# Trait collections::fmt::Binary [−] [src]

    pub trait Binary {
        fn fmt(&self, &mut Formatter) -> Result<(), Error>;
    }

Format trait for the `b` character.

The `Binary` trait should format its output as a number in binary.

The alternate flag, `#`, adds a `0b` in front of the output.

For more information on formatters, see the module-level documentation.

# Examples

Basic usage with `i32`:

fn main() { let x = 42; // 42 is '101010' in binary assert_eq!(format!("{:b}", x), "101010"); assert_eq!(format!("{:#b}", x), "0b101010"); }

    let x = 42; // 42 is '101010' in binary

    assert_eq!(format!("{:b}", x), "101010");
    assert_eq!(format!("{:#b}", x), "0b101010");

Implementing `Binary` on a type:

fn main() { use std::fmt; struct Length(i32); impl fmt::Binary for Length { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { let val = self.0; write!(f, "{:b}", val) // delegate to i32's implementation } } let l = Length(107); println!("l as binary is: {:b}", l); }

    use std::fmt;

    struct Length(i32);

    impl fmt::Binary for Length {
        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
            let val = self.0;

            write!(f, "{:b}", val) // delegate to i32's implementation
        }
    }

    let l = Length(107);

    println!("l as binary is: {:b}", l);

## Required Methods

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

Formats the value using the given formatter.

## Implementors

# Help

## Keyboard Shortcuts

?
  Show this help dialog
S
  Focus the search field
⇤
  Move up in search results
⇥
  Move down in search results
⏎
  Go to active search result

## Search Tricks

Prefix searches with a type followed by a colon (e.g. `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g. `vec -> usize`)