How to capture stdout/stderr with googletest?

Question

Is it possible to capture the stdout and stderr when using the googletest framework?

For example, I would like to call a function that writes errors to the console (

Answer 1

Putting Wgaffa's suggestion (which I like) to a Google Test fixture, one might write:

namespace {

    class MyTestFixture : public ::testing::Test {
    protected:
        MyTestFixture() : sbuf{nullptr} {
            // intentionally empty
        }

        ~MyTestFixture() override = default;

        // Called before each unit test
        void SetUp() override {
            // Save cout's buffer...
            sbuf = std::cout.rdbuf();
            // Redirect cout to our stringstream buffer or any other ostream
            std::cout.rdbuf(buffer.rdbuf());
        }

        // Called after each unit test
        void TearDown() override {
            // When done redirect cout to its old self
            std::cout.rdbuf(sbuf);
            sbuf = nullptr;
        }

        // The following objects can be reused in each unit test

        // This can be an ofstream as well or any other ostream
        std::stringstream buffer{};
        // Save cout's buffer here
        std::streambuf *sbuf;
    };

    TEST_F(MyTestFixture, StackOverflowTest) {
        std::string expected{"Hello"};
        // Use cout as usual
        std::cout << expected;
        std::string actual{buffer.str()};
        EXPECT_EQ(expected, actual);
    }
} // end namespace