Enum std::num::FpCategory
1.0.0· source · [−]pub enum FpCategory {
Nan,
Infinite,
Zero,
Subnormal,
Normal,
}Expand description
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!(nan.classify(), FpCategory::Nan);
assert_eq!(sub.classify(), FpCategory::Subnormal);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.)