Trait frame_support::dispatch::fmt::UpperExp 1.0.0[−][src]
Expand description
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" );