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| 1 | +// HACK(eddyb) this is a copy of `syntax::ptr`, minus the mutation (the HIR is |
| 2 | +// frozen anyway). The only reason for doing this instead of replacing `P<T>` |
| 3 | +// with `Box<T>` in HIR, is that `&Box<[T]>` doesn't implement `IntoIterator`. |
| 4 | + |
| 5 | +use std::fmt::{self, Display, Debug}; |
| 6 | +use std::iter::FromIterator; |
| 7 | +use std::ops::Deref; |
| 8 | +use std::{slice, vec}; |
| 9 | + |
| 10 | +use serialize::{Encodable, Decodable, Encoder, Decoder}; |
| 11 | + |
| 12 | +use rustc_data_structures::stable_hasher::{StableHasher, StableHasherResult, |
| 13 | + HashStable}; |
| 14 | +/// An owned smart pointer. |
| 15 | +#[derive(Hash, PartialEq, Eq)] |
| 16 | +pub struct P<T: ?Sized> { |
| 17 | + ptr: Box<T> |
| 18 | +} |
| 19 | + |
| 20 | +/// Construct a `P<T>` from a `T` value. |
| 21 | +#[allow(non_snake_case)] |
| 22 | +pub fn P<T: 'static>(value: T) -> P<T> { |
| 23 | + P { |
| 24 | + ptr: box value |
| 25 | + } |
| 26 | +} |
| 27 | + |
| 28 | +impl<T: 'static> P<T> { |
| 29 | + // HACK(eddyb) used by HIR lowering in a few places still. |
| 30 | + // NOTE: do not make this more public than `pub(super)`. |
| 31 | + pub(super) fn into_inner(self) -> T { |
| 32 | + *self.ptr |
| 33 | + } |
| 34 | +} |
| 35 | + |
| 36 | +impl<T: ?Sized> Deref for P<T> { |
| 37 | + type Target = T; |
| 38 | + |
| 39 | + fn deref(&self) -> &T { |
| 40 | + &self.ptr |
| 41 | + } |
| 42 | +} |
| 43 | + |
| 44 | +impl<T: ?Sized + Debug> Debug for P<T> { |
| 45 | + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| 46 | + Debug::fmt(&self.ptr, f) |
| 47 | + } |
| 48 | +} |
| 49 | + |
| 50 | +impl<T: Display> Display for P<T> { |
| 51 | + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| 52 | + Display::fmt(&**self, f) |
| 53 | + } |
| 54 | +} |
| 55 | + |
| 56 | +impl<T: 'static + Decodable> Decodable for P<T> { |
| 57 | + fn decode<D: Decoder>(d: &mut D) -> Result<P<T>, D::Error> { |
| 58 | + Decodable::decode(d).map(P) |
| 59 | + } |
| 60 | +} |
| 61 | + |
| 62 | +impl<T: Encodable> Encodable for P<T> { |
| 63 | + fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> { |
| 64 | + (**self).encode(s) |
| 65 | + } |
| 66 | +} |
| 67 | + |
| 68 | +impl<T> P<[T]> { |
| 69 | + pub const fn new() -> P<[T]> { |
| 70 | + // HACK(eddyb) bypass the lack of a `const fn` to create an empty `Box<[T]>` |
| 71 | + // (as trait methods, `default` in this case, can't be `const fn` yet). |
| 72 | + P { |
| 73 | + ptr: unsafe { |
| 74 | + use std::ptr::NonNull; |
| 75 | + std::mem::transmute(NonNull::<[T; 0]>::dangling() as NonNull<[T]>) |
| 76 | + }, |
| 77 | + } |
| 78 | + } |
| 79 | + |
| 80 | + #[inline(never)] |
| 81 | + pub fn from_vec(v: Vec<T>) -> P<[T]> { |
| 82 | + P { ptr: v.into_boxed_slice() } |
| 83 | + } |
| 84 | + |
| 85 | + // HACK(eddyb) used by HIR lowering in a few places still. |
| 86 | + // NOTE: do not make this more public than `pub(super)`, |
| 87 | + // and do not make this into an `IntoIterator` impl. |
| 88 | + pub(super) fn into_iter(self) -> vec::IntoIter<T> { |
| 89 | + self.ptr.into_vec().into_iter() |
| 90 | + } |
| 91 | +} |
| 92 | + |
| 93 | + |
| 94 | +impl<T> Default for P<[T]> { |
| 95 | + /// Creates an empty `P<[T]>`. |
| 96 | + fn default() -> P<[T]> { |
| 97 | + P::new() |
| 98 | + } |
| 99 | +} |
| 100 | + |
| 101 | +impl<T> From<Vec<T>> for P<[T]> { |
| 102 | + fn from(v: Vec<T>) -> Self { |
| 103 | + P::from_vec(v) |
| 104 | + } |
| 105 | +} |
| 106 | + |
| 107 | +impl<T> FromIterator<T> for P<[T]> { |
| 108 | + fn from_iter<I: IntoIterator<Item=T>>(iter: I) -> P<[T]> { |
| 109 | + P::from_vec(iter.into_iter().collect()) |
| 110 | + } |
| 111 | +} |
| 112 | + |
| 113 | +impl<'a, T> IntoIterator for &'a P<[T]> { |
| 114 | + type Item = &'a T; |
| 115 | + type IntoIter = slice::Iter<'a, T>; |
| 116 | + fn into_iter(self) -> Self::IntoIter { |
| 117 | + self.ptr.into_iter() |
| 118 | + } |
| 119 | +} |
| 120 | + |
| 121 | +impl<T: Encodable> Encodable for P<[T]> { |
| 122 | + fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> { |
| 123 | + Encodable::encode(&**self, s) |
| 124 | + } |
| 125 | +} |
| 126 | + |
| 127 | +impl<T: Decodable> Decodable for P<[T]> { |
| 128 | + fn decode<D: Decoder>(d: &mut D) -> Result<P<[T]>, D::Error> { |
| 129 | + Ok(P::from_vec(Decodable::decode(d)?)) |
| 130 | + } |
| 131 | +} |
| 132 | + |
| 133 | +impl<CTX, T> HashStable<CTX> for P<T> |
| 134 | + where T: ?Sized + HashStable<CTX> |
| 135 | +{ |
| 136 | + fn hash_stable<W: StableHasherResult>(&self, |
| 137 | + hcx: &mut CTX, |
| 138 | + hasher: &mut StableHasher<W>) { |
| 139 | + (**self).hash_stable(hcx, hasher); |
| 140 | + } |
| 141 | +} |
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