#![feature(hash_default)]
use std::hash::{Hash, SipHasher, Hasher};
+use std::mem::size_of;
#[derive(Hash)]
struct Person {
#[derive(Hash)] struct __H__H;
#[derive(Hash)] enum Collision<__H> { __H { __H__H: __H } }
+#[derive(Hash)]
+enum E { A=1, B }
+
fn hash<T: Hash>(t: &T) -> u64 {
let mut s = SipHasher::new_with_keys(0, 0);
t.hash(&mut s);
s.finish()
}
+struct FakeHasher<'a>(&'a mut Vec<u8>);
+impl<'a> Hasher for FakeHasher<'a> {
+ fn finish(&self) -> u64 {
+ unimplemented!()
+ }
+
+ fn write(&mut self, bytes: &[u8]) {
+ self.0.extend(bytes);
+ }
+}
+
+fn fake_hash(v: &mut Vec<u8>, e: E) {
+ e.hash(&mut FakeHasher(v));
+}
+
fn main() {
let person1 = Person {
id: 5,
};
assert_eq!(hash(&person1), hash(&person1));
assert!(hash(&person1) != hash(&person2));
+
+ // test #21714
+ let mut va = vec![];
+ let mut vb = vec![];
+ fake_hash(&mut va, E::A);
+ fake_hash(&mut vb, E::B);
+ assert!(va != vb);
}