Struct HashableF32 

pub struct HashableF32(pub f32);

A wrapper around f32 that implements Eq and Hash based on bit patterns.

Tuple Fields

0: f32

Implementations

impl HashableF32

pub const fn new(value: f32) -> Self

Creates a new HashableF32 from an f32 value.

pub const fn into_inner(self) -> f32

Consumes the HashableF32 and returns the inner f32 value.

pub const fn as_inner(&self) -> &f32

Returns a reference to the inner f32 value.

Methods from Deref<Target = f32>

pub const RADIX: u32 = 2

pub const BITS: u32 = 32

pub const MANTISSA_DIGITS: u32 = 24

pub const DIGITS: u32 = 6

pub const EPSILON: f32 = 1.19209290e-07_f32

pub const MIN: f32 = -3.40282347e+38_f32

pub const MIN_POSITIVE: f32 = 1.17549435e-38_f32

pub const MAX: f32 = 3.40282347e+38_f32

pub const MIN_EXP: i32 = -125

pub const MAX_EXP: i32 = 128

pub const MIN_10_EXP: i32 = -37

pub const MAX_10_EXP: i32 = 38

pub const NAN: f32

pub const INFINITY: f32

pub const NEG_INFINITY: f32

pub const MAX_EXACT_INTEGER: i32

pub const MIN_EXACT_INTEGER: i32

pub const SIGN_MASK: u32 = 0x8000_0000

pub const EXPONENT_MASK: u32 = 0x7f80_0000

pub const MANTISSA_MASK: u32 = 0x007f_ffff

pub fn total_cmp(&self, other: &f32) -> Ordering

Returns the ordering between self and other.

Unlike the standard partial comparison between floating point numbers, this comparison always produces an ordering in accordance to the totalOrder predicate as defined in the IEEE 754 (2008 revision) floating point standard. The values are ordered in the following sequence:

• negative quiet NaN
• negative signaling NaN
• negative infinity
• negative numbers
• negative subnormal numbers
• negative zero
• positive zero
• positive subnormal numbers
• positive numbers
• positive infinity
• positive signaling NaN
• positive quiet NaN.

The ordering established by this function does not always agree with the PartialOrd and PartialEq implementations of f32. For example, they consider negative and positive zero equal, while total_cmp doesn’t.

The interpretation of the signaling NaN bit follows the definition in the IEEE 754 standard, which may not match the interpretation by some of the older, non-conformant (e.g. MIPS) hardware implementations.

Example

struct GoodBoy {
    name: String,
    weight: f32,
}

let mut bois = vec![
    GoodBoy { name: "Pucci".to_owned(), weight: 0.1 },
    GoodBoy { name: "Woofer".to_owned(), weight: 99.0 },
    GoodBoy { name: "Yapper".to_owned(), weight: 10.0 },
    GoodBoy { name: "Chonk".to_owned(), weight: f32::INFINITY },
    GoodBoy { name: "Abs. Unit".to_owned(), weight: f32::NAN },
    GoodBoy { name: "Floaty".to_owned(), weight: -5.0 },
];

bois.sort_by(|a, b| a.weight.total_cmp(&b.weight));

// `f32::NAN` could be positive or negative, which will affect the sort order.
if f32::NAN.is_sign_negative() {
    assert!(bois.into_iter().map(|b| b.weight)
        .zip([f32::NAN, -5.0, 0.1, 10.0, 99.0, f32::INFINITY].iter())
        .all(|(a, b)| a.to_bits() == b.to_bits()))
} else {
    assert!(bois.into_iter().map(|b| b.weight)
        .zip([-5.0, 0.1, 10.0, 99.0, f32::INFINITY, f32::NAN].iter())
        .all(|(a, b)| a.to_bits() == b.to_bits()))
}

Trait Implementations

impl Clone for HashableF32

fn clone(&self) -> HashableF32

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for HashableF32

impl Debug for HashableF32

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

Formats the value using the given formatter.

impl Deref for HashableF32

type Target = f32

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Display for HashableF32

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

Formats the value using the given formatter.

impl Eq for HashableF32

impl From<HashableF32> for f32

fn from(value: HashableF32) -> Self

Converts to this type from the input type.

impl From<f32> for HashableF32

fn from(value: f32) -> Self

Converts to this type from the input type.

impl Hash for HashableF32

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for HashableF32

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for HashableF32

fn partial_cmp(&self, other: &HashableF32) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.