use core::{
cmp, hash,
iter::DoubleEndedIterator,
mem,
ops::{Deref, DerefMut},
pin::Pin,
};
#[derive(Clone, Copy, Debug)]
#[cfg_attr(feature = "validation", derive(bytecheck::CheckBytes))]
#[repr(u8)]
pub enum ArchivedOption<T> {
None,
Some(T),
}
impl<T> ArchivedOption<T> {
#[inline]
pub fn is_none(&self) -> bool {
match self {
ArchivedOption::None => true,
ArchivedOption::Some(_) => false,
}
}
#[inline]
pub fn is_some(&self) -> bool {
match self {
ArchivedOption::None => false,
ArchivedOption::Some(_) => true,
}
}
#[inline]
pub const fn as_ref(&self) -> Option<&T> {
match self {
ArchivedOption::None => None,
ArchivedOption::Some(value) => Some(value),
}
}
#[inline]
pub fn as_mut(&mut self) -> Option<&mut T> {
match self {
ArchivedOption::None => None,
ArchivedOption::Some(value) => Some(value),
}
}
#[inline]
pub fn as_pin_ref(self: Pin<&Self>) -> Option<Pin<&T>> {
unsafe { Pin::get_ref(self).as_ref().map(|x| Pin::new_unchecked(x)) }
}
#[inline]
pub fn as_pin_mut(self: Pin<&mut Self>) -> Option<Pin<&mut T>> {
unsafe {
Pin::get_unchecked_mut(self)
.as_mut()
.map(|x| Pin::new_unchecked(x))
}
}
#[inline]
pub const fn iter(&self) -> Iter<'_, T> {
Iter {
inner: self.as_ref(),
}
}
#[inline]
pub fn iter_mut(&mut self) -> IterMut<'_, T> {
IterMut {
inner: self.as_mut(),
}
}
#[inline]
pub fn get_or_insert(&mut self, v: T) -> &mut T {
self.get_or_insert_with(move || v)
}
#[inline]
pub fn get_or_insert_with<F: FnOnce() -> T>(&mut self, f: F) -> &mut T {
if let ArchivedOption::Some(ref mut value) = self {
value
} else {
*self = ArchivedOption::Some(f());
self.as_mut().unwrap()
}
}
}
impl<T: Deref> ArchivedOption<T> {
#[inline]
pub fn as_deref(&self) -> Option<&<T as Deref>::Target> {
self.as_ref().map(|x| x.deref())
}
}
impl<T: DerefMut> ArchivedOption<T> {
#[inline]
pub fn as_deref_mut(&mut self) -> Option<&mut <T as Deref>::Target> {
self.as_mut().map(|x| x.deref_mut())
}
}
impl<T: Eq> Eq for ArchivedOption<T> {}
impl<T: hash::Hash> hash::Hash for ArchivedOption<T> {
#[inline]
fn hash<H: hash::Hasher>(&self, state: &mut H) {
self.as_ref().hash(state)
}
}
impl<T: Ord> Ord for ArchivedOption<T> {
#[inline]
fn cmp(&self, other: &Self) -> cmp::Ordering {
self.as_ref().cmp(&other.as_ref())
}
}
impl<T: PartialEq> PartialEq for ArchivedOption<T> {
#[inline]
fn eq(&self, other: &Self) -> bool {
self.as_ref().eq(&other.as_ref())
}
}
impl<T: PartialOrd> PartialOrd for ArchivedOption<T> {
#[inline]
fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> {
self.as_ref().partial_cmp(&other.as_ref())
}
}
impl<T, U: PartialEq<T>> PartialEq<Option<T>> for ArchivedOption<U> {
#[inline]
fn eq(&self, other: &Option<T>) -> bool {
if let ArchivedOption::Some(self_value) = self {
if let Some(other_value) = other {
self_value.eq(other_value)
} else {
false
}
} else {
other.is_none()
}
}
}
impl<T: PartialEq<U>, U> PartialEq<ArchivedOption<T>> for Option<U> {
#[inline]
fn eq(&self, other: &ArchivedOption<T>) -> bool {
other.eq(self)
}
}
pub struct Iter<'a, T> {
pub(crate) inner: Option<&'a T>,
}
impl<'a, T> Iterator for Iter<'a, T> {
type Item = &'a T;
fn next(&mut self) -> Option<Self::Item> {
let mut result = None;
mem::swap(&mut self.inner, &mut result);
result
}
}
impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
fn next_back(&mut self) -> Option<Self::Item> {
self.next()
}
}
pub struct IterMut<'a, T> {
pub(crate) inner: Option<&'a mut T>,
}
impl<'a, T> Iterator for IterMut<'a, T> {
type Item = &'a mut T;
fn next(&mut self) -> Option<Self::Item> {
let mut result = None;
mem::swap(&mut self.inner, &mut result);
result
}
}
impl<'a, T> DoubleEndedIterator for IterMut<'a, T> {
fn next_back(&mut self) -> Option<Self::Item> {
self.next()
}
}