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!
, being an important macro in testing,
checks whether an expression returns true
.
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
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.
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.
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.
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.
fn bitand(self, other: &bool) -> <bool as BitAnd<bool>>::Output
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impl<'_> BitOrAssign<&'_ bool> for bool
1.22.0[src]
fn bitor_assign(&mut self, other: &bool)
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impl BitOrAssign<bool> for bool
1.8.0[src]
fn bitor_assign(&mut self, other: bool)
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impl PartialOrd<bool> for bool
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fn partial_cmp(&self, other: &bool) -> Option<Ordering>
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#[must_use]
fn lt(&self, other: &Rhs) -> bool
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This method tests less than (for self
and other
) and is used by the <
operator. Read more
#[must_use]
fn le(&self, other: &Rhs) -> bool
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This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
#[must_use]
fn gt(&self, other: &Rhs) -> bool
[src]
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
#[must_use]
fn ge(&self, other: &Rhs) -> bool
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This method tests greater than or equal to (for self
and other
) and is used by the >=
operator. Read more
impl Hash for bool
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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,
Feeds a slice of this type into the given [Hasher
]. Read more
impl Default for bool
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impl Eq for bool
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impl Clone for bool
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fn clone(&self) -> bool
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fn clone_from(&mut self, source: &Self)
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Performs copy-assignment from source
. Read more
impl<'_> Not for &'_ bool
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type Output = <bool as Not>::Output
The resulting type after applying the !
operator.
fn not(self) -> <bool as Not>::Output
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impl Not for bool
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impl BitAndAssign<bool> for bool
1.8.0[src]
fn bitand_assign(&mut self, other: bool)
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impl<'_> BitAndAssign<&'_ bool> for bool
1.22.0[src]
fn bitand_assign(&mut self, other: &bool)
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impl Debug for bool
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impl Copy for bool
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impl Ord for bool
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fn cmp(&self, other: &bool) -> Ordering
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fn max(self, other: Self) -> Self
1.21.0[src]
Compares and returns the maximum of two values. Read more
fn min(self, other: Self) -> Self
1.21.0[src]
Compares and returns the minimum of two values. Read more
fn clamp(self, min: Self, max: Self) -> Self
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Restrict a value to a certain interval. Read more
impl BitXor<bool> for bool
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type Output = bool
The resulting type after applying the ^
operator.
fn bitxor(self, other: bool) -> 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.
fn bitxor(self, other: &bool) -> <bool as BitXor<bool>>::Output
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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.
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.
fn bitxor(self, other: &bool) -> <bool as BitXor<bool>>::Output
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impl PartialEq<bool> for bool
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impl BitXorAssign<bool> for bool
1.8.0[src]
fn bitxor_assign(&mut self, other: bool)
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impl<'_> BitXorAssign<&'_ bool> for bool
1.22.0[src]
fn bitxor_assign(&mut self, other: &bool)
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impl Display for 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.
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.
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.
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.
fn bitor(self, rhs: bool) -> 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.
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