Trait UpperExp

pub trait UpperExp {
    // Required method
    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> ;
}

core E formatting.

Re-exported from core::fmt:: .

---

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!("{x:E}"), "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: {l:E}"),
    "l in scientific notation is: 1E2"
);

assert_eq!(
    format!("l in scientific notation is: {l:05E}"),
    "l in scientific notation is: 001E2"
);

Required Methods

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

Errors

This function should return Err if, and only if, the provided Formatter returns Err. String formatting is considered an infallible operation; this function only returns a Result because writing to the underlying stream might fail and it must provide a way to propagate the fact that an error has occurred back up the stack.

Implementors

impl UpperExp for f32

impl UpperExp for f64

impl UpperExp for i8

impl UpperExp for i16

impl UpperExp for i32

impl UpperExp for i64

impl UpperExp for i128

impl UpperExp for isize

impl UpperExp for u8

impl UpperExp for u16

impl UpperExp for u32

impl UpperExp for u64

impl UpperExp for u128

impl UpperExp for usize

impl UpperExp for f32_be

impl UpperExp for f32_le

impl UpperExp for f64_be

impl UpperExp for f64_le

impl UpperExp for i16_be

impl UpperExp for i16_le

impl UpperExp for i32_be

impl UpperExp for i32_le

impl UpperExp for i64_be

impl UpperExp for i64_le

impl UpperExp for i128_be

impl UpperExp for i128_le

impl UpperExp for u16_be

impl UpperExp for u16_le

impl UpperExp for u32_be

impl UpperExp for u32_le

impl UpperExp for u64_be

impl UpperExp for u64_le

impl UpperExp for u128_be

impl UpperExp for u128_le

impl UpperExp for f32_ube

impl UpperExp for f32_ule

impl UpperExp for f64_ube

impl UpperExp for f64_ule

impl UpperExp for i16_ube

impl UpperExp for i16_ule

impl UpperExp for i32_ube

impl UpperExp for i32_ule

impl UpperExp for i64_ube

impl UpperExp for i64_ule

impl UpperExp for i128_ube

impl UpperExp for i128_ule

impl UpperExp for u16_ube

impl UpperExp for u16_ule

impl UpperExp for u32_ube

impl UpperExp for u32_ule

impl UpperExp for u64_ube

impl UpperExp for u64_ule

impl UpperExp for u128_ube

impl UpperExp for u128_ule

impl UpperExp for f32x4

impl UpperExp for f32x8

impl UpperExp for f64x2

impl UpperExp for f64x4

impl UpperExp for i8x16

impl UpperExp for i8x32

impl UpperExp for i16x8

impl UpperExp for i16x16

impl UpperExp for i32x4

impl UpperExp for i32x8

impl UpperExp for i64x2

impl UpperExp for i64x4

impl UpperExp for u8x16

impl UpperExp for u16x8

impl UpperExp for u16x16

impl UpperExp for u32x4

impl UpperExp for u32x8

impl UpperExp for u64x2

impl UpperExp for u64x4

impl UpperExp for ExampleBitfield

Available on crate feature _bit_u8 and doc only.

impl UpperExp for ExampleBitfieldCustom

Available on crate feature _bit_u8 and doc only.

impl UpperExp for ExampleBitfieldExtra

Available on crate feature _bit_u8 and doc only.

impl UpperExp for ExampleEnumSet

Available on doc only.

impl UpperExp for m128

impl UpperExp for m128d

impl UpperExp for m128i

impl UpperExp for m256

impl UpperExp for m256d

impl UpperExp for m256i

impl<'t, T, F, U> UpperExp for OptionFmtOrElse<'t, T, F>

where T: UpperExp, F: Fn() -> U, U: Display,

impl<'t, T, U> UpperExp for OptionFmtOr<'t, T, U>

where T: UpperExp, U: Display,

impl<T> UpperExp for &T

where T: UpperExp + ?Sized,

impl<T> UpperExp for &mut T

where T: UpperExp + ?Sized,

impl<T> UpperExp for NonZero<T>

where T: ZeroablePrimitive + UpperExp,

impl<T> UpperExp for OptionFmt<'_, T>

where T: UpperExp,

impl<T: UpperExp> UpperExp for Bitwise<T>

impl<T: UpperExp> UpperExp for Frac<T>

impl<T: UpperExp> UpperExp for Int<T>