Trait alloc::fmt::UpperHex

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

X formatting.

The UpperHex trait should format its output as a number in hexadecimal, with A through F in upper 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");
Run

Implementing UpperHex on a type:

use std::fmt;

struct Length(i32);

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

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

let l = Length(i32::MAX);

assert_eq!(format!("l as hex is: {l:X}"), "l as hex is: 7FFFFFFF");

assert_eq!(format!("l as hex is: {l:#010X}"), "l as hex is: 0x7FFFFFFF");
Run

Required Methods§

source

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

Formats the value using the given formatter.

Implementors§

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impl UpperHex for i8

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impl UpperHex for i16

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impl UpperHex for i32

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impl UpperHex for i64

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impl UpperHex for i128

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impl UpperHex for isize

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impl UpperHex for u8

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impl UpperHex for u16

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impl UpperHex for u32

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impl UpperHex for u64

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impl UpperHex for u128

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impl UpperHex for usize

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

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

1.28.0 · source§

impl<T> UpperHex for NonZero<T>

1.74.0 · source§

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

1.11.0 · source§

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