Function on_request_impl

include/boost/beast/http/parser.hpp:387–416

    parser(Arg1&& arg1, std::false_type, ArgN&&... argn);

    void
    on_request_impl(
        verb method,
        string_view method_str,
        string_view target,
        int version,
        error_code& ec,
        std::true_type)
    {
        // If this assert goes off, it means you tried to re-use a
        // parser after it was done reading a message. This is not
        // allowed, you need to create a new parser for each message.
        // The easiest way to do that is to store the parser in
        // an optional object.

        BOOST_ASSERT(! used_);
        if(used_)
        {
            BOOST_BEAST_ASSIGN_EC(ec, error::stale_parser);
            return;
        }
        used_ = true;

        m_.target(target);
        if(method != verb::unknown)
            m_.method(method);
        else
            m_.method_string(method_str);
        m_.version(version);
    }

    void
    on_request_impl(