// A version of coerce-expect-unsized that uses type ascription. // Doesn't work so far, but supposed to work eventually #![feature(box_syntax, type_ascription)] use std::fmt::Debug; pub fn main() { let _ = box { [1, 2, 3] }: Box<[i32]>; //~ ERROR mismatched types let _ = box if true { [1, 2, 3] } else { [1, 3, 4] }: Box<[i32]>; //~ ERROR mismatched types let _ = box match true { true => [1, 2, 3], false => [1, 3, 4] }: Box<[i32]>; //~^ ERROR mismatched types let _ = box { |x| (x as u8) }: Box _>; //~ ERROR mismatched types let _ = box if true { false } else { true }: Box; //~ ERROR mismatched types let _ = box match true { true => 'a', false => 'b' }: Box; //~ ERROR mismatched types let _ = &{ [1, 2, 3] }: &[i32]; //~ ERROR mismatched types let _ = &if true { [1, 2, 3] } else { [1, 3, 4] }: &[i32]; //~ ERROR mismatched types let _ = &match true { true => [1, 2, 3], false => [1, 3, 4] }: &[i32]; //~^ ERROR mismatched types let _ = &{ |x| (x as u8) }: &dyn Fn(i32) -> _; //~ ERROR mismatched types let _ = &if true { false } else { true }: &dyn Debug; //~ ERROR mismatched types let _ = &match true { true => 'a', false => 'b' }: &dyn Debug; //~ ERROR mismatched types let _ = Box::new([1, 2, 3]): Box<[i32]>; //~ ERROR mismatched types let _ = Box::new(|x| (x as u8)): Box _>; //~ ERROR mismatched types let _ = vec![ Box::new(|x| (x as u8)), box |x| (x as i16 as u8), ]: Vec _>>; }