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

# Trait collections::fmt::UpperHex 1.0.0 [−] [src]

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

Format trait for the `X` character.

The `UpperHex` trait should format its output as a number in hexadecimal, with `A` through `F` in upper case.

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");

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;

            write!(f, "{:X}", val) // delegate to i32's implementation
        }
    }

    let l = Length(9);

    println!("l as hex is: {:X}", l);

## Required Methods

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

Formats the value using the given formatter.

## Implementors

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

# Help

## Keyboard Shortcuts

?
  Show this help dialog
S
  Focus the search field
⇤
  Move up in search results
⇥
  Move down in search results
⏎
  Go to active search result
+
  Collapse/expand all sections

## Search Tricks

Prefix searches with a type followed by a colon (e.g. `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g. `vec -> usize` or `* -> vec`)