src/test/ui/transmutability/abstraction/abstracted_assume.rs

   1 // check-pass
   2 //! The implementation should behave correctly when the `ASSUME` parameters are
   3 //! provided indirectly through an abstraction.
   4
   5 #![crate_type = "lib"]
   6 #![feature(transmutability)]
   7 #![allow(dead_code, incomplete_features, non_camel_case_types)]
   8
   9 mod assert {
  10     use std::mem::BikeshedIntrinsicFrom;
  11
  12     pub fn is_transmutable<
  13         Src,
  14         Dst,
  15         Context,
  16         const ASSUME_ALIGNMENT: bool,
  17         const ASSUME_LIFETIMES: bool,
  18         const ASSUME_VALIDITY: bool,
  19         const ASSUME_VISIBILITY: bool,
  20     >()
  21     where
  22         Dst: BikeshedIntrinsicFrom<
  23             Src,
  24             Context,
  25             ASSUME_ALIGNMENT,
  26             ASSUME_LIFETIMES,
  27             ASSUME_VALIDITY,
  28             ASSUME_VISIBILITY,
  29         >,
  30     {}
  31 }
  32
  33 fn direct() {
  34     struct Context;
  35     #[repr(C)] struct Src;
  36     #[repr(C)] struct Dst;
  37
  38     assert::is_transmutable::<Src, Dst, Context, false, false, false, false>();
  39 }
  40
  41 fn via_const() {
  42     struct Context;
  43     #[repr(C)] struct Src;
  44     #[repr(C)] struct Dst;
  45
  46     const FALSE: bool = false;
  47
  48     assert::is_transmutable::<Src, Dst, Context, FALSE, FALSE, FALSE, FALSE>();
  49 }
  50
  51 fn via_associated_const() {
  52     struct Context;
  53     #[repr(C)] struct Src;
  54     #[repr(C)] struct Dst;
  55
  56     trait Trait {
  57         const FALSE: bool = true;
  58     }
  59
  60     struct Ty;
  61
  62     impl Trait for Ty {}
  63
  64     assert::is_transmutable::<
  65         Src,
  66         Dst,
  67         Context,
  68         {Ty::FALSE},
  69         {Ty::FALSE},
  70         {Ty::FALSE},
  71         {Ty::FALSE}
  72     >();
  73 }