url_view uv("https://www.example.com/path/to/file.txt?id=1001&name=John%20Doe");
for (auto v : uv.params())
std::cout << v.key << "=" << v.value << "\n";
// id=1001
// name=John Doe
url u = uv;
u.set_scheme("http")
.set_encoded_host("boost.org")
.set_encoded_path("/index.htm")
.remove_query()
.params().append({"key", "value"});
std::cout << u;
// http://boost.org/index.htm?key=value
