|  | use core::alloc::{Allocator, Layout}; | 
|  | use core::num::NonZero; | 
|  | 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::swap; | 
|  | use std::ops::Bound::*; | 
|  | use std::panic::{AssertUnwindSafe, catch_unwind}; | 
|  | use std::rc::Rc; | 
|  | use std::sync::atomic::{AtomicU32, Ordering}; | 
|  | use std::vec::{Drain, IntoIter}; | 
|  |  | 
|  | use crate::testing::macros::struct_with_counted_drop; | 
|  |  | 
|  | 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() { | 
|  | struct_with_counted_drop!(Elem(i32), DROPS); | 
|  |  | 
|  | let mut v = vec![Elem(1), Elem(2), Elem(3), Elem(4), Elem(5)]; | 
|  |  | 
|  | assert_eq!(DROPS.get(), 0); | 
|  | v.truncate(3); | 
|  | assert_eq!(DROPS.get(), 2); | 
|  | v.truncate(0); | 
|  | assert_eq!(DROPS.get(), 5); | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | #[should_panic] | 
|  | fn test_vec_truncate_fail() { | 
|  | struct BadElem(i32); | 
|  |  | 
|  | impl Drop for BadElem { | 
|  | fn drop(&mut self) { | 
|  | if let BadElem(0xbadbeef) = self { | 
|  | 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() { | 
|  | struct_with_counted_drop!(D(u32, bool), DROPS => |this: &D| if this.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!(DROPS.get(), 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() { | 
|  | struct_with_counted_drop!(D(bool), DROPS => |this: &D| if this.0 { panic!("panic in `drop`"); }); | 
|  |  | 
|  | let v = vec![D(false), D(true), D(false)]; | 
|  |  | 
|  | catch_unwind(move || drop(v.into_iter())).ok(); | 
|  |  | 
|  | assert_eq!(DROPS.get(), 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(NonZero::new(usize::MAX - 3).unwrap())); | 
|  |  | 
|  | assert_eq!(i.advance_by(usize::MAX), Err(NonZero::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) % 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(NonZero::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; 1024]; | 
|  | let srcptr = src.as_ptr(); | 
|  | let src_bytes = src.capacity(); | 
|  | let iter = src.into_iter().array_chunks::<4>(); | 
|  | assert_in_place_trait(&iter); | 
|  | let sink = iter.collect::<Vec<_>>(); | 
|  | let sinkptr = sink.as_ptr(); | 
|  | assert_eq!(srcptr.addr(), sinkptr.addr()); | 
|  | assert_eq!(src_bytes, sink.capacity() * 4); | 
|  |  | 
|  | 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); | 
|  | } | 
|  |  | 
|  | #[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() { | 
|  | struct_with_counted_drop!( | 
|  | Old(usize), DROP_COUNTER_OLD[|this: &Old| this.0, usize] => | 
|  | |this: &Old| { | 
|  | if this.0 == 3 { panic!(); } println!("Dropped Old: {}", this.0) | 
|  | } | 
|  | ); | 
|  | struct_with_counted_drop!( | 
|  | New(usize), DROP_COUNTER_NEW[|this: &New| this.0, usize] => | 
|  | |this: &New| println!("Dropped New: {}", this.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<_>>(); | 
|  | })); | 
|  |  | 
|  | DROP_COUNTER_OLD.with_borrow(|c| assert_eq!(c.get(&0), Some(&1))); | 
|  | DROP_COUNTER_OLD.with_borrow(|c| assert_eq!(c.get(&1), Some(&1))); | 
|  | DROP_COUNTER_OLD.with_borrow(|c| assert_eq!(c.get(&2), Some(&1))); | 
|  | DROP_COUNTER_OLD.with_borrow(|c| assert_eq!(c.get(&3), Some(&1))); | 
|  | DROP_COUNTER_OLD.with_borrow(|c| assert_eq!(c.get(&4), Some(&1))); | 
|  |  | 
|  | DROP_COUNTER_NEW.with_borrow(|c| assert_eq!(c.get(&0), Some(&1))); | 
|  | DROP_COUNTER_NEW.with_borrow(|c| assert_eq!(c.get(&1), Some(&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()); | 
|  | } | 
|  |  | 
|  | // regression test for #135103, similar to the one above Flatten/FlatMap had an unsound InPlaceIterable | 
|  | // implementation. | 
|  | #[test] | 
|  | fn test_flatten_clone() { | 
|  | const S: String = String::new(); | 
|  |  | 
|  | let v = vec![[S, "Hello World!".into()], [S, S]]; | 
|  | let mut i = v.into_iter().flatten(); | 
|  | let _ = i.next(); | 
|  | let result: Vec<String> = i.clone().collect(); | 
|  | assert_eq!(result, ["Hello World!", "", ""]); | 
|  | } | 
|  |  | 
|  | #[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_ranges() { | 
|  | let mut vec = vec![0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; | 
|  |  | 
|  | let mut count = 0; | 
|  | let it = vec.extract_if(1..=3, |_| { | 
|  | count += 1; | 
|  | true | 
|  | }); | 
|  | assert_eq!(it.collect::<Vec<_>>(), vec![1, 2, 3]); | 
|  | assert_eq!(vec, vec![0, 4, 5, 6, 7, 8, 9, 10]); | 
|  | assert_eq!(count, 3); | 
|  |  | 
|  | let it = vec.extract_if(1..=3, |_| false); | 
|  | assert_eq!(it.collect::<Vec<_>>(), vec![]); | 
|  | assert_eq!(vec, vec![0, 4, 5, 6, 7, 8, 9, 10]); | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | #[should_panic] | 
|  | fn extract_if_out_of_bounds() { | 
|  | let mut vec = vec![0, 1]; | 
|  | let _ = vec.extract_if(5.., |_| true).for_each(drop); | 
|  | } | 
|  |  | 
|  | #[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]); | 
|  | } | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | #[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); | 
|  | } | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | #[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 | 
|  | fn test_try_with_capacity() { | 
|  | let mut vec: Vec<u32> = Vec::try_with_capacity(5).unwrap(); | 
|  | assert_eq!(0, vec.len()); | 
|  | assert!(vec.capacity() >= 5 && vec.capacity() <= isize::MAX as usize / 4); | 
|  | assert!(vec.spare_capacity_mut().len() >= 5); | 
|  |  | 
|  | assert!(Vec::<u16>::try_with_capacity(isize::MAX as usize + 1).is_err()); | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | #[cfg_attr(miri, ignore)] // Miri does not support signalling OOM | 
|  | 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 | 
|  | 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; | 
|  | use core::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::without_provenance_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]); | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | fn test_pop_if() { | 
|  | let mut v = vec![1, 2, 3, 4]; | 
|  | let pred = |x: &mut i32| *x % 2 == 0; | 
|  |  | 
|  | assert_eq!(v.pop_if(pred), Some(4)); | 
|  | assert_eq!(v, [1, 2, 3]); | 
|  |  | 
|  | assert_eq!(v.pop_if(pred), None); | 
|  | assert_eq!(v, [1, 2, 3]); | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | fn test_pop_if_empty() { | 
|  | let mut v = Vec::<i32>::new(); | 
|  | assert_eq!(v.pop_if(|_| true), None); | 
|  | assert!(v.is_empty()); | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | fn test_pop_if_mutates() { | 
|  | let mut v = vec![1]; | 
|  | let pred = |x: &mut i32| { | 
|  | *x += 1; | 
|  | false | 
|  | }; | 
|  | assert_eq!(v.pop_if(pred), None); | 
|  | assert_eq!(v, [2]); | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | fn test_peek_mut() { | 
|  | let mut vec = Vec::new(); | 
|  | assert!(vec.peek_mut().is_none()); | 
|  | vec.push(1); | 
|  | vec.push(2); | 
|  | if let Some(mut p) = vec.peek_mut() { | 
|  | assert_eq!(*p, 2); | 
|  | *p = 0; | 
|  | assert_eq!(*p, 0); | 
|  | p.pop(); | 
|  | assert_eq!(vec.len(), 1); | 
|  | } else { | 
|  | unreachable!() | 
|  | } | 
|  | } | 
|  |  | 
|  | /// This assortment of tests, in combination with miri, verifies we handle UB on fishy arguments | 
|  | /// in the stdlib. Draining and extending the allocation are fairly well-tested earlier, but | 
|  | /// `vec.insert(usize::MAX, val)` once slipped by! | 
|  | /// | 
|  | /// All code that manipulates the collection types should be tested with "trivially wrong" args. | 
|  | #[test] | 
|  | fn max_dont_panic() { | 
|  | let mut v = vec![0]; | 
|  | let _ = v.get(usize::MAX); | 
|  | v.shrink_to(usize::MAX); | 
|  | v.truncate(usize::MAX); | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | #[should_panic] | 
|  | fn max_insert() { | 
|  | let mut v = vec![0]; | 
|  | v.insert(usize::MAX, 1); | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | #[should_panic] | 
|  | fn max_remove() { | 
|  | let mut v = vec![0]; | 
|  | v.remove(usize::MAX); | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | #[should_panic] | 
|  | fn max_splice() { | 
|  | let mut v = vec![0]; | 
|  | v.splice(usize::MAX.., core::iter::once(1)); | 
|  | } | 
|  |  | 
|  | #[test] | 
|  | #[should_panic] | 
|  | fn max_swap_remove() { | 
|  | let mut v = vec![0]; | 
|  | v.swap_remove(usize::MAX); | 
|  | } | 
|  |  | 
|  | // Regression test for #135338 | 
|  | #[test] | 
|  | fn vec_null_ptr_roundtrip() { | 
|  | let ptr = std::ptr::from_ref(&42); | 
|  | let zero = ptr.with_addr(0); | 
|  | let roundtripped = vec![zero; 1].pop().unwrap(); | 
|  | let new = roundtripped.with_addr(ptr.addr()); | 
|  | unsafe { new.read() }; | 
|  | } |