Trait alloc::fmt::LowerHex

pub trait LowerHex {
    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>;
}

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 x = 42; // 42 is '2a' in hex

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

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

Formats the value using the given formatter.

Implementations on Foreign Types

impl LowerHex for NonZeroU32

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

impl LowerHex for NonZeroI128

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

impl LowerHex for u8

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

impl LowerHex for NonZeroUsize

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

impl LowerHex for u128

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

impl LowerHex for i16

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

impl LowerHex for u32

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

impl LowerHex for NonZeroI64

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

impl LowerHex for i128

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

impl LowerHex for NonZeroI16

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

impl LowerHex for i8

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

impl LowerHex for NonZeroIsize

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

impl LowerHex for isize

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

impl LowerHex for u16

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

impl LowerHex for usize

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

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

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

impl<T, const LANES: usize> LowerHex for Simd<T, LANES> where
    T: SimdElement + LowerHex,
    LaneCount<LANES>: SupportedLaneCount, 

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

impl LowerHex for NonZeroU16

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

impl LowerHex for NonZeroU128

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

impl LowerHex for NonZeroI8

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

impl LowerHex for i64

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

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

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

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

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

impl LowerHex for i32

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

impl LowerHex for u64

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

impl LowerHex for NonZeroU8

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

impl LowerHex for NonZeroI32

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

impl LowerHex for NonZeroU64

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

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

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

Implementors