rust/tests/run-pass/vec.rs
2020-04-05 18:26:51 +02:00

130 lines
3.0 KiB
Rust

fn make_vec() -> Vec<u8> {
let mut v = Vec::with_capacity(4);
v.push(1);
v.push(2);
v
}
fn make_vec_macro() -> Vec<u8> {
vec![1, 2]
}
fn make_vec_macro_repeat() -> Vec<u8> {
vec![42; 5]
}
fn make_vec_macro_repeat_zeroed() -> Vec<u8> {
vec![0; 7]
}
fn vec_into_iter() -> u8 {
vec![1, 2, 3, 4]
.into_iter()
.map(|x| x * x)
.fold(0, |x, y| x + y)
}
fn vec_into_iter_rev() -> u8 {
vec![1, 2, 3, 4]
.into_iter()
.map(|x| x * x)
.fold(0, |x, y| x + y)
}
fn vec_into_iter_zst() -> usize {
vec![[0u64; 0], [0u64; 0]]
.into_iter()
.rev()
.map(|x| x.len())
.sum()
}
fn vec_into_iter_rev_zst() -> usize {
vec![[0u64; 0], [0u64; 0]]
.into_iter()
.rev()
.map(|x| x.len())
.sum()
}
fn vec_iter_and_mut() {
let mut v = vec![1,2,3,4];
for i in v.iter_mut() {
*i += 1;
}
assert_eq!(v.iter().sum::<i32>(), 2+3+4+5);
}
fn vec_iter_and_mut_rev() {
let mut v = vec![1,2,3,4];
for i in v.iter_mut().rev() {
*i += 1;
}
assert_eq!(v.iter().sum::<i32>(), 2+3+4+5);
}
fn vec_reallocate() -> Vec<u8> {
let mut v = vec![1, 2];
v.push(3);
v.push(4);
v.push(5);
v
}
fn vec_push_ptr_stable() {
let mut v = Vec::with_capacity(10);
v.push(0);
let v0 = unsafe { &*(&v[0] as *const _) }; // laundering the lifetime -- we take care that `v` does not reallocate, so that's okay.
v.push(1);
let _val = *v0;
}
fn vec_extend_ptr_stable() {
let mut v = Vec::with_capacity(10);
v.push(0);
let v0 = unsafe { &*(&v[0] as *const _) }; // laundering the lifetime -- we take care that `v` does not reallocate, so that's okay.
// `slice::Iter` (with `T: Copy`) specialization
v.extend(&[1]);
let _val = *v0;
// `vec::IntoIter` specialization
v.extend(vec![2]);
let _val = *v0;
// `TrustedLen` specialization
v.extend(std::iter::once(3));
let _val = *v0;
// base case
v.extend(std::iter::once(3).filter(|_| true));
let _val = *v0;
}
fn vec_truncate_ptr_stable() {
let mut v = vec![0; 10];
let v0 = unsafe { &*(&v[0] as *const _) }; // laundering the lifetime -- we take care that `v` does not reallocate, so that's okay.
v.truncate(5);
let _val = *v0;
}
fn main() {
assert_eq!(vec_reallocate().len(), 5);
assert_eq!(vec_into_iter(), 30);
assert_eq!(vec_into_iter_rev(), 30);
vec_iter_and_mut();
assert_eq!(vec_into_iter_zst(), 0);
assert_eq!(vec_into_iter_rev_zst(), 0);
vec_iter_and_mut_rev();
assert_eq!(make_vec().capacity(), 4);
assert_eq!(make_vec_macro(), [1, 2]);
assert_eq!(make_vec_macro_repeat(), [42; 5]);
assert_eq!(make_vec_macro_repeat_zeroed(), [0; 7]);
// Test interesting empty slice comparison
// (one is a real pointer, one an integer pointer).
assert_eq!((200..-5).step_by(1).collect::<Vec<isize>>(), []);
vec_push_ptr_stable();
vec_extend_ptr_stable();
vec_truncate_ptr_stable();
}