logo
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
//! Niched archived `Option<NonZero>` integers that use less space.

use crate::Archived;
use core::{
    cmp, fmt, hash,
    num::{
        NonZeroI128, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI8, NonZeroU128, NonZeroU16,
        NonZeroU32, NonZeroU64, NonZeroU8,
    },
    pin::Pin,
};

macro_rules! impl_archived_option_nonzero {
    ($ar:ident, $nz:ty, $ne:ty) => {
        #[doc = concat!("A niched archived `Option<", stringify!($nz), ">`")]
        #[repr(transparent)]
        pub struct $ar {
            inner: Archived<$ne>,
        }

        impl $ar {
            /// Returns `true` if the option is a `None` value.
            #[inline]
            pub fn is_none(&self) -> bool {
                self.inner == 0
            }

            /// Returns `true` if the option is a `Some` value.
            #[inline]
            pub fn is_some(&self) -> bool {
                self.inner != 0
            }

            #[doc = concat!("Converts to an `Option<&Archived<", stringify!($nz), ">>`")]
            pub fn as_ref(&self) -> Option<&Archived<$nz>> {
                if self.inner != 0 {
                    let as_nonzero = unsafe {
                        // SAFETY: NonZero types have the same memory layout and bit patterns as
                        // their integer counterparts, regardless of endianness
                        &*(&self.inner as *const _ as *const Archived<$nz>)
                    };
                    Some(as_nonzero)
                } else {
                    None
                }
            }

            #[doc = concat!("Converts to an `Option<&mut Archived<", stringify!($nz), ">>`")]
            pub fn as_mut(&mut self) -> Option<&mut Archived<$nz>> {
                if self.inner != 0 {
                    let as_nonzero = unsafe {
                        // SAFETY: NonZero types have the same memory layout and bit patterns as
                        // their integer counterparts, regardless of endianness
                        &mut *(&mut self.inner as *mut _ as *mut Archived<$nz>)
                    };
                    Some(as_nonzero)
                } else {
                    None
                }
            }

            #[doc = concat!("Converts from `Pin<&ArchivedOption", stringify!($nz), ">` to `Option<Pin<&Archived<", stringify!($nz), ">>>`.")]
            #[inline]
            pub fn as_pin_ref(self: Pin<&Self>) -> Option<Pin<&Archived<$nz>>> {
                unsafe { Pin::get_ref(self).as_ref().map(|x| Pin::new_unchecked(x)) }
            }

            #[doc = concat!("Converts from `Pin<&mut ArchivedOption", stringify!($nz), ">` to `Option<Pin<&mut Archived<", stringify!($nz), ">>>`.")]
            #[inline]
            pub fn as_pin_mut(self: Pin<&mut Self>) -> Option<Pin<&mut Archived<$nz>>> {
                unsafe {
                    Pin::get_unchecked_mut(self)
                        .as_mut()
                        .map(|x| Pin::new_unchecked(x))
                }
            }

            /// Returns an iterator over the possibly contained value.
            #[inline]
            pub fn iter(&self) -> Iter<'_, Archived<$nz>> {
                Iter {
                    inner: self.as_ref(),
                }
            }

            /// Returns a mutable iterator over the possibly contained value.
            #[inline]
            pub fn iter_mut(&mut self) -> IterMut<'_, Archived<$nz>> {
                IterMut {
                    inner: self.as_mut(),
                }
            }

            /// Inserts `v` into the option if it is `None`, then returns a mutable
            /// reference to the contained value.
            #[inline]
            pub fn get_or_insert(&mut self, v: $nz) -> &mut Archived<$nz> {
                self.get_or_insert_with(move || v)
            }

            /// Inserts a value computed from `f` into the option if it is `None`, then
            /// returns a mutable reference to the contained value.
            #[inline]
            pub fn get_or_insert_with<F: FnOnce() -> $nz>(&mut self, f: F) -> &mut Archived<$nz> {
                if self.inner == 0 {
                    self.inner = f().get().into();
                }
                unsafe {
                    // SAFETY: self.inner is nonzero
                    &mut *(&mut self.inner as *mut _ as *mut Archived<$nz>)
                }
            }

            /// Resolves an `ArchivedOptionNonZero` from an `Option<NonZero>`.
            ///
            /// # Safety
            ///
            /// - `pos` must be the position of `out` within the archive
            #[inline]
            pub unsafe fn resolve_from_option(field: Option<$nz>, out: *mut Self) {
                let (_, fo) = out_field!(out.inner);
                if let Some(nz) = field {
                    fo.write(nz.get().into());
                } else {
                    fo.write((0 as $ne).into());
                }
            }
        }

        impl fmt::Debug for $ar {
            #[inline]
            fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
                match self.as_ref() {
                    Some(inner) => inner.fmt(f),
                    None => f.debug_tuple("None").finish(),
                }
            }
        }

        impl Eq for $ar {}

        impl hash::Hash for $ar {
            #[inline]
            fn hash<H: hash::Hasher>(&self, state: &mut H) {
                self.as_ref().hash(state)
            }
        }

        impl Ord for $ar {
            #[inline]
            fn cmp(&self, other: &Self) -> cmp::Ordering {
                self.as_ref().cmp(&other.as_ref())
            }
        }

        impl PartialEq for $ar {
            #[inline]
            fn eq(&self, other: &Self) -> bool {
                self.as_ref().eq(&other.as_ref())
            }
        }

        impl PartialOrd for $ar {
            #[inline]
            fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> {
                self.as_ref().partial_cmp(&other.as_ref())
            }
        }
    };
}

impl_archived_option_nonzero!(ArchivedOptionNonZeroI8, NonZeroI8, i8);
impl_archived_option_nonzero!(ArchivedOptionNonZeroI16, NonZeroI16, i16);
impl_archived_option_nonzero!(ArchivedOptionNonZeroI32, NonZeroI32, i32);
impl_archived_option_nonzero!(ArchivedOptionNonZeroI64, NonZeroI64, i64);
impl_archived_option_nonzero!(ArchivedOptionNonZeroI128, NonZeroI128, i128);

impl_archived_option_nonzero!(ArchivedOptionNonZeroU8, NonZeroU8, u8);
impl_archived_option_nonzero!(ArchivedOptionNonZeroU16, NonZeroU16, u16);
impl_archived_option_nonzero!(ArchivedOptionNonZeroU32, NonZeroU32, u32);
impl_archived_option_nonzero!(ArchivedOptionNonZeroU64, NonZeroU64, u64);
impl_archived_option_nonzero!(ArchivedOptionNonZeroU128, NonZeroU128, u128);

/// An iterator over a reference to the `Some` variant of an `ArchivedOptionNonZero` integer.
///
/// This iterator yields one value if the `ArchivedOptionNonZero` integer is a `Some`, otherwise
/// none.
pub type Iter<'a, T> = crate::option::Iter<'a, T>;

/// An iterator over a mutable reference to the `Some` variant of an `ArchivedOptionNonZero`
/// integer.
///
/// This iterator yields one value if the `ArchivedOptionNonZero` integer is a `Some`, otherwise
/// none.
pub type IterMut<'a, T> = crate::option::IterMut<'a, T>;