Struct PositiveFloat 

pub struct PositiveFloat(/* private fields */);

A positive-only, 64 bit precision floating point number.

Implementations

impl PositiveFloat

pub fn try_new(f: f64) -> Result<Self, TryFromFloatError>

Attempt to create a new PositiveFloat.

Errors

Returns an error if the provided float is not finite or less than or equal to 0.0.

pub const fn one() -> Self

Create a new PositiveFloat with the value 1.0.

Methods from Deref<Target = f64>

pub const RADIX: u32 = 2

pub const BITS: u32 = 64

pub const MANTISSA_DIGITS: u32 = 53

pub const DIGITS: u32 = 15

pub const EPSILON: f64 = 2.2204460492503131e-16_f64

pub const MIN: f64 = -1.7976931348623157e+308_f64

pub const MIN_POSITIVE: f64 = 2.2250738585072014e-308_f64

pub const MAX: f64 = 1.7976931348623157e+308_f64

pub const MIN_EXP: i32 = -1021

pub const MAX_EXP: i32 = 1024

pub const MIN_10_EXP: i32 = -307

pub const MAX_10_EXP: i32 = 308

pub const NAN: f64

pub const INFINITY: f64

pub const NEG_INFINITY: f64

pub const MAX_EXACT_INTEGER: i64

pub const MIN_EXACT_INTEGER: i64

pub fn total_cmp(&self, other: &f64) -> 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 f64. 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: f64,
}

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: f64::INFINITY },
    GoodBoy { name: "Abs. Unit".to_owned(), weight: f64::NAN },
    GoodBoy { name: "Floaty".to_owned(), weight: -5.0 },
];

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

// `f64::NAN` could be positive or negative, which will affect the sort order.
if f64::NAN.is_sign_negative() {
    assert!(bois.into_iter().map(|b| b.weight)
        .zip([f64::NAN, -5.0, 0.1, 10.0, 99.0, f64::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, f64::INFINITY, f64::NAN].iter())
        .all(|(a, b)| a.to_bits() == b.to_bits()))
}

Trait Implementations

impl Clone for PositiveFloat

fn clone(&self) -> PositiveFloat

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PositiveFloat

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

Formats the value using the given formatter.

impl Deref for PositiveFloat

type Target = f64

The resulting type after dereferencing.

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

Dereferences the value.

impl From<PositiveFloat> for f64

fn from(value: PositiveFloat) -> Self

Converts to this type from the input type.

impl PartialEq for PositiveFloat

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl PartialOrd for PositiveFloat

fn partial_cmp(&self, other: &PositiveFloat) -> 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.

impl TryFrom<f64> for PositiveFloat

type Error = TryFromFloatError

The type returned in the event of a conversion error.

fn try_from(value: f64) -> Result<Self, Self::Error>

Performs the conversion.

impl Copy for PositiveFloat

impl StructuralPartialEq for PositiveFloat