Trait sp_std::fmt::UpperHex 1.0.0[−][src]
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");
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: {:X}", l), "l as hex is: 7FFFFFFF"); assert_eq!(format!("l as hex is: {:#010X}", l), "l as hex is: 0x7FFFFFFF");