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; // 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 = self.0; write!(f, "{}E1", val / 10) } } let l = Length(100); println!("l in scientific notation is: {:E}", l);
impl UpperExp for f64
impl<'a, T> UpperExp for &'a mut T where
T: UpperExp + ?Sized,
impl UpperExp for f32
impl<'a, T> UpperExp for &'a T where
T: UpperExp + ?Sized,
© 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