// edition:2021 // run-pass // Test precise capture when using boxes struct MetaData { x: String, name: String } struct Data { m: MetaData } struct BoxedData(Box); struct EvenMoreBoxedData(Box); // Mutate disjoint paths, one inside one outside the closure fn box_1() { let m = MetaData { x: format!("x"), name: format!("name") }; let d = Data { m }; let b = BoxedData(Box::new(d)); let mut e = EvenMoreBoxedData(Box::new(b)); let mut c = || { e.0.0.m.x = format!("not-x"); }; e.0.0.m.name = format!("not-name"); c(); } // Mutate a path inside the closure and read a disjoint path outside the closure fn box_2() { let m = MetaData { x: format!("x"), name: format!("name") }; let d = Data { m }; let b = BoxedData(Box::new(d)); let mut e = EvenMoreBoxedData(Box::new(b)); let mut c = || { e.0.0.m.x = format!("not-x"); }; println!("{}", e.0.0.m.name); c(); } // Read a path inside the closure and mutate a disjoint path outside the closure fn box_3() { let m = MetaData { x: format!("x"), name: format!("name") }; let d = Data { m }; let b = BoxedData(Box::new(d)); let mut e = EvenMoreBoxedData(Box::new(b)); let c = || { println!("{}", e.0.0.m.name); }; e.0.0.m.x = format!("not-x"); c(); } // Read disjoint paths, one inside the closure and one outside the closure. fn box_4() { let m = MetaData { x: format!("x"), name: format!("name") }; let d = Data { m }; let b = BoxedData(Box::new(d)); let e = EvenMoreBoxedData(Box::new(b)); let c = || { println!("{}", e.0.0.m.name); }; println!("{}", e.0.0.m.x); c(); } // Read the same path, once inside the closure and once outside the closure. fn box_5() { let m = MetaData { x: format!("x"), name: format!("name") }; let d = Data { m }; let b = BoxedData(Box::new(d)); let e = EvenMoreBoxedData(Box::new(b)); let c = || { println!("{}", e.0.0.m.name); }; println!("{}", e.0.0.m.name); c(); } fn main() { box_1(); box_2(); box_3(); box_4(); box_5(); }