extern crate serde;
#[macro_use]
extern crate serde_derive;
extern crate serde_json;

#[derive(Serialize)]
struct Foo {
    bar: i32
}

fn main() {
    let s = serde_json::to_string(&Foo { bar: 42 })
                .expect("Unable to serialize foo");
    println!("{}", s);
}