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//! Useful traits for manipulating sequences of data stored in `GenericArray`s↩
↩
use super::*;↩
use core::ops::{Add, Sub};↩
use core::mem::MaybeUninit;↩
use core::ptr;↩
use typenum::operator_aliases::*;↩
↩
/// Defines some sequence with an associated length and iteration capabilities.↩
///↩
/// This is useful for passing N-length generic arrays as generics.↩
pub unsafe trait GenericSequence<T>: Sized + IntoIterator {↩
/// `GenericArray` associated length↩
type Length: ArrayLength<T>;↩
↩
/// Concrete sequence type used in conjuction with reference implementations of `GenericSequence`↩
type Sequence: GenericSequence<T, Length = Self::Length> + FromIterator<T>;↩
↩
/// Initializes a new sequence instance using the given function.↩
///↩
/// If the generator function panics while initializing the sequence,↩
/// any already initialized elements will be dropped.↩
fn generate<F>(f: F) -> Self::Sequence↩
where↩
F: FnMut(usize) -> T;↩
↩
#[doc(hidden)]↩
fn inverted_zip<B, U, F>(↩
self,↩
lhs: GenericArray<B, Self::Length>,↩
mut f: F,↩
) -> MappedSequence<GenericArray<B, Self::Length>, B, U>↩
where↩
GenericArray<B, Self::Length>: GenericSequence<B, Length = Self::Length>↩
+ MappedGenericSequence<B, U>,↩
Self: MappedGenericSequence<T, U>,↩
Self::Length: ArrayLength<B> + ArrayLength<U>,↩
F: FnMut(B, Self::Item) -> U,↩
{↩
unsafe {↩
let mut left = ArrayConsumer::new(lhs);↩
↩
let (left_array_iter, left_position) = left.iter_position();↩
↩
FromIterator::from_iter(left_array_iter.zip(self.into_iter()).map(↩
|(l, right_value)| {↩
let left_value = ptr::read(l);↩
↩
*left_position += 1;↩
↩
f(left_value, right_value)↩
},↩
))↩
}↩
}↩
↩
#[doc(hidden)]↩
fn inverted_zip2<B, Lhs, U, F>(self, lhs: Lhs, mut f: F) -> MappedSequence<Lhs, B, U>↩
where↩
Lhs: GenericSequence<B, Length = Self::Length> + MappedGenericSequence<B, U>,↩
Self: MappedGenericSequence<T, U>,↩
Self::Length: ArrayLength<B> + ArrayLength<U>,↩
F: FnMut(Lhs::Item, Self::Item) -> U,↩
{↩
FromIterator::from_iter(lhs.into_iter().zip(self.into_iter()).map(|(l, r)| f(l, r)))↩
}↩
}↩
↩
/// Accessor for `GenericSequence` item type, which is really `IntoIterator::Item`↩
///↩
/// For deeply nested generic mapped sequence types, like shown in `tests/generics.rs`,↩
/// this can be useful for keeping things organized.↩
pub type SequenceItem<T> = <T as IntoIterator>::Item;↩
↩
unsafe impl<'a, T: 'a, S: GenericSequence<T>> GenericSequence<T> for &'a S↩
where↩
&'a S: IntoIterator,↩
{↩
type Length = S::Length;↩
type Sequence = S::Sequence;↩
↩
#[inline]↩
fn generate<F>(f: F) -> Self::Sequence↩
where↩
F: FnMut(usize) -> T,↩
{↩
S::generate(f)↩
}↩
}↩
↩
unsafe impl<'a, T: 'a, S: GenericSequence<T>> GenericSequence<T> for &'a mut S↩
where↩
&'a mut S: IntoIterator,↩
{↩
type Length = S::Length;↩
type Sequence = S::Sequence;↩
↩
#[inline]↩
fn generate<F>(f: F) -> Self::Sequence↩
where↩
F: FnMut(usize) -> T,↩
{↩
S::generate(f)↩
}↩
}↩
↩
/// Defines any `GenericSequence` which can be lengthened or extended by appending↩
/// or prepending an element to it.↩
///↩
/// Any lengthened sequence can be shortened back to the original using `pop_front` or `pop_back`↩
pub unsafe trait Lengthen<T>: Sized + GenericSequence<T> {↩
/// `GenericSequence` that has one more element than `Self`↩
type Longer: Shorten<T, Shorter = Self>;↩
↩
/// Returns a new array with the given element appended to the end of it.↩
///↩
/// Example:↩
///↩
/// ```rust↩
/// # use generic_array::{arr, sequence::Lengthen};↩
/// # fn main() {↩
/// let a = arr![i32; 1, 2, 3];↩
///↩
/// let b = a.append(4);↩
///↩
/// assert_eq!(b, arr![i32; 1, 2, 3, 4]);↩
/// # }↩
/// ```↩
fn append(self, last: T) -> Self::Longer;↩
↩
/// Returns a new array with the given element prepended to the front of it.↩
///↩
/// Example:↩
///↩
/// ```rust↩
/// # use generic_array::{arr, sequence::Lengthen};↩
/// # fn main() {↩
/// let a = arr![i32; 1, 2, 3];↩
///↩
/// let b = a.prepend(4);↩
///↩
/// assert_eq!(b, arr![i32; 4, 1, 2, 3]);↩
/// # }↩
/// ```↩
fn prepend(self, first: T) -> Self::Longer;↩
}↩
↩
/// Defines a `GenericSequence` which can be shortened by removing the first or last element from it.↩
///↩
/// Additionally, any shortened sequence can be lengthened by↩
/// appending or prepending an element to it.↩
pub unsafe trait Shorten<T>: Sized + GenericSequence<T> {↩
/// `GenericSequence` that has one less element than `Self`↩
type Shorter: Lengthen<T, Longer = Self>;↩
↩
/// Returns a new array without the last element, and the last element.↩
///↩
/// Example:↩
///↩
/// ```rust↩
/// # use generic_array::{arr, sequence::Shorten};↩
/// # fn main() {↩
/// let a = arr![i32; 1, 2, 3, 4];↩
///↩
/// let (init, last) = a.pop_back();↩
///↩
/// assert_eq!(init, arr![i32; 1, 2, 3]);↩
/// assert_eq!(last, 4);↩
/// # }↩
/// ```↩
fn pop_back(self) -> (Self::Shorter, T);↩
↩
/// Returns a new array without the first element, and the first element.↩
/// Example:↩
///↩
/// ```rust↩
/// # use generic_array::{arr, sequence::Shorten};↩
/// # fn main() {↩
/// let a = arr![i32; 1, 2, 3, 4];↩
///↩
/// let (head, tail) = a.pop_front();↩
///↩
/// assert_eq!(head, 1);↩
/// assert_eq!(tail, arr![i32; 2, 3, 4]);↩
/// # }↩
/// ```↩
fn pop_front(self) -> (T, Self::Shorter);↩
}↩
↩
unsafe impl<T, N: ArrayLength<T>> Lengthen<T> for GenericArray<T, N>↩
where↩
N: Add<B1>,↩
Add1<N>: ArrayLength<T>,↩
Add1<N>: Sub<B1, Output = N>,↩
Sub1<Add1<N>>: ArrayLength<T>,↩
{↩
type Longer = GenericArray<T, Add1<N>>;↩
↩
fn append(self, last: T) -> Self::Longer {↩
let mut longer: MaybeUninit<Self::Longer> = MaybeUninit::uninit();↩
↩
// Note this is *mut Self, so add(1) increments by the whole array↩
let out_ptr = longer.as_mut_ptr() as *mut Self;↩
↩
unsafe {↩
// write self first↩
ptr::write(out_ptr, self);↩
// increment past self, then write the last↩
ptr::write(out_ptr.add(1) as *mut T, last);↩
↩
longer.assume_init()↩
}↩
}↩
↩
fn prepend(self, first: T) -> Self::Longer {↩
let mut longer: MaybeUninit<Self::Longer> = MaybeUninit::uninit();↩
↩
// Note this is *mut T, so add(1) increments by a single T↩
let out_ptr = longer.as_mut_ptr() as *mut T;↩
↩
unsafe {↩
// write the first at the start↩
ptr::write(out_ptr, first);↩
// increment past the first, then write self↩
ptr::write(out_ptr.add(1) as *mut Self, self);↩
↩
longer.assume_init()↩
}↩
}↩
}↩
↩
unsafe impl<T, N: ArrayLength<T>> Shorten<T> for GenericArray<T, N>↩
where↩
N: Sub<B1>,↩
Sub1<N>: ArrayLength<T>,↩
Sub1<N>: Add<B1, Output = N>,↩
Add1<Sub1<N>>: ArrayLength<T>,↩
{↩
type Shorter = GenericArray<T, Sub1<N>>;↩
↩
fn pop_back(self) -> (Self::Shorter, T) {↩
let whole = ManuallyDrop::new(self);↩
↩
unsafe {↩
let init = ptr::read(whole.as_ptr() as _);↩
let last = ptr::read(whole.as_ptr().add(Sub1::<N>::USIZE) as _);↩
↩
(init, last)↩
}↩
}↩
↩
fn pop_front(self) -> (T, Self::Shorter) {↩
// ensure this doesn't get dropped↩
let whole = ManuallyDrop::new(self);↩
↩
unsafe {↩
let head = ptr::read(whole.as_ptr() as _);↩
let tail = ptr::read(whole.as_ptr().offset(1) as _);↩
↩
(head, tail)↩
}↩
}↩
}↩
↩
/// Defines a `GenericSequence` that can be split into two parts at a given pivot index.↩
pub unsafe trait Split<T, K>: GenericSequence<T>↩
where↩
K: ArrayLength<T>,↩
{↩
/// First part of the resulting split array↩
type First: GenericSequence<T>;↩
/// Second part of the resulting split array↩
type Second: GenericSequence<T>;↩
↩
/// Splits an array at the given index, returning the separate parts of the array.↩
fn split(self) -> (Self::First, Self::Second);↩
}↩
↩
unsafe impl<T, N, K> Split<T, K> for GenericArray<T, N>↩
where↩
N: ArrayLength<T>,↩
K: ArrayLength<T>,↩
N: Sub<K>,↩
Diff<N, K>: ArrayLength<T>,↩
{↩
type First = GenericArray<T, K>;↩
type Second = GenericArray<T, Diff<N, K>>;↩
↩
fn split(self) -> (Self::First, Self::Second) {↩
unsafe {↩
// ensure this doesn't get dropped↩
let whole = ManuallyDrop::new(self);↩
↩
let head = ptr::read(whole.as_ptr() as *const _);↩
let tail = ptr::read(whole.as_ptr().add(K::USIZE) as *const _);↩
↩
(head, tail)↩
}↩
}↩
}↩
↩
unsafe impl<'a, T, N, K> Split<T, K> for &'a GenericArray<T, N>↩
where↩
N: ArrayLength<T>,↩
K: ArrayLength<T> + 'static,↩
N: Sub<K>,↩
Diff<N, K>: ArrayLength<T>,↩
{↩
type First = &'a GenericArray<T, K>;↩
type Second = &'a GenericArray<T, Diff<N, K>>;↩
↩
fn split(self) -> (Self::First, Self::Second) {↩
unsafe {↩
let ptr_to_first: *const T = self.as_ptr();↩
let head = &*(ptr_to_first as *const _);↩
let tail = &*(ptr_to_first.add(K::USIZE) as *const _);↩
(head, tail)↩
}↩
}↩
}↩
↩
unsafe impl<'a, T, N, K> Split<T, K> for &'a mut GenericArray<T, N>↩
where↩
N: ArrayLength<T>,↩
K: ArrayLength<T> + 'static,↩
N: Sub<K>,↩
Diff<N, K>: ArrayLength<T>,↩
{↩
type First = &'a mut GenericArray<T, K>;↩
type Second = &'a mut GenericArray<T, Diff<N, K>>;↩
↩
fn split(self) -> (Self::First, Self::Second) {↩
unsafe {↩
let ptr_to_first: *mut T = self.as_mut_ptr();↩
let head = &mut *(ptr_to_first as *mut _);↩
let tail = &mut *(ptr_to_first.add(K::USIZE) as *mut _);↩
(head, tail)↩
}↩
}↩
}↩
↩
/// Defines `GenericSequence`s which can be joined together, forming a larger array.↩
pub unsafe trait Concat<T, M>: GenericSequence<T>↩
where↩
M: ArrayLength<T>,↩
{↩
/// Sequence to be concatenated with `self`↩
type Rest: GenericSequence<T, Length = M>;↩
↩
/// Resulting sequence formed by the concatenation.↩
type Output: GenericSequence<T>;↩
↩
/// Concatenate, or join, two sequences.↩
fn concat(self, rest: Self::Rest) -> Self::Output;↩
}↩
↩
unsafe impl<T, N, M> Concat<T, M> for GenericArray<T, N>↩
where↩
N: ArrayLength<T> + Add<M>,↩
M: ArrayLength<T>,↩
Sum<N, M>: ArrayLength<T>,↩
{↩
type Rest = GenericArray<T, M>;↩
type Output = GenericArray<T, Sum<N, M>>;↩
↩
fn concat(self, rest: Self::Rest) -> Self::Output {↩
let mut output: MaybeUninit<Self::Output> = MaybeUninit::uninit();↩
↩
let out_ptr = output.as_mut_ptr() as *mut Self;↩
↩
unsafe {↩
// write all of self to the pointer↩
ptr::write(out_ptr, self);↩
// increment past self, then write the rest↩
ptr::write(out_ptr.add(1) as *mut _, rest);↩
↩
output.assume_init()↩
}↩
}↩
}↩