Struct F64Finite 

pub struct F64Finite(/* private fields */);

A finite floating point number

Suitable for stats items in voites’ routerstatus entries: https://spec.torproject.org/dir-spec/consensus-formats.html#item:stats

Invariants:

• Is finite. (So not NaN or Inf.) Might be denormal.

String representation:

• Parses any valid C-like notation.

• Never uses exponential notation to display.

• Output can be rather large, up to 326 characters! This is a spec bug. The spec forbids us from using exponential notation. https://gitlab.torproject.org/tpo/core/torspec/-/work_items/416

We may to change this in the future to use exponentials notation for output. See https://gitlab.torproject.org/tpo/core/torspec/-/work_items/416

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 const SIGN_MASK: u64 = 0x8000_0000_0000_0000

pub const EXPONENT_MASK: u64 = 0x7ff0_0000_0000_0000

pub const MANTISSA_MASK: u64 = 0x000f_ffff_ffff_ffff

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 F64Finite

fn clone(&self) -> F64Finite

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for F64Finite

impl Debug for F64Finite

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

Formats the value using the given formatter.

impl Deref for F64Finite

type Target = f64

The resulting type after dereferencing.

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

Dereferences the value.

impl Display for F64Finite

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

Formats the value using the given formatter.

impl Eq for F64Finite

impl From<F64Finite> for f64

fn from(value: F64Finite) -> Self

Converts to this type from the input type.

impl FromStr for F64Finite

type Err = F64FiniteParseError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> StdResult<Self, F64FiniteParseError>

Parses a string s to return a value of this type.

impl NormalItemArgument for F64Finite

impl Ord for F64Finite

fn cmp(&self, other: &F64Finite) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for F64Finite

fn eq(&self, other: &F64Finite) -> 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 F64Finite

fn partial_cmp(&self, other: &F64Finite) -> 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 StructuralPartialEq for F64Finite

impl TryFrom<f64> for F64Finite

type Error = F64FiniteError

The type returned in the event of a conversion error.

fn try_from(v: f64) -> Result<Self, F64FiniteError>

Performs the conversion.