Enum std::num::FpCategory

pub enum FpCategory {
    Nan,
    Infinite,
    Zero,
    Subnormal,
    Normal,
}

A classification of floating point numbers.

This enum is used as the return type for f32::classify and f64::classify. See their documentation for more.

Examples

use std::num::FpCategory;

let num = 12.4_f32;
let inf = f32::INFINITY;
let zero = 0f32;
let sub: f32 = 1.1754942e-38;
let nan = f32::NAN;

assert_eq!(num.classify(), FpCategory::Normal);
assert_eq!(inf.classify(), FpCategory::Infinite);
assert_eq!(zero.classify(), FpCategory::Zero);
assert_eq!(sub.classify(), FpCategory::Subnormal);
assert_eq!(nan.classify(), FpCategory::Nan);

Variants

Nan

NaN (not a number): this value results from calculations like (-1.0).sqrt().

See the documentation for f32 for more information on the unusual properties of NaN.

Infinite

Positive or negative infinity, which often results from dividing a nonzero number by zero.

Zero

Positive or negative zero.

See the documentation for f32 for more information on the signedness of zeroes.

Subnormal

“Subnormal” or “denormal” floating point representation (less precise, relative to their magnitude, than Normal).

Subnormal numbers are larger in magnitude than Zero but smaller in magnitude than all Normal numbers.

Normal

A regular floating point number, not any of the exceptional categories.

The smallest positive normal numbers are f32::MIN_POSITIVE and f64::MIN_POSITIVE, and the largest positive normal numbers are f32::MAX and f64::MAX. (Unlike signed integers, floating point numbers are symmetric in their range, so negating any of these constants will produce their negative counterpart.)

Trait Implementations

impl Clone for FpCategory

fn clone(&self) -> FpCategory

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FpCategory

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

Formats the value using the given formatter.

impl PartialEq for FpCategory

fn eq(&self, other: &FpCategory) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for FpCategory

impl Eq for FpCategory

impl StructuralPartialEq for FpCategory