Octal in alloc::fmt - Rust
Description: `o` formatting.
Keywords: rust, rustlang, rust-lang, Octal

# Trait alloc::fmt::Octal
1.0.0[−][src]

    pub trait Octal {
        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!("{:o}", x), "52");
    assert_eq!(format!("{:#o}", x), "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: {:o}", l), "l as octal is: 11");

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

Run

## Required methods

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

Formats the value using the given formatter.

## Implementations on Foreign Types

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

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

1.34.0[src]

### impl Octal for NonZeroI128

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

1.34.0[src]

### impl Octal for NonZeroI32

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

1.28.0[src]

### impl Octal for NonZeroU32

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

1.28.0[src]

### impl Octal for NonZeroU8

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

1.34.0[src]

### impl Octal for NonZeroI8

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

1.28.0[src]

### impl Octal for NonZeroU64

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

1.11.0[src]

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

[src]

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

1.28.0[src]

### impl Octal for NonZeroUsize

[src]

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

1.34.0[src]

### impl Octal for NonZeroI16

[src]

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

1.34.0[src]

### impl Octal for NonZeroIsize

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

1.28.0[src]

### impl Octal for NonZeroU16

[src]

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

1.28.0[src]

### impl Octal for NonZeroU128

[src]

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

1.34.0[src]

### impl Octal for NonZeroI64

[src]

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

## Implementors

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### impl Octal for i8

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### impl Octal for i16

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### impl Octal for i32

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### impl Octal for i64

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### impl Octal for i128

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### impl Octal for isize

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### impl Octal for u8

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### impl Octal for u16

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### impl Octal for u32

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### impl Octal for u64

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### impl Octal for u128

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### impl Octal for usize

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### impl<'_, T> Octal for &'_ T where
T: Octal + ?Sized,

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### impl<'_, T> Octal for &'_ mut T where
T: Octal + ?Sized,