src/test/ui/regions/regions-bounded-method-type-parameters-trait-bound.rs

   1 // Check that explicit region bounds are allowed on the various
   2 // nominal types (but not on other types) and that they are type
   3 // checked.
   4
   5 // revisions: base nll
   6 // ignore-compare-mode-nll
   7 //[nll] compile-flags: -Z borrowck=mir
   8
   9 struct Inv<'a> { // invariant w/r/t 'a
  10     x: &'a mut &'a isize
  11 }
  12
  13 trait Foo<'x> {
  14     fn method<'y:'x>(self, y: Inv<'y>);
  15 }
  16
  17 fn caller1<'a,'b,F:Foo<'a>>(a: Inv<'a>, b: Inv<'b>, f: F) {
  18     // Here the value provided for 'y is 'a, and hence 'a:'a holds.
  19     f.method(a);
  20 }
  21
  22 fn caller2<'a,'b,F:Foo<'a>>(a: Inv<'a>, b: Inv<'b>, f: F) {
  23     // Here the value provided for 'y is 'b, and hence 'b:'a does not hold.
  24     f.method(b);
  25     //[base]~^ ERROR lifetime mismatch [E0623]
  26     //[nll]~^^ ERROR lifetime may not live long enough
  27 }
  28
  29 fn caller3<'a,'b:'a,F:Foo<'a>>(a: Inv<'a>, b: Inv<'b>, f: F) {
  30     // Here the value provided for 'y is 'b, and hence 'b:'a holds.
  31     f.method(b);
  32 }
  33
  34 fn main() { }