use core::fmt;
use core::iter::FusedIterator;
use core::iter::IntoIterator;
use phf_shared::{PhfBorrow, PhfHash};
use crate::{map, Map};
pub struct Set<T: 'static> {
    #[doc(hidden)]
    pub map: Map<T, ()>,
}
impl<T> fmt::Debug for Set<T>
where
    T: fmt::Debug,
{
    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
        fmt.debug_set().entries(self).finish()
    }
}
impl<T> Set<T> {
    #[inline]
    pub const fn len(&self) -> usize {
        self.map.len()
    }
    #[inline]
    pub const fn is_empty(&self) -> bool {
        self.len() == 0
    }
    pub fn get_key<U: ?Sized>(&self, key: &U) -> Option<&T>
    where
        U: Eq + PhfHash,
        T: PhfBorrow<U>,
    {
        self.map.get_key(key)
    }
    pub fn contains<U: ?Sized>(&self, value: &U) -> bool
    where
        U: Eq + PhfHash,
        T: PhfBorrow<U>,
    {
        self.map.contains_key(value)
    }
    pub fn iter(&self) -> Iter<'_, T> {
        Iter {
            iter: self.map.keys(),
        }
    }
}
impl<T> Set<T>
where
    T: Eq + PhfHash + PhfBorrow<T>,
{
    pub fn is_disjoint(&self, other: &Set<T>) -> bool {
        !self.iter().any(|value| other.contains(value))
    }
    pub fn is_subset(&self, other: &Set<T>) -> bool {
        self.iter().all(|value| other.contains(value))
    }
    pub fn is_superset(&self, other: &Set<T>) -> bool {
        other.is_subset(self)
    }
}
impl<'a, T> IntoIterator for &'a Set<T> {
    type Item = &'a T;
    type IntoIter = Iter<'a, T>;
    fn into_iter(self) -> Iter<'a, T> {
        self.iter()
    }
}
pub struct Iter<'a, T: 'static> {
    iter: map::Keys<'a, T, ()>,
}
impl<'a, T> Clone for Iter<'a, T> {
    #[inline]
    fn clone(&self) -> Self {
        Self {
            iter: self.iter.clone(),
        }
    }
}
impl<'a, T> fmt::Debug for Iter<'a, T>
where
    T: fmt::Debug,
{
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.debug_list().entries(self.clone()).finish()
    }
}
impl<'a, T> Iterator for Iter<'a, T> {
    type Item = &'a T;
    fn next(&mut self) -> Option<&'a T> {
        self.iter.next()
    }
    fn size_hint(&self) -> (usize, Option<usize>) {
        self.iter.size_hint()
    }
}
impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
    fn next_back(&mut self) -> Option<&'a T> {
        self.iter.next_back()
    }
}
impl<'a, T> ExactSizeIterator for Iter<'a, T> {}
impl<'a, T> FusedIterator for Iter<'a, T> {}