Trait std::fmt::Octal

1.0.0 · source ·
pub trait Octal {
    // Required method
    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>;
}
Expand description

o formatting.

The Octal trait should format its output as a number in base-8.

For primitive signed integers (i8 to i128, and isize), negative values are formatted as the two’s complement representation.

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

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

§Examples

Basic usage with i32:

let x = 42; // 42 is '52' in octal

assert_eq!(format!("{x:o}"), "52");
assert_eq!(format!("{x:#o}"), "0o52");

assert_eq!(format!("{:o}", -16), "37777777760");
Run

Implementing Octal on a type:

use std::fmt;

struct Length(i32);

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

        fmt::Octal::fmt(&val, f) // delegate to i32's implementation
    }
}

let l = Length(9);

assert_eq!(format!("l as octal is: {l:o}"), "l as octal is: 11");

assert_eq!(format!("l as octal is: {l:#06o}"), "l as octal is: 0o0011");
Run

Required Methods§

source

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

Formats the value using the given formatter.

Implementors§

source§

impl Octal for i8

source§

impl Octal for i16

source§

impl Octal for i32

source§

impl Octal for i64

source§

impl Octal for i128

source§

impl Octal for isize

source§

impl Octal for u8

source§

impl Octal for u16

source§

impl Octal for u32

source§

impl Octal for u64

source§

impl Octal for u128

source§

impl Octal for usize

source§

impl<T> Octal for &T
where T: Octal + ?Sized,

source§

impl<T> Octal for &mut T
where T: Octal + ?Sized,

1.28.0 · source§

impl<T> Octal for NonZero<T>

1.74.0 · source§

impl<T> Octal for Saturating<T>
where T: Octal,

1.11.0 · source§

impl<T> Octal for Wrapping<T>
where T: Octal,