std::fmt::UpperExp - Rust (original) (raw)

Trait std::fmt::UpperExp1.0.0 [−] [src]

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.

Basic usage with f32:

let x = 42.0;

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 = self.0; write!(f, "{}E1", val / 10) } }

let l = Length(100);

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