creusot_std/std/iter/
empty.rs

1use crate::{prelude::*, std::iter::Empty};
2
3impl<T> IteratorSpec for Empty<T> {
4    #[logic(open, prophetic)]
5    fn completed(&mut self) -> bool {
6        resolve(self)
7    }
8
9    #[logic(open)]
10    fn produces(self, visited: Seq<T>, o: Self) -> bool {
11        pearlite! { visited == Seq::empty() && self == o }
12    }
13
14    #[logic(law)]
15    #[ensures(self.produces(Seq::empty(), self))]
16    fn produces_refl(self) {}
17
18    #[logic(law)]
19    #[requires(a.produces(ab, b))]
20    #[requires(b.produces(bc, c))]
21    #[ensures(a.produces(ab.concat(bc), c))]
22    fn produces_trans(a: Self, ab: Seq<T>, b: Self, bc: Seq<T>, c: Self) {
23        proof_assert!(Seq::<T>::empty().concat(Seq::empty()) == Seq::empty())
24    }
25}
26
27extern_spec! {
28    impl<T> Iterator for Empty<T> {
29        #[check(ghost)]
30        #[ensures(result == None && self.completed())]
31        fn next(&mut self) -> Option<T>;
32    }
33}
creusot_std/std/iter/empty.rs

creusot_std/std/iter/
empty.rs
