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

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

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

`E` formatting.

The `UpperExp` trait should format its output in scientific notation with an upper-case `E`.

For more information on formatters, see the module-level documentation.

# Examples

Basic usage with `f64`:

    let x = 42.0; // 42.0 is '4.2E1' in scientific notation

    assert_eq!(format!("{:E}", x), "4.2E1");

Run

Implementing `UpperExp` on a type:

    use std::fmt;

    struct Length(i32);

    impl fmt::UpperExp for Length {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            let val = f64::from(self.0);
            fmt::UpperExp::fmt(&val, f) // delegate to f64's implementation
        }
    }

    let l = Length(100);

    assert_eq!(
        format!("l in scientific notation is: {:E}", l),
        "l in scientific notation is: 1E2"
    );

    assert_eq!(
        format!("l in scientific notation is: {:05E}", l),
        "l in scientific notation is: 001E2"
    );

Run

## Required methods

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

Formats the value using the given formatter.

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## Implementors

### `impl UpperExp for f32`[src]

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

### `impl UpperExp for f64`[src]

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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