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.
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);
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!"),
} 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);
impl Default for bool
[src]
fn default() -> bool
[src]
Returns the default value of false
impl PartialOrd<bool> for bool
[src]
fn partial_cmp(&self, other: &bool) -> Option<Ordering>
[src]
This method returns an ordering between self and other values if one exists. Read more
fn lt(&self, other: &Rhs) -> bool
[src]
This method tests less than (for self and other) and is used by the < operator. Read more
fn le(&self, other: &Rhs) -> bool
[src]
This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
fn gt(&self, other: &Rhs) -> bool
[src]
This method tests greater than (for self and other) and is used by the > operator. Read more
fn ge(&self, other: &Rhs) -> bool
[src]
This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
impl BitXorAssign<bool> for bool
fn bitxor_assign(&mut self, other: bool)
[src]
Performs the ^= operation.
impl<'a> BitXorAssign<&'a bool> for bool
fn bitxor_assign(&mut self, other: &'a bool)
[src]
Performs the ^= operation.
impl BitAndAssign<bool> for bool
fn bitand_assign(&mut self, other: bool)
[src]
Performs the &= operation.
impl<'a> BitAndAssign<&'a bool> for bool
fn bitand_assign(&mut self, other: &'a bool)
[src]
Performs the &= operation.
impl Eq for bool
[src]
impl<'a> BitOr<bool> for &'a bool
[src]
type Output = <bool as BitOr<bool>>::OutputThe resulting type after applying the | operator.
fn bitor(self, other: bool) -> <bool as BitOr<bool>>::Output
[src]
Performs the | operation.
impl BitOr<bool> for bool
[src]
type Output = boolThe resulting type after applying the | operator.
fn bitor(self, rhs: bool) -> bool
[src]
Performs the | operation.
impl<'a, 'b> BitOr<&'a bool> for &'b bool
[src]
type Output = <bool as BitOr<bool>>::OutputThe resulting type after applying the | operator.
fn bitor(self, other: &'a bool) -> <bool as BitOr<bool>>::Output
[src]
Performs the | operation.
impl<'a> BitOr<&'a bool> for bool
[src]
type Output = <bool as BitOr<bool>>::OutputThe resulting type after applying the | operator.
fn bitor(self, other: &'a bool) -> <bool as BitOr<bool>>::Output
[src]
Performs the | operation.
impl Hash for bool
[src]
fn hash<H>(&self, state: &mut H) where
H: Hasher,
[src]
Feeds this value into the given [Hasher]. Read more
fn hash_slice<H>(data: &[Self], state: &mut H) where
H: Hasher,
Feeds a slice of this type into the given [Hasher]. Read more
impl Display for bool
[src]
fn fmt(&self, f: &mut Formatter) -> Result<(), Error>
[src]
Formats the value using the given formatter. Read more
impl<'a> BitAnd<&'a bool> for bool
[src]
type Output = <bool as BitAnd<bool>>::OutputThe resulting type after applying the & operator.
fn bitand(self, other: &'a bool) -> <bool as BitAnd<bool>>::Output
[src]
Performs the & operation.
impl<'a> BitAnd<bool> for &'a bool
[src]
type Output = <bool as BitAnd<bool>>::OutputThe resulting type after applying the & operator.
fn bitand(self, other: bool) -> <bool as BitAnd<bool>>::Output
[src]
Performs the & operation.
impl BitAnd<bool> for bool
[src]
type Output = boolThe resulting type after applying the & operator.
fn bitand(self, rhs: bool) -> bool
[src]
Performs the & operation.
impl<'a, 'b> BitAnd<&'a bool> for &'b bool
[src]
type Output = <bool as BitAnd<bool>>::OutputThe resulting type after applying the & operator.
fn bitand(self, other: &'a bool) -> <bool as BitAnd<bool>>::Output
[src]
Performs the & operation.
impl Ord for bool
[src]
fn cmp(&self, other: &bool) -> Ordering
[src]
This method returns an Ordering between self and other. Read more
fn max(self, other: Self) -> Self
Compares and returns the maximum of two values. Read more
fn min(self, other: Self) -> Self
Compares and returns the minimum of two values. Read more
impl<'a> BitOrAssign<&'a bool> for bool
fn bitor_assign(&mut self, other: &'a bool)
[src]
Performs the |= operation.
impl BitOrAssign<bool> for bool
fn bitor_assign(&mut self, other: bool)
[src]
Performs the |= operation.
impl PartialEq<bool> for bool
[src]
fn eq(&self, other: &bool) -> bool
[src]
This method tests for self and other values to be equal, and is used by ==. Read more
fn ne(&self, other: &bool) -> bool
[src]
This method tests for !=.
impl<'a> BitXor<bool> for &'a bool
[src]
type Output = <bool as BitXor<bool>>::OutputThe resulting type after applying the ^ operator.
fn bitxor(self, other: bool) -> <bool as BitXor<bool>>::Output
[src]
Performs the ^ operation.
impl BitXor<bool> for bool
[src]
type Output = boolThe resulting type after applying the ^ operator.
fn bitxor(self, other: bool) -> bool
[src]
Performs the ^ operation.
impl<'a, 'b> BitXor<&'a bool> for &'b bool
[src]
type Output = <bool as BitXor<bool>>::OutputThe resulting type after applying the ^ operator.
fn bitxor(self, other: &'a bool) -> <bool as BitXor<bool>>::Output
[src]
Performs the ^ operation.
impl<'a> BitXor<&'a bool> for bool
[src]
type Output = <bool as BitXor<bool>>::OutputThe resulting type after applying the ^ operator.
fn bitxor(self, other: &'a bool) -> <bool as BitXor<bool>>::Output
[src]
Performs the ^ operation.
impl Not for bool
[src]
type Output = boolThe resulting type after applying the ! operator.
fn not(self) -> bool
[src]
Performs the unary ! operation.
impl<'a> Not for &'a bool
[src]
type Output = <bool as Not>::OutputThe resulting type after applying the ! operator.
fn not(self) -> <bool as Not>::Output
[src]
Performs the unary ! operation.
impl FromStr for bool
[src]
type Err = ParseBoolErrorThe associated error which can be returned from parsing.
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.
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()); 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()); impl Debug for bool
[src]
fn fmt(&self, f: &mut Formatter) -> Result<(), Error>
[src]
Formats the value using the given formatter. Read more
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/primitive.bool.html