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https://github.com/rust-lang/rust.git
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404 lines
12 KiB
Rust
404 lines
12 KiB
Rust
use core::ops::DerefMut;
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use core::option::*;
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fn op1() -> Result<isize, &'static str> {
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Ok(666)
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}
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fn op2() -> Result<isize, &'static str> {
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Err("sadface")
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}
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#[test]
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fn test_and() {
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assert_eq!(op1().and(Ok(667)).unwrap(), 667);
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assert_eq!(op1().and(Err::<i32, &'static str>("bad")).unwrap_err(), "bad");
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assert_eq!(op2().and(Ok(667)).unwrap_err(), "sadface");
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assert_eq!(op2().and(Err::<i32, &'static str>("bad")).unwrap_err(), "sadface");
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}
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#[test]
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fn test_and_then() {
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assert_eq!(op1().and_then(|i| Ok::<isize, &'static str>(i + 1)).unwrap(), 667);
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assert_eq!(op1().and_then(|_| Err::<isize, &'static str>("bad")).unwrap_err(), "bad");
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assert_eq!(op2().and_then(|i| Ok::<isize, &'static str>(i + 1)).unwrap_err(), "sadface");
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assert_eq!(op2().and_then(|_| Err::<isize, &'static str>("bad")).unwrap_err(), "sadface");
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}
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#[test]
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fn test_or() {
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assert_eq!(op1().or(Ok::<_, &'static str>(667)).unwrap(), 666);
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assert_eq!(op1().or(Err("bad")).unwrap(), 666);
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assert_eq!(op2().or(Ok::<_, &'static str>(667)).unwrap(), 667);
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assert_eq!(op2().or(Err("bad")).unwrap_err(), "bad");
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}
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#[test]
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fn test_or_else() {
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assert_eq!(op1().or_else(|_| Ok::<isize, &'static str>(667)).unwrap(), 666);
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assert_eq!(op1().or_else(|e| Err::<isize, &'static str>(e)).unwrap(), 666);
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assert_eq!(op2().or_else(|_| Ok::<isize, &'static str>(667)).unwrap(), 667);
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assert_eq!(op2().or_else(|e| Err::<isize, &'static str>(e)).unwrap_err(), "sadface");
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}
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#[test]
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fn test_impl_map() {
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assert!(Ok::<isize, isize>(1).map(|x| x + 1) == Ok(2));
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assert!(Err::<isize, isize>(1).map(|x| x + 1) == Err(1));
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}
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#[test]
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fn test_impl_map_err() {
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assert!(Ok::<isize, isize>(1).map_err(|x| x + 1) == Ok(1));
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assert!(Err::<isize, isize>(1).map_err(|x| x + 1) == Err(2));
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}
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#[test]
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fn test_collect() {
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let v: Result<Vec<isize>, ()> = (0..0).map(|_| Ok::<isize, ()>(0)).collect();
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assert!(v == Ok(vec![]));
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let v: Result<Vec<isize>, ()> = (0..3).map(|x| Ok::<isize, ()>(x)).collect();
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assert!(v == Ok(vec![0, 1, 2]));
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let v: Result<Vec<isize>, isize> = (0..3).map(|x| if x > 1 { Err(x) } else { Ok(x) }).collect();
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assert!(v == Err(2));
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// test that it does not take more elements than it needs
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let mut functions: [Box<dyn Fn() -> Result<(), isize>>; 3] =
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[box || Ok(()), box || Err(1), box || panic!()];
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let v: Result<Vec<()>, isize> = functions.iter_mut().map(|f| (*f)()).collect();
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assert!(v == Err(1));
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}
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#[test]
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fn test_fmt_default() {
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let ok: Result<isize, &'static str> = Ok(100);
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let err: Result<isize, &'static str> = Err("Err");
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let s = format!("{:?}", ok);
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assert_eq!(s, "Ok(100)");
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let s = format!("{:?}", err);
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assert_eq!(s, "Err(\"Err\")");
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}
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#[test]
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fn test_unwrap_or() {
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let ok: Result<isize, &'static str> = Ok(100);
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let ok_err: Result<isize, &'static str> = Err("Err");
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assert_eq!(ok.unwrap_or(50), 100);
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assert_eq!(ok_err.unwrap_or(50), 50);
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}
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#[test]
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fn test_ok_or_err() {
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let ok: Result<isize, isize> = Ok(100);
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let err: Result<isize, isize> = Err(200);
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assert_eq!(ok.into_ok_or_err(), 100);
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assert_eq!(err.into_ok_or_err(), 200);
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}
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#[test]
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fn test_unwrap_or_else() {
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fn handler(msg: &'static str) -> isize {
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if msg == "I got this." { 50 } else { panic!("BadBad") }
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}
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let ok: Result<isize, &'static str> = Ok(100);
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let ok_err: Result<isize, &'static str> = Err("I got this.");
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assert_eq!(ok.unwrap_or_else(handler), 100);
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assert_eq!(ok_err.unwrap_or_else(handler), 50);
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}
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#[test]
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#[should_panic]
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pub fn test_unwrap_or_else_panic() {
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fn handler(msg: &'static str) -> isize {
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if msg == "I got this." { 50 } else { panic!("BadBad") }
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}
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let bad_err: Result<isize, &'static str> = Err("Unrecoverable mess.");
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let _: isize = bad_err.unwrap_or_else(handler);
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}
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#[test]
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fn test_unwrap_unchecked() {
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let ok: Result<isize, &'static str> = Ok(100);
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assert_eq!(unsafe { ok.unwrap_unchecked() }, 100);
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}
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#[test]
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fn test_unwrap_err_unchecked() {
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let ok_err: Result<isize, &'static str> = Err("Err");
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assert_eq!(unsafe { ok_err.unwrap_err_unchecked() }, "Err");
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}
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#[test]
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pub fn test_expect_ok() {
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let ok: Result<isize, &'static str> = Ok(100);
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assert_eq!(ok.expect("Unexpected error"), 100);
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}
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#[test]
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#[should_panic(expected = "Got expected error: \"All good\"")]
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pub fn test_expect_err() {
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let err: Result<isize, &'static str> = Err("All good");
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err.expect("Got expected error");
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}
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#[test]
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pub fn test_expect_err_err() {
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let ok: Result<&'static str, isize> = Err(100);
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assert_eq!(ok.expect_err("Unexpected ok"), 100);
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}
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#[test]
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#[should_panic(expected = "Got expected ok: \"All good\"")]
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pub fn test_expect_err_ok() {
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let err: Result<&'static str, isize> = Ok("All good");
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err.expect_err("Got expected ok");
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}
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#[test]
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pub fn test_iter() {
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let ok: Result<isize, &'static str> = Ok(100);
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let mut it = ok.iter();
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assert_eq!(it.size_hint(), (1, Some(1)));
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assert_eq!(it.next(), Some(&100));
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assert_eq!(it.size_hint(), (0, Some(0)));
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assert!(it.next().is_none());
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assert_eq!((&ok).into_iter().next(), Some(&100));
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let err: Result<isize, &'static str> = Err("error");
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assert_eq!(err.iter().next(), None);
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}
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#[test]
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pub fn test_iter_mut() {
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let mut ok: Result<isize, &'static str> = Ok(100);
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for loc in ok.iter_mut() {
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*loc = 200;
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}
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assert_eq!(ok, Ok(200));
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for loc in &mut ok {
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*loc = 300;
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}
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assert_eq!(ok, Ok(300));
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let mut err: Result<isize, &'static str> = Err("error");
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for loc in err.iter_mut() {
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*loc = 200;
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}
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assert_eq!(err, Err("error"));
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}
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#[test]
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pub fn test_unwrap_or_default() {
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assert_eq!(op1().unwrap_or_default(), 666);
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assert_eq!(op2().unwrap_or_default(), 0);
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}
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#[test]
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pub fn test_into_ok() {
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fn infallible_op() -> Result<isize, !> {
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Ok(666)
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}
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assert_eq!(infallible_op().into_ok(), 666);
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enum MyNeverToken {}
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impl From<MyNeverToken> for ! {
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fn from(never: MyNeverToken) -> ! {
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match never {}
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}
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}
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fn infallible_op2() -> Result<isize, MyNeverToken> {
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Ok(667)
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}
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assert_eq!(infallible_op2().into_ok(), 667);
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}
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#[test]
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pub fn test_into_err() {
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fn until_error_op() -> Result<!, isize> {
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Err(666)
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}
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assert_eq!(until_error_op().into_err(), 666);
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enum MyNeverToken {}
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impl From<MyNeverToken> for ! {
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fn from(never: MyNeverToken) -> ! {
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match never {}
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}
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}
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fn until_error_op2() -> Result<MyNeverToken, isize> {
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Err(667)
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}
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assert_eq!(until_error_op2().into_err(), 667);
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}
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#[test]
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fn test_try() {
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fn try_result_some() -> Option<u8> {
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let val = Ok(1)?;
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Some(val)
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}
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assert_eq!(try_result_some(), Some(1));
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fn try_result_none() -> Option<u8> {
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let val = Err(NoneError)?;
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Some(val)
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}
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assert_eq!(try_result_none(), None);
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fn try_result_ok() -> Result<u8, u8> {
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let result: Result<u8, u8> = Ok(1);
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let val = result?;
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Ok(val)
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}
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assert_eq!(try_result_ok(), Ok(1));
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fn try_result_err() -> Result<u8, u8> {
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let result: Result<u8, u8> = Err(1);
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let val = result?;
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Ok(val)
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}
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assert_eq!(try_result_err(), Err(1));
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}
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#[test]
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fn test_result_as_deref() {
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// &Result<T: Deref, E>::Ok(T).as_deref() ->
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// Result<&T::Deref::Target, &E>::Ok(&*T)
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let ref_ok = &Result::Ok::<&i32, u8>(&42);
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let expected_result = Result::Ok::<&i32, &u8>(&42);
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assert_eq!(ref_ok.as_deref(), expected_result);
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let ref_ok = &Result::Ok::<String, u32>(String::from("a result"));
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let expected_result = Result::Ok::<&str, &u32>("a result");
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assert_eq!(ref_ok.as_deref(), expected_result);
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let ref_ok = &Result::Ok::<Vec<i32>, u32>(vec![1, 2, 3, 4, 5]);
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let expected_result = Result::Ok::<&[i32], &u32>([1, 2, 3, 4, 5].as_slice());
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assert_eq!(ref_ok.as_deref(), expected_result);
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// &Result<T: Deref, E>::Err(T).as_deref() ->
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// Result<&T::Deref::Target, &E>::Err(&*E)
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let val = 41;
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let ref_err = &Result::Err::<&u8, i32>(val);
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let expected_result = Result::Err::<&u8, &i32>(&val);
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assert_eq!(ref_err.as_deref(), expected_result);
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let s = String::from("an error");
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let ref_err = &Result::Err::<&u32, String>(s.clone());
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let expected_result = Result::Err::<&u32, &String>(&s);
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assert_eq!(ref_err.as_deref(), expected_result);
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let v = vec![5, 4, 3, 2, 1];
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let ref_err = &Result::Err::<&u32, Vec<i32>>(v.clone());
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let expected_result = Result::Err::<&u32, &Vec<i32>>(&v);
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assert_eq!(ref_err.as_deref(), expected_result);
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}
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#[test]
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fn test_result_as_deref_mut() {
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// &mut Result<T: DerefMut, E>::Ok(T).as_deref_mut() ->
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// Result<&mut T::DerefMut::Target, &mut E>::Ok(&mut *T)
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let mut val = 42;
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let mut expected_val = 42;
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let mut_ok = &mut Result::Ok::<&mut i32, u8>(&mut val);
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let expected_result = Result::Ok::<&mut i32, &mut u8>(&mut expected_val);
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assert_eq!(mut_ok.as_deref_mut(), expected_result);
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let mut expected_string = String::from("a result");
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let mut_ok = &mut Result::Ok::<String, u32>(expected_string.clone());
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let expected_result = Result::Ok::<&mut str, &mut u32>(expected_string.deref_mut());
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assert_eq!(mut_ok.as_deref_mut(), expected_result);
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let mut expected_vec = vec![1, 2, 3, 4, 5];
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let mut_ok = &mut Result::Ok::<Vec<i32>, u32>(expected_vec.clone());
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let expected_result = Result::Ok::<&mut [i32], &mut u32>(expected_vec.as_mut_slice());
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assert_eq!(mut_ok.as_deref_mut(), expected_result);
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// &mut Result<T: DerefMut, E>::Err(T).as_deref_mut() ->
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// Result<&mut T, &mut E>::Err(&mut *E)
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let mut val = 41;
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let mut_err = &mut Result::Err::<&mut u8, i32>(val);
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let expected_result = Result::Err::<&mut u8, &mut i32>(&mut val);
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assert_eq!(mut_err.as_deref_mut(), expected_result);
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let mut expected_string = String::from("an error");
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let mut_err = &mut Result::Err::<&mut u32, String>(expected_string.clone());
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let expected_result = Result::Err::<&mut u32, &mut String>(&mut expected_string);
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assert_eq!(mut_err.as_deref_mut(), expected_result);
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let mut expected_vec = vec![5, 4, 3, 2, 1];
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let mut_err = &mut Result::Err::<&mut u32, Vec<i32>>(expected_vec.clone());
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let expected_result = Result::Err::<&mut u32, &mut Vec<i32>>(&mut expected_vec);
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assert_eq!(mut_err.as_deref_mut(), expected_result);
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}
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#[test]
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fn result_const() {
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// test that the methods of `Result` are usable in a const context
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const RESULT: Result<usize, bool> = Ok(32);
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const REF: Result<&usize, &bool> = RESULT.as_ref();
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assert_eq!(REF, Ok(&32));
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const IS_OK: bool = RESULT.is_ok();
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assert!(IS_OK);
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const IS_ERR: bool = RESULT.is_err();
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assert!(!IS_ERR)
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}
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#[test]
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fn result_opt_conversions() {
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#[derive(Copy, Clone, Debug, PartialEq)]
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struct BadNumErr;
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fn try_num(x: i32) -> Result<i32, BadNumErr> {
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if x <= 5 { Ok(x + 1) } else { Err(BadNumErr) }
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}
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type ResOpt = Result<Option<i32>, BadNumErr>;
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type OptRes = Option<Result<i32, BadNumErr>>;
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let mut x: ResOpt = Ok(Some(5));
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let mut y: OptRes = Some(Ok(5));
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assert_eq!(x, y.transpose());
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assert_eq!(x.transpose(), y);
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x = Ok(None);
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y = None;
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assert_eq!(x, y.transpose());
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assert_eq!(x.transpose(), y);
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x = Err(BadNumErr);
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y = Some(Err(BadNumErr));
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assert_eq!(x, y.transpose());
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assert_eq!(x.transpose(), y);
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let res: Result<Vec<i32>, BadNumErr> = (0..10)
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.map(|x| {
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let y = try_num(x)?;
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Ok(if y % 2 == 0 { Some(y - 1) } else { None })
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})
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.filter_map(Result::transpose)
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.collect();
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assert_eq!(res, Err(BadNumErr))
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}
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