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772e80a650
rust/library/alloc/tests/vec.rs
Matthias Krüger 772e80a650
Rollup merge of #119917 - Zalathar:split-off, r=cuviper 
Remove special-case handling of `vec.split_off(0)`

#76682 added special handling to `Vec::split_off` for the case where `at == 0`. Instead of copying the vector's contents into a freshly-allocated vector and returning it, the special-case code steals the old vector's allocation, and replaces it with a new (empty) buffer with the same capacity.

That eliminates the need to copy the existing elements, but comes at a surprising cost, as seen in #119913. The returned vector's capacity is no longer determined by the size of its contents (as would be expected for a freshly-allocated vector), and instead uses the full capacity of the old vector.

In cases where the capacity is large but the size is small, that results in a much larger capacity than would be expected from reading the documentation of `split_off`. This is especially bad when `split_off` is called in a loop (to recycle a buffer), and the returned vectors have a wide variety of lengths.

I believe it's better to remove the special-case code, and treat `at == 0` just like any other value:
- The current documentation states that `split_off` returns a “newly allocated vector”, which is not actually true in the current implementation when `at == 0`.
- If the value of `at` could be non-zero at runtime, then the caller has already agreed to the cost of a full memcpy of the taken elements in the general case. Avoiding that copy would be nice if it were close to free, but the different handling of capacity means that it is not.
- If the caller specifically wants to avoid copying in the case where `at == 0`, they can easily implement that behaviour themselves using `mem::replace`.

Fixes #119913.
2024-01-26 14:43:30 +01:00

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use core::alloc::{Allocator, Layout};
use core::num::NonZeroUsize;
use core::ptr::NonNull;
use core::{assert_eq, assert_ne};
use std::alloc::System;
use std::assert_matches::assert_matches;
use std::borrow::Cow;
use std::cell::Cell;
use std::collections::TryReserveErrorKind::*;
use std::fmt::Debug;
use std::hint;
use std::iter::InPlaceIterable;
use std::mem;
use std::mem::{size_of, swap};
use std::ops::Bound::*;
use std::panic::{catch_unwind, AssertUnwindSafe};
use std::rc::Rc;
use std::sync::atomic::{AtomicU32, Ordering};
use std::vec::{Drain, IntoIter};
struct DropCounter<'a> {
count: &'a mut u32,
}
impl Drop for DropCounter<'_> {
fn drop(&mut self) {
*self.count += 1;
}
}
#[test]
fn test_small_vec_struct() {
assert_eq!(size_of::<Vec<u8>>(), size_of::<usize>() * 3);
}
#[test]
fn test_double_drop() {
struct TwoVec<T> {
x: Vec<T>,
y: Vec<T>,
}
let (mut count_x, mut count_y) = (0, 0);
{
let mut tv = TwoVec { x: Vec::new(), y: Vec::new() };
tv.x.push(DropCounter { count: &mut count_x });
tv.y.push(DropCounter { count: &mut count_y });
// If Vec had a drop flag, here is where it would be zeroed.
// Instead, it should rely on its internal state to prevent
// doing anything significant when dropped multiple times.
drop(tv.x);
// Here tv goes out of scope, tv.y should be dropped, but not tv.x.
}
assert_eq!(count_x, 1);
assert_eq!(count_y, 1);
}
#[test]
fn test_reserve() {
let mut v = Vec::new();
assert_eq!(v.capacity(), 0);
v.reserve(2);
assert!(v.capacity() >= 2);
for i in 0..16 {
v.push(i);
}
assert!(v.capacity() >= 16);
v.reserve(16);
assert!(v.capacity() >= 32);
v.push(16);
v.reserve(16);
assert!(v.capacity() >= 33)
}
#[test]
fn test_zst_capacity() {
assert_eq!(Vec::<()>::new().capacity(), usize::MAX);
}
#[test]
fn test_indexing() {
let v: Vec<isize> = vec![10, 20];
assert_eq!(v[0], 10);
assert_eq!(v[1], 20);
let mut x: usize = 0;
assert_eq!(v[x], 10);
assert_eq!(v[x + 1], 20);
x = x + 1;
assert_eq!(v[x], 20);
assert_eq!(v[x - 1], 10);
}
#[test]
fn test_debug_fmt() {
let vec1: Vec<isize> = vec![];
assert_eq!("[]", format!("{:?}", vec1));
let vec2 = vec![0, 1];
assert_eq!("[0, 1]", format!("{:?}", vec2));
let slice: &[isize] = &[4, 5];
assert_eq!("[4, 5]", format!("{slice:?}"));
}
#[test]
fn test_push() {
let mut v = vec![];
v.push(1);
assert_eq!(v, [1]);
v.push(2);
assert_eq!(v, [1, 2]);
v.push(3);
assert_eq!(v, [1, 2, 3]);
}
#[test]
fn test_extend() {
let mut v = Vec::new();
let mut w = Vec::new();
v.extend(w.clone());
assert_eq!(v, &[]);
v.extend(0..3);
for i in 0..3 {
w.push(i)
}
assert_eq!(v, w);
v.extend(3..10);
for i in 3..10 {
w.push(i)
}
assert_eq!(v, w);
v.extend(w.clone()); // specializes to `append`
assert!(v.iter().eq(w.iter().chain(w.iter())));
// Zero sized types
#[derive(PartialEq, Debug)]
struct Foo;
let mut a = Vec::new();
let b = vec![Foo, Foo];
a.extend(b);
assert_eq!(a, &[Foo, Foo]);
// Double drop
let mut count_x = 0;
{
let mut x = Vec::new();
let y = vec![DropCounter { count: &mut count_x }];
x.extend(y);
}
assert_eq!(count_x, 1);
}
#[test]
fn test_extend_from_slice() {
let a: Vec<isize> = vec![1, 2, 3, 4, 5];
let b: Vec<isize> = vec![6, 7, 8, 9, 0];
let mut v: Vec<isize> = a;
v.extend_from_slice(&b);
assert_eq!(v, [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]);
}
#[test]
fn test_extend_ref() {
let mut v = vec![1, 2];
v.extend(&[3, 4, 5]);
assert_eq!(v.len(), 5);
assert_eq!(v, [1, 2, 3, 4, 5]);
let w = vec![6, 7];
v.extend(&w);
assert_eq!(v.len(), 7);
assert_eq!(v, [1, 2, 3, 4, 5, 6, 7]);
}
#[test]
fn test_slice_from_ref() {
let values = vec![1, 2, 3, 4, 5];
let slice = &values[1..3];
assert_eq!(slice, [2, 3]);
}
#[test]
fn test_slice_from_mut() {
let mut values = vec![1, 2, 3, 4, 5];
{
let slice = &mut values[2..];
assert!(slice == [3, 4, 5]);
for p in slice {
*p += 2;
}
}
assert!(values == [1, 2, 5, 6, 7]);
}
#[test]
fn test_slice_to_mut() {
let mut values = vec![1, 2, 3, 4, 5];
{
let slice = &mut values[..2];
assert!(slice == [1, 2]);
for p in slice {
*p += 1;
}
}
assert!(values == [2, 3, 3, 4, 5]);
}
#[test]
fn test_split_at_mut() {
let mut values = vec![1, 2, 3, 4, 5];
{
let (left, right) = values.split_at_mut(2);
{
let left: &[_] = left;
assert!(&left[..left.len()] == &[1, 2]);
}
for p in left {
*p += 1;
}
{
let right: &[_] = right;
assert!(&right[..right.len()] == &[3, 4, 5]);
}
for p in right {
*p += 2;
}
}
assert_eq!(values, [2, 3, 5, 6, 7]);
}
#[test]
fn test_clone() {
let v: Vec<i32> = vec![];
let w = vec![1, 2, 3];
assert_eq!(v, v.clone());
let z = w.clone();
assert_eq!(w, z);
// they should be disjoint in memory.
assert!(w.as_ptr() != z.as_ptr())
}
#[test]
fn test_clone_from() {
let mut v = vec![];
let three: Vec<Box<_>> = vec![Box::new(1), Box::new(2), Box::new(3)];
let two: Vec<Box<_>> = vec![Box::new(4), Box::new(5)];
// zero, long
v.clone_from(&three);
assert_eq!(v, three);
// equal
v.clone_from(&three);
assert_eq!(v, three);
// long, short
v.clone_from(&two);
assert_eq!(v, two);
// short, long
v.clone_from(&three);
assert_eq!(v, three)
}
#[test]
fn test_retain() {
let mut vec = vec![1, 2, 3, 4];
vec.retain(|&x| x % 2 == 0);
assert_eq!(vec, [2, 4]);
}
#[test]
fn test_retain_predicate_order() {
for to_keep in [true, false] {
let mut number_of_executions = 0;
let mut vec = vec![1, 2, 3, 4];
let mut next_expected = 1;
vec.retain(|&x| {
assert_eq!(next_expected, x);
next_expected += 1;
number_of_executions += 1;
to_keep
});
assert_eq!(number_of_executions, 4);
}
}
#[test]
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
fn test_retain_pred_panic_with_hole() {
let v = (0..5).map(Rc::new).collect::<Vec<_>>();
catch_unwind(AssertUnwindSafe(|| {
let mut v = v.clone();
v.retain(|r| match **r {
0 => true,
1 => false,
2 => true,
_ => panic!(),
});
}))
.unwrap_err();
// Everything is dropped when predicate panicked.
assert!(v.iter().all(|r| Rc::strong_count(r) == 1));
}
#[test]
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
fn test_retain_pred_panic_no_hole() {
let v = (0..5).map(Rc::new).collect::<Vec<_>>();
catch_unwind(AssertUnwindSafe(|| {
let mut v = v.clone();
v.retain(|r| match **r {
0 | 1 | 2 => true,
_ => panic!(),
});
}))
.unwrap_err();
// Everything is dropped when predicate panicked.
assert!(v.iter().all(|r| Rc::strong_count(r) == 1));
}
#[test]
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
fn test_retain_drop_panic() {
struct Wrap(Rc<i32>);
impl Drop for Wrap {
fn drop(&mut self) {
if *self.0 == 3 {
panic!();
}
}
}
let v = (0..5).map(|x| Rc::new(x)).collect::<Vec<_>>();
catch_unwind(AssertUnwindSafe(|| {
let mut v = v.iter().map(|r| Wrap(r.clone())).collect::<Vec<_>>();
v.retain(|w| match *w.0 {
0 => true,
1 => false,
2 => true,
3 => false, // Drop panic.
_ => true,
});
}))
.unwrap_err();
// Other elements are dropped when `drop` of one element panicked.
// The panicked wrapper also has its Rc dropped.
assert!(v.iter().all(|r| Rc::strong_count(r) == 1));
}
#[test]
fn test_retain_maybeuninits() {
// This test aimed to be run under miri.
use core::mem::MaybeUninit;
let mut vec: Vec<_> = [1i32, 2, 3, 4].map(|v| MaybeUninit::new(vec![v])).into();
vec.retain(|x| {
// SAFETY: Retain must visit every element of Vec in original order and exactly once.
// Our values is initialized at creation of Vec.
let v = unsafe { x.assume_init_ref()[0] };
if v & 1 == 0 {
return true;
}
// SAFETY: Value is initialized.
// Value wouldn't be dropped by `Vec::retain`
// because `MaybeUninit` doesn't drop content.
drop(unsafe { x.assume_init_read() });
false
});
let vec: Vec<i32> = vec
.into_iter()
.map(|x| unsafe {
// SAFETY: All values dropped in retain predicate must be removed by `Vec::retain`.
// Remaining values are initialized.
x.assume_init()[0]
})
.collect();
assert_eq!(vec, [2, 4]);
}
#[test]
fn test_dedup() {
fn case(a: Vec<i32>, b: Vec<i32>) {
let mut v = a;
v.dedup();
assert_eq!(v, b);
}
case(vec![], vec![]);
case(vec![1], vec![1]);
case(vec![1, 1], vec![1]);
case(vec![1, 2, 3], vec![1, 2, 3]);
case(vec![1, 1, 2, 3], vec![1, 2, 3]);
case(vec![1, 2, 2, 3], vec![1, 2, 3]);
case(vec![1, 2, 3, 3], vec![1, 2, 3]);
case(vec![1, 1, 2, 2, 2, 3, 3], vec![1, 2, 3]);
}
#[test]
fn test_dedup_by_key() {
fn case(a: Vec<i32>, b: Vec<i32>) {
let mut v = a;
v.dedup_by_key(|i| *i / 10);
assert_eq!(v, b);
}
case(vec![], vec![]);
case(vec![10], vec![10]);
case(vec![10, 11], vec![10]);
case(vec![10, 20, 30], vec![10, 20, 30]);
case(vec![10, 11, 20, 30], vec![10, 20, 30]);
case(vec![10, 20, 21, 30], vec![10, 20, 30]);
case(vec![10, 20, 30, 31], vec![10, 20, 30]);
case(vec![10, 11, 20, 21, 22, 30, 31], vec![10, 20, 30]);
}
#[test]
fn test_dedup_by() {
let mut vec = vec!["foo", "bar", "Bar", "baz", "bar"];
vec.dedup_by(|a, b| a.eq_ignore_ascii_case(b));
assert_eq!(vec, ["foo", "bar", "baz", "bar"]);
let mut vec = vec![("foo", 1), ("foo", 2), ("bar", 3), ("bar", 4), ("bar", 5)];
vec.dedup_by(|a, b| {
a.0 == b.0 && {
b.1 += a.1;
true
}
});
assert_eq!(vec, [("foo", 3), ("bar", 12)]);
}
#[test]
fn test_dedup_unique() {
let mut v0: Vec<Box<_>> = vec![Box::new(1), Box::new(1), Box::new(2), Box::new(3)];
v0.dedup();
let mut v1: Vec<Box<_>> = vec![Box::new(1), Box::new(2), Box::new(2), Box::new(3)];
v1.dedup();
let mut v2: Vec<Box<_>> = vec![Box::new(1), Box::new(2), Box::new(3), Box::new(3)];
v2.dedup();
// If the boxed pointers were leaked or otherwise misused, valgrind
// and/or rt should raise errors.
}
#[test]
fn zero_sized_values() {
let mut v = Vec::new();
assert_eq!(v.len(), 0);
v.push(());
assert_eq!(v.len(), 1);
v.push(());
assert_eq!(v.len(), 2);
assert_eq!(v.pop(), Some(()));
assert_eq!(v.pop(), Some(()));
assert_eq!(v.pop(), None);
assert_eq!(v.iter().count(), 0);
v.push(());
assert_eq!(v.iter().count(), 1);
v.push(());
assert_eq!(v.iter().count(), 2);
for &() in &v {}
assert_eq!(v.iter_mut().count(), 2);
v.push(());
assert_eq!(v.iter_mut().count(), 3);
v.push(());
assert_eq!(v.iter_mut().count(), 4);
for &mut () in &mut v {}
unsafe {
v.set_len(0);
}
assert_eq!(v.iter_mut().count(), 0);
}
#[test]
fn test_partition() {
assert_eq!([].into_iter().partition(|x: &i32| *x < 3), (vec![], vec![]));
assert_eq!([1, 2, 3].into_iter().partition(|x| *x < 4), (vec![1, 2, 3], vec![]));
assert_eq!([1, 2, 3].into_iter().partition(|x| *x < 2), (vec![1], vec![2, 3]));
assert_eq!([1, 2, 3].into_iter().partition(|x| *x < 0), (vec![], vec![1, 2, 3]));
}
#[test]
fn test_zip_unzip() {
let z1 = vec![(1, 4), (2, 5), (3, 6)];
let (left, right): (Vec<_>, Vec<_>) = z1.iter().cloned().unzip();
assert_eq!((1, 4), (left[0], right[0]));
assert_eq!((2, 5), (left[1], right[1]));
assert_eq!((3, 6), (left[2], right[2]));
}
#[test]
fn test_cmp() {
let x: &[isize] = &[1, 2, 3, 4, 5];
let cmp: &[isize] = &[1, 2, 3, 4, 5];
assert_eq!(&x[..], cmp);
let cmp: &[isize] = &[3, 4, 5];
assert_eq!(&x[2..], cmp);
let cmp: &[isize] = &[1, 2, 3];
assert_eq!(&x[..3], cmp);
let cmp: &[isize] = &[2, 3, 4];
assert_eq!(&x[1..4], cmp);
let x: Vec<isize> = vec![1, 2, 3, 4, 5];
let cmp: &[isize] = &[1, 2, 3, 4, 5];
assert_eq!(&x[..], cmp);
let cmp: &[isize] = &[3, 4, 5];
assert_eq!(&x[2..], cmp);
let cmp: &[isize] = &[1, 2, 3];
assert_eq!(&x[..3], cmp);
let cmp: &[isize] = &[2, 3, 4];
assert_eq!(&x[1..4], cmp);
}
#[test]
fn test_vec_truncate_drop() {
static mut DROPS: u32 = 0;
struct Elem(#[allow(dead_code)] i32);
impl Drop for Elem {
fn drop(&mut self) {
unsafe {
DROPS += 1;
}
}
}
let mut v = vec![Elem(1), Elem(2), Elem(3), Elem(4), Elem(5)];
assert_eq!(unsafe { DROPS }, 0);
v.truncate(3);
assert_eq!(unsafe { DROPS }, 2);
v.truncate(0);
assert_eq!(unsafe { DROPS }, 5);
}
#[test]
#[should_panic]
fn test_vec_truncate_fail() {
struct BadElem(i32);
impl Drop for BadElem {
fn drop(&mut self) {
let BadElem(ref mut x) = *self;
if *x == 0xbadbeef {
panic!("BadElem panic: 0xbadbeef")
}
}
}
let mut v = vec![BadElem(1), BadElem(2), BadElem(0xbadbeef), BadElem(4)];
v.truncate(0);
}
#[test]
fn test_index() {
let vec = vec![1, 2, 3];
assert!(vec[1] == 2);
}
#[test]
#[should_panic]
fn test_index_out_of_bounds() {
let vec = vec![1, 2, 3];
let _ = vec[3];
}
#[test]
#[should_panic]
fn test_slice_out_of_bounds_1() {
let x = vec![1, 2, 3, 4, 5];
let _ = &x[!0..];
}
#[test]
#[should_panic]
fn test_slice_out_of_bounds_2() {
let x = vec![1, 2, 3, 4, 5];
let _ = &x[..6];
}
#[test]
#[should_panic]
fn test_slice_out_of_bounds_3() {
let x = vec![1, 2, 3, 4, 5];
let _ = &x[!0..4];
}
#[test]
#[should_panic]
fn test_slice_out_of_bounds_4() {
let x = vec![1, 2, 3, 4, 5];
let _ = &x[1..6];
}
#[test]
#[should_panic]
fn test_slice_out_of_bounds_5() {
let x = vec![1, 2, 3, 4, 5];
let _ = &x[3..2];
}
#[test]
#[should_panic]
fn test_swap_remove_empty() {
let mut vec = Vec::<i32>::new();
vec.swap_remove(0);
}
#[test]
fn test_move_items() {
let vec = vec![1, 2, 3];
let mut vec2 = vec![];
for i in vec {
vec2.push(i);
}
assert_eq!(vec2, [1, 2, 3]);
}
#[test]
fn test_move_items_reverse() {
let vec = vec![1, 2, 3];
let mut vec2 = vec![];
for i in vec.into_iter().rev() {
vec2.push(i);
}
assert_eq!(vec2, [3, 2, 1]);
}
#[test]
fn test_move_items_zero_sized() {
let vec = vec![(), (), ()];
let mut vec2 = vec![];
for i in vec {
vec2.push(i);
}
assert_eq!(vec2, [(), (), ()]);
}
#[test]
fn test_drain_empty_vec() {
let mut vec: Vec<i32> = vec![];
let mut vec2: Vec<i32> = vec![];
for i in vec.drain(..) {
vec2.push(i);
}
assert!(vec.is_empty());
assert!(vec2.is_empty());
}
#[test]
fn test_drain_items() {
let mut vec = vec![1, 2, 3];
let mut vec2 = vec![];
for i in vec.drain(..) {
vec2.push(i);
}
assert_eq!(vec, []);
assert_eq!(vec2, [1, 2, 3]);
}
#[test]
fn test_drain_items_reverse() {
let mut vec = vec![1, 2, 3];
let mut vec2 = vec![];
for i in vec.drain(..).rev() {
vec2.push(i);
}
assert_eq!(vec, []);
assert_eq!(vec2, [3, 2, 1]);
}
#[test]
fn test_drain_items_zero_sized() {
let mut vec = vec![(), (), ()];
let mut vec2 = vec![];
for i in vec.drain(..) {
vec2.push(i);
}
assert_eq!(vec, []);
assert_eq!(vec2, [(), (), ()]);
}
#[test]
#[should_panic]
fn test_drain_out_of_bounds() {
let mut v = vec![1, 2, 3, 4, 5];
v.drain(5..6);
}
#[test]
fn test_drain_range() {
let mut v = vec![1, 2, 3, 4, 5];
for _ in v.drain(4..) {}
assert_eq!(v, &[1, 2, 3, 4]);
let mut v: Vec<_> = (1..6).map(|x| x.to_string()).collect();
for _ in v.drain(1..4) {}
assert_eq!(v, &[1.to_string(), 5.to_string()]);
let mut v: Vec<_> = (1..6).map(|x| x.to_string()).collect();
for _ in v.drain(1..4).rev() {}
assert_eq!(v, &[1.to_string(), 5.to_string()]);
let mut v: Vec<_> = vec![(); 5];
for _ in v.drain(1..4).rev() {}
assert_eq!(v, &[(), ()]);
}
#[test]
fn test_drain_inclusive_range() {
let mut v = vec!['a', 'b', 'c', 'd', 'e'];
for _ in v.drain(1..=3) {}
assert_eq!(v, &['a', 'e']);
let mut v: Vec<_> = (0..=5).map(|x| x.to_string()).collect();
for _ in v.drain(1..=5) {}
assert_eq!(v, &["0".to_string()]);
let mut v: Vec<String> = (0..=5).map(|x| x.to_string()).collect();
for _ in v.drain(0..=5) {}
assert_eq!(v, Vec::<String>::new());
let mut v: Vec<_> = (0..=5).map(|x| x.to_string()).collect();
for _ in v.drain(0..=3) {}
assert_eq!(v, &["4".to_string(), "5".to_string()]);
let mut v: Vec<_> = (0..=1).map(|x| x.to_string()).collect();
for _ in v.drain(..=0) {}
assert_eq!(v, &["1".to_string()]);
}
#[test]
fn test_drain_max_vec_size() {
let mut v = Vec::<()>::with_capacity(usize::MAX);
unsafe {
v.set_len(usize::MAX);
}
for _ in v.drain(usize::MAX - 1..) {}
assert_eq!(v.len(), usize::MAX - 1);
let mut v = Vec::<()>::with_capacity(usize::MAX);
unsafe {
v.set_len(usize::MAX);
}
for _ in v.drain(usize::MAX - 1..=usize::MAX - 1) {}
assert_eq!(v.len(), usize::MAX - 1);
}
#[test]
#[should_panic]
fn test_drain_index_overflow() {
let mut v = Vec::<()>::with_capacity(usize::MAX);
unsafe {
v.set_len(usize::MAX);
}
v.drain(0..=usize::MAX);
}
#[test]
#[should_panic]
fn test_drain_inclusive_out_of_bounds() {
let mut v = vec![1, 2, 3, 4, 5];
v.drain(5..=5);
}
#[test]
#[should_panic]
fn test_drain_start_overflow() {
let mut v = vec![1, 2, 3];
v.drain((Excluded(usize::MAX), Included(0)));
}
#[test]
#[should_panic]
fn test_drain_end_overflow() {
let mut v = vec![1, 2, 3];
v.drain((Included(0), Included(usize::MAX)));
}
#[test]
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
fn test_drain_leak() {
static mut DROPS: i32 = 0;
#[derive(Debug, PartialEq)]
struct D(u32, bool);
impl Drop for D {
fn drop(&mut self) {
unsafe {
DROPS += 1;
}
if self.1 {
panic!("panic in `drop`");
}
}
}
let mut v = vec![
D(0, false),
D(1, false),
D(2, false),
D(3, false),
D(4, true),
D(5, false),
D(6, false),
];
catch_unwind(AssertUnwindSafe(|| {
v.drain(2..=5);
}))
.ok();
assert_eq!(unsafe { DROPS }, 4);
assert_eq!(v, vec![D(0, false), D(1, false), D(6, false),]);
}
#[test]
fn test_drain_keep_rest() {
let mut v = vec![0, 1, 2, 3, 4, 5, 6];
let mut drain = v.drain(1..6);
assert_eq!(drain.next(), Some(1));
assert_eq!(drain.next_back(), Some(5));
assert_eq!(drain.next(), Some(2));
drain.keep_rest();
assert_eq!(v, &[0, 3, 4, 6]);
}
#[test]
fn test_drain_keep_rest_all() {
let mut v = vec![0, 1, 2, 3, 4, 5, 6];
v.drain(1..6).keep_rest();
assert_eq!(v, &[0, 1, 2, 3, 4, 5, 6]);
}
#[test]
fn test_drain_keep_rest_none() {
let mut v = vec![0, 1, 2, 3, 4, 5, 6];
let mut drain = v.drain(1..6);
drain.by_ref().for_each(drop);
drain.keep_rest();
assert_eq!(v, &[0, 6]);
}
#[test]
fn test_splice() {
let mut v = vec![1, 2, 3, 4, 5];
let a = [10, 11, 12];
v.splice(2..4, a);
assert_eq!(v, &[1, 2, 10, 11, 12, 5]);
v.splice(1..3, Some(20));
assert_eq!(v, &[1, 20, 11, 12, 5]);
}
#[test]
fn test_splice_inclusive_range() {
let mut v = vec![1, 2, 3, 4, 5];
let a = [10, 11, 12];
let t1: Vec<_> = v.splice(2..=3, a).collect();
assert_eq!(v, &[1, 2, 10, 11, 12, 5]);
assert_eq!(t1, &[3, 4]);
let t2: Vec<_> = v.splice(1..=2, Some(20)).collect();
assert_eq!(v, &[1, 20, 11, 12, 5]);
assert_eq!(t2, &[2, 10]);
}
#[test]
#[should_panic]
fn test_splice_out_of_bounds() {
let mut v = vec![1, 2, 3, 4, 5];
let a = [10, 11, 12];
v.splice(5..6, a);
}
#[test]
#[should_panic]
fn test_splice_inclusive_out_of_bounds() {
let mut v = vec![1, 2, 3, 4, 5];
let a = [10, 11, 12];
v.splice(5..=5, a);
}
#[test]
fn test_splice_items_zero_sized() {
let mut vec = vec![(), (), ()];
let vec2 = vec![];
let t: Vec<_> = vec.splice(1..2, vec2.iter().cloned()).collect();
assert_eq!(vec, &[(), ()]);
assert_eq!(t, &[()]);
}
#[test]
fn test_splice_unbounded() {
let mut vec = vec![1, 2, 3, 4, 5];
let t: Vec<_> = vec.splice(.., None).collect();
assert_eq!(vec, &[]);
assert_eq!(t, &[1, 2, 3, 4, 5]);
}
#[test]
fn test_splice_forget() {
let mut v = vec![1, 2, 3, 4, 5];
let a = [10, 11, 12];
std::mem::forget(v.splice(2..4, a));
assert_eq!(v, &[1, 2]);
}
#[test]
fn test_into_boxed_slice() {
let xs = vec![1, 2, 3];
let ys = xs.into_boxed_slice();
assert_eq!(&*ys, [1, 2, 3]);
}
#[test]
fn test_append() {
let mut vec = vec![1, 2, 3];
let mut vec2 = vec![4, 5, 6];
vec.append(&mut vec2);
assert_eq!(vec, [1, 2, 3, 4, 5, 6]);
assert_eq!(vec2, []);
}
#[test]
fn test_split_off() {
let mut vec = vec![1, 2, 3, 4, 5, 6];
let orig_ptr = vec.as_ptr();
let orig_capacity = vec.capacity();
let split_off = vec.split_off(4);
assert_eq!(vec, [1, 2, 3, 4]);
assert_eq!(split_off, [5, 6]);
assert_eq!(vec.capacity(), orig_capacity);
assert_eq!(vec.as_ptr(), orig_ptr);
}
#[test]
fn test_split_off_take_all() {
// Allocate enough capacity that we can tell whether the split-off vector's
// capacity is based on its size, or (incorrectly) on the original capacity.
let mut vec = Vec::with_capacity(1000);
vec.extend([1, 2, 3, 4, 5, 6]);
let orig_ptr = vec.as_ptr();
let orig_capacity = vec.capacity();
let split_off = vec.split_off(0);
assert_eq!(vec, []);
assert_eq!(split_off, [1, 2, 3, 4, 5, 6]);
assert_eq!(vec.capacity(), orig_capacity);
assert_eq!(vec.as_ptr(), orig_ptr);
// The split-off vector should be newly-allocated, and should not have
// stolen the original vector's allocation.
assert!(split_off.capacity() < orig_capacity);
assert_ne!(split_off.as_ptr(), orig_ptr);
}
#[test]
fn test_into_iter_as_slice() {
let vec = vec!['a', 'b', 'c'];
let mut into_iter = vec.into_iter();
assert_eq!(into_iter.as_slice(), &['a', 'b', 'c']);
let _ = into_iter.next().unwrap();
assert_eq!(into_iter.as_slice(), &['b', 'c']);
let _ = into_iter.next().unwrap();
let _ = into_iter.next().unwrap();
assert_eq!(into_iter.as_slice(), &[]);
}
#[test]
fn test_into_iter_as_mut_slice() {
let vec = vec!['a', 'b', 'c'];
let mut into_iter = vec.into_iter();
assert_eq!(into_iter.as_slice(), &['a', 'b', 'c']);
into_iter.as_mut_slice()[0] = 'x';
into_iter.as_mut_slice()[1] = 'y';
assert_eq!(into_iter.next().unwrap(), 'x');
assert_eq!(into_iter.as_slice(), &['y', 'c']);
}
#[test]
fn test_into_iter_debug() {
let vec = vec!['a', 'b', 'c'];
let into_iter = vec.into_iter();
let debug = format!("{into_iter:?}");
assert_eq!(debug, "IntoIter(['a', 'b', 'c'])");
}
#[test]
fn test_into_iter_count() {
assert_eq!([1, 2, 3].into_iter().count(), 3);
}
#[test]
fn test_into_iter_next_chunk() {
let mut iter = b"lorem".to_vec().into_iter();
assert_eq!(iter.next_chunk().unwrap(), [b'l', b'o']); // N is inferred as 2
assert_eq!(iter.next_chunk().unwrap(), [b'r', b'e', b'm']); // N is inferred as 3
assert_eq!(iter.next_chunk::<4>().unwrap_err().as_slice(), &[]); // N is explicitly 4
}
#[test]
fn test_into_iter_clone() {
fn iter_equal<I: Iterator<Item = i32>>(it: I, slice: &[i32]) {
let v: Vec<i32> = it.collect();
assert_eq!(&v[..], slice);
}
let mut it = [1, 2, 3].into_iter();
iter_equal(it.clone(), &[1, 2, 3]);
assert_eq!(it.next(), Some(1));
let mut it = it.rev();
iter_equal(it.clone(), &[3, 2]);
assert_eq!(it.next(), Some(3));
iter_equal(it.clone(), &[2]);
assert_eq!(it.next(), Some(2));
iter_equal(it.clone(), &[]);
assert_eq!(it.next(), None);
}
#[test]
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
fn test_into_iter_leak() {
static mut DROPS: i32 = 0;
struct D(bool);
impl Drop for D {
fn drop(&mut self) {
unsafe {
DROPS += 1;
}
if self.0 {
panic!("panic in `drop`");
}
}
}
let v = vec![D(false), D(true), D(false)];
catch_unwind(move || drop(v.into_iter())).ok();
assert_eq!(unsafe { DROPS }, 3);
}
#[test]
fn test_into_iter_advance_by() {
let mut i = vec![1, 2, 3, 4, 5].into_iter();
assert_eq!(i.advance_by(0), Ok(()));
assert_eq!(i.advance_back_by(0), Ok(()));
assert_eq!(i.as_slice(), [1, 2, 3, 4, 5]);
assert_eq!(i.advance_by(1), Ok(()));
assert_eq!(i.advance_back_by(1), Ok(()));
assert_eq!(i.as_slice(), [2, 3, 4]);
assert_eq!(i.advance_back_by(usize::MAX), Err(NonZeroUsize::new(usize::MAX - 3).unwrap()));
assert_eq!(i.advance_by(usize::MAX), Err(NonZeroUsize::new(usize::MAX).unwrap()));
assert_eq!(i.advance_by(0), Ok(()));
assert_eq!(i.advance_back_by(0), Ok(()));
assert_eq!(i.len(), 0);
}
#[test]
fn test_into_iter_drop_allocator() {
struct ReferenceCountedAllocator<'a>(#[allow(dead_code)] DropCounter<'a>);
unsafe impl Allocator for ReferenceCountedAllocator<'_> {
fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, core::alloc::AllocError> {
System.allocate(layout)
}
unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
// Safety: Invariants passed to caller.
unsafe { System.deallocate(ptr, layout) }
}
}
let mut drop_count = 0;
let allocator = ReferenceCountedAllocator(DropCounter { count: &mut drop_count });
let _ = Vec::<u32, _>::new_in(allocator);
assert_eq!(drop_count, 1);
let allocator = ReferenceCountedAllocator(DropCounter { count: &mut drop_count });
let _ = Vec::<u32, _>::new_in(allocator).into_iter();
assert_eq!(drop_count, 2);
}
#[test]
fn test_into_iter_zst() {
#[derive(Debug, Clone)]
struct AlignedZstWithDrop([u64; 0]);
impl Drop for AlignedZstWithDrop {
fn drop(&mut self) {
let addr = self as *mut _ as usize;
assert!(hint::black_box(addr) % mem::align_of::<u64>() == 0);
}
}
const C: AlignedZstWithDrop = AlignedZstWithDrop([0u64; 0]);
for _ in vec![C].into_iter() {}
for _ in vec![C; 5].into_iter().rev() {}
let mut it = vec![C, C].into_iter();
assert_eq!(it.advance_by(1), Ok(()));
drop(it);
let mut it = vec![C, C].into_iter();
it.next_chunk::<1>().unwrap();
drop(it);
let mut it = vec![C, C].into_iter();
it.next_chunk::<4>().unwrap_err();
drop(it);
}
#[test]
fn test_from_iter_specialization() {
let src: Vec<usize> = vec![0usize; 1];
let srcptr = src.as_ptr();
let sink = src.into_iter().collect::<Vec<_>>();
let sinkptr = sink.as_ptr();
assert_eq!(srcptr, sinkptr);
}
#[test]
fn test_from_iter_partially_drained_in_place_specialization() {
let src: Vec<usize> = vec![0usize; 10];
let srcptr = src.as_ptr();
let mut iter = src.into_iter();
iter.next();
iter.next();
let sink = iter.collect::<Vec<_>>();
let sinkptr = sink.as_ptr();
assert_eq!(srcptr, sinkptr);
}
#[test]
fn test_from_iter_specialization_with_iterator_adapters() {
fn assert_in_place_trait<T: InPlaceIterable>(_: &T) {}
let owned: Vec<usize> = vec![0usize; 256];
let refd: Vec<&usize> = owned.iter().collect();
let src: Vec<&&usize> = refd.iter().collect();
let srcptr = src.as_ptr();
let iter = src
.into_iter()
.copied()
.cloned()
.enumerate()
.map(|i| i.0 + i.1)
.zip(std::iter::repeat(1usize))
.map(|(a, b)| a + b)
.map_while(Option::Some)
.skip(1)
.map(|e| if e != usize::MAX { Ok(std::num::NonZeroUsize::new(e)) } else { Err(()) });
assert_in_place_trait(&iter);
let sink = iter.collect::<Result<Vec<_>, _>>().unwrap();
let sinkptr = sink.as_ptr();
assert_eq!(srcptr as *const usize, sinkptr as *const usize);
}
#[test]
fn test_in_place_specialization_step_up_down() {
fn assert_in_place_trait<T: InPlaceIterable>(_: &T) {}
let src = vec![[0u8; 4]; 256];
let srcptr = src.as_ptr();
let src_cap = src.capacity();
let iter = src.into_iter().flatten();
assert_in_place_trait(&iter);
let sink = iter.collect::<Vec<_>>();
let sinkptr = sink.as_ptr();
assert_eq!(srcptr as *const u8, sinkptr);
assert_eq!(src_cap * 4, sink.capacity());
let iter = sink.into_iter().array_chunks::<4>();
assert_in_place_trait(&iter);
let sink = iter.collect::<Vec<_>>();
let sinkptr = sink.as_ptr();
assert_eq!(srcptr, sinkptr);
assert_eq!(src_cap, sink.capacity());
let mut src: Vec<u8> = Vec::with_capacity(17);
let src_bytes = src.capacity();
src.resize(8, 0u8);
let sink: Vec<[u8; 4]> = src.into_iter().array_chunks::<4>().collect();
let sink_bytes = sink.capacity() * 4;
assert_ne!(src_bytes, sink_bytes);
assert_eq!(sink.len(), 2);
let mut src: Vec<[u8; 3]> = Vec::with_capacity(17);
src.resize(8, [0; 3]);
let iter = src.into_iter().map(|[a, b, _]| [a, b]);
assert_in_place_trait(&iter);
let sink: Vec<[u8; 2]> = iter.collect();
assert_eq!(sink.len(), 8);
assert!(sink.capacity() <= 25);
let src = vec![[0u8; 4]; 256];
let srcptr = src.as_ptr();
let iter = src.into_iter().flat_map(|a| a.into_iter().map(|b| b.wrapping_add(1)));
assert_in_place_trait(&iter);
let sink = iter.collect::<Vec<_>>();
assert_eq!(srcptr as *const u8, sink.as_ptr());
}
#[test]
fn test_from_iter_specialization_head_tail_drop() {
let drop_count: Vec<_> = (0..=2).map(|_| Rc::new(())).collect();
let src: Vec<_> = drop_count.iter().cloned().collect();
let srcptr = src.as_ptr();
let iter = src.into_iter();
let sink: Vec<_> = iter.skip(1).take(1).collect();
let sinkptr = sink.as_ptr();
assert_eq!(srcptr, sinkptr, "specialization was applied");
assert_eq!(Rc::strong_count(&drop_count[0]), 1, "front was dropped");
assert_eq!(Rc::strong_count(&drop_count[1]), 2, "one element was collected");
assert_eq!(Rc::strong_count(&drop_count[2]), 1, "tail was dropped");
assert_eq!(sink.len(), 1);
}
#[test]
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
fn test_from_iter_specialization_panic_during_iteration_drops() {
let drop_count: Vec<_> = (0..=2).map(|_| Rc::new(())).collect();
let src: Vec<_> = drop_count.iter().cloned().collect();
let iter = src.into_iter();
let _ = std::panic::catch_unwind(AssertUnwindSafe(|| {
let _ = iter
.enumerate()
.filter_map(|(i, e)| {
if i == 1 {
std::panic!("aborting iteration");
}
Some(e)
})
.collect::<Vec<_>>();
}));
assert!(
drop_count.iter().map(Rc::strong_count).all(|count| count == 1),
"all items were dropped once"
);
}
#[test]
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
fn test_from_iter_specialization_panic_during_drop_doesnt_leak() {
static mut DROP_COUNTER_OLD: [usize; 5] = [0; 5];
static mut DROP_COUNTER_NEW: [usize; 2] = [0; 2];
#[derive(Debug)]
struct Old(usize);
impl Drop for Old {
fn drop(&mut self) {
unsafe {
DROP_COUNTER_OLD[self.0] += 1;
}
if self.0 == 3 {
panic!();
}
println!("Dropped Old: {}", self.0);
}
}
#[derive(Debug)]
struct New(usize);
impl Drop for New {
fn drop(&mut self) {
unsafe {
DROP_COUNTER_NEW[self.0] += 1;
}
println!("Dropped New: {}", self.0);
}
}
let _ = std::panic::catch_unwind(AssertUnwindSafe(|| {
let v = vec![Old(0), Old(1), Old(2), Old(3), Old(4)];
let _ = v.into_iter().map(|x| New(x.0)).take(2).collect::<Vec<_>>();
}));
assert_eq!(unsafe { DROP_COUNTER_OLD[0] }, 1);
assert_eq!(unsafe { DROP_COUNTER_OLD[1] }, 1);
assert_eq!(unsafe { DROP_COUNTER_OLD[2] }, 1);
assert_eq!(unsafe { DROP_COUNTER_OLD[3] }, 1);
assert_eq!(unsafe { DROP_COUNTER_OLD[4] }, 1);
assert_eq!(unsafe { DROP_COUNTER_NEW[0] }, 1);
assert_eq!(unsafe { DROP_COUNTER_NEW[1] }, 1);
}
// regression test for issue #85322. Peekable previously implemented InPlaceIterable,
// but due to an interaction with IntoIter's current Clone implementation it failed to uphold
// the contract.
#[test]
fn test_collect_after_iterator_clone() {
let v = vec![0; 5];
let mut i = v.into_iter().map(|i| i + 1).peekable();
i.peek();
let v = i.clone().collect::<Vec<_>>();
assert_eq!(v, [1, 1, 1, 1, 1]);
assert!(v.len() <= v.capacity());
}
#[test]
fn test_cow_from() {
let borrowed: &[_] = &["borrowed", "(slice)"];
let owned = vec!["owned", "(vec)"];
match (Cow::from(owned.clone()), Cow::from(borrowed)) {
(Cow::Owned(o), Cow::Borrowed(b)) => assert!(o == owned && b == borrowed),
_ => panic!("invalid `Cow::from`"),
}
}
#[test]
fn test_from_cow() {
let borrowed: &[_] = &["borrowed", "(slice)"];
let owned = vec!["owned", "(vec)"];
assert_eq!(Vec::from(Cow::Borrowed(borrowed)), vec!["borrowed", "(slice)"]);
assert_eq!(Vec::from(Cow::Owned(owned)), vec!["owned", "(vec)"]);
}
#[allow(dead_code)]
fn assert_covariance() {
fn drain<'new>(d: Drain<'static, &'static str>) -> Drain<'new, &'new str> {
d
}
fn into_iter<'new>(i: IntoIter<&'static str>) -> IntoIter<&'new str> {
i
}
}
#[test]
fn from_into_inner() {
let vec = vec![1, 2, 3];
let ptr = vec.as_ptr();
let vec = vec.into_iter().collect::<Vec<_>>();
assert_eq!(vec, [1, 2, 3]);
assert_eq!(vec.as_ptr(), ptr);
let ptr = &vec[1] as *const _;
let mut it = vec.into_iter();
it.next().unwrap();
let vec = it.collect::<Vec<_>>();
assert_eq!(vec, [2, 3]);
assert!(ptr != vec.as_ptr());
}
#[test]
fn overaligned_allocations() {
#[repr(align(256))]
struct Foo(usize);
let mut v = vec![Foo(273)];
for i in 0..0x1000 {
v.reserve_exact(i);
assert!(v[0].0 == 273);
assert!(v.as_ptr() as usize & 0xff == 0);
v.shrink_to_fit();
assert!(v[0].0 == 273);
assert!(v.as_ptr() as usize & 0xff == 0);
}
}
#[test]
fn extract_if_empty() {
let mut vec: Vec<i32> = vec![];
{
let mut iter = vec.extract_if(|_| true);
assert_eq!(iter.size_hint(), (0, Some(0)));
assert_eq!(iter.next(), None);
assert_eq!(iter.size_hint(), (0, Some(0)));
assert_eq!(iter.next(), None);
assert_eq!(iter.size_hint(), (0, Some(0)));
}
assert_eq!(vec.len(), 0);
assert_eq!(vec, vec![]);
}
#[test]
fn extract_if_zst() {
let mut vec = vec![(), (), (), (), ()];
let initial_len = vec.len();
let mut count = 0;
{
let mut iter = vec.extract_if(|_| true);
assert_eq!(iter.size_hint(), (0, Some(initial_len)));
while let Some(_) = iter.next() {
count += 1;
assert_eq!(iter.size_hint(), (0, Some(initial_len - count)));
}
assert_eq!(iter.size_hint(), (0, Some(0)));
assert_eq!(iter.next(), None);
assert_eq!(iter.size_hint(), (0, Some(0)));
}
assert_eq!(count, initial_len);
assert_eq!(vec.len(), 0);
assert_eq!(vec, vec![]);
}
#[test]
fn extract_if_false() {
let mut vec = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
let initial_len = vec.len();
let mut count = 0;
{
let mut iter = vec.extract_if(|_| false);
assert_eq!(iter.size_hint(), (0, Some(initial_len)));
for _ in iter.by_ref() {
count += 1;
}
assert_eq!(iter.size_hint(), (0, Some(0)));
assert_eq!(iter.next(), None);
assert_eq!(iter.size_hint(), (0, Some(0)));
}
assert_eq!(count, 0);
assert_eq!(vec.len(), initial_len);
assert_eq!(vec, vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
}
#[test]
fn extract_if_true() {
let mut vec = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
let initial_len = vec.len();
let mut count = 0;
{
let mut iter = vec.extract_if(|_| true);
assert_eq!(iter.size_hint(), (0, Some(initial_len)));
while let Some(_) = iter.next() {
count += 1;
assert_eq!(iter.size_hint(), (0, Some(initial_len - count)));
}
assert_eq!(iter.size_hint(), (0, Some(0)));
assert_eq!(iter.next(), None);
assert_eq!(iter.size_hint(), (0, Some(0)));
}
assert_eq!(count, initial_len);
assert_eq!(vec.len(), 0);
assert_eq!(vec, vec![]);
}
#[test]
fn extract_if_complex() {
{
// [+xxx++++++xxxxx++++x+x++]
let mut vec = vec![
1, 2, 4, 6, 7, 9, 11, 13, 15, 17, 18, 20, 22, 24, 26, 27, 29, 31, 33, 34, 35, 36, 37,
39,
];
let removed = vec.extract_if(|x| *x % 2 == 0).collect::<Vec<_>>();
assert_eq!(removed.len(), 10);
assert_eq!(removed, vec![2, 4, 6, 18, 20, 22, 24, 26, 34, 36]);
assert_eq!(vec.len(), 14);
assert_eq!(vec, vec![1, 7, 9, 11, 13, 15, 17, 27, 29, 31, 33, 35, 37, 39]);
}
{
// [xxx++++++xxxxx++++x+x++]
let mut vec = vec![
2, 4, 6, 7, 9, 11, 13, 15, 17, 18, 20, 22, 24, 26, 27, 29, 31, 33, 34, 35, 36, 37, 39,
];
let removed = vec.extract_if(|x| *x % 2 == 0).collect::<Vec<_>>();
assert_eq!(removed.len(), 10);
assert_eq!(removed, vec![2, 4, 6, 18, 20, 22, 24, 26, 34, 36]);
assert_eq!(vec.len(), 13);
assert_eq!(vec, vec![7, 9, 11, 13, 15, 17, 27, 29, 31, 33, 35, 37, 39]);
}
{
// [xxx++++++xxxxx++++x+x]
let mut vec =
vec![2, 4, 6, 7, 9, 11, 13, 15, 17, 18, 20, 22, 24, 26, 27, 29, 31, 33, 34, 35, 36];
let removed = vec.extract_if(|x| *x % 2 == 0).collect::<Vec<_>>();
assert_eq!(removed.len(), 10);
assert_eq!(removed, vec![2, 4, 6, 18, 20, 22, 24, 26, 34, 36]);
assert_eq!(vec.len(), 11);
assert_eq!(vec, vec![7, 9, 11, 13, 15, 17, 27, 29, 31, 33, 35]);
}
{
// [xxxxxxxxxx+++++++++++]
let mut vec = vec![2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19];
let removed = vec.extract_if(|x| *x % 2 == 0).collect::<Vec<_>>();
assert_eq!(removed.len(), 10);
assert_eq!(removed, vec![2, 4, 6, 8, 10, 12, 14, 16, 18, 20]);
assert_eq!(vec.len(), 10);
assert_eq!(vec, vec![1, 3, 5, 7, 9, 11, 13, 15, 17, 19]);
}
{
// [+++++++++++xxxxxxxxxx]
let mut vec = vec![1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20];
let removed = vec.extract_if(|x| *x % 2 == 0).collect::<Vec<_>>();
assert_eq!(removed.len(), 10);
assert_eq!(removed, vec![2, 4, 6, 8, 10, 12, 14, 16, 18, 20]);
assert_eq!(vec.len(), 10);
assert_eq!(vec, vec![1, 3, 5, 7, 9, 11, 13, 15, 17, 19]);
}
}
// FIXME: re-enable emscripten once it can unwind again
#[test]
#[cfg(not(target_os = "emscripten"))]
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
fn extract_if_consumed_panic() {
use std::rc::Rc;
use std::sync::Mutex;
struct Check {
index: usize,
drop_counts: Rc<Mutex<Vec<usize>>>,
}
impl Drop for Check {
fn drop(&mut self) {
self.drop_counts.lock().unwrap()[self.index] += 1;
println!("drop: {}", self.index);
}
}
let check_count = 10;
let drop_counts = Rc::new(Mutex::new(vec![0_usize; check_count]));
let mut data: Vec<Check> = (0..check_count)
.map(|index| Check { index, drop_counts: Rc::clone(&drop_counts) })
.collect();
let _ = std::panic::catch_unwind(move || {
let filter = |c: &mut Check| {
if c.index == 2 {
panic!("panic at index: {}", c.index);
}
// Verify that if the filter could panic again on another element
// that it would not cause a double panic and all elements of the
// vec would still be dropped exactly once.
if c.index == 4 {
panic!("panic at index: {}", c.index);
}
c.index < 6
};
let drain = data.extract_if(filter);
// NOTE: The ExtractIf is explicitly consumed
drain.for_each(drop);
});
let drop_counts = drop_counts.lock().unwrap();
assert_eq!(check_count, drop_counts.len());
for (index, count) in drop_counts.iter().cloned().enumerate() {
assert_eq!(1, count, "unexpected drop count at index: {} (count: {})", index, count);
}
}
// FIXME: Re-enable emscripten once it can catch panics
#[test]
#[cfg(not(target_os = "emscripten"))]
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
fn extract_if_unconsumed_panic() {
use std::rc::Rc;
use std::sync::Mutex;
struct Check {
index: usize,
drop_counts: Rc<Mutex<Vec<usize>>>,
}
impl Drop for Check {
fn drop(&mut self) {
self.drop_counts.lock().unwrap()[self.index] += 1;
println!("drop: {}", self.index);
}
}
let check_count = 10;
let drop_counts = Rc::new(Mutex::new(vec![0_usize; check_count]));
let mut data: Vec<Check> = (0..check_count)
.map(|index| Check { index, drop_counts: Rc::clone(&drop_counts) })
.collect();
let _ = std::panic::catch_unwind(move || {
let filter = |c: &mut Check| {
if c.index == 2 {
panic!("panic at index: {}", c.index);
}
// Verify that if the filter could panic again on another element
// that it would not cause a double panic and all elements of the
// vec would still be dropped exactly once.
if c.index == 4 {
panic!("panic at index: {}", c.index);
}
c.index < 6
};
let _drain = data.extract_if(filter);
// NOTE: The ExtractIf is dropped without being consumed
});
let drop_counts = drop_counts.lock().unwrap();
assert_eq!(check_count, drop_counts.len());
for (index, count) in drop_counts.iter().cloned().enumerate() {
assert_eq!(1, count, "unexpected drop count at index: {} (count: {})", index, count);
}
}
#[test]
fn extract_if_unconsumed() {
let mut vec = vec![1, 2, 3, 4];
let drain = vec.extract_if(|&mut x| x % 2 != 0);
drop(drain);
assert_eq!(vec, [1, 2, 3, 4]);
}
#[test]
fn test_reserve_exact() {
// This is all the same as test_reserve
let mut v = Vec::new();
assert_eq!(v.capacity(), 0);
v.reserve_exact(2);
assert!(v.capacity() >= 2);
for i in 0..16 {
v.push(i);
}
assert!(v.capacity() >= 16);
v.reserve_exact(16);
assert!(v.capacity() >= 32);
v.push(16);
v.reserve_exact(16);
assert!(v.capacity() >= 33)
}
#[test]
#[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
#[cfg_attr(target_os = "android", ignore)] // Android used in CI has a broken dlmalloc
fn test_try_reserve() {
// These are the interesting cases:
// * exactly isize::MAX should never trigger a CapacityOverflow (can be OOM)
// * > isize::MAX should always fail
// * On 16/32-bit should CapacityOverflow
// * On 64-bit should OOM
// * overflow may trigger when adding `len` to `cap` (in number of elements)
// * overflow may trigger when multiplying `new_cap` by size_of::<T> (to get bytes)
const MAX_CAP: usize = isize::MAX as usize;
const MAX_USIZE: usize = usize::MAX;
{
// Note: basic stuff is checked by test_reserve
let mut empty_bytes: Vec<u8> = Vec::new();
// Check isize::MAX doesn't count as an overflow
if let Err(CapacityOverflow) = empty_bytes.try_reserve(MAX_CAP).map_err(|e| e.kind()) {
panic!("isize::MAX shouldn't trigger an overflow!");
}
// Play it again, frank! (just to be sure)
if let Err(CapacityOverflow) = empty_bytes.try_reserve(MAX_CAP).map_err(|e| e.kind()) {
panic!("isize::MAX shouldn't trigger an overflow!");
}
// Check isize::MAX + 1 does count as overflow
assert_matches!(
empty_bytes.try_reserve(MAX_CAP + 1).map_err(|e| e.kind()),
Err(CapacityOverflow),
"isize::MAX + 1 should trigger an overflow!"
);
// Check usize::MAX does count as overflow
assert_matches!(
empty_bytes.try_reserve(MAX_USIZE).map_err(|e| e.kind()),
Err(CapacityOverflow),
"usize::MAX should trigger an overflow!"
);
}
{
// Same basic idea, but with non-zero len
let mut ten_bytes: Vec<u8> = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
if let Err(CapacityOverflow) = ten_bytes.try_reserve(MAX_CAP - 10).map_err(|e| e.kind()) {
panic!("isize::MAX shouldn't trigger an overflow!");
}
if let Err(CapacityOverflow) = ten_bytes.try_reserve(MAX_CAP - 10).map_err(|e| e.kind()) {
panic!("isize::MAX shouldn't trigger an overflow!");
}
assert_matches!(
ten_bytes.try_reserve(MAX_CAP - 9).map_err(|e| e.kind()),
Err(CapacityOverflow),
"isize::MAX + 1 should trigger an overflow!"
);
// Should always overflow in the add-to-len
assert_matches!(
ten_bytes.try_reserve(MAX_USIZE).map_err(|e| e.kind()),
Err(CapacityOverflow),
"usize::MAX should trigger an overflow!"
);
}
{
// Same basic idea, but with interesting type size
let mut ten_u32s: Vec<u32> = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
if let Err(CapacityOverflow) = ten_u32s.try_reserve(MAX_CAP / 4 - 10).map_err(|e| e.kind())
{
panic!("isize::MAX shouldn't trigger an overflow!");
}
if let Err(CapacityOverflow) = ten_u32s.try_reserve(MAX_CAP / 4 - 10).map_err(|e| e.kind())
{
panic!("isize::MAX shouldn't trigger an overflow!");
}
assert_matches!(
ten_u32s.try_reserve(MAX_CAP / 4 - 9).map_err(|e| e.kind()),
Err(CapacityOverflow),
"isize::MAX + 1 should trigger an overflow!"
);
// Should fail in the mul-by-size
assert_matches!(
ten_u32s.try_reserve(MAX_USIZE - 20).map_err(|e| e.kind()),
Err(CapacityOverflow),
"usize::MAX should trigger an overflow!"
);
}
}
#[test]
#[cfg_attr(miri, ignore)] // Miri does not support signalling OOM
#[cfg_attr(target_os = "android", ignore)] // Android used in CI has a broken dlmalloc
fn test_try_reserve_exact() {
// This is exactly the same as test_try_reserve with the method changed.
// See that test for comments.
const MAX_CAP: usize = isize::MAX as usize;
const MAX_USIZE: usize = usize::MAX;
{
let mut empty_bytes: Vec<u8> = Vec::new();
if let Err(CapacityOverflow) = empty_bytes.try_reserve_exact(MAX_CAP).map_err(|e| e.kind())
{
panic!("isize::MAX shouldn't trigger an overflow!");
}
if let Err(CapacityOverflow) = empty_bytes.try_reserve_exact(MAX_CAP).map_err(|e| e.kind())
{
panic!("isize::MAX shouldn't trigger an overflow!");
}
assert_matches!(
empty_bytes.try_reserve_exact(MAX_CAP + 1).map_err(|e| e.kind()),
Err(CapacityOverflow),
"isize::MAX + 1 should trigger an overflow!"
);
assert_matches!(
empty_bytes.try_reserve_exact(MAX_USIZE).map_err(|e| e.kind()),
Err(CapacityOverflow),
"usize::MAX should trigger an overflow!"
);
}
{
let mut ten_bytes: Vec<u8> = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
if let Err(CapacityOverflow) =
ten_bytes.try_reserve_exact(MAX_CAP - 10).map_err(|e| e.kind())
{
panic!("isize::MAX shouldn't trigger an overflow!");
}
if let Err(CapacityOverflow) =
ten_bytes.try_reserve_exact(MAX_CAP - 10).map_err(|e| e.kind())
{
panic!("isize::MAX shouldn't trigger an overflow!");
}
assert_matches!(
ten_bytes.try_reserve_exact(MAX_CAP - 9).map_err(|e| e.kind()),
Err(CapacityOverflow),
"isize::MAX + 1 should trigger an overflow!"
);
assert_matches!(
ten_bytes.try_reserve_exact(MAX_USIZE).map_err(|e| e.kind()),
Err(CapacityOverflow),
"usize::MAX should trigger an overflow!"
);
}
{
let mut ten_u32s: Vec<u32> = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
if let Err(CapacityOverflow) =
ten_u32s.try_reserve_exact(MAX_CAP / 4 - 10).map_err(|e| e.kind())
{
panic!("isize::MAX shouldn't trigger an overflow!");
}
if let Err(CapacityOverflow) =
ten_u32s.try_reserve_exact(MAX_CAP / 4 - 10).map_err(|e| e.kind())
{
panic!("isize::MAX shouldn't trigger an overflow!");
}
assert_matches!(
ten_u32s.try_reserve_exact(MAX_CAP / 4 - 9).map_err(|e| e.kind()),
Err(CapacityOverflow),
"isize::MAX + 1 should trigger an overflow!"
);
assert_matches!(
ten_u32s.try_reserve_exact(MAX_USIZE - 20).map_err(|e| e.kind()),
Err(CapacityOverflow),
"usize::MAX should trigger an overflow!"
);
}
}
#[test]
fn test_stable_pointers() {
/// Pull an element from the iterator, then drop it.
/// Useful to cover both the `next` and `drop` paths of an iterator.
fn next_then_drop<I: Iterator>(mut i: I) {
i.next().unwrap();
drop(i);
}
// Test that, if we reserved enough space, adding and removing elements does not
// invalidate references into the vector (such as `v0`). This test also
// runs in Miri, which would detect such problems.
// Note that this test does *not* constitute a stable guarantee that all these functions do not
// reallocate! Only what is explicitly documented at
// <https://doc.rust-lang.org/nightly/std/vec/struct.Vec.html#guarantees> is stably guaranteed.
let mut v = Vec::with_capacity(128);
v.push(13);
// Laundering the lifetime -- we take care that `v` does not reallocate, so that's okay.
let v0 = &mut v[0];
let v0 = unsafe { &mut *(v0 as *mut _) };
// Now do a bunch of things and occasionally use `v0` again to assert it is still valid.
// Pushing/inserting and popping/removing
v.push(1);
v.push(2);
v.insert(1, 1);
assert_eq!(*v0, 13);
v.remove(1);
v.pop().unwrap();
assert_eq!(*v0, 13);
v.push(1);
v.swap_remove(1);
assert_eq!(v.len(), 2);
v.swap_remove(1); // swap_remove the last element
assert_eq!(*v0, 13);
// Appending
v.append(&mut vec![27, 19]);
assert_eq!(*v0, 13);
// Extending
v.extend_from_slice(&[1, 2]);
v.extend(&[1, 2]); // `slice::Iter` (with `T: Copy`) specialization
v.extend(vec![2, 3]); // `vec::IntoIter` specialization
v.extend(std::iter::once(3)); // `TrustedLen` specialization
v.extend(std::iter::empty::<i32>()); // `TrustedLen` specialization with empty iterator
v.extend(std::iter::once(3).filter(|_| true)); // base case
v.extend(std::iter::once(&3)); // `cloned` specialization
assert_eq!(*v0, 13);
// Truncation
v.truncate(2);
assert_eq!(*v0, 13);
// Resizing
v.resize_with(v.len() + 10, || 42);
assert_eq!(*v0, 13);
v.resize_with(2, || panic!());
assert_eq!(*v0, 13);
// No-op reservation
v.reserve(32);
v.reserve_exact(32);
assert_eq!(*v0, 13);
// Partial draining
v.resize_with(10, || 42);
next_then_drop(v.drain(5..));
assert_eq!(*v0, 13);
// Splicing
v.resize_with(10, || 42);
next_then_drop(v.splice(5.., vec![1, 2, 3, 4, 5])); // empty tail after range
assert_eq!(*v0, 13);
next_then_drop(v.splice(5..8, vec![1])); // replacement is smaller than original range
assert_eq!(*v0, 13);
next_then_drop(v.splice(5..6, [1; 10].into_iter().filter(|_| true))); // lower bound not exact
assert_eq!(*v0, 13);
// spare_capacity_mut
v.spare_capacity_mut();
assert_eq!(*v0, 13);
// Smoke test that would fire even outside Miri if an actual relocation happened.
// Also ensures the pointer is still writeable after all this.
*v0 -= 13;
assert_eq!(v[0], 0);
}
// https://github.com/rust-lang/rust/pull/49496 introduced specialization based on:
//
// ```
// unsafe impl<T: ?Sized> IsZero for *mut T {
// fn is_zero(&self) -> bool {
// (*self).is_null()
// }
// }
// ```
//
// … to call `RawVec::with_capacity_zeroed` for creating `Vec<*mut T>`,
// which is incorrect for fat pointers since `<*mut T>::is_null` only looks at the data component.
// That is, a fat pointer can be “null” without being made entirely of zero bits.
#[test]
fn vec_macro_repeating_null_raw_fat_pointer() {
let raw_dyn = &mut (|| ()) as &mut dyn Fn() as *mut dyn Fn();
let vtable = dbg!(ptr_metadata(raw_dyn));
let null_raw_dyn = ptr_from_raw_parts(std::ptr::null_mut(), vtable);
assert!(null_raw_dyn.is_null());
let vec = vec![null_raw_dyn; 1];
dbg!(ptr_metadata(vec[0]));
assert!(std::ptr::eq(vec[0], null_raw_dyn));
// Polyfill for https://github.com/rust-lang/rfcs/pull/2580
fn ptr_metadata(ptr: *mut dyn Fn()) -> *mut () {
unsafe { std::mem::transmute::<*mut dyn Fn(), DynRepr>(ptr).vtable }
}
fn ptr_from_raw_parts(data: *mut (), vtable: *mut ()) -> *mut dyn Fn() {
unsafe { std::mem::transmute::<DynRepr, *mut dyn Fn()>(DynRepr { data, vtable }) }
}
#[repr(C)]
struct DynRepr {
data: *mut (),
vtable: *mut (),
}
}
// This test will likely fail if you change the capacities used in
// `RawVec::grow_amortized`.
#[test]
fn test_push_growth_strategy() {
// If the element size is 1, we jump from 0 to 8, then double.
{
let mut v1: Vec<u8> = vec![];
assert_eq!(v1.capacity(), 0);
for _ in 0..8 {
v1.push(0);
assert_eq!(v1.capacity(), 8);
}
for _ in 8..16 {
v1.push(0);
assert_eq!(v1.capacity(), 16);
}
for _ in 16..32 {
v1.push(0);
assert_eq!(v1.capacity(), 32);
}
for _ in 32..64 {
v1.push(0);
assert_eq!(v1.capacity(), 64);
}
}
// If the element size is 2..=1024, we jump from 0 to 4, then double.
{
let mut v2: Vec<u16> = vec![];
let mut v1024: Vec<[u8; 1024]> = vec![];
assert_eq!(v2.capacity(), 0);
assert_eq!(v1024.capacity(), 0);
for _ in 0..4 {
v2.push(0);
v1024.push([0; 1024]);
assert_eq!(v2.capacity(), 4);
assert_eq!(v1024.capacity(), 4);
}
for _ in 4..8 {
v2.push(0);
v1024.push([0; 1024]);
assert_eq!(v2.capacity(), 8);
assert_eq!(v1024.capacity(), 8);
}
for _ in 8..16 {
v2.push(0);
v1024.push([0; 1024]);
assert_eq!(v2.capacity(), 16);
assert_eq!(v1024.capacity(), 16);
}
for _ in 16..32 {
v2.push(0);
v1024.push([0; 1024]);
assert_eq!(v2.capacity(), 32);
assert_eq!(v1024.capacity(), 32);
}
for _ in 32..64 {
v2.push(0);
v1024.push([0; 1024]);
assert_eq!(v2.capacity(), 64);
assert_eq!(v1024.capacity(), 64);
}
}
// If the element size is > 1024, we jump from 0 to 1, then double.
{
let mut v1025: Vec<[u8; 1025]> = vec![];
assert_eq!(v1025.capacity(), 0);
for _ in 0..1 {
v1025.push([0; 1025]);
assert_eq!(v1025.capacity(), 1);
}
for _ in 1..2 {
v1025.push([0; 1025]);
assert_eq!(v1025.capacity(), 2);
}
for _ in 2..4 {
v1025.push([0; 1025]);
assert_eq!(v1025.capacity(), 4);
}
for _ in 4..8 {
v1025.push([0; 1025]);
assert_eq!(v1025.capacity(), 8);
}
for _ in 8..16 {
v1025.push([0; 1025]);
assert_eq!(v1025.capacity(), 16);
}
for _ in 16..32 {
v1025.push([0; 1025]);
assert_eq!(v1025.capacity(), 32);
}
for _ in 32..64 {
v1025.push([0; 1025]);
assert_eq!(v1025.capacity(), 64);
}
}
}
macro_rules! generate_assert_eq_vec_and_prim {
($name:ident<$B:ident>($type:ty)) => {
fn $name<A: PartialEq<$B> + Debug, $B: Debug>(a: Vec<A>, b: $type) {
assert!(a == b);
assert_eq!(a, b);
}
};
}
generate_assert_eq_vec_and_prim! { assert_eq_vec_and_slice <B>(&[B]) }
generate_assert_eq_vec_and_prim! { assert_eq_vec_and_array_3<B>([B; 3]) }
#[test]
fn partialeq_vec_and_prim() {
assert_eq_vec_and_slice(vec![1, 2, 3], &[1, 2, 3]);
assert_eq_vec_and_array_3(vec![1, 2, 3], [1, 2, 3]);
}
macro_rules! assert_partial_eq_valid {
($a2:expr, $a3:expr; $b2:expr, $b3: expr) => {
assert!($a2 == $b2);
assert!($a2 != $b3);
assert!($a3 != $b2);
assert!($a3 == $b3);
assert_eq!($a2, $b2);
assert_ne!($a2, $b3);
assert_ne!($a3, $b2);
assert_eq!($a3, $b3);
};
}
#[test]
fn partialeq_vec_full() {
let vec2: Vec<_> = vec![1, 2];
let vec3: Vec<_> = vec![1, 2, 3];
let slice2: &[_] = &[1, 2];
let slice3: &[_] = &[1, 2, 3];
let slicemut2: &[_] = &mut [1, 2];
let slicemut3: &[_] = &mut [1, 2, 3];
let array2: [_; 2] = [1, 2];
let array3: [_; 3] = [1, 2, 3];
let arrayref2: &[_; 2] = &[1, 2];
let arrayref3: &[_; 3] = &[1, 2, 3];
assert_partial_eq_valid!(vec2,vec3; vec2,vec3);
assert_partial_eq_valid!(vec2,vec3; slice2,slice3);
assert_partial_eq_valid!(vec2,vec3; slicemut2,slicemut3);
assert_partial_eq_valid!(slice2,slice3; vec2,vec3);
assert_partial_eq_valid!(slicemut2,slicemut3; vec2,vec3);
assert_partial_eq_valid!(vec2,vec3; array2,array3);
assert_partial_eq_valid!(vec2,vec3; arrayref2,arrayref3);
assert_partial_eq_valid!(vec2,vec3; arrayref2[..],arrayref3[..]);
}
#[test]
fn test_vec_cycle() {
#[derive(Debug)]
struct C<'a> {
v: Vec<Cell<Option<&'a C<'a>>>>,
}
impl<'a> C<'a> {
fn new() -> C<'a> {
C { v: Vec::new() }
}
}
let mut c1 = C::new();
let mut c2 = C::new();
let mut c3 = C::new();
// Push
c1.v.push(Cell::new(None));
c1.v.push(Cell::new(None));
c2.v.push(Cell::new(None));
c2.v.push(Cell::new(None));
c3.v.push(Cell::new(None));
c3.v.push(Cell::new(None));
// Set
c1.v[0].set(Some(&c2));
c1.v[1].set(Some(&c3));
c2.v[0].set(Some(&c2));
c2.v[1].set(Some(&c3));
c3.v[0].set(Some(&c1));
c3.v[1].set(Some(&c2));
}
#[test]
fn test_vec_cycle_wrapped() {
struct Refs<'a> {
v: Vec<Cell<Option<&'a C<'a>>>>,
}
struct C<'a> {
refs: Refs<'a>,
}
impl<'a> Refs<'a> {
fn new() -> Refs<'a> {
Refs { v: Vec::new() }
}
}
impl<'a> C<'a> {
fn new() -> C<'a> {
C { refs: Refs::new() }
}
}
let mut c1 = C::new();
let mut c2 = C::new();
let mut c3 = C::new();
c1.refs.v.push(Cell::new(None));
c1.refs.v.push(Cell::new(None));
c2.refs.v.push(Cell::new(None));
c2.refs.v.push(Cell::new(None));
c3.refs.v.push(Cell::new(None));
c3.refs.v.push(Cell::new(None));
c1.refs.v[0].set(Some(&c2));
c1.refs.v[1].set(Some(&c3));
c2.refs.v[0].set(Some(&c2));
c2.refs.v[1].set(Some(&c3));
c3.refs.v[0].set(Some(&c1));
c3.refs.v[1].set(Some(&c2));
}
#[test]
fn test_zero_sized_capacity() {
for len in [0, 1, 2, 4, 8, 16, 32, 64, 128, 256] {
let v = Vec::<()>::with_capacity(len);
assert_eq!(v.len(), 0);
assert_eq!(v.capacity(), usize::MAX);
}
}
#[test]
fn test_zero_sized_vec_push() {
const N: usize = 8;
for len in 0..N {
let mut tester = Vec::with_capacity(len);
assert_eq!(tester.len(), 0);
assert!(tester.capacity() >= len);
for _ in 0..len {
tester.push(());
}
assert_eq!(tester.len(), len);
assert_eq!(tester.iter().count(), len);
tester.clear();
}
}
#[test]
fn test_vec_macro_repeat() {
assert_eq!(vec![1; 3], vec![1, 1, 1]);
assert_eq!(vec![1; 2], vec![1, 1]);
assert_eq!(vec![1; 1], vec![1]);
assert_eq!(vec![1; 0], vec![]);
// from_elem syntax (see RFC 832)
let el = Box::new(1);
let n = 3;
assert_eq!(vec![el; n], vec![Box::new(1), Box::new(1), Box::new(1)]);
}
#[test]
fn test_vec_swap() {
let mut a: Vec<isize> = vec![0, 1, 2, 3, 4, 5, 6];
a.swap(2, 4);
assert_eq!(a[2], 4);
assert_eq!(a[4], 2);
let mut n = 42;
swap(&mut n, &mut a[0]);
assert_eq!(a[0], 42);
assert_eq!(n, 0);
}
#[test]
fn test_extend_from_within_spec() {
#[derive(Copy)]
struct CopyOnly;
impl Clone for CopyOnly {
fn clone(&self) -> Self {
panic!("extend_from_within must use specialization on copy");
}
}
vec![CopyOnly, CopyOnly].extend_from_within(..);
}
#[test]
fn test_extend_from_within_clone() {
let mut v = vec![String::from("sssss"), String::from("12334567890"), String::from("c")];
v.extend_from_within(1..);
assert_eq!(v, ["sssss", "12334567890", "c", "12334567890", "c"]);
}
#[test]
fn test_extend_from_within_complete_rande() {
let mut v = vec![0, 1, 2, 3];
v.extend_from_within(..);
assert_eq!(v, [0, 1, 2, 3, 0, 1, 2, 3]);
}
#[test]
fn test_extend_from_within_empty_rande() {
let mut v = vec![0, 1, 2, 3];
v.extend_from_within(1..1);
assert_eq!(v, [0, 1, 2, 3]);
}
#[test]
#[should_panic]
fn test_extend_from_within_out_of_rande() {
let mut v = vec![0, 1];
v.extend_from_within(..3);
}
#[test]
fn test_extend_from_within_zst() {
let mut v = vec![(); 8];
v.extend_from_within(3..7);
assert_eq!(v, [(); 12]);
}
#[test]
fn test_extend_from_within_empty_vec() {
let mut v = Vec::<i32>::new();
v.extend_from_within(..);
assert_eq!(v, []);
}
#[test]
fn test_extend_from_within() {
let mut v = vec![String::from("a"), String::from("b"), String::from("c")];
v.extend_from_within(1..=2);
v.extend_from_within(..=1);
assert_eq!(v, ["a", "b", "c", "b", "c", "a", "b"]);
}
#[test]
fn test_vec_dedup_by() {
let mut vec: Vec<i32> = vec![1, -1, 2, 3, 1, -5, 5, -2, 2];
vec.dedup_by(|a, b| a.abs() == b.abs());
assert_eq!(vec, [1, 2, 3, 1, -5, -2]);
}
#[test]
fn test_vec_dedup_empty() {
let mut vec: Vec<i32> = Vec::new();
vec.dedup();
assert_eq!(vec, []);
}
#[test]
fn test_vec_dedup_one() {
let mut vec = vec![12i32];
vec.dedup();
assert_eq!(vec, [12]);
}
#[test]
fn test_vec_dedup_multiple_ident() {
let mut vec = vec![12, 12, 12, 12, 12, 11, 11, 11, 11, 11, 11];
vec.dedup();
assert_eq!(vec, [12, 11]);
}
#[test]
fn test_vec_dedup_partialeq() {
#[derive(Debug)]
struct Foo(i32, #[allow(dead_code)] i32);
impl PartialEq for Foo {
fn eq(&self, other: &Foo) -> bool {
self.0 == other.0
}
}
let mut vec = vec![Foo(0, 1), Foo(0, 5), Foo(1, 7), Foo(1, 9)];
vec.dedup();
assert_eq!(vec, [Foo(0, 1), Foo(1, 7)]);
}
#[test]
fn test_vec_dedup() {
let mut vec: Vec<bool> = Vec::with_capacity(8);
let mut template = vec.clone();
for x in 0u8..255u8 {
vec.clear();
template.clear();
let iter = (0..8).map(move |bit| (x >> bit) & 1 == 1);
vec.extend(iter);
template.extend_from_slice(&vec);
let (dedup, _) = template.partition_dedup();
vec.dedup();
assert_eq!(vec, dedup);
}
}
#[test]
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
fn test_vec_dedup_panicking() {
#[derive(Debug)]
struct Panic<'a> {
drop_counter: &'a Cell<u32>,
value: bool,
index: usize,
}
impl<'a> PartialEq for Panic<'a> {
fn eq(&self, other: &Self) -> bool {
self.value == other.value
}
}
impl<'a> Drop for Panic<'a> {
fn drop(&mut self) {
self.drop_counter.set(self.drop_counter.get() + 1);
if !std::thread::panicking() {
assert!(self.index != 4);
}
}
}
let drop_counter = &Cell::new(0);
let expected = [
Panic { drop_counter, value: false, index: 0 },
Panic { drop_counter, value: false, index: 5 },
Panic { drop_counter, value: true, index: 6 },
Panic { drop_counter, value: true, index: 7 },
];
let mut vec = vec![
Panic { drop_counter, value: false, index: 0 },
// these elements get deduplicated
Panic { drop_counter, value: false, index: 1 },
Panic { drop_counter, value: false, index: 2 },
Panic { drop_counter, value: false, index: 3 },
Panic { drop_counter, value: false, index: 4 },
// here it panics while dropping the item with index==4
Panic { drop_counter, value: false, index: 5 },
Panic { drop_counter, value: true, index: 6 },
Panic { drop_counter, value: true, index: 7 },
];
let _ = catch_unwind(AssertUnwindSafe(|| vec.dedup())).unwrap_err();
assert_eq!(drop_counter.get(), 4);
let ok = vec.iter().zip(expected.iter()).all(|(x, y)| x.index == y.index);
if !ok {
panic!("expected: {expected:?}\ngot: {vec:?}\n");
}
}
// Regression test for issue #82533
#[test]
#[cfg_attr(not(panic = "unwind"), ignore = "test requires unwinding support")]
fn test_extend_from_within_panicking_clone() {
struct Panic<'dc> {
drop_count: &'dc AtomicU32,
aaaaa: bool,
}
impl Clone for Panic<'_> {
fn clone(&self) -> Self {
if self.aaaaa {
panic!("panic! at the clone");
}
Self { ..*self }
}
}
impl Drop for Panic<'_> {
fn drop(&mut self) {
self.drop_count.fetch_add(1, Ordering::SeqCst);
}
}
let count = core::sync::atomic::AtomicU32::new(0);
let mut vec = vec![
Panic { drop_count: &count, aaaaa: false },
Panic { drop_count: &count, aaaaa: true },
Panic { drop_count: &count, aaaaa: false },
];
// This should clone&append one Panic{..} at the end, and then panic while
// cloning second Panic{..}. This means that `Panic::drop` should be called
// 4 times (3 for items already in vector, 1 for just appended).
//
// Previously just appended item was leaked, making drop_count = 3, instead of 4.
std::panic::catch_unwind(move || vec.extend_from_within(..)).unwrap_err();
assert_eq!(count.load(Ordering::SeqCst), 4);
}
#[test]
#[should_panic = "vec len overflow"]
fn test_into_flattened_size_overflow() {
let v = vec![[(); usize::MAX]; 2];
let _ = v.into_flattened();
}
#[test]
fn test_box_zero_allocator() {
use core::{alloc::AllocError, cell::RefCell};
use std::collections::HashSet;
// Track ZST allocations and ensure that they all have a matching free.
struct ZstTracker {
state: RefCell<(HashSet<usize>, usize)>,
}
unsafe impl Allocator for ZstTracker {
fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
let ptr = if layout.size() == 0 {
let mut state = self.state.borrow_mut();
let addr = state.1;
assert!(state.0.insert(addr));
state.1 += 1;
std::println!("allocating {addr}");
std::ptr::invalid_mut(addr)
} else {
unsafe { std::alloc::alloc(layout) }
};
Ok(NonNull::slice_from_raw_parts(NonNull::new(ptr).ok_or(AllocError)?, layout.size()))
}
unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
if layout.size() == 0 {
let addr = ptr.as_ptr() as usize;
let mut state = self.state.borrow_mut();
std::println!("freeing {addr}");
assert!(state.0.remove(&addr), "ZST free that wasn't allocated");
} else {
unsafe { std::alloc::dealloc(ptr.as_ptr(), layout) }
}
}
}
// Start the state at 100 to avoid returning null pointers.
let alloc = ZstTracker { state: RefCell::new((HashSet::new(), 100)) };
// Ensure that unsizing retains the same behavior.
{
let b1: Box<[u8; 0], &ZstTracker> = Box::new_in([], &alloc);
let b2: Box<[u8], &ZstTracker> = b1.clone();
let _b3: Box<[u8], &ZstTracker> = b2.clone();
}
// Ensure that shrinking doesn't leak a ZST allocation.
{
let mut v1: Vec<u8, &ZstTracker> = Vec::with_capacity_in(100, &alloc);
v1.shrink_to_fit();
}
// Ensure that conversion to/from vec works.
{
let v1: Vec<(), &ZstTracker> = Vec::with_capacity_in(100, &alloc);
let _b1: Box<[()], &ZstTracker> = v1.into_boxed_slice();
let b2: Box<[()], &ZstTracker> = Box::new_in([(), (), ()], &alloc);
let _v2: Vec<(), &ZstTracker> = b2.into();
}
// Ensure all ZSTs have been freed.
assert!(alloc.state.borrow().0.is_empty());
}
#[test]
fn test_vec_from_array_ref() {
assert_eq!(Vec::from(&[1, 2, 3]), vec![1, 2, 3]);
}
#[test]
fn test_vec_from_array_mut_ref() {
assert_eq!(Vec::from(&mut [1, 2, 3]), vec![1, 2, 3]);
}
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