Trait kernel::fmt::LowerHex

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

x formatting.

The LowerHex trait should format its output as a number in hexadecimal, with a through f in lower case.

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

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

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

§Examples

Basic usage with i32:

let y = 42; // 42 is '2a' in hex

assert_eq!(format!("{y:x}"), "2a");
assert_eq!(format!("{y:#x}"), "0x2a");

assert_eq!(format!("{:x}", -16), "fffffff0");

Implementing LowerHex on a type:

use std::fmt;

struct Length(i32);

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

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

let l = Length(9);

assert_eq!(format!("l as hex is: {l:x}"), "l as hex is: 9");

assert_eq!(format!("l as hex is: {l:#010x}"), "l as hex is: 0x00000009");

Required Methods§

1.0.0 · source

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

Formats the value using the given formatter.

§Errors

This function should return Err if, and only if, the provided Formatter returns Err. String formatting is considered an infallible operation; this function only returns a Result because writing to the underlying stream might fail and it must provide a way to propagate the fact that an error has occurred back up the stack.

Implementors§

1.0.0 · source§

impl LowerHex for i8

1.0.0 · source§

impl LowerHex for i16

1.0.0 · source§

impl LowerHex for i32

1.0.0 · source§

impl LowerHex for i64

1.0.0 · source§

impl LowerHex for i128

1.0.0 · source§

impl LowerHex for isize

1.0.0 · source§

impl LowerHex for u8

1.0.0 · source§

impl LowerHex for u16

1.0.0 · source§

impl LowerHex for u32

1.0.0 · source§

impl LowerHex for u64

1.0.0 · source§

impl LowerHex for u128

1.0.0 · source§

impl LowerHex for usize

source§

impl LowerHex for TaskId

source§

impl LowerHex for Packing8

source§

impl LowerHex for Packing16

source§

impl LowerHex for Packing32

source§

impl LowerHex for Packing64

source§

impl LowerHex for Packing128

source§

impl LowerHex for PackingUsize

source§

impl LowerHex for Braced

source§

impl LowerHex for Hyphenated

source§

impl LowerHex for Simple

source§

impl LowerHex for Urn

source§

impl LowerHex for Uuid

source§

impl LowerHex for Modifiers

1.0.0 · source§

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

1.0.0 · source§

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

source§

impl<T> LowerHex for Pair8<T>

source§

impl<T> LowerHex for Pair16<T>

source§

impl<T> LowerHex for Pair32<T>

source§

impl<T> LowerHex for Pair64<T>

source§

impl<T> LowerHex for Pair128<T>

source§

impl<T> LowerHex for PairUsize<T>

source§

impl<T> LowerHex for FmtOption<'_, T>
where T: LowerHex,

1.28.0 · source§

impl<T> LowerHex for NonZero<T>

1.74.0 · source§

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

1.11.0 · source§

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

source§

impl<T, F> LowerHex for Pack8<T, F>

source§

impl<T, F> LowerHex for Pack16<T, F>

source§

impl<T, F> LowerHex for Pack32<T, F>

source§

impl<T, F> LowerHex for Pack64<T, F>

source§

impl<T, F> LowerHex for Pack128<T, F>

source§

impl<T, F> LowerHex for PackUsize<T, F>