diff options
Diffstat (limited to 'src/test/ui/closures/closure-expected-type/expect-region-supply-region.rs')
-rw-r--r-- | src/test/ui/closures/closure-expected-type/expect-region-supply-region.rs | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/src/test/ui/closures/closure-expected-type/expect-region-supply-region.rs b/src/test/ui/closures/closure-expected-type/expect-region-supply-region.rs new file mode 100644 index 000000000..55c6aa795 --- /dev/null +++ b/src/test/ui/closures/closure-expected-type/expect-region-supply-region.rs @@ -0,0 +1,57 @@ +#![allow(warnings)] + +fn closure_expecting_bound<F>(_: F) +where + F: FnOnce(&u32), +{ +} + +fn closure_expecting_free<'a, F>(_: F) +where + F: FnOnce(&'a u32), +{ +} + +fn expect_bound_supply_nothing() { + // Because `x` is inferred to have a bound region, we cannot allow + // it to escape into `f`: + let mut f: Option<&u32> = None; + closure_expecting_bound(|x| { + f = Some(x); //~ ERROR borrowed data escapes outside of closure + }); +} + +fn expect_bound_supply_bound() { + // Because `x` is inferred to have a bound region, we cannot allow + // it to escape into `f`, even with an explicit type annotation on + // closure: + let mut f: Option<&u32> = None; + closure_expecting_bound(|x: &u32| { + f = Some(x); //~ ERROR borrowed data escapes outside of closure + }); +} + +fn expect_free_supply_nothing() { + let mut f: Option<&u32> = None; + closure_expecting_free(|x| f = Some(x)); // OK +} + +fn expect_free_supply_bound() { + let mut f: Option<&u32> = None; + + // Here, even though the annotation `&u32` could be seen as being + // bound in the closure, we permit it to be defined as a free + // region (which is inferred to something in the fn body). + closure_expecting_free(|x: &u32| f = Some(x)); // OK +} + +fn expect_free_supply_named<'x>() { + let mut f: Option<&u32> = None; + + // Here, even though the annotation `&u32` could be seen as being + // bound in the closure, we permit it to be defined as a free + // region (which is inferred to something in the fn body). + closure_expecting_free(|x: &'x u32| f = Some(x)); // OK +} + +fn main() {} |