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Diffstat (limited to 'tests/ui/higher-rank-trait-bounds/hrtb-fn-like-trait.rs')
-rw-r--r-- | tests/ui/higher-rank-trait-bounds/hrtb-fn-like-trait.rs | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/tests/ui/higher-rank-trait-bounds/hrtb-fn-like-trait.rs b/tests/ui/higher-rank-trait-bounds/hrtb-fn-like-trait.rs new file mode 100644 index 000000000..afab9986c --- /dev/null +++ b/tests/ui/higher-rank-trait-bounds/hrtb-fn-like-trait.rs @@ -0,0 +1,27 @@ +// run-pass +// A basic test of using a higher-ranked trait bound. + + +trait FnLike<A,R> { + fn call(&self, arg: A) -> R; +} + +struct Identity; + +impl<'a, T> FnLike<&'a T, &'a T> for Identity { + fn call(&self, arg: &'a T) -> &'a T { + arg + } +} + +fn call_repeatedly<F>(f: F) + where F : for<'a> FnLike<&'a isize, &'a isize> +{ + let x = 3; + let y = f.call(&x); + assert_eq!(3, *y); +} + +fn main() { + call_repeatedly(Identity); +} |