bool - Rust
Description: API documentation for the Rust `bool` primitive in crate `std`.
Keywords: rust, rustlang, rust-lang, bool

# 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 Default for bool`

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####

`fn default() -> bool`

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Returns the default value of `false`

###

`impl Hash for bool`

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####

`fn hash<H>(&self, state: &mut H) where H: Hasher,`

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Feeds this value into the given [`Hasher`]. Read more

####

`fn hash_slice<H>(data: &[Self], state: &mut H) where H: Hasher,`

1.3.0
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Feeds a slice of this type into the given [`Hasher`]. Read more

###

`impl BitXorAssign<bool> for bool`

1.8.0
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####

`fn bitxor_assign(&mut self, other: bool)`

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Performs the `^=` operation.

###

`impl<'a> BitXorAssign<&'a bool> for bool`

1.22.0
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####

`fn bitxor_assign(&mut self, other: &'a bool)`

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Performs the `^=` operation.

###

`impl BitOrAssign<bool> for bool`

1.8.0
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####

`fn bitor_assign(&mut self, other: bool)`

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Performs the `|=` operation.

###

`impl<'a> BitOrAssign<&'a bool> for bool`

1.22.0
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####

`fn bitor_assign(&mut self, other: &'a bool)`

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Performs the `|=` operation.

###

`impl BitAndAssign<bool> for bool`

1.8.0
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####

`fn bitand_assign(&mut self, other: bool)`

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Performs the `&=` operation.

###

`impl<'a> BitAndAssign<&'a bool> for bool`

1.22.0
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####

`fn bitand_assign(&mut self, other: &'a bool)`

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Performs the `&=` operation.

###

`impl Debug for bool`

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####

`fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`

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Formats the value using the given formatter. Read more

###

`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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Performs the `|` operation.

###

`impl<'a, 'b> BitOr<&'a bool> for &'b bool`

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#### `type Output = <bool as BitOr<bool>>::Output`

The resulting type after applying the `|` operator.

####

`fn bitor(self, other: &'a bool) -> <bool as BitOr<bool>>::Output`

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Performs the `|` operation.

###

`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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Performs the `|` operation.

###

`impl<'a> BitOr<&'a 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: &'a bool) -> <bool as BitOr<bool>>::Output`

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Performs the `|` operation.

###

`impl Clone for bool`

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####

`fn clone(&self) -> bool`

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Returns a copy of the value. Read more

####

`fn clone_from(&mut self, source: &Self)`

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Performs copy-assignment from `source`. Read more

###

`impl PartialOrd<bool> for bool`

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####

`fn partial_cmp(&self, other: &bool) -> Option<Ordering>`

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This method returns an ordering between `self` and `other` values if one exists. Read more

####

`#[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`

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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 Ord for bool`

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####

`fn cmp(&self, other: &bool) -> Ordering`

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This method returns an `Ordering` between `self` and `other`. Read more

####

`fn max(self, other: Self) -> Self`

1.21.0
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Compares and returns the maximum of two values. Read more

####

`fn min(self, other: Self) -> Self`

1.21.0
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Compares and returns the minimum of two values. Read more

###

`impl<'a> BitXor<&'a 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: &'a bool) -> <bool as BitXor<bool>>::Output`

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Performs the `^` operation.

###

`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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Performs the `^` operation.

###

`impl<'a, 'b> BitXor<&'a bool> for &'b bool`

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#### `type Output = <bool as BitXor<bool>>::Output`

The resulting type after applying the `^` operator.

####

`fn bitxor(self, other: &'a bool) -> <bool as BitXor<bool>>::Output`

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Performs the `^` operation.

###

`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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Performs the `^` operation.

###

`impl Eq for bool`

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###

`impl PartialEq<bool> for bool`

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####

`fn eq(&self, other: &bool) -> bool`

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This method tests for `self` and `other` values to be equal, and is used by `==`. Read more

####

`fn ne(&self, other: &bool) -> bool`

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This method tests for `!=`.

###

`impl Not for bool`

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#### `type Output = bool`

The resulting type after applying the `!` operator.

####

`fn not(self) -> bool`

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Performs the unary `!` operation.

###

`impl<'a> Not for &'a 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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Performs the unary `!` operation.

###

`impl Copy for bool`

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###

`impl Display for bool`

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####

`fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`

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Formats the value using the given formatter. Read more

###

`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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Performs the `&` operation.

###

`impl<'a> BitAnd<&'a 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: &'a bool) -> <bool as BitAnd<bool>>::Output`

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Performs the `&` operation.

###

`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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Performs the `&` operation.

###

`impl<'a, 'b> BitAnd<&'a bool> for &'b bool`

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#### `type Output = <bool as BitAnd<bool>>::Output`

The resulting type after applying the `&` operator.

####

`fn bitand(self, other: &'a bool) -> <bool as BitAnd<bool>>::Output`

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Performs the `&` operation.

###

`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

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