Append string data to std::vector<std::byte>>

Question

I'm implementing a HTTP server and the API I follow define the raw response data as a std::vector<std::byte>>.

I store http responses headers as std::string in my code and at some point I have to write them to to raw response data before sending it back.

The thing is, I cannot find a clean way to write/append data from a std::string to my std::vector<std::byte>> (by clean way I mean not looping on the string and appending each char).

What is the best way to do that ?

Side question: What is the best way to read a string from a std::vector<std::byte>> ?

Answer 1

Just use the ranged-insert overload (#4):

void extend(std::vector<std::byte>& v, std::string const& s) {
    auto bytes = reinterpret_cast<std::byte const*>(s.data());
    v.insert(v.end(), bytes, bytes + s.size());
}

You can read char as byte, it's a permitted alias.