core::fmt::LowerHex - Rust
Description: API documentation for the Rust `LowerHex` trait in crate `core`.
Keywords: rust, rustlang, rust-lang, LowerHex

# Trait core::fmt::LowerHex 1.0.0 [−] [src]

    pub trait LowerHex {
        fn fmt(&self, f: &mut Formatter) -> Result;
    }

`x` formatting.

The `LowerHex` trait should format its output as a number in hexadecimal, with `a` through `f` in lower 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");Run

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);Run

## Required Methods

### `fn fmt(&self, f: &mut Formatter) -> Result`

Formats the value using the given formatter.

## Implementors

- [src]
  `impl<T: LowerHex> LowerHex for Wrapping<T>`
- `impl LowerHex for isize`
- `impl LowerHex for usize`
- `impl LowerHex for i8`
- `impl LowerHex for u8`
- `impl LowerHex for i16`
- `impl LowerHex for u16`
- `impl LowerHex for i32`
- `impl LowerHex for u32`
- `impl LowerHex for i64`
- `impl LowerHex for u64`
- `impl LowerHex for i128`
- `impl LowerHex for u128`
- `impl<'a, T: ?Sized + LowerHex> LowerHex for &'a T`
- `impl<'a, T: ?Sized + LowerHex> LowerHex for &'a mut T`

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