and design notes host on OneNote.

Hello world:

string func() {
    return "Non mocked.";
}

TEST(HelloWorld, First) {
    EXPECT_CALL(*MOCKER(func), MOCK_FUNCTION()).Times(Exactly(1))
        .WillOnce(Return("Hello world."));
    EXPECT_EQ("Hello world.", func());
}

Here is the prototype when I try to solve this problem.