src/test/ui/nll/outlives-suggestion-simple.rs

   1 // Test the simplest of outlives suggestions.
   2
   3 #![feature(nll)]
   4
   5 fn foo1<'a, 'b>(x: &'a usize) -> &'b usize {
   6     x //~ERROR lifetime may not live long enough
   7 }
   8
   9 fn foo2<'a>(x: &'a usize) -> &'static usize {
  10     x //~ERROR lifetime may not live long enough
  11 }
  12
  13 fn foo3<'a, 'b>(x: &'a usize, y: &'b usize) -> (&'b usize, &'a usize) {
  14     (x, y) //~ERROR lifetime may not live long enough
  15            //~^ERROR lifetime may not live long enough
  16 }
  17
  18 fn foo4<'a, 'b, 'c>(x: &'a usize) -> (&'b usize, &'c usize) {
  19     // FIXME: ideally, we suggest 'a: 'b + 'c, but as of today (may 04, 2019), the null error
  20     // reporting stops after the first error in a MIR def so as not to produce too many errors, so
  21     // currently we only report 'a: 'b. The user would then re-run and get another error.
  22     (x, x) //~ERROR lifetime may not live long enough
  23 }
  24
  25 struct Foo<'a> {
  26     x: &'a usize,
  27 }
  28
  29 impl Foo<'static> {
  30     pub fn foo<'a>(x: &'a usize) -> Self {
  31         Foo { x } //~ERROR lifetime may not live long enough
  32     }
  33 }
  34
  35 struct Bar<'a> {
  36     x: &'a usize,
  37 }
  38
  39 impl<'a> Bar<'a> {
  40     pub fn get<'b>(&self) -> &'b usize {
  41         self.x //~ERROR lifetime may not live long enough
  42     }
  43 }
  44
  45 // source: https://stackoverflow.com/questions/41417057/why-do-i-get-a-lifetime-error-when-i-use-a-mutable-reference-in-a-struct-instead
  46 struct Baz<'a> {
  47     x: &'a mut i32,
  48 }
  49
  50 impl<'a> Baz<'a> {
  51     fn get<'b>(&'b self) -> &'a i32 {
  52         self.x //~ERROR lifetime may not live long enough
  53     }
  54 }
  55
  56 // source: https://stackoverflow.com/questions/41204134/rust-lifetime-error
  57 struct Bar2<'a> {
  58     bar: &'a str,
  59 }
  60 impl<'a> Bar2<'a> {
  61     fn new(foo: &'a Foo2<'a>) -> Bar2<'a> {
  62         Bar2 { bar: foo.raw }
  63     }
  64 }
  65
  66 pub struct Foo2<'a> {
  67     raw: &'a str,
  68     cell: std::cell::Cell<&'a str>,
  69 }
  70 impl<'a> Foo2<'a> {
  71     // should not produce outlives suggestions to name 'self
  72     fn get_bar(&self) -> Bar2 {
  73         Bar2::new(&self) //~ERROR borrowed data escapes outside of associated function
  74     }
  75 }
  76
  77 fn main() {}