tests/ui/transmutability/enums/repr/should_require_well_defined_layout.rs

   1 //! An enum must have a well-defined layout to participate in a transmutation.
   2
   3 #![crate_type = "lib"]
   4 #![feature(repr128)]
   5 #![feature(transmutability)]
   6 #![allow(dead_code, incomplete_features, non_camel_case_types)]
   7
   8 mod assert {
   9     use std::mem::{Assume, BikeshedIntrinsicFrom};
  10     pub struct Context;
  11
  12     pub fn is_maybe_transmutable<Src, Dst>()
  13     where
  14         Dst: BikeshedIntrinsicFrom<Src, Context, {
  15             Assume {
  16                 alignment: true,
  17                 lifetimes: true,
  18                 safety: true,
  19                 validity: true,
  20             }
  21         }>
  22     {}
  23 }
  24
  25 fn should_reject_repr_rust() {
  26     fn void() {
  27         enum repr_rust {}
  28         assert::is_maybe_transmutable::<repr_rust, ()>(); //~ ERROR cannot be safely transmuted
  29         assert::is_maybe_transmutable::<u128, repr_rust>(); //~ ERROR cannot be safely transmuted
  30     }
  31
  32     fn singleton() {
  33         enum repr_rust { V }
  34         assert::is_maybe_transmutable::<repr_rust, ()>(); //~ ERROR cannot be safely transmuted
  35         assert::is_maybe_transmutable::<u128, repr_rust>(); //~ ERROR cannot be safely transmuted
  36     }
  37
  38     fn duplex() {
  39         enum repr_rust { A, B }
  40         assert::is_maybe_transmutable::<repr_rust, ()>(); //~ ERROR cannot be safely transmuted
  41         assert::is_maybe_transmutable::<u128, repr_rust>(); //~ ERROR cannot be safely transmuted
  42     }
  43 }
  44
  45 fn should_accept_primitive_reprs()
  46 {
  47     fn should_accept_repr_i8() {
  48         #[repr(i8)] enum repr_i8 { V }
  49         assert::is_maybe_transmutable::<repr_i8, ()>();
  50         assert::is_maybe_transmutable::<i8, repr_i8>();
  51     }
  52
  53     fn should_accept_repr_u8() {
  54         #[repr(u8)] enum repr_u8 { V }
  55         assert::is_maybe_transmutable::<repr_u8, ()>();
  56         assert::is_maybe_transmutable::<u8, repr_u8>();
  57     }
  58
  59     fn should_accept_repr_i16() {
  60         #[repr(i16)] enum repr_i16 { V }
  61         assert::is_maybe_transmutable::<repr_i16, ()>();
  62         assert::is_maybe_transmutable::<i16, repr_i16>();
  63     }
  64
  65     fn should_accept_repr_u16() {
  66         #[repr(u16)] enum repr_u16 { V }
  67         assert::is_maybe_transmutable::<repr_u16, ()>();
  68         assert::is_maybe_transmutable::<u16, repr_u16>();
  69     }
  70
  71     fn should_accept_repr_i32() {
  72         #[repr(i32)] enum repr_i32 { V }
  73         assert::is_maybe_transmutable::<repr_i32, ()>();
  74         assert::is_maybe_transmutable::<i32, repr_i32>();
  75     }
  76
  77     fn should_accept_repr_u32() {
  78         #[repr(u32)] enum repr_u32 { V }
  79         assert::is_maybe_transmutable::<repr_u32, ()>();
  80         assert::is_maybe_transmutable::<u32, repr_u32>();
  81     }
  82
  83     fn should_accept_repr_i64() {
  84         #[repr(i64)] enum repr_i64 { V }
  85         assert::is_maybe_transmutable::<repr_i64, ()>();
  86         assert::is_maybe_transmutable::<i64, repr_i64>();
  87     }
  88
  89     fn should_accept_repr_u64() {
  90         #[repr(u64)] enum repr_u64 { V }
  91         assert::is_maybe_transmutable::<repr_u64, ()>();
  92         assert::is_maybe_transmutable::<u64, repr_u64>();
  93     }
  94
  95     fn should_accept_repr_i128() {
  96         #[repr(i128)] enum repr_i128 { V }
  97         assert::is_maybe_transmutable::<repr_i128, ()>();
  98         assert::is_maybe_transmutable::<i128, repr_i128>();
  99     }
 100
 101     fn should_accept_repr_u128() {
 102         #[repr(u128)] enum repr_u128 { V }
 103         assert::is_maybe_transmutable::<repr_u128, ()>();
 104         assert::is_maybe_transmutable::<u128, repr_u128>();
 105     }
 106
 107     fn should_accept_repr_isize() {
 108         #[repr(isize)] enum repr_isize { V }
 109         assert::is_maybe_transmutable::<repr_isize, ()>();
 110         assert::is_maybe_transmutable::<isize, repr_isize>();
 111     }
 112
 113     fn should_accept_repr_usize() {
 114         #[repr(usize)] enum repr_usize { V }
 115         assert::is_maybe_transmutable::<repr_usize, ()>();
 116         assert::is_maybe_transmutable::<usize, repr_usize>();
 117     }
 118 }
 119
 120 fn should_accept_repr_C() {
 121     #[repr(C)] enum repr_c { V }
 122     assert::is_maybe_transmutable::<repr_c, ()>();
 123     assert::is_maybe_transmutable::<i128, repr_c>();
 124 }