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 //
   4 // Update: after a change to the way casts are done, we have more type information
   5 // around and so the errors here are no longer exactly the same.
   6 //
   7 // Update: With PR #81479 some of the previously rejected cases are now allowed.
   8 // New test cases added.
   9
  10 struct X {
  11     y: [u8; 2],
  12 }
  13
  14 fn main() {
  15     let x1 = X { y: [0, 0] };
  16
  17     // No longer a type mismatch - the `_` can be fully resolved by type inference.
  18     let p1: *const u8 = &x1.y as *const _;
  19     let p1: *mut u8 = &x1.y as *mut _;
  20     //~^ ERROR: casting `&[u8; 2]` as `*mut u8` is invalid
  21     let t1: *const [u8; 2] = &x1.y as *const _;
  22     let t1: *mut [u8; 2] = &x1.y as *mut _;
  23     //~^ ERROR: casting `&[u8; 2]` as `*mut [u8; 2]` is invalid
  24     let h1: *const [u8; 2] = &x1.y as *const [u8; 2];
  25     let t1: *mut [u8; 2] = &x1.y as *mut [u8; 2];
  26     //~^ ERROR: casting `&[u8; 2]` as `*mut [u8; 2]` is invalid
  27
  28     let mut x1 = X { y: [0, 0] };
  29
  30     let p1: *mut u8 = &mut x1.y as *mut _;
  31     let p2: *const u8 = &mut x1.y as *const _;
  32     let t1: *mut [u8; 2] = &mut x1.y as *mut _;
  33     let h1: *mut [u8; 2] = &mut x1.y as *mut [u8; 2];
  34 }