src/test/ui/uninhabited/privately-uninhabited-mir-call.rs

   1 // Verifies that MIR building for a call expression respects
   2 // privacy when checking if a call return type is uninhabited.
   3
   4 pub mod widget {
   5     enum Unimplemented {}
   6     pub struct Widget(Unimplemented);
   7
   8     impl Widget {
   9         pub fn new() -> Widget {
  10             todo!();
  11         }
  12     }
  13
  14     pub fn f() {
  15         let x: &mut u32;
  16         Widget::new();
  17         // Ok. Widget type returned from new is known to be uninhabited
  18         // and the following code is considered unreachable.
  19         *x = 1;
  20     }
  21 }
  22
  23 fn main() {
  24     let y: &mut u32;
  25     widget::Widget::new();
  26     // Error. Widget type is not known to be uninhabited here,
  27     // so the following code is considered reachable.
  28     *y = 2; //~ ERROR E0381
  29 }