src/test/ui/higher-lifetime-bounds.rs

   1 #![allow(dead_code, non_camel_case_types)]
   2
   3 // Test that bounds on higher-kinded lifetime binders are rejected.
   4
   5 fn bar1<'a, 'b>(
   6     x: &'a i32,
   7     y: &'b i32,
   8     f: for<'xa, 'xb: 'xa+'xa> fn(&'xa i32, &'xb i32) -> &'xa i32)
   9     //~^ ERROR lifetime bounds cannot be used in this context
  10 {
  11     // If the bound in f's type would matter, the call below would (have to)
  12     // be rejected.
  13     f(x, y);
  14 }
  15
  16 fn bar2<'a, 'b, F: for<'xa, 'xb: 'xa> Fn(&'xa i32, &'xb i32) -> &'xa i32>(
  17     //~^ ERROR lifetime bounds cannot be used in this context
  18     x: &'a i32,
  19     y: &'b i32,
  20     f: F)
  21 {
  22     // If the bound in f's type would matter, the call below would (have to)
  23     // be rejected.
  24     f(x, y);
  25 }
  26
  27 fn bar3<'a, 'b, F>(
  28     x: &'a i32,
  29     y: &'b i32,
  30     f: F)
  31     where F: for<'xa, 'xb: 'xa> Fn(&'xa i32, &'xb i32) -> &'xa i32
  32     //~^ ERROR lifetime bounds cannot be used in this context
  33 {
  34     // If the bound in f's type would matter, the call below would (have to)
  35     // be rejected.
  36     f(x, y);
  37 }
  38
  39 fn bar4<'a, 'b, F>(
  40     x: &'a i32,
  41     y: &'b i32,
  42     f: F)
  43     where for<'xa, 'xb: 'xa> F: Fn(&'xa i32, &'xb i32) -> &'xa i32
  44     //~^ ERROR lifetime bounds cannot be used in this context
  45 {
  46     // If the bound in f's type would matter, the call below would (have to)
  47     // be rejected.
  48     f(x, y);
  49 }
  50
  51 struct S1<F: for<'xa, 'xb: 'xa> Fn(&'xa i32, &'xb i32) -> &'xa i32>(F);
  52 //~^ ERROR lifetime bounds cannot be used in this context
  53 struct S2<F>(F) where F: for<'xa, 'xb: 'xa> Fn(&'xa i32, &'xb i32) -> &'xa i32;
  54 //~^ ERROR lifetime bounds cannot be used in this context
  55 struct S3<F>(F) where for<'xa, 'xb: 'xa> F: Fn(&'xa i32, &'xb i32) -> &'xa i32;
  56 //~^ ERROR lifetime bounds cannot be used in this context
  57
  58 struct S_fnty(for<'xa, 'xb: 'xa> fn(&'xa i32, &'xb i32) -> &'xa i32);
  59 //~^ ERROR lifetime bounds cannot be used in this context
  60
  61 type T1 = Box<dyn for<'xa, 'xb: 'xa> Fn(&'xa i32, &'xb i32) -> &'xa i32>;
  62 //~^ ERROR lifetime bounds cannot be used in this context
  63
  64 fn main() {
  65     let _ : Option<for<'xa, 'xb: 'xa> fn(&'xa i32, &'xb i32) -> &'xa i32> = None;
  66     //~^ ERROR lifetime bounds cannot be used in this context
  67     let _ : Option<Box<dyn for<'xa, 'xb: 'xa> Fn(&'xa i32, &'xb i32) -> &'xa i32>> = None;
  68     //~^ ERROR lifetime bounds cannot be used in this context
  69 }