Please use unsigned char instead of std::byte or add support for it.

[igromanru]

Hi, what is the reason that you are using std::byte instead of more primitive type unsigned char?
I wanted to use msgpack23 in my project and I run directly into an issue that other libraries use unsigned char, which forces me to transform std::vector<std::byte> to std::vector<unsigned char>.
I personally also never use std::byte.

[rwindegger]

Hi @igromanru,

I'm using std::byte to distinguish the payload from just random numbers. I think it's a good practice to use specific types.

For your issue with the other libraries I've added two examples for your use case. See examples for more information.

I hope this helps and you enjoy using my library.

[igromanru]

So there’s no technical reason for it?
I don’t think it’s good practice, because it breaks the chain and requires an extra step.
I encrypt/decrypt the data, both the library I use for AES encryption and the conversion to Base64 work straightforwardly with unsigned char, which makes the extra conversion to/from std::byte redundant, just for semantic reasons.

I'm pretty sure a better practice would be to allow the library user to pass any technically compatible type it works with.
Something like:

template<typename T>
concept ByteType = std::same_as<T, std::byte> ||
                   std::same_as<T, char> ||
                   std::same_as<T, unsigned char> ||
                   std::same_as<T, std::uint8_t>;

template<ByteType T, std::output_iterator<T> Iter>
class Packer final { ... };

[rwindegger]

Hi @igromanru.

I was playing around with your idea and somehow it seems to break type deduction. So the user needs to specify the types explicitly and I think that is not favorable as the code for using the Packer looks something like:

            std::vector<std::byte> data{};
            auto const inserter = std::back_insert_iterator(data);
            msgpack23::Packer<std::byte, std::back_insert_iterator<std::vector<std::byte>>> packer{inserter};

I'm happy to accept a PR when you have an idea how to handle that.