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#![feature(unsized_fn_params)]
pub trait Foo {
fn foo(self) -> String;
}
impl Foo for [char] {
fn foo(self) -> String {
self.iter().collect()
}
}
impl Foo for str {
fn foo(self) -> String {
self.to_owned()
}
}
impl Foo for dyn FnMut() -> String {
fn foo(mut self) -> String {
self()
}
}
fn main() {
let x = *(Box::new(['h', 'e', 'l', 'l', 'o']) as Box<[char]>); //~ERROR the size for values of type `[char]` cannot be known at compilation time
assert_eq!(&x.foo() as &str, "hello");
let x = Box::new(['h', 'e', 'l', 'l', 'o']) as Box<[char]>;
assert_eq!(&x.foo() as &str, "hello");
let x = "hello".to_owned().into_boxed_str();
assert_eq!(&x.foo() as &str, "hello");
let x = *("hello".to_owned().into_boxed_str()); //~ERROR the size for values of type `str` cannot be known at compilation time
assert_eq!(&x.foo() as &str, "hello");
let x = "hello".to_owned().into_boxed_str();
assert_eq!(&x.foo() as &str, "hello");
let x = *(Box::new(|| "hello".to_owned()) as Box<dyn FnMut() -> String>); //~ERROR the size for values of type `dyn FnMut() -> String` cannot be known at compilation time
assert_eq!(&x.foo() as &str, "hello");
let x = Box::new(|| "hello".to_owned()) as Box<dyn FnMut() -> String>;
assert_eq!(&x.foo() as &str, "hello");
}
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