Method on_read_header

boost-http/http-client.cpp:103–130

  }

  void on_read_header(beast::error_code error, std::size_t) {
    if (error) {
      return fail("read_headers", std::move(error));
    }

    const auto &res = parser_.get();

    auto status_code = res.result_int();
    std::string content_type;

    auto it = res.find(http::field::content_type);
    if (it != res.end()) {
      content_type = it->value();
    }

    std::vector<std::pair<std::string, std::string>> headers;
    for (auto &h : res) {
      if (!allow_header(h.name_string())) {
        continue;
      }
      headers.emplace_back(h.name_string(), h.value());
    }

    sent_answer_ = true;
    callback_->receive_answer(status_code, std::move(content_type), std::move(headers), "", false);

    read_payload();
  }

  void read_payload() {
    auto &b = parser_.get().body();