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

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

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

`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;

            fmt::LowerHex::fmt(&val, f) // delegate to i32's implementation
        }
    }

    let l = Length(9);

    assert_eq!(format!("l as hex is: {:x}", l), "l as hex is: 9");

    assert_eq!(format!("l as hex is: {:#010x}", l), "l as hex is: 0x00000009");

Run

## Required methods

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

Formats the value using the given formatter.

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## Implementations on Foreign Types

### `impl LowerHex for NonZeroI8`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for NonZeroU32`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for NonZeroI16`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for NonZeroIsize`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for NonZeroU8`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for NonZeroI128`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for NonZeroUsize`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for NonZeroU64`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl<T> LowerHex for Wrapping<T> where
T: LowerHex,` [src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for NonZeroI32`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for NonZeroI64`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for NonZeroU16`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for NonZeroU128`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

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## Implementors

### `impl LowerHex for i8`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for i16`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for i32`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for i64`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for i128`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for isize`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for u8`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for u16`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for u32`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for u64`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for u128`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl LowerHex for usize`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl<'_, T> LowerHex for &'_ T where
T: LowerHex + ?Sized,` [src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

### `impl<'_, T> LowerHex for &'_ mut T where
T: LowerHex + ?Sized,` [src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

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