Function ModularCast

libs/routing/coding.hpp:70–79

// (modulo 2^n where n is the number of bits used to represent the unsigned type)
template <typename Unsigned, typename Signed = std::make_signed_t<Unsigned>>
Signed ModularCast(Unsigned value)
{
  static_assert(std::is_unsigned<Unsigned>::value, "T should be an unsigned type");

  if (value <= static_cast<Unsigned>(std::numeric_limits<Signed>::max()))
    return static_cast<Signed>(value);

  auto constexpr minSignedT = std::numeric_limits<Signed>::min();
  return static_cast<Signed>(value - static_cast<Unsigned>(minSignedT)) + minSignedT;
}

// Encodes current as delta compared with prev.
template <typename T, typename UnsignedT = std::make_unsigned_t<T>>