use core::cell::Cell; use core::clone::Clone; use core::mem; use core::ops::DerefMut; use core::option::*; #[test] fn test_get_ptr() { unsafe { let x: Box<_> = box 0; let addr_x: *const isize = mem::transmute(&*x); let opt = Some(x); let y = opt.unwrap(); let addr_y: *const isize = mem::transmute(&*y); assert_eq!(addr_x, addr_y); } } #[test] fn test_get_str() { let x = "test".to_string(); let addr_x = x.as_ptr(); let opt = Some(x); let y = opt.unwrap(); let addr_y = y.as_ptr(); assert_eq!(addr_x, addr_y); } #[test] fn test_get_resource() { use core::cell::RefCell; use std::rc::Rc; struct R { i: Rc>, } impl Drop for R { fn drop(&mut self) { let ii = &*self.i; let i = *ii.borrow(); *ii.borrow_mut() = i + 1; } } fn r(i: Rc>) -> R { R { i } } let i = Rc::new(RefCell::new(0)); { let x = r(i.clone()); let opt = Some(x); let _y = opt.unwrap(); } assert_eq!(*i.borrow(), 1); } #[test] fn test_option_dance() { let x = Some(()); let mut y = Some(5); let mut y2 = 0; for _x in x { y2 = y.take().unwrap(); } assert_eq!(y2, 5); assert!(y.is_none()); } #[test] #[should_panic] fn test_option_too_much_dance() { struct A; let mut y = Some(A); let _y2 = y.take().unwrap(); let _y3 = y.take().unwrap(); } #[test] fn test_and() { let x: Option = Some(1); assert_eq!(x.and(Some(2)), Some(2)); assert_eq!(x.and(None::), None); let x: Option = None; assert_eq!(x.and(Some(2)), None); assert_eq!(x.and(None::), None); } #[test] fn test_and_then() { let x: Option = Some(1); assert_eq!(x.and_then(|x| Some(x + 1)), Some(2)); assert_eq!(x.and_then(|_| None::), None); let x: Option = None; assert_eq!(x.and_then(|x| Some(x + 1)), None); assert_eq!(x.and_then(|_| None::), None); } #[test] fn test_or() { let x: Option = Some(1); assert_eq!(x.or(Some(2)), Some(1)); assert_eq!(x.or(None), Some(1)); let x: Option = None; assert_eq!(x.or(Some(2)), Some(2)); assert_eq!(x.or(None), None); } #[test] fn test_or_else() { let x: Option = Some(1); assert_eq!(x.or_else(|| Some(2)), Some(1)); assert_eq!(x.or_else(|| None), Some(1)); let x: Option = None; assert_eq!(x.or_else(|| Some(2)), Some(2)); assert_eq!(x.or_else(|| None), None); } #[test] fn test_unwrap() { assert_eq!(Some(1).unwrap(), 1); let s = Some("hello".to_string()).unwrap(); assert_eq!(s, "hello"); } #[test] #[should_panic] fn test_unwrap_panic1() { let x: Option = None; x.unwrap(); } #[test] #[should_panic] fn test_unwrap_panic2() { let x: Option = None; x.unwrap(); } #[test] fn test_unwrap_or() { let x: Option = Some(1); assert_eq!(x.unwrap_or(2), 1); let x: Option = None; assert_eq!(x.unwrap_or(2), 2); } #[test] fn test_unwrap_or_else() { let x: Option = Some(1); assert_eq!(x.unwrap_or_else(|| 2), 1); let x: Option = None; assert_eq!(x.unwrap_or_else(|| 2), 2); } #[test] fn test_unwrap_unchecked() { assert_eq!(unsafe { Some(1).unwrap_unchecked() }, 1); let s = unsafe { Some("hello".to_string()).unwrap_unchecked() }; assert_eq!(s, "hello"); } #[test] fn test_iter() { let val = 5; let x = Some(val); let mut it = x.iter(); assert_eq!(it.size_hint(), (1, Some(1))); assert_eq!(it.next(), Some(&val)); assert_eq!(it.size_hint(), (0, Some(0))); assert!(it.next().is_none()); let mut it = (&x).into_iter(); assert_eq!(it.next(), Some(&val)); } #[test] fn test_mut_iter() { let mut val = 5; let new_val = 11; let mut x = Some(val); { let mut it = x.iter_mut(); assert_eq!(it.size_hint(), (1, Some(1))); match it.next() { Some(interior) => { assert_eq!(*interior, val); *interior = new_val; } None => assert!(false), } assert_eq!(it.size_hint(), (0, Some(0))); assert!(it.next().is_none()); } assert_eq!(x, Some(new_val)); let mut y = Some(val); let mut it = (&mut y).into_iter(); assert_eq!(it.next(), Some(&mut val)); } #[test] fn test_ord() { let small = Some(1.0f64); let big = Some(5.0f64); let nan = Some(0.0f64 / 0.0); assert!(!(nan < big)); assert!(!(nan > big)); assert!(small < big); assert!(None < big); assert!(big > None); } #[test] fn test_collect() { let v: Option> = (0..0).map(|_| Some(0)).collect(); assert!(v == Some(vec![])); let v: Option> = (0..3).map(|x| Some(x)).collect(); assert!(v == Some(vec![0, 1, 2])); let v: Option> = (0..3).map(|x| if x > 1 { None } else { Some(x) }).collect(); assert!(v == None); // test that it does not take more elements than it needs let mut functions: [Box Option<()>>; 3] = [box || Some(()), box || None, box || panic!()]; let v: Option> = functions.iter_mut().map(|f| (*f)()).collect(); assert!(v == None); } #[test] fn test_copied() { let val = 1; let val_ref = &val; let opt_none: Option<&'static u32> = None; let opt_ref = Some(&val); let opt_ref_ref = Some(&val_ref); // None works assert_eq!(opt_none.clone(), None); assert_eq!(opt_none.copied(), None); // Immutable ref works assert_eq!(opt_ref.clone(), Some(&val)); assert_eq!(opt_ref.copied(), Some(1)); // Double Immutable ref works assert_eq!(opt_ref_ref.clone(), Some(&val_ref)); assert_eq!(opt_ref_ref.clone().copied(), Some(&val)); assert_eq!(opt_ref_ref.copied().copied(), Some(1)); } #[test] fn test_cloned() { let val = 1; let val_ref = &val; let opt_none: Option<&'static u32> = None; let opt_ref = Some(&val); let opt_ref_ref = Some(&val_ref); // None works assert_eq!(opt_none.clone(), None); assert_eq!(opt_none.cloned(), None); // Immutable ref works assert_eq!(opt_ref.clone(), Some(&val)); assert_eq!(opt_ref.cloned(), Some(1)); // Double Immutable ref works assert_eq!(opt_ref_ref.clone(), Some(&val_ref)); assert_eq!(opt_ref_ref.clone().cloned(), Some(&val)); assert_eq!(opt_ref_ref.cloned().cloned(), Some(1)); } #[test] fn test_try() { fn try_option_some() -> Option { let val = Some(1)?; Some(val) } assert_eq!(try_option_some(), Some(1)); fn try_option_none() -> Option { let val = None?; Some(val) } assert_eq!(try_option_none(), None); } #[test] fn test_option_as_deref() { // Some: &Option::Some(T) -> Option<&T::Deref::Target>::Some(&*T) let ref_option = &Some(&42); assert_eq!(ref_option.as_deref(), Some(&42)); let ref_option = &Some(String::from("a result")); assert_eq!(ref_option.as_deref(), Some("a result")); let ref_option = &Some(vec![1, 2, 3, 4, 5]); assert_eq!(ref_option.as_deref(), Some([1, 2, 3, 4, 5].as_slice())); // None: &Option>::None -> None let ref_option: &Option<&i32> = &None; assert_eq!(ref_option.as_deref(), None); } #[test] fn test_option_as_deref_mut() { // Some: &mut Option::Some(T) -> Option<&mut T::Deref::Target>::Some(&mut *T) let mut val = 42; let ref_option = &mut Some(&mut val); assert_eq!(ref_option.as_deref_mut(), Some(&mut 42)); let ref_option = &mut Some(String::from("a result")); assert_eq!(ref_option.as_deref_mut(), Some(String::from("a result").deref_mut())); let ref_option = &mut Some(vec![1, 2, 3, 4, 5]); assert_eq!(ref_option.as_deref_mut(), Some([1, 2, 3, 4, 5].as_mut_slice())); // None: &mut Option>::None -> None let ref_option: &mut Option<&mut i32> = &mut None; assert_eq!(ref_option.as_deref_mut(), None); } #[test] fn test_replace() { let mut x = Some(2); let old = x.replace(5); assert_eq!(x, Some(5)); assert_eq!(old, Some(2)); let mut x = None; let old = x.replace(3); assert_eq!(x, Some(3)); assert_eq!(old, None); } #[test] fn option_const() { // test that the methods of `Option` are usable in a const context const OPTION: Option = Some(32); const REF: Option<&usize> = OPTION.as_ref(); assert_eq!(REF, Some(&32)); const IS_SOME: bool = OPTION.is_some(); assert!(IS_SOME); const IS_NONE: bool = OPTION.is_none(); assert!(!IS_NONE); } #[test] fn test_unwrap_drop() { struct Dtor<'a> { x: &'a Cell, } impl<'a> std::ops::Drop for Dtor<'a> { fn drop(&mut self) { self.x.set(self.x.get() - 1); } } fn unwrap(o: Option) -> T { match o { Some(v) => v, None => panic!(), } } let x = &Cell::new(1); { let b = Some(Dtor { x }); let _c = unwrap(b); } assert_eq!(x.get(), 0); } #[test] pub fn option_ext() { let thing = "{{ f }}"; let f = thing.find("{{"); if f.is_none() { println!("None!"); } }