rust/library/alloc/tests/borrow.rs
surechen 40ae34194c remove redundant imports
detects redundant imports that can be eliminated.

for #117772 :

In order to facilitate review and modification, split the checking code and
removing redundant imports code into two PR.
2023-12-10 10:56:22 +08:00

61 lines
1.3 KiB
Rust

use std::borrow::Cow;
use std::ffi::{CStr, OsStr};
use std::path::Path;
use std::rc::Rc;
use std::sync::Arc;
macro_rules! test_from_cow {
($value:ident => $($ty:ty),+) => {$(
let borrowed = <$ty>::from(Cow::Borrowed($value));
let owned = <$ty>::from(Cow::Owned($value.to_owned()));
assert_eq!($value, &*borrowed);
assert_eq!($value, &*owned);
)+};
($value:ident : & $ty:ty) => {
test_from_cow!($value => Box<$ty>, Rc<$ty>, Arc<$ty>);
}
}
#[test]
fn test_from_cow_slice() {
let slice: &[i32] = &[1, 2, 3];
test_from_cow!(slice: &[i32]);
}
#[test]
fn test_from_cow_str() {
let string = "hello";
test_from_cow!(string: &str);
}
#[test]
fn test_from_cow_c_str() {
let string = CStr::from_bytes_with_nul(b"hello\0").unwrap();
test_from_cow!(string: &CStr);
}
#[test]
fn test_from_cow_os_str() {
let string = OsStr::new("hello");
test_from_cow!(string: &OsStr);
}
#[test]
fn test_from_cow_path() {
let path = Path::new("hello");
test_from_cow!(path: &Path);
}
#[test]
fn cow_const() {
// test that the methods of `Cow` are usable in a const context
const COW: Cow<'_, str> = Cow::Borrowed("moo");
const IS_BORROWED: bool = COW.is_borrowed();
assert!(IS_BORROWED);
const IS_OWNED: bool = COW.is_owned();
assert!(!IS_OWNED);
}