Method operator+

test/bvar_status_unittest.cpp:187–189

    Foo() : x(0) {}
    explicit Foo(int x2) : x(x2) {}
    Foo operator+(const Foo& rhs) const {
        return Foo(x + rhs.x);
    }
};

std::ostream& operator<<(std::ostream& os, const Foo& f) {