Trait collections::fmt::LowerHex
[−]
[src]
pub trait LowerHex { fn fmt(&self, &mut Formatter) -> Result<(), Error>; }
Format trait for the x
character.
The LowerHex
trait should format its output as a number in hexadecimal, with a
through f
in lower case.
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");
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; write!(f, "{:x}", val) // delegate to i32's implementation } } let l = Length(9); println!("l as hex is: {:x}", l);