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Trait std::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");

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"
);

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]

impl UpperExp for f64[src]

impl UpperExp for i8[src]

impl UpperExp for i16[src]

impl UpperExp for i32[src]

impl UpperExp for i64[src]

impl UpperExp for i128[src]

impl UpperExp for isize[src]

impl UpperExp for u8[src]

impl UpperExp for u16[src]

impl UpperExp for u32[src]

impl UpperExp for u64[src]

impl UpperExp for u128[src]

impl UpperExp for usize[src]

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

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

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© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/fmt/trait.UpperExp.html