#![allow(non_camel_case_types)]
#[cfg(feature = "use_core")]
extern crate core;
#[macro_use]
extern crate derivative;
use std::hash::{Hash, Hasher};
use std::collections::hash_map::DefaultHasher;
#[derive(Derivative)]
#[derivative(Hash)]
struct Person {
id: u16,
name: String,
phone: u64,
}
#[derive(Derivative)]
#[derivative(Hash)] struct __H__H;
#[derive(Derivative)]
#[allow(dead_code)] #[derivative(Hash)] struct Collision<__H> ( __H );
#[derive(Derivative)]
#[derivative(Hash)]
enum E { A=1, B }
fn hash<T: Hash>(t: &T) -> u64 {
let mut s = DefaultHasher::new();
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));
}
#[test]
fn main() {
let person1 = Person {
id: 5,
name: "Janet".to_string(),
phone: 555_666_777,
};
let person2 = Person {
id: 5,
name: "Bob".to_string(),
phone: 555_666_777,
};
assert_eq!(hash(&person1), hash(&person1));
assert!(hash(&person1) != hash(&person2));
let mut va = vec![];
let mut vb = vec![];
fake_hash(&mut va, E::A);
fake_hash(&mut vb, E::B);
assert!(va != vb);
}