to_query-0.5.3 has been yanked.
to_query
Structure to HTTP GET Query Parameters.

use to_query::STQuery;
#[derive(STQuery)]
struct HelloStruct {
name: String,
age: Option<u32>,
money: u32,
bank: Option<Bank>,
}
#[derive(STQuery)]
struct Bank {
bank_name: String,
number: Option<u32>,
}
let object = HelloStruct {
name: "hello".to_owned(),
age: None,
money: 0,
bank: Some(Bank {
bank_name: "CoolBank".to_owned(),
number: None,
}),
};
assert_eq!(object.get_query(), "name=hello&money=0&bank_name=CoolBank")