rust/tests/ui/dst/dst-bad-assign.rs
2023-01-11 09:32:08 +00:00

42 lines
838 B
Rust

// Forbid assignment into a dynamically sized type.
struct Fat<T: ?Sized> {
f1: isize,
f2: &'static str,
ptr: T
}
#[derive(PartialEq,Eq)]
struct Bar;
#[derive(PartialEq,Eq)]
struct Bar1 {
f: isize
}
trait ToBar {
fn to_bar(&self) -> Bar;
fn to_val(&self) -> isize;
}
impl ToBar for Bar1 {
fn to_bar(&self) -> Bar {
Bar
}
fn to_val(&self) -> isize {
self.f
}
}
pub fn main() {
// Assignment.
let f5: &mut Fat<dyn ToBar> = &mut Fat { f1: 5, f2: "some str", ptr: Bar1 {f :42} };
let z: Box<dyn ToBar> = Box::new(Bar1 {f: 36});
f5.ptr = Bar1 {f: 36};
//~^ ERROR mismatched types
//~| expected trait object `dyn ToBar`, found struct `Bar1`
//~| expected trait object `dyn ToBar`
//~| found struct `Bar1`
//~| ERROR the size for values of type
}