Trait std::fmt::LowerExp1.0.0 [] [src]

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

e formatting.

The LowerExp trait should format its output in scientific notation with a lower-case e.

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


Basic usage with i32:

let x = 42.0; // 42.0 is '4.2e1' in scientific notation

assert_eq!(format!("{:e}", x), "4.2e1");Run

Implementing LowerExp on a type:

use std::fmt;

struct Length(i32);

impl fmt::LowerExp for Length {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        let val = self.0;
        write!(f, "{}e1", val / 10)

let l = Length(100);

println!("l in scientific notation is: {:e}", l);Run

Required Methods

Formats the value using the given formatter.