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use std::collections::{HashMap, HashSet};
use std::default::Default;
use std::hash::{Hasher, Hash, BuildHasherDefault};
pub type FnvHashMap<K, V> = HashMap<K, V, BuildHasherDefault<FnvHasher>>;
pub type FnvHashSet<V> = HashSet<V, BuildHasherDefault<FnvHasher>>;
#[allow(non_snake_case)]
pub fn FnvHashMap<K: Hash + Eq, V>() -> FnvHashMap<K, V> {
HashMap::default()
}
#[allow(non_snake_case)]
pub fn FnvHashSet<V: Hash + Eq>() -> FnvHashSet<V> {
HashSet::default()
}
pub struct FnvHasher(u64);
impl Default for FnvHasher {
#[inline]
fn default() -> FnvHasher {
FnvHasher(0xcbf29ce484222325)
}
}
impl Hasher for FnvHasher {
#[inline]
fn write(&mut self, bytes: &[u8]) {
let FnvHasher(mut hash) = *self;
for byte in bytes {
hash = hash ^ (*byte as u64);
hash = hash.wrapping_mul(0x100000001b3);
}
*self = FnvHasher(hash);
}
#[inline]
fn finish(&self) -> u64 {
self.0
}
}
pub fn hash<T: Hash>(v: &T) -> u64 {
let mut state = FnvHasher::default();
v.hash(&mut state);
state.finish()
}