src/librustc_error_codes/error_codes/E0515.md

   1 Cannot return value that references local variable
   2
   3 Local variables, function parameters and temporaries are all dropped before the
   4 end of the function body. So a reference to them cannot be returned.
   5
   6 Erroneous code example:
   7
   8 ```compile_fail,E0515
   9 fn get_dangling_reference() -> &'static i32 {
  10     let x = 0;
  11     &x
  12 }
  13 ```
  14
  15 ```compile_fail,E0515
  16 use std::slice::Iter;
  17 fn get_dangling_iterator<'a>() -> Iter<'a, i32> {
  18     let v = vec![1, 2, 3];
  19     v.iter()
  20 }
  21 ```
  22
  23 Consider returning an owned value instead:
  24
  25 ```
  26 use std::vec::IntoIter;
  27
  28 fn get_integer() -> i32 {
  29     let x = 0;
  30     x
  31 }
  32
  33 fn get_owned_iterator() -> IntoIter<i32> {
  34     let v = vec![1, 2, 3];
  35     v.into_iter()
  36 }
  37 ```