Trait std::fmt::LowerExp
[−]
[src]
pub trait LowerExp { fn fmt(&self, &mut Formatter) -> Result<(), Error>; }
Format trait for the e
character.
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.
Examples
Basic usage with i32
:
let x = 42.0; // 42.0 is '4.2e1' in scientific notation assert_eq!(format!("{:e}", x), "4.2e1");
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);