template<int Bytes>

struct CustomUintFormatter

{

static_assert(Bytes > 0 && Bytes <= 8, "CustomUintFormatter Bytes out of range");

static constexpr uint64_t MAX = 0xffffffffffffffff >> (8 * (8 - Bytes));

template <typename Stream, typename I> void Ser(Stream& s, I v)

{

if (v < 0 || v > MAX) throw std::ios_base::failure("CustomUintFormatter value out of range");

uint64_t raw = htole64(v);

s.write((const char*)&raw, Bytes);

}

template <typename Stream, typename I> void Unser(Stream& s, I& v)

{

static_assert(std::numeric_limits<I>::max() >= MAX && std::numeric_limits<I>::min() <= 0, "CustomUintFormatter type too small");

uint64_t raw = 0;

s.read((char*)&raw, Bytes);

v = le64toh(raw);

}

};