SEAL_NODISCARD inline constexpr T mul_safe()

in native/src/seal/util/common.h [138:178]

• 37 lines of code
• 13 McCabe index (conditional complexity)

        SEAL_NODISCARD inline constexpr T mul_safe(T in1, T in2)
        {
            SEAL_IF_CONSTEXPR(std::is_unsigned<T>::value)
            {
                if (in1 && (in2 > (std::numeric_limits<T>::max)() / in1))
                {
                    throw std::logic_error("unsigned overflow");
                }
            }
            else
            {
                // Positive inputs
                if ((in1 > 0) && (in2 > 0) && (in2 > (std::numeric_limits<T>::max)() / in1))
                {
                    throw std::logic_error("signed overflow");
                }
#if (SEAL_COMPILER == SEAL_COMPILER_MSVC) && !defined(SEAL_USE_IF_CONSTEXPR)
#pragma warning(push)
#pragma warning(disable : 4146)
#endif
                // Negative inputs
                else if ((in1 < 0) && (in2 < 0) && ((-in2) > (std::numeric_limits<T>::max)() / (-in1)))
                {
                    throw std::logic_error("signed overflow");
                }
                // Negative in1; positive in2
                else if ((in1 < 0) && (in2 > 0) && (in2 > (std::numeric_limits<T>::max)() / (-in1)))
                {
                    throw std::logic_error("signed underflow");
                }
#if (SEAL_COMPILER == SEAL_COMPILER_MSVC) && !defined(SEAL_USE_IF_CONSTEXPR)
#pragma warning(pop)
#endif
                // Positive in1; negative in2
                else if ((in1 > 0) && (in2 < 0) && (in2 < (std::numeric_limits<T>::min)() / in1))
                {
                    throw std::logic_error("signed underflow");
                }
            }
            return static_cast<T>(in1 * in2);
        }