LowerHex in alloc::fmt - Rust
Description: `x` formatting.
Keywords: rust, rustlang, rust-lang, LowerHex

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

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

Expand description

`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

[src]

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

Formats the value using the given formatter.

## Implementations on Foreign Types

1.28.0[src]

### impl LowerHex for NonZeroU16

[src]

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

1.34.0[src]

### impl LowerHex for NonZeroI8

[src]

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

1.28.0[src]

### impl LowerHex for NonZeroU8

[src]

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

1.28.0[src]

### impl LowerHex for NonZeroU128

[src]

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

1.34.0[src]

### impl LowerHex for NonZeroI32

[src]

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

1.34.0[src]

### impl LowerHex for NonZeroI128

[src]

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

1.11.0[src]

### impl<T> LowerHex for Wrapping<T> where
T: LowerHex,

[src]

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

1.34.0[src]

### impl LowerHex for NonZeroI16

[src]

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

1.28.0[src]

### impl LowerHex for NonZeroU64

[src]

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

1.28.0[src]

### impl LowerHex for NonZeroU32

[src]

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

1.28.0[src]

### impl LowerHex for NonZeroUsize

[src]

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

1.34.0[src]

### impl LowerHex for NonZeroI64

[src]

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

1.34.0[src]

### impl LowerHex for NonZeroIsize

[src]

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

## Implementors

[src]

### impl LowerHex for i8

[src]

### impl LowerHex for i16

[src]

### impl LowerHex for i32

[src]

### impl LowerHex for i64

[src]

### impl LowerHex for i128

[src]

### impl LowerHex for isize

[src]

### impl LowerHex for u8

[src]

### impl LowerHex for u16

[src]

### impl LowerHex for u32

[src]

### impl LowerHex for u64

[src]

### impl LowerHex for u128

[src]

### impl LowerHex for usize

[src]

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

[src]

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