对大整数使用varint/zigzag压缩编码

[RFoe]

https://github.com/RFoe/coasync/blob/a466688370ce4bc5feefc8a55d960de447dfbfde/include/coasync/detail/meta/serde_stream_base.hpp#L159-L160

或许是这样

template <typename T> 
awaitable<void> COASYNC_API serialize(T const& value) 
requires std::integral<T> and sizeof(T) > bigint_size 
{...};