Visual C++ 2013 std::string memory leak

During development of proprietary app. I have noticed memory leak, related to std::string in a MS Visual C++ 2013, Update 4.

Take a look at the following (basic) code prototype which causes memory leak:

static std::string MemoryLeakTest()
{
    static size_t const test_size = 2002;
    std::unique_ptr<char[]> result1(new char[test_size]);
    std::string result2(result1.get(), test_size);
    return result2;
}

calling it by:

std::string const testML = MemoryLeakTest();
std::cout << testML << std::endl;

Am I doing something wrong, or is it a memory leak in a Visual C++ STL?