803 lines
27 KiB
Rust
803 lines
27 KiB
Rust
//! # A `Vec<T: ?Sized>`
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//!
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//! [`DynVec`], a dynamic length collection of unsized elements, akin to [`std::vec::Vec`].
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//!
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//! # Examples
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//!
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//! You can create a vector with [`DynVec::new`]:
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//!
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//! ```
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//! # use std::fmt::Debug;
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//! # use dyn_vec::DynVec;
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//! let vec: DynVec<dyn Debug> = DynVec::new();
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//! # assert_eq!(format!("{:?}", vec), "[]");
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//! ```
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//!
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//! or with the [`dyn_vec!`] macro:
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//!
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//! ```
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//! # use dyn_vec::{dyn_vec, DynVec};
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//! # use std::fmt::Debug;
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//! let vec: DynVec<i32> = dyn_vec![1, 2, 3];
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//! // check the docs for `dyn_vec!` for more info on this syntax
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//! let vec_boxed: DynVec<dyn Debug> = dyn_vec![box:
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//! Box::new(1) as _,
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//! Box::new("foo") as _,
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//! Box::new(true) as _
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//! ];
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//! let vec_unsized: DynVec<dyn Debug> = dyn_vec![unsized: 1, "foo", true];
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//! let vec_from_elem: DynVec<i32> = dyn_vec![3; 5];
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//! # assert_eq!(vec, [1, 2, 3]);
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//! # assert_eq!(format!("{:?}", vec_boxed), r#"[1, "foo", true]"#);
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//! # assert_eq!(format!("{:?}", vec_unsized), r#"[1, "foo", true]"#);
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//! # assert_eq!(vec_from_elem, [3; 5]);
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//! ```
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//!
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//! A vector can be pushed to with [`DynVec::push`]:
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//!
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//! ```
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//! # use dyn_vec::{dyn_vec, DynVec};
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//! let mut vec: DynVec<i32> = dyn_vec![];
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//! vec.push(1);
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//! vec.push(2);
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//! vec.push(3);
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//! # assert_eq!(format!("{:?}", vec), "[1, 2, 3]");
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//! ```
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//!
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//! ...and with [`push_box`] and [`push_unsize`] ([`push_unsize_stable`] without the `"unstable"`feature):
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//!
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//! ```
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//! # use dyn_vec::{dyn_vec, DynVec};
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//! # use std::fmt::Debug;
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//! let mut vec: DynVec<dyn Debug> = dyn_vec![];
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//! vec.push_box(Box::new(1));
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//! vec.push_box(Box::new("foo"));
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//! vec.push_box(Box::new(true));
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//!
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//! // these closures are only needed for the `_stable` versions
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//! vec.push_unsize_stable(2, |v| v as _);
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//! vec.push_unsize_stable("bar", |v| v as _);
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//! vec.push_unsize_stable(false, |v| v as _);
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//! # assert_eq!(format!("{:?}", vec), r#"[1, "foo", true, 2, "bar", false]"#);
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//! ```
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//!
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//! Finally, a vector can be [`unsize`]d to another vector ([`unsize_stable`] on stable):
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//!
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//! ```
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//! # use dyn_vec::{dyn_vec, DynVec};
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//! # use std::fmt::Debug;
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//! let vec: DynVec<i32> = dyn_vec![1, 2, 3];
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//! // vec.push_unsize_stable("foo", |v| v as _); // not yet...
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//! let mut vec: DynVec<dyn Debug> = vec.unsize_stable(|v| v as _);
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//! vec.push_unsize_stable("foo", |v| v as _); // now we can!
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//! # assert_eq!(format!("{:?}", vec), r#"[1, 2, 3, "foo"]"#);
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//! ```
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//!
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//! To use the `_stable` variations, one can generally add the argument `|v| v as _`.
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//!
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//! # Stability
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//!
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//! This crate is currently stable, but lacks some functionality. To enable this functionality, use
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//! the `"unstable"` crate feature, which depends on the following nightly features:
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//! - [`#![feature(coerce_unsized)]`](https://github.com/rust-lang/rust/issues/18598)
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//!
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//! and enables the following functionality:
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//! - [`DynVec::push_unsize`]
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//! - [`DynVec::unsize`]
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//! - [`DynVec::extend_unsize`]
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//!
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//! In addition, the `"unstable"` feature also enables dependence on the following nightly features
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//! in order to conform to [strict provenance](https://github.com/rust-lang/rust/issues/95228):
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//! - [`#![feature(set_ptr_value)]`](https://github.com/rust-lang/rust/issues/75091)
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//! - [`#![feature(pointer_byte_offsets)]`](https://github.com/rust-lang/rust/issues/96283)
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//!
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//! # Data Layout
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//!
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//! ```text
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//! DynVec<T>
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//! ┌────┬────┬────┬────┐
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//! │ptr │len │cap │end │
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//! └─┬──┴────┴─┬──┴─┬──┘
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//! │ │ │
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//! │ └────┼───────────────────────────────────────────────┐
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//! ┌─┘ └───────────────────┐ │
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//! │ │ │
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//! ▼ ▼ ▼
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//! ┌────┬────┬─────┬──────────┬───┬─────┬───────────────┬───┬───┬───┐
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//! │pad │elem│pad │elem │pad│elem │ │ptr│ptr│ptr│
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//! └────┴────┴─────┴──────────┴───┴─────┴───────────────┴─┬─┴─┬─┴─┬─┘
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//! ▲ ▲ ▲ ▲ │ │ │ ▲
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//! │ │ │ └───────────────────────┘ │ │ │
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//! │ │ └──────────────────────────────────────────┘ │ │
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//! │ └─────────────────────────────────────────────────────────┘ │
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//! │ │
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//! └─────────────── aligned to align_of::<*const T>() ──────────────┘
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//! ```
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//!
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//! [`DynVec<T: ?Sized>`]: DynVec
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//! [`DynVec::push_unsize`]: DynVec::push_unsize
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//! [`DynVec::unsize`]: DynVec::unsize
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//! [`DynVec::extend_unsize`]: DynVec::extend_unsize
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//! [`push_box`]: DynVec::push_box
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//! [`push_unsize`]: DynVec::push_unsize
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//! [`push_unsize_stable`]: DynVec::push_unsize_stable
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//! [`unsize`]: DynVec::unsize
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//! [`unsize_stable`]: DynVec::unsize_stable
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#![cfg_attr(
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feature = "unstable",
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feature(coerce_unsized),
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feature(set_ptr_value),
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feature(pointer_byte_offsets)
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)]
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#![cfg_attr(doc, feature(doc_cfg))]
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#![warn(missing_docs)]
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#![warn(clippy::pedantic)]
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#![warn(clippy::nursery)]
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#![allow(clippy::must_use_candidate)]
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#![allow(unstable_name_collisions)]
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#![cfg_attr(test, feature(test))]
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#[cfg(test)]
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mod bench;
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#[cfg(test)]
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mod test;
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mod impls;
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mod iter;
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mod ptr_ext;
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use ptr_ext::{ConstPtrExt, MutPtrExt, PtrExt};
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pub use iter::*;
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use core::panic;
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use std::{
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alloc::{alloc, dealloc, handle_alloc_error, Layout},
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any::Any,
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marker::PhantomData,
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mem::{self, align_of, align_of_val, size_of, size_of_val, ManuallyDrop},
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ops::{Index, IndexMut},
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ptr::{drop_in_place, NonNull},
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slice,
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};
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#[cfg(any(doc, feature = "unstable"))]
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use std::ops::CoerceUnsized;
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type Coercer<T, U> = for<'a> fn(&'a T) -> &'a U;
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/// A heap allocated, dynamic length collection of `?Sized` elements.
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///
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/// See [`std::vec::Vec`] (the standard library `Vec` type) for more information.
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pub struct DynVec<T: ?Sized> {
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ptr: NonNull<u8>,
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len: usize,
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capacity: usize,
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end_ptr: NonNull<u8>,
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_phantom: PhantomData<T>,
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}
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/// The extra data stored at the end of the allocation.
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type Extra<T> = *const T;
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impl<T: ?Sized> DynVec<T> {
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/// Creates a new, empty vector.
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pub const fn new() -> Self {
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let ptr = NonNull::dangling();
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Self {
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ptr,
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len: 0,
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capacity: 0,
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end_ptr: ptr,
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_phantom: PhantomData,
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}
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}
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/// Creates a new vector that holds `len` copies of `v`.
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///
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/// Only avaliable when `T: Sized`.
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pub fn from_elem(v: T, len: usize) -> Self
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where
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T: Sized + Clone,
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{
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let mut vec = Self::with_capacity(len);
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for _ in 0..len {
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vec.push(v.clone());
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}
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vec
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}
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/// Creates a new vector that can hold the given amount of `T`s.
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///
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/// Only avaliable when `T: Sized`.
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pub fn with_capacity(cap: usize) -> Self
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where
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T: Sized,
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{
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Self::with_capacity_for::<T>(cap)
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}
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/// Creates a new vector with the given capacity, measured in bytes.
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pub fn with_capacity_bytes(cap: usize) -> Self {
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let mut vec = Self::new();
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unsafe {
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vec.realloc(cap);
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}
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vec
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}
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/// Creates a new vector with enough capacity to hold the given amount of `U`s.
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pub fn with_capacity_for<U>(cap: usize) -> Self {
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Self::with_capacity_bytes(cap * (size_of::<U>() + size_of::<Extra<U>>()))
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}
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/// Decomposes the vector into its raw components.
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///
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/// Returns the pointer to the underlying alloctaion, the number of elements,
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/// the size of the allocation in bytes, and the total size of all of the
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/// vector's elements.
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pub fn into_raw_parts(self) -> (*mut u8, usize, usize, usize) {
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let mut this = ManuallyDrop::new(self);
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(
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this.as_mut_ptr(),
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this.len(),
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this.capacity(),
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this.data_size(),
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)
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}
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/// Reconstructs a vector from its raw components.
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///
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/// # Safety
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/// - `ptr` must be non-null and point to an allocation with the proper
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/// data layout, as documented in the crate-level docs.
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/// - `len` must be less than or equal to the number of initialized
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/// elements in the allocation.
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/// - `capacity` must be equal to the size of the allocation in bytes.
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/// - `data_size` must be equal to the number of bytes taken up by the
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/// first `len` elements of the vector, including leading (but not trailing)
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/// padding.
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/// - The allocation must have been allocated with alignment equal to
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/// `align_of::<*const T>()`
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///
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/// All of these conditions are upheld by the values returned from
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/// `into_raw_parts`.
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pub const unsafe fn from_raw_parts(
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ptr: *mut u8,
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len: usize,
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capacity: usize,
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data_size: usize,
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) -> Self {
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Self {
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ptr: NonNull::new_unchecked(ptr),
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len,
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capacity,
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end_ptr: NonNull::new_unchecked(ptr.add(data_size)),
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_phantom: PhantomData,
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}
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}
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/// Appends an element to the end of the vector.
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///
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/// Only avaliable if `T: Sized`.
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pub fn push(&mut self, v: T)
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where
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T: Sized,
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{
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unsafe { self.push_raw(&*ManuallyDrop::new(v)) }
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}
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/// Appends a (possibly unsized) boxed element to the end of the vector.
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pub fn push_box(&mut self, v: Box<T>) {
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let ptr = Box::into_raw(v);
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unsafe {
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let layout = Layout::for_value(&*ptr); // ref it *before* its logically uninit
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self.push_raw(ptr);
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dealloc(ptr.cast(), layout);
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}
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}
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/// Appends a sized element of type `U` to the end of the vector, given that it can be `CoerceUnsized` to a `T`.
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#[cfg(any(doc, feature = "unstable"))]
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#[cfg_attr(doc, doc(cfg(feature = "unstable")))]
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pub fn push_unsize<U>(&mut self, v: U)
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where
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for<'a> &'a U: CoerceUnsized<&'a T>,
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{
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// TODO: maybe make this not call the stable version for perf?
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self.push_unsize_stable(v, |v| v as _);
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}
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/// Appends a sized element of type `U` to the end of the vector, given that it can be `CoerceUnsized` to a `T`.
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///
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/// The coercion is done through a closure, since `CoerceUnsized` is unstable. Usually you can pass `|v| v as _`.
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pub fn push_unsize_stable<U>(&mut self, v: U, coercer: Coercer<U, T>) {
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let v_unsized: &T = coercer(&v);
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unsafe { self.push_raw(v_unsized) };
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mem::forget(v);
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}
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unsafe fn push_raw(&mut self, v: *const T) {
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if !self.will_fit(&*v) {
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let new_alloc_size = self.capacity * 2 + size_of_val(&*v) * 2 + size_of::<Extra<T>>();
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self.realloc(new_alloc_size);
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}
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self.push_raw_unchecked(v);
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}
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/// Given an element, returns a pointer to where it would be written if it was pushed, assuming no reallocation is needed.
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///
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/// The pointer will be aligned, but writing to it may overwrite data belonging to the vector.
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/// To check for this, call `will_fit`.
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/// In addition, the extra data for the element must be set using `set_extra_from_ptr`.
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fn get_next_elem_ptr(&self, v: &T) -> *mut u8 {
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self.end_ptr.as_ptr().align_up(align_of_val(v))
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}
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/// Checks if a given element will fit in the vector without reallocations.
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pub fn will_fit(&self, v: &T) -> bool {
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let remaining_space = self.get_ptr_to_extra(self.len).addr() - self.end_ptr.as_ptr().addr();
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let needed_space = size_of_val(v) + size_of::<Extra<T>>();
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remaining_space >= needed_space
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}
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unsafe fn push_raw_unchecked(&mut self, v: *const T) {
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let dest = self.get_next_elem_ptr(&*v).with_meta_from(v);
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v.copy_val_to(dest);
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self.set_extra_from_ptr(self.len, dest);
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self.end_ptr = NonNull::new_unchecked(dest.get_end().cast());
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self.len += 1;
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}
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/// Pops an element off the end of the vector, putting it in a [`Box`].
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pub fn pop(&mut self) -> Option<Box<T>> {
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unsafe {
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self.len = self.len.checked_sub(1)?;
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let el = self.get_ptr(self.len);
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Some(el.read_to_box())
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}
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}
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unsafe fn realloc(&mut self, size: usize) {
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let layout = Layout::from_size_align_unchecked(size, align_of::<Extra<T>>()).pad_to_align();
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let new_alloc = NonNull::new(alloc(layout)).unwrap_or_else(|| handle_alloc_error(layout));
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if self.capacity == 0 {
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// will panic if OOM
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self.ptr = new_alloc;
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self.end_ptr = self.ptr;
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} else {
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// cannot use mem::realloc here
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// data
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let mut ptr = new_alloc.as_ptr();
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for i in 0..self.len {
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let v = self.get_ptr(i);
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ptr = ptr.align_up(align_of_val(&*v));
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v.copy_val_to(ptr);
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self.set_extra_from_ptr(i, ptr.with_meta_from(v));
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ptr = ptr.wrapping_add(size_of_val(&*v));
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}
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self.end_ptr = NonNull::new_unchecked(ptr);
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// extra
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let extra_src = self.get_ptr_to_extra(self.len);
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let extra_dst = {
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let current_alloc_end = self.ptr.as_ptr().wrapping_add(self.capacity);
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let new_alloc_end = new_alloc.as_ptr().wrapping_add(layout.size());
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let extra_len = current_alloc_end.addr() - extra_src.addr();
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new_alloc_end.wrapping_sub(extra_len)
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};
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extra_src.copy_to(extra_dst.cast(), self.len);
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dealloc(
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self.ptr.as_ptr(),
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Layout::from_size_align_unchecked(self.capacity, 8),
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);
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self.ptr = new_alloc;
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}
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self.capacity = layout.size();
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}
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/// for internal use
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///
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/// # Note: 1-indexed, to allow getting a pointer to the end of the alloc easily
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fn get_ptr_to_extra(&self, index: usize) -> *mut Extra<T> {
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self.ptr
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.as_ptr()
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.add_bytes(self.capacity)
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.cast::<Extra<T>>()
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.wrapping_sub(index)
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}
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unsafe fn set_extra_from_ptr(&self, index: usize, ptr: *const T) {
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self.get_ptr_to_extra(index + 1).write(ptr);
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}
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unsafe fn get_ptr(&self, index: usize) -> *const T {
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*self.get_ptr_to_extra(index + 1)
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}
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unsafe fn get_ptr_before_pad(&self, index: usize) -> *const T {
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self.get_ptr(index).with_addr_from(if index > 0 {
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self.get_ptr(index - 1).get_end().cast()
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} else {
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self.ptr.as_ptr()
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})
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}
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/// Gets a reference to the element at the specified index.
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///
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/// Returns `None` if the index is out-of-bounds.
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pub fn get(&self, index: usize) -> Option<&T> {
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if index < self.len {
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Some(unsafe { self.get_unchecked(index) })
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} else {
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None
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}
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}
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/// Gets a reference to the element at the specified index.
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///
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/// # Safety
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///
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/// Immediate UB if the index is out-of-bounds.
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pub unsafe fn get_unchecked(&self, index: usize) -> &T {
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&*self.get_ptr(index)
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}
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/// Gets a mutable reference to the element at the specified index.
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///
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/// Returns `None` if the index is out-of-bounds.
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pub fn get_mut(&mut self, index: usize) -> Option<&mut T> {
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if index < self.len {
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Some(unsafe { self.get_unchecked_mut(index) })
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} else {
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None
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}
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}
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|
|
|
/// Gets a mutable reference to the element at the specified index.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// Immediate UB if the index is out-of-bounds.
|
|
pub unsafe fn get_unchecked_mut(&mut self, index: usize) -> &mut T {
|
|
&mut *(self.get_ptr(index) as *mut _)
|
|
}
|
|
|
|
/// Returns the length of the vector, which is how many items it contains.
|
|
pub const fn len(&self) -> usize {
|
|
self.len
|
|
}
|
|
|
|
/// Returns `true` if the vector holds no elements.
|
|
pub const fn is_empty(&self) -> bool {
|
|
self.len == 0
|
|
}
|
|
|
|
/// Returns the capacity, which is the size of the allocation in bytes.
|
|
///
|
|
/// Note the distinction from [`std::vec::Vec::capacity`], which returns how many *elements* it can hold.
|
|
pub const fn capacity(&self) -> usize {
|
|
self.capacity
|
|
}
|
|
|
|
/// Returns a pointer to the allocation of the vector.
|
|
pub const fn as_ptr(&self) -> *const u8 {
|
|
self.ptr.as_ptr()
|
|
}
|
|
|
|
/// Returns a mutable pointer to the allocation of the vector.
|
|
pub fn as_mut_ptr(&mut self) -> *mut u8 {
|
|
self.ptr.as_ptr()
|
|
}
|
|
|
|
/// Returns a pointer to the end of the last element of the vector.
|
|
pub const fn as_end_ptr(&self) -> *const u8 {
|
|
self.end_ptr.as_ptr()
|
|
}
|
|
|
|
/// Returns a mutable pointer to the end of the last element of the vector.
|
|
pub fn as_end_ptr_mut(&mut self) -> *mut u8 {
|
|
self.end_ptr.as_ptr()
|
|
}
|
|
|
|
/// Returns the size (in bytes) of the elements (and padding) of the vector.
|
|
///
|
|
/// Same as `self.as_end_ptr() as usize - self.as_ptr() as usize`.
|
|
pub fn data_size(&self) -> usize {
|
|
self.as_end_ptr() as usize - self.as_ptr() as usize
|
|
}
|
|
|
|
/// Converts a `DynVec<T: Sized>` into a `DynVec<U: ?Sized>`, given that `T` can be `CoerceUnsized` into `U`.
|
|
#[cfg(any(doc, feature = "unstable"))]
|
|
#[cfg_attr(doc, doc(cfg(feature = "unstable")))]
|
|
pub fn unsize<U: ?Sized>(self) -> DynVec<U>
|
|
where
|
|
for<'a> &'a T: CoerceUnsized<&'a U>,
|
|
{
|
|
// TODO: maybe make this not call the stable version for perf?
|
|
self.unsize_stable(|v| v as _)
|
|
}
|
|
|
|
/// Converts a `DynVec<T: Sized>` into a `DynVec<U: ?Sized>`, given that `T` can be `CoerceUnsized` into `U`.
|
|
///
|
|
/// The coercion is done through a closure, since `CoerceUnsized` is unstable. Usually you can pass `|v| v as _`.
|
|
pub fn unsize_stable<U: ?Sized>(mut self, coercer: Coercer<T, U>) -> DynVec<U> {
|
|
if size_of::<Extra<U>>() > size_of::<Extra<T>>() {
|
|
let elem_size = self.end_ptr.as_ptr().addr() - self.ptr.as_ptr().addr();
|
|
let extra_size = self.len * size_of::<Extra<U>>();
|
|
let needed_size = elem_size + extra_size;
|
|
if needed_size > self.capacity {
|
|
unsafe {
|
|
self.realloc(needed_size);
|
|
}
|
|
}
|
|
}
|
|
|
|
let new_vec = DynVec::<U> {
|
|
ptr: self.ptr,
|
|
len: self.len,
|
|
capacity: self.capacity,
|
|
end_ptr: self.end_ptr,
|
|
_phantom: PhantomData,
|
|
};
|
|
|
|
if size_of::<Extra<U>>() > size_of::<Extra<T>>() {
|
|
// new extra larger than old extra, must go from back to front
|
|
|
|
for i in (0..self.len).rev() {
|
|
// using references here is necessary for unsizing coercion to work
|
|
let current = unsafe { &*self.get_ptr(i) };
|
|
unsafe { new_vec.set_extra_from_ptr(i, coercer(current)) }
|
|
}
|
|
} else {
|
|
// new extra smaller or same size as old extra, must go from front to back
|
|
|
|
for i in 0..self.len {
|
|
// using references here is necessary for unsizing coercion to work
|
|
let current = unsafe { &*self.get_ptr(i) };
|
|
unsafe { new_vec.set_extra_from_ptr(i, coercer(current)) }
|
|
}
|
|
}
|
|
|
|
mem::forget(self);
|
|
new_vec
|
|
}
|
|
|
|
unsafe fn dealloc(&self) {
|
|
if self.capacity != 0 {
|
|
dealloc(
|
|
self.ptr.as_ptr(),
|
|
Layout::from_size_align_unchecked(self.capacity, align_of::<Extra<T>>()),
|
|
);
|
|
}
|
|
}
|
|
|
|
/// Extends this vector with an iterator.
|
|
///
|
|
/// Similar to [`Extend::extend`], but seperate to prevent conflicting implementations.
|
|
#[cfg(any(doc, feature = "unstable"))]
|
|
#[cfg_attr(doc, doc(cfg(feature = "unstable")))]
|
|
pub fn extend_unsize<U, I: IntoIterator<Item = U>>(&mut self, iter: I)
|
|
where
|
|
for<'a> &'a U: CoerceUnsized<&'a T>,
|
|
{
|
|
// TODO: maybe make this not call the stable version for perf?
|
|
self.extend_unsize_stable(iter, |v| v as _);
|
|
}
|
|
|
|
/// Extends this vector with an iterator.
|
|
///
|
|
/// Similar to [`Extend::extend`], but seperate to prevent conflicting implementations.
|
|
///
|
|
/// The coercion is done through a closure, since `CoerceUnsized` is unstable. Usually you can pass `|v| v as _`.
|
|
pub fn extend_unsize_stable<U, I: IntoIterator<Item = U>>(
|
|
&mut self,
|
|
iter: I,
|
|
coercer: Coercer<U, T>,
|
|
) {
|
|
for item in iter {
|
|
self.push_unsize_stable(item, coercer);
|
|
}
|
|
}
|
|
|
|
/// Removes the element at the specified index, shifting other elements over to fill the gap.
|
|
pub fn remove(&mut self, index: usize) -> Option<Box<T>> {
|
|
if index >= self.len {
|
|
return None;
|
|
}
|
|
|
|
if index == self.len - 1 {
|
|
return self.pop();
|
|
}
|
|
|
|
unsafe {
|
|
let res = Some(self.get_ptr(index).read_to_box());
|
|
|
|
// starting from the now-empty spot, up to but not including the end...
|
|
for index in index..self.len - 1 {
|
|
// get a pointer to the end of the previous element
|
|
let mut new_ptr = self.get_ptr_before_pad(index);
|
|
// align it up to the align of the NEXT element
|
|
let next_ptr = self.get_ptr(index + 1);
|
|
new_ptr = new_ptr.align_up(align_of_val(&*next_ptr));
|
|
|
|
// if its the same, we can break as the rest will be useless
|
|
if new_ptr == next_ptr {
|
|
break;
|
|
}
|
|
|
|
// data
|
|
next_ptr.copy_val_to(new_ptr as *mut T);
|
|
|
|
// extra
|
|
self.set_extra_from_ptr(index, new_ptr.with_meta_from(next_ptr));
|
|
}
|
|
|
|
self.len -= 1;
|
|
|
|
res
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<T> DynVec<[T]> {
|
|
/// Returns a slice over all the elements in the vector.
|
|
///
|
|
/// Only avaliable for `DynVec<[T]>`.
|
|
pub fn as_slice_flatten(&self) -> &[T] {
|
|
if self.len == 0 {
|
|
return unsafe { slice::from_raw_parts(NonNull::dangling().as_ptr(), 0) };
|
|
}
|
|
|
|
// SAFETY: the slices should be contiguous by the logic of `push_raw_unchecked`
|
|
unsafe {
|
|
slice::from_raw_parts(self.get_ptr(0).data_ptr().cast(), {
|
|
let start = self.get_ptr(0).addr();
|
|
let end = self.end_ptr.as_ptr().addr();
|
|
debug_assert_eq!((end - start) % size_of::<T>(), 0);
|
|
(end - start) / size_of::<T>() // integer division!
|
|
})
|
|
}
|
|
}
|
|
|
|
/// Returns a mutable slice over all the elements in the vector.
|
|
///
|
|
/// Only avaliable for `DynVec<[T]>`.
|
|
pub fn as_mut_slice_flatten(&mut self) -> &mut [T] {
|
|
if self.len == 0 {
|
|
return unsafe { slice::from_raw_parts_mut(NonNull::dangling().as_ptr(), 0) };
|
|
}
|
|
|
|
// SAFETY: the slices should be contiguous by the logic of `push_raw_unchecked`
|
|
unsafe {
|
|
slice::from_raw_parts_mut(self.get_ptr(0).data_ptr() as _, {
|
|
let start = self.get_ptr(0).addr();
|
|
let end = self.end_ptr.as_ptr().addr();
|
|
debug_assert_eq!((end - start) % size_of::<T>(), 0);
|
|
(end - start) / size_of::<T>() // integer division!
|
|
})
|
|
}
|
|
}
|
|
}
|
|
|
|
impl DynVec<dyn Any> {
|
|
/// Gets a reference to the element at then specified index, downcasting it to the specified type.
|
|
///
|
|
/// Same as `self.get(index).map(|v| v.downcast()).flatten()`.
|
|
pub fn downcast_get<T: Any>(&self, index: usize) -> Option<&T> {
|
|
self.get(index)?.downcast_ref()
|
|
}
|
|
|
|
/// Gets a mutable reference to the element at then specified index, downcasting it to the specified type.
|
|
///
|
|
/// Same as `self.get_mut(index).map(|v| v.downcast_mut()).flatten()`.
|
|
pub fn downcast_get_mut<T: Any>(&mut self, index: usize) -> Option<&mut T> {
|
|
self.get_mut(index)?.downcast_mut()
|
|
}
|
|
|
|
/// Pops an element off the end of the vector, downcasting it to the specified type.
|
|
///
|
|
/// If the element is not of type `T`, the element will not be popped.
|
|
///
|
|
/// Same as `self.pop().map(|v| v.downcast()).flatten()`, but without an intermediate allocation.
|
|
pub fn downcast_pop<T: Any>(&mut self) -> Option<T> {
|
|
unsafe {
|
|
let el = self.get_unchecked_mut(self.len.checked_sub(1)?);
|
|
let v = Some((el.downcast_mut()? as *mut T).read());
|
|
self.len -= 1;
|
|
v
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<T: ?Sized> Drop for DynVec<T> {
|
|
fn drop(&mut self) {
|
|
unsafe {
|
|
for el in self.iter_mut() {
|
|
drop_in_place(el);
|
|
}
|
|
|
|
self.dealloc();
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<T: ?Sized> Index<usize> for DynVec<T> {
|
|
type Output = T;
|
|
|
|
#[track_caller]
|
|
fn index(&self, index: usize) -> &Self::Output {
|
|
self.get(index).unwrap_or_else(|| {
|
|
panic!(
|
|
"index out of bounds: the len is {} but the index is {}",
|
|
self.len, index
|
|
)
|
|
})
|
|
}
|
|
}
|
|
|
|
impl<T: ?Sized> IndexMut<usize> for DynVec<T> {
|
|
#[track_caller]
|
|
fn index_mut(&mut self, index: usize) -> &mut Self::Output {
|
|
let len = self.len;
|
|
self.get_mut(index).unwrap_or_else(|| {
|
|
panic!(
|
|
"index out of bounds: the len is {} but the index is {}",
|
|
len, index
|
|
)
|
|
})
|
|
}
|
|
}
|
|
|
|
/// Creates a [`DynVec`].
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// # use dyn_vec::{dyn_vec, DynVec};
|
|
/// # use std::fmt::Debug;
|
|
/// let vec1: DynVec<i32> = dyn_vec![1, 2, 3];
|
|
/// let vec2: DynVec<dyn Debug> = dyn_vec![box:
|
|
/// Box::new(1) as _,
|
|
/// Box::new(String::from("foo")) as _,
|
|
/// Box::new(true) as _
|
|
/// ];
|
|
/// let vec3: DynVec<dyn Debug> = dyn_vec![unsized: 1, String::from("foo"), true];
|
|
/// ```
|
|
#[macro_export]
|
|
macro_rules! dyn_vec {
|
|
() => {
|
|
$crate::DynVec::new();
|
|
};
|
|
(box: $($elem:expr),+ $(,)?) => {{
|
|
let mut vec = $crate::DynVec::new();
|
|
$(vec.push_box($elem);)+
|
|
vec
|
|
}};
|
|
(unsized: $($elem:expr),+ $(,)?) => {{
|
|
let mut vec = $crate::DynVec::new();
|
|
// TODO: when stuff stabilizes change this
|
|
$(vec.push_unsize_stable($elem, |v| v as _);)+
|
|
vec
|
|
}};
|
|
($elem:expr; $n:expr) => {
|
|
$crate::DynVec::from_elem($elem, $n)
|
|
};
|
|
($($elem:expr),+ $(,)?) => {{
|
|
let mut vec = $crate::DynVec::new();
|
|
$(vec.push($elem);)+
|
|
vec
|
|
}};
|
|
}
|