Crate noisy_float [−] [src]
This crate contains floating point types that panic if they are set to an illegal value, such as NaN.
The name "Noisy Float" comes from the terms "quiet NaN" and "signaling NaN"; "signaling" was too long to put in a struct/crate name, so "noisy" is used instead, being the opposite of "quiet."
The standard types defined in noisy_float::types
follow the principle
demonstrated by Rust's handling of integer overflow:
a bad arithmetic operation is considered an error,
but it is too costly to check everywhere in optimized builds.
For each floating point number that is created, a debug_assert!
invocation is used
to check if it is valid or not.
This way, there are guarantees when developing code that floating point
numbers have valid values,
but during a release run there is no overhead for using these floating
point types compared to using f32
or f64
directly.
This crate makes use of the floating point and number traits in the
popular num_traits
crate.
Examples
An example using the R64
type, which corresponds to finite f64
values.
use noisy_float::prelude::*; fn geometric_mean(a: R64, b: R64) -> R64 { (a * b).sqrt() //used just like regular floating point numbers } fn mean(a: R64, b: R64) -> R64 { (a + b) * 0.5 //the RHS of ops can be the underlying float type } println!("geometric_mean(10.0, 20.0) = {}", geometric_mean(r64(10.0), r64(20.0))); //prints 14.142... assert!(mean(r64(10.0), r64(20.0)) == 15.0);
An example using the N32
type, which corresponds to non-NaN f32
values.
The float types in this crate are able to implement Eq
and Ord
properly,
since NaN is not allowed.
use noisy_float::prelude::*; let values = vec![n32(3.0), n32(-1.5), n32(71.3), N32::infinity()]; assert!(values.iter().cloned().min() == Some(n32(-1.5))); assert!(values.iter().cloned().max() == Some(N32::infinity()));
Features
This crate has the following cargo features:
serde-1
: Enable serialization for allNoisyFloats
using serde 1.0 and will transparently serialize then as floats
Modules
checkers |
Standard implementations of |
prelude |
Prelude for the |
types |
Standard definitions of |
Structs
NoisyFloat |
A floating point number with a restricted set of legal values. |
Traits
FloatChecker |
Trait for checking whether a floating point number is valid. |