Function sign

source/math.cpp:58–69

    }

    sign_t sign(const double& number)
    {
        int s = (double(0) < number) - (number < double(0));
        sign_t result = sign_t::ZERO;
        if (s > 0) {
            result = sign_t::POSITIVE;
        } else if (s < 0) {
            result = sign_t::NEGATIVE;
        }
        return result;

    }

    std::ostream& operator<<(std::ostream& os, const vec3& v)
    {