src/test/ui/array-slice-vec/vector-cast-weirdness.rs

   1 // Issue #14893. Tests that casts from vectors don't behave strangely in the
   2 // presence of the `_` type shorthand notation.
   3 // Update: after a change to the way casts are done, we have more type information
   4 // around and so the errors here are no longer exactly the same.
   5
   6 struct X {
   7     y: [u8; 2],
   8 }
   9
  10 fn main() {
  11     let x1 = X { y: [0, 0] };
  12
  13     // No longer a type mismatch - the `_` can be fully resolved by type inference.
  14     let p1: *const u8 = &x1.y as *const _;
  15     let t1: *const [u8; 2] = &x1.y as *const _;
  16     let h1: *const [u8; 2] = &x1.y as *const [u8; 2];
  17
  18     let mut x1 = X { y: [0, 0] };
  19
  20     // This is still an error since we don't allow casts from &mut [T; n] to *mut T.
  21     let p1: *mut u8 = &mut x1.y as *mut _;  //~ ERROR casting
  22     let t1: *mut [u8; 2] = &mut x1.y as *mut _;
  23     let h1: *mut [u8; 2] = &mut x1.y as *mut [u8; 2];
  24 }