难道真的无法理解构造tcp :: resolver :: query的参数

#include<iostream>
#include<boost/asio.hpp>

int main() {
    boost::asio::io_context io_context;
    boost::asio::ip::tcp::resolver resolver(io_context);
    boost::asio::ip::tcp::resolver::query query("www.example.com", "http");
    boost::asio::ip::tcp::resolver::iterator iterator = resolver.resolve(query);

    while (iterator != boost::asio::ip::tcp::resolver::iterator()) {
        boost::asio::ip::tcp::endpoint endpoint = *iterator;
        std::cout<< endpoint.address().to_string()<< std::endl;
        iterator++;
    }

    return 0;
}