Trait scale_info::prelude::fmt::UpperHex

pub trait UpperHex {
    // Required method
    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.

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

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 Bytes

impl UpperHex for BytesMut

impl<'a, T, O> UpperHex for Domain<'a, Const, T, O>

where O: BitOrder, T: BitStore,

impl<A, O> UpperHex for BitArray<A, O>

where O: BitOrder, A: BitViewSized,

impl<T> UpperHex for &T

where T: UpperHex + ?Sized,

impl<T> UpperHex for &mut T

where T: UpperHex + ?Sized,

impl<T> UpperHex for FmtBinary<T>

where T: Binary + UpperHex,

impl<T> UpperHex for FmtDisplay<T>

where T: Display + UpperHex,

impl<T> UpperHex for FmtList<T>

where &'a T: for<'a> IntoIterator, <&'a T as IntoIterator>::Item: for<'a> UpperHex,

impl<T> UpperHex for FmtLowerExp<T>

where T: LowerExp + UpperHex,

impl<T> UpperHex for FmtLowerHex<T>

where T: LowerHex + UpperHex,

impl<T> UpperHex for FmtOctal<T>

where T: Octal + UpperHex,

impl<T> UpperHex for FmtPointer<T>

where T: Pointer + UpperHex,

impl<T> UpperHex for FmtUpperExp<T>

where T: UpperExp + UpperHex,

impl<T> UpperHex for FmtUpperHex<T>

where T: UpperHex,

impl<T> UpperHex for NonZero<T>

where T: ZeroablePrimitive + UpperHex,

impl<T> UpperHex for Saturating<T>

where T: UpperHex,

impl<T> UpperHex for Wrapping<T>

where T: UpperHex,

impl<T, O> UpperHex for BitBox<T, O>

where O: BitOrder, T: BitStore,

impl<T, O> UpperHex for BitSlice<T, O>

where T: BitStore, O: BitOrder,

Bit-Slice Rendering

This implementation prints the contents of a &BitSlice in one of binary, octal, or hexadecimal. It is important to note that this does not render the raw underlying memory! They render the semantically-ordered contents of the bit-slice as numerals. This distinction matters if you use type parameters that differ from those presumed by your debugger (which is usually <u8, Msb0>).

The output separates the T elements as individual list items, and renders each element as a base- 2, 8, or 16 numeric string. When walking an element, the bits traversed by the bit-slice are considered to be stored in most-significant-bit-first ordering. This means that index [0] is the high bit of the left-most digit, and index [n] is the low bit of the right-most digit, in a given printed word.

In order to render according to expectations of the Arabic numeral system, an element being transcribed is chunked into digits from the least-significant end of its rendered form. This is most noticeable in octal, which will always have a smaller ceiling on the left-most digit in a printed word, while the right-most digit in that word is able to use the full 0 ..= 7 numeral range.

Examples

use bitvec::prelude::*;

let data = [
  0b000000_10u8,
// digits print LTR
  0b10_001_101,
// significance is computed RTL
  0b01_000000,
];
let bits = &data.view_bits::<Msb0>()[6 .. 18];

assert_eq!(format!("{:b}", bits), "[10, 10001101, 01]");
assert_eq!(format!("{:o}", bits), "[2, 215, 1]");
assert_eq!(format!("{:X}", bits), "[2, 8D, 1]");

The {:#} format modifier causes the standard 0b, 0o, or 0x prefix to be applied to each printed word. The other format specifiers are not interpreted by this implementation, and apply to the entire rendered text, not to individual words.

impl<T, O> UpperHex for BitVec<T, O>

where O: BitOrder, T: BitStore,