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

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