tests/ui/rfcs/rfc1623.rs

   1 // run-pass
   2 #![allow(unused_variables)]
   3 #![allow(non_upper_case_globals)]
   4
   5 #![allow(dead_code)]
   6
   7 // very simple test for a 'static static with default lifetime
   8 static STATIC_STR: &str = "&'static str";
   9 const CONST_STR: &str = "&'static str";
  10
  11 // this should be the same as without default:
  12 static EXPLICIT_STATIC_STR: &'static str = "&'static str";
  13 const EXPLICIT_CONST_STR: &'static str = "&'static str";
  14
  15 // a function that elides to an unbound lifetime for both in- and output
  16 fn id_u8_slice(arg: &[u8]) -> &[u8] {
  17     arg
  18 }
  19
  20 // one with a function, argument elided
  21 static STATIC_SIMPLE_FN: &fn(&[u8]) -> &[u8] = &(id_u8_slice as fn(&[u8]) -> &[u8]);
  22 const CONST_SIMPLE_FN: &fn(&[u8]) -> &[u8] = &(id_u8_slice as fn(&[u8]) -> &[u8]);
  23
  24 // this should be the same as without elision
  25 static STATIC_NON_ELIDED_fN: &for<'a> fn(&'a [u8]) -> &'a [u8] =
  26     &(id_u8_slice as for<'a> fn(&'a [u8]) -> &'a [u8]);
  27 const CONST_NON_ELIDED_fN: &for<'a> fn(&'a [u8]) -> &'a [u8] =
  28     &(id_u8_slice as for<'a> fn(&'a [u8]) -> &'a [u8]);
  29
  30 // another function that elides, each to a different unbound lifetime
  31 fn multi_args(a: &u8, b: &u8, c: &u8) {}
  32
  33 static STATIC_MULTI_FN: &fn(&u8, &u8, &u8) = &(multi_args as fn(&u8, &u8, &u8));
  34 const CONST_MULTI_FN: &fn(&u8, &u8, &u8) = &(multi_args as fn(&u8, &u8, &u8));
  35
  36 struct Foo<'a> {
  37     bools: &'a [bool],
  38 }
  39
  40 static STATIC_FOO: Foo = Foo { bools: &[true, false] };
  41 const CONST_FOO: Foo = Foo { bools: &[true, false] };
  42
  43 type Bar<'a> = Foo<'a>;
  44
  45 static STATIC_BAR: Bar = Bar { bools: &[true, false] };
  46 const CONST_BAR: Bar = Bar { bools: &[true, false] };
  47
  48 type Baz<'a> = fn(&'a [u8]) -> Option<u8>;
  49
  50 fn baz(e: &[u8]) -> Option<u8> {
  51     e.first().map(|x| *x)
  52 }
  53
  54 static STATIC_BAZ: &Baz = &(baz as Baz);
  55 const CONST_BAZ: &Baz = &(baz as Baz);
  56
  57 static BYTES: &[u8] = &[1, 2, 3];
  58
  59 fn main() {
  60     // make sure that the lifetime is actually elided (and not defaulted)
  61     let x = &[1u8, 2, 3];
  62     STATIC_SIMPLE_FN(x);
  63     CONST_SIMPLE_FN(x);
  64
  65     STATIC_BAZ(BYTES); // neees static lifetime
  66     CONST_BAZ(BYTES);
  67
  68     // make sure this works with different lifetimes
  69     let a = &1;
  70     {
  71         let b = &2;
  72         let c = &3;
  73         CONST_MULTI_FN(a, b, c);
  74     }
  75 }