pub trait UpperHex {
// Required method
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>;
}Available on crate feature
mtls only.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 y = 42; // 42 is '2A' in hex
assert_eq!(format!("{y:X}"), "2A");
assert_eq!(format!("{y:#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: {l:X}"), "l as hex is: 7FFFFFFF");
assert_eq!(format!("l as hex is: {l:#010X}"), "l as hex is: 0x7FFFFFFF");Required Methods§
1.0.0 · sourcefn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
Formats the value using the given formatter.
§Errors
This function should return Err if, and only if, the provided Formatter returns Err.
String formatting is considered an infallible operation; this function only
returns a Result because writing to the underlying stream might fail and it must
provide a way to propagate the fact that an error has occurred back up the stack.
Implementors§
impl UpperHex for i8
impl UpperHex for i16
impl UpperHex for i32
impl UpperHex for i64
impl UpperHex for i128
impl UpperHex for isize
impl UpperHex for u8
impl UpperHex for u16
impl UpperHex for u32
impl UpperHex for u64
impl UpperHex for u128
impl UpperHex for usize
impl UpperHex for Braced
impl UpperHex for Hyphenated
impl UpperHex for Simple
impl UpperHex for Urn
impl UpperHex for Uuid
impl UpperHex for RequestId
Available on crate feature
trace only.