pub trait Octal {
// Required method
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>;
}Expand description
o formatting.
The Octal trait should format its output as a number in base-8.
For primitive signed integers (i8 to i128, and isize),
negative values are formatted as the two’s complement representation.
The alternate flag, #, adds a 0o 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 '52' in octal
assert_eq!(format!("{x:o}"), "52");
assert_eq!(format!("{x:#o}"), "0o52");
assert_eq!(format!("{:o}", -16), "37777777760");Implementing Octal on a type:
use std::fmt;
struct Length(i32);
impl fmt::Octal for Length {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let val = self.0;
fmt::Octal::fmt(&val, f) // delegate to i32's implementation
}
}
let l = Length(9);
assert_eq!(format!("l as octal is: {l:o}"), "l as octal is: 11");
assert_eq!(format!("l as octal is: {l:#06o}"), "l as octal is: 0o0011");Required Methods§
Implementors§
impl Octal for i8
impl Octal for i16
impl Octal for i32
impl Octal for i64
impl Octal for i128
impl Octal for isize
impl Octal for u8
impl Octal for u16
impl Octal for u32
impl Octal for u64
impl Octal for u128
impl Octal for usize
impl Octal for AccessRights
impl Octal for BigInt
impl Octal for BigUint
impl<O, T> Octal for BitSlice<O, T>
Render the contents of a BitSlice in a numeric format.
These implementations render the bits of memory contained in a
BitSlice as one of the three numeric bases that the Rust format
system supports:
Binaryrenders each bit individually as0or1,Octalrenders clusters of three bits as the numbers0through7,- and
UpperHexandLowerHexrender clusters of four bits as the numbers0through9andAthroughF.
The formatters produce a “word” for each element T of memory. The
chunked formats (octal and hexadecimal) operate somewhat peculiarly:
they show the semantic value of the memory, as interpreted by the
ordering parameter’s implementation rather than the raw value of
memory you might observe with a debugger. In order to ease the
process of expanding numbers back into bits, each digit is grouped to
the right edge of the memory element. So, for example, the byte
0xFF would be rendered in as 0o377 rather than 0o773.
Rendered words are chunked by memory elements, rather than by as clean as possible a number of digits, in order to aid visualization of the slice’s place in memory.