diff options
Diffstat (limited to 'tests/ui/higher-rank-trait-bounds/hrtb-identity-fn-borrows.rs')
-rw-r--r-- | tests/ui/higher-rank-trait-bounds/hrtb-identity-fn-borrows.rs | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/tests/ui/higher-rank-trait-bounds/hrtb-identity-fn-borrows.rs b/tests/ui/higher-rank-trait-bounds/hrtb-identity-fn-borrows.rs new file mode 100644 index 000000000..89fc4705a --- /dev/null +++ b/tests/ui/higher-rank-trait-bounds/hrtb-identity-fn-borrows.rs @@ -0,0 +1,26 @@ +// Test that the `'a` in the where clause correctly links the region +// of the output to the region of the input. + +trait FnLike<A,R> { + fn call(&self, arg: A) -> R; +} + +fn call_repeatedly<F>(f: F) + where F : for<'a> FnLike<&'a isize, &'a isize> +{ + // Result is stored: cannot re-assign `x` + let mut x = 3; + let y = f.call(&x); + x = 5; //~ ERROR cannot assign to `x` because it is borrowed + + // Result is not stored: can re-assign `x` + let mut x = 3; + f.call(&x); + f.call(&x); + f.call(&x); + x = 5; + drop(y); +} + +fn main() { +} |