Primitive Type bool1.0.0[−]
The boolean type.
The bool represents a value, which could only be either true or false. If you cast
a bool into an integer, true will be 1 and false will be 0.
Basic usage
bool implements various traits, such as BitAnd, BitOr, Not, etc.,
which allow us to perform boolean operations using &, | and !.
if requires a bool value as its conditional. assert!, which is an
important macro in testing, checks whether an expression is true and panics
if it isn’t.
let bool_val = true & false | false; assert!(!bool_val);Run
Examples
A trivial example of the usage of bool:
let praise_the_borrow_checker = true; // using the `if` conditional if praise_the_borrow_checker { println!("oh, yeah!"); } else { println!("what?!!"); } // ... or, a match pattern match praise_the_borrow_checker { true => println!("keep praising!"), false => println!("you should praise!"), }Run
Also, since bool implements the Copy trait, we don’t
have to worry about the move semantics (just like the integer and float primitives).
Now an example of bool cast to integer type:
assert_eq!(true as i32, 1); assert_eq!(false as i32, 0);Run
Implementations
impl bool[src]
impl bool[src]pub fn then_some<T>(self, t: T) -> Option<T>[src]
Returns Some(t) if the bool is true, or None otherwise.
Examples
#![feature(bool_to_option)] assert_eq!(false.then_some(0), None); assert_eq!(true.then_some(0), Some(0));Run
pub fn then<T, F>(self, f: F) -> Option<T> where
F: FnOnce() -> T, 1.50.0[src]
F: FnOnce() -> T,
Trait Implementations
impl<'_> BitAndAssign<&'_ bool> for bool1.22.0[src]
impl<'_> BitAndAssign<&'_ bool> for bool1.22.0[src]pub fn bitand_assign(&mut self, other: &bool)[src]
impl BitAndAssign<bool> for bool1.8.0[src]
impl BitAndAssign<bool> for bool1.8.0[src]pub fn bitand_assign(&mut self, other: bool)[src]
impl<'_> BitOrAssign<&'_ bool> for bool1.22.0[src]
impl<'_> BitOrAssign<&'_ bool> for bool1.22.0[src]pub fn bitor_assign(&mut self, other: &bool)[src]
impl BitOrAssign<bool> for bool1.8.0[src]
impl BitOrAssign<bool> for bool1.8.0[src]pub fn bitor_assign(&mut self, other: bool)[src]
impl<'_> BitXorAssign<&'_ bool> for bool1.22.0[src]
impl<'_> BitXorAssign<&'_ bool> for bool1.22.0[src]pub fn bitxor_assign(&mut self, other: &bool)[src]
impl BitXorAssign<bool> for bool1.8.0[src]
impl BitXorAssign<bool> for bool1.8.0[src]pub fn bitxor_assign(&mut self, other: bool)[src]
impl FromStr for bool[src]
impl FromStr for bool[src]type Err = ParseBoolError
The associated error which can be returned from parsing.
pub fn from_str(s: &str) -> Result<bool, ParseBoolError>[src]
Parse a bool from a string.
Yields a Result<bool, ParseBoolError>, because s may or may not
actually be parseable.
Examples
use std::str::FromStr; assert_eq!(FromStr::from_str("true"), Ok(true)); assert_eq!(FromStr::from_str("false"), Ok(false)); assert!(<bool as FromStr>::from_str("not even a boolean").is_err());Run
Note, in many cases, the .parse() method on str is more proper.
assert_eq!("true".parse(), Ok(true)); assert_eq!("false".parse(), Ok(false)); assert!("not even a boolean".parse::<bool>().is_err());Run
impl PartialOrd<bool> for bool[src]
impl PartialOrd<bool> for bool[src]impl Copy for bool[src]
impl Eq for bool[src]
Auto Trait Implementations
impl RefUnwindSafe for bool
impl Send for bool
impl Sync for bool
impl Unpin for bool
impl UnwindSafe for bool
Blanket Implementations
impl<T> Borrow<T> for T where
T: ?Sized, [src]
impl<T> Borrow<T> for T where
T: ?Sized, [src]pub fn borrow(&self) -> &TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Future + Unpin + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W[src]
Notable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Future + Unpin + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut Wimpl<T> BorrowMut<T> for T where
T: ?Sized, [src]
impl<T> BorrowMut<T> for T where
T: ?Sized, [src]pub fn borrow_mut(&mut self) -> &mut TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Future + Unpin + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W[src]
Notable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Future + Unpin + ?Sized, type Output = <F as Future>::Output;impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<R: Read + ?Sized> Read for &mut Rimpl<W: Write + ?Sized> Write for &mut W