Trait std::fmt::UpperHex1.0.0 [] [src]

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

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.


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;

        write!(f, "{:X}", val) // delegate to i32's implementation

let l = Length(9);

println!("l as hex is: {:X}", l);Run

Required Methods

Formats the value using the given formatter.