1.0.0[−]Primitive Type bool
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
always demands a bool
value. assert!
, which is an important macro in testing,
checks whether an expression returns 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
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pub fn then_some<T>(self, t: T) -> Option<T>
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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,
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F: FnOnce() -> T,
Trait Implementations
impl<'_> BitAnd<&'_ bool> for bool
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type Output = <bool as BitAnd<bool>>::Output
The resulting type after applying the &
operator.
pub fn bitand(self, other: &bool) -> <bool as BitAnd<bool>>::Output
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impl<'_, '_> BitAnd<&'_ bool> for &'_ bool
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type Output = <bool as BitAnd<bool>>::Output
The resulting type after applying the &
operator.
pub fn bitand(self, other: &bool) -> <bool as BitAnd<bool>>::Output
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impl BitAnd<bool> for bool
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type Output = bool
The resulting type after applying the &
operator.
pub fn bitand(self, rhs: bool) -> bool
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impl<'a> BitAnd<bool> for &'a bool
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type Output = <bool as BitAnd<bool>>::Output
The resulting type after applying the &
operator.
pub fn bitand(self, other: bool) -> <bool as BitAnd<bool>>::Output
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impl<'_> BitAndAssign<&'_ bool> for bool
1.22.0[src]
pub fn bitand_assign(&mut self, other: &bool)
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impl BitAndAssign<bool> for bool
1.8.0[src]
pub fn bitand_assign(&mut self, other: bool)
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impl<'_> BitOr<&'_ bool> for bool
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type Output = <bool as BitOr<bool>>::Output
The resulting type after applying the |
operator.
pub fn bitor(self, other: &bool) -> <bool as BitOr<bool>>::Output
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impl<'_, '_> BitOr<&'_ bool> for &'_ bool
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type Output = <bool as BitOr<bool>>::Output
The resulting type after applying the |
operator.
pub fn bitor(self, other: &bool) -> <bool as BitOr<bool>>::Output
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impl BitOr<bool> for bool
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type Output = bool
The resulting type after applying the |
operator.
pub fn bitor(self, rhs: bool) -> bool
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impl<'a> BitOr<bool> for &'a bool
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type Output = <bool as BitOr<bool>>::Output
The resulting type after applying the |
operator.
pub fn bitor(self, other: bool) -> <bool as BitOr<bool>>::Output
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impl<'_> BitOrAssign<&'_ bool> for bool
1.22.0[src]
pub fn bitor_assign(&mut self, other: &bool)
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impl BitOrAssign<bool> for bool
1.8.0[src]
pub fn bitor_assign(&mut self, other: bool)
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impl<'_> BitXor<&'_ bool> for bool
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type Output = <bool as BitXor<bool>>::Output
The resulting type after applying the ^
operator.
pub fn bitxor(self, other: &bool) -> <bool as BitXor<bool>>::Output
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impl<'_, '_> BitXor<&'_ bool> for &'_ bool
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type Output = <bool as BitXor<bool>>::Output
The resulting type after applying the ^
operator.
pub fn bitxor(self, other: &bool) -> <bool as BitXor<bool>>::Output
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impl BitXor<bool> for bool
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type Output = bool
The resulting type after applying the ^
operator.
pub fn bitxor(self, other: bool) -> bool
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impl<'a> BitXor<bool> for &'a bool
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type Output = <bool as BitXor<bool>>::Output
The resulting type after applying the ^
operator.
pub fn bitxor(self, other: bool) -> <bool as BitXor<bool>>::Output
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impl<'_> BitXorAssign<&'_ bool> for bool
1.22.0[src]
pub fn bitxor_assign(&mut self, other: &bool)
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impl BitXorAssign<bool> for bool
1.8.0[src]
pub fn bitxor_assign(&mut self, other: bool)
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impl Clone for bool
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impl Copy for bool
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impl Debug for bool
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impl Default for bool
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impl Display for bool
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impl Eq for bool
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impl FromStr for bool
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type Err = ParseBoolError
The associated error which can be returned from parsing.
pub fn from_str(s: &str) -> Result<bool, ParseBoolError>
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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 Hash for bool
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pub fn hash<H>(&self, state: &mut H) where
H: Hasher,
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H: Hasher,
fn hash_slice<H>(data: &[Self], state: &mut H) where
H: Hasher,
1.3.0[src]
H: Hasher,
impl<'_> Not for &'_ bool
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type Output = <bool as Not>::Output
The resulting type after applying the !
operator.
pub fn not(self) -> <bool as Not>::Output
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impl Not for bool
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impl Ord for bool
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pub fn cmp(&self, other: &bool) -> Ordering
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#[must_use]fn max(self, other: Self) -> Self
1.21.0[src]
#[must_use]fn min(self, other: Self) -> Self
1.21.0[src]
#[must_use]fn clamp(self, min: Self, max: Self) -> Self
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impl PartialEq<bool> for bool
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impl PartialOrd<bool> for bool
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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> Any for T where
T: 'static + ?Sized,
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T: 'static + ?Sized,
impl<T> Borrow<T> for T where
T: ?Sized,
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T: ?Sized,
pub fn borrow(&self) -> &TⓘNotable traits for &'_ mut I
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<R: Read + ?Sized, '_> Read for &'_ mut Rimpl<W: Write + ?Sized, '_> Write for &'_ mut W
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Notable traits for &'_ mut I
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<R: Read + ?Sized, '_> Read for &'_ mut Rimpl<W: Write + ?Sized, '_> Write for &'_ mut W
impl<T> BorrowMut<T> for T where
T: ?Sized,
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T: ?Sized,
pub fn borrow_mut(&mut self) -> &mut TⓘNotable traits for &'_ mut I
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<R: Read + ?Sized, '_> Read for &'_ mut Rimpl<W: Write + ?Sized, '_> Write for &'_ mut W
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Notable traits for &'_ mut I
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<R: Read + ?Sized, '_> Read for &'_ mut Rimpl<W: Write + ?Sized, '_> Write for &'_ mut W
impl<T> From<T> for T
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impl<T, U> Into<U> for T where
U: From<T>,
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U: From<T>,
impl<T> ToOwned for T where
T: Clone,
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T: Clone,
type Owned = T
The resulting type after obtaining ownership.
pub fn to_owned(&self) -> T
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pub fn clone_into(&self, target: &mut T)
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impl<T> ToString for T where
T: Display + ?Sized,
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T: Display + ?Sized,
impl<T, U> TryFrom<U> for T where
U: Into<T>,
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U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
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impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
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U: TryFrom<T>,