1 // compile-flags: -Zborrowck=mir
5 // Test that we relate the type of the fn type to the type of the fn
6 // ptr when doing a `ReifyFnPointer` cast.
8 // This test is a bit tortured, let me explain:
11 // The `where 'a: 'a` clause here ensures that `'a` is early bound,
12 // which is needed below to ensure that this test hits the path we are
14 fn foo<'a>(x: &'a u32) -> &'a u32
21 fn bar<'a>(x: &'a u32) -> &'static u32 {
22 // Here, the type of `foo` is `typeof(foo::<'x>)` for some fresh variable `'x`.
23 // During NLL region analysis, this will get renumbered to `typeof(foo::<'?0>)`
24 // where `'?0` is a new region variable.
26 // (Note that if `'a` on `foo` were late-bound, the type would be
27 // `typeof(foo)`, which would interact differently with because
28 // the renumbering later.)
30 // This type is then coerced to a fn type `fn(&'?1 u32) -> &'?2
31 // u32`. Here, the `'?1` and `'?2` will have been created during
32 // the NLL region renumbering.
34 // The MIR type checker must therefore relate `'?0` to `'?1` and `'?2`
35 // as part of checking the `ReifyFnPointer`.
36 let f: fn(_) -> _ = foo;
38 //~^ ERROR lifetime may not live long enough