Some compilation problems

[kobtsev]

std::convertible_to evaluates to false for same types of rd::expected<void, E>

Checked on:
msvc (cl 19.35.32215) /std:c++20
clang (15.0.0) -std=c++20

Some code to explain below:
godbolt clang 15 - issue 1

#include <concepts>
#include <system_error>
#include <rd/expected.hpp>

template <typename T>
using result = rd::expected<T, std::error_code>;

static_assert(std::convertible_to<result<std::size_t>, result<int>>); // successfully, ok
static_assert(std::convertible_to<result<void>, result<void>>); // failure, why? 

Second assertion failed, Why can't identical rd::expected types be converted to each other? Is there a semantic reason for this behavior?

It may be related to another issue:
godbolt clang 15 - issue 2

#include <system_error>
#include <concepts>
#include <span>
#include <variant>
#include <rd/expected.hpp>

template <typename T>
using result = rd::expected<T, std::error_code>;

template <typename T>
using raw_result = std::variant<T, rd::unexpected<std::error_code>>;

struct data_header { 
    std::size_t data_length; 
    static raw_result<data_header> from_buffer(std::span<std::byte> buffer) noexcept; // compile
};

struct tpkt_header { 
    std::size_t length; 
    static result<tpkt_header> from_buffer(std::span<std::byte> buffer) noexcept; // won't compile
};