src/test/ui/type-id-higher-rank.rs

   1 // run-pass
   2 // Test that type IDs correctly account for higher-rank lifetimes
   3 // Also acts as a regression test for an ICE (issue #19791)
   4
   5 use std::any::{Any, TypeId};
   6
   7 struct Struct<'a>(&'a ());
   8 trait Trait<'a> {}
   9
  10 fn main() {
  11     // Bare fns
  12     {
  13         let a = TypeId::of::<fn(&'static isize, &'static isize)>();
  14         let b = TypeId::of::<for<'a> fn(&'static isize, &'a isize)>();
  15         let c = TypeId::of::<for<'a, 'b> fn(&'a isize, &'b isize)>();
  16         let d = TypeId::of::<for<'a, 'b> fn(&'b isize, &'a isize)>();
  17         assert!(a != b);
  18         assert!(a != c);
  19         assert!(a != d);
  20         assert!(b != c);
  21         assert!(b != d);
  22         assert_eq!(c, d);
  23
  24         // Make sure De Bruijn indices are handled correctly
  25         let e = TypeId::of::<for<'a> fn(fn(&'a isize) -> &'a isize)>();
  26         let f = TypeId::of::<fn(for<'a> fn(&'a isize) -> &'a isize)>();
  27         assert!(e != f);
  28
  29         // Make sure lifetime parameters of items are not ignored.
  30         let g = TypeId::of::<for<'a> fn(&'a dyn Trait<'a>) -> Struct<'a>>();
  31         let h = TypeId::of::<for<'a> fn(&'a dyn Trait<'a>) -> Struct<'static>>();
  32         let i = TypeId::of::<for<'a, 'b> fn(&'a dyn Trait<'b>) -> Struct<'b>>();
  33         assert!(g != h);
  34         assert!(g != i);
  35         assert!(h != i);
  36
  37         // Make sure lifetime anonymization handles nesting correctly
  38         let j = TypeId::of::<fn(for<'a> fn(&'a isize) -> &'a usize)>();
  39         let k = TypeId::of::<fn(for<'b> fn(&'b isize) -> &'b usize)>();
  40         assert_eq!(j, k);
  41     }
  42     // Boxed unboxed closures
  43     {
  44         let a = TypeId::of::<Box<dyn Fn(&'static isize, &'static isize)>>();
  45         let b = TypeId::of::<Box<dyn for<'a> Fn(&'static isize, &'a isize)>>();
  46         let c = TypeId::of::<Box<dyn for<'a, 'b> Fn(&'a isize, &'b isize)>>();
  47         let d = TypeId::of::<Box<dyn for<'a, 'b> Fn(&'b isize, &'a isize)>>();
  48         assert!(a != b);
  49         assert!(a != c);
  50         assert!(a != d);
  51         assert!(b != c);
  52         assert!(b != d);
  53         assert_eq!(c, d);
  54
  55         // Make sure De Bruijn indices are handled correctly
  56         let e = TypeId::of::<Box<dyn for<'a> Fn(Box<dyn Fn(&'a isize) -> &'a isize>)>>();
  57         let f = TypeId::of::<Box<dyn Fn(Box<dyn for<'a> Fn(&'a isize) -> &'a isize>)>>();
  58         assert!(e != f);
  59     }
  60     // Raw unboxed closures
  61     // Note that every unboxed closure has its own anonymous type,
  62     // so no two IDs should equal each other, even when compatible
  63     {
  64         let a = id(|_: &isize, _: &isize| {});
  65         let b = id(|_: &isize, _: &isize| {});
  66         assert!(a != b);
  67     }
  68
  69     fn id<T:Any>(_: T) -> TypeId {
  70         TypeId::of::<T>()
  71     }
  72 }