diff options
Diffstat (limited to 'src/test/ui/regions/regions-ret-borrowed.rs')
-rw-r--r-- | src/test/ui/regions/regions-ret-borrowed.rs | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/test/ui/regions/regions-ret-borrowed.rs b/src/test/ui/regions/regions-ret-borrowed.rs new file mode 100644 index 000000000..bdb0341c9 --- /dev/null +++ b/src/test/ui/regions/regions-ret-borrowed.rs @@ -0,0 +1,20 @@ +// Ensure that you cannot use generic types to return a region outside +// of its bound. Here, in the `return_it()` fn, we call with() but +// with R bound to &isize from the return_it. Meanwhile, with() +// provides a value that is only good within its own stack frame. This +// used to successfully compile because we failed to account for the +// fact that fn(x: &isize) rebound the region &. + +fn with<R, F>(f: F) -> R where F: FnOnce(&isize) -> R { + f(&3) +} + +fn return_it<'a>() -> &'a isize { + with(|o| o) + //~^ ERROR lifetime may not live long enough +} + +fn main() { + let x = return_it(); + println!("foo={}", *x); +} |