Struct sscanf::FullF32

pub struct FullF32(pub f32);

A Wrapper around f32 whose RegexRepresentation also includes special floating point values like nan, inf, 2.0e5, …

This is not part of the regular f32 parser because having a Number match against Text like with nan is usually not desirable:

let input = "Match a Banana against a number";
let output = scanf!(input, "{}{}{}", String, f32, String);
// There are no Numbers in input, so expect None
assert!(output.is_none());

let output = scanf!(input, "{}{}{}", String, FullF32, String);
// The 'nan' part in "Banana" is parsed as f32::NaN
assert!(output.is_some());
assert!(output.unwrap().1.is_nan());

See FromStr on f32 for the full syntax

Methods from Deref<Target = f32>

pub const RADIX: u32

pub const MANTISSA_DIGITS: u32

pub const DIGITS: u32

pub const EPSILON: f32

pub const MIN: f32

pub const MIN_POSITIVE: f32

pub const MAX: f32

pub const MIN_EXP: i32

pub const MAX_EXP: i32

pub const MIN_10_EXP: i32

pub const MAX_10_EXP: i32

pub const NAN: f32

pub const INFINITY: f32

pub const NEG_INFINITY: f32

pub fn as_ne_bytes(&self) -> &[u8; 4]

🔬 This is a nightly-only experimental API. (num_as_ne_bytes)

Return the memory representation of this floating point number as a byte array in native byte order.

to_ne_bytes should be preferred over this whenever possible.

Examples

#![feature(num_as_ne_bytes)]
let num = 12.5f32;
let bytes = num.as_ne_bytes();
assert_eq!(
    bytes,
    if cfg!(target_endian = "big") {
        &[0x41, 0x48, 0x00, 0x00]
    } else {
        &[0x00, 0x00, 0x48, 0x41]
    }
);

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

🔬 This is a nightly-only experimental API. (total_cmp)

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

• 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

Note that this function does not always agree with the PartialOrd and PartialEq implementations of f32. In particular, they regard negative and positive zero as equal, while total_cmp doesn’t.

Example

#![feature(total_cmp)]
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));

Trait Implementations

impl Clone for FullF32

fn clone(&self) -> FullF32

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for FullF32

impl Debug for FullF32

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

Formats the value using the given formatter.

impl Deref for FullF32

type Target = f32

The resulting type after dereferencing.

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

Dereferences the value.

impl DerefMut for FullF32

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl FromStr for FullF32

type Err = <f32 as FromStr>::Err

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

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

impl PartialEq<FullF32> for FullF32

fn eq(&self, other: &FullF32) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &FullF32) -> bool

This method tests for !=.

impl PartialEq<FullF32> for f32

fn eq(&self, rhs: &FullF32) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<f32> for FullF32

fn eq(&self, rhs: &f32) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl RegexRepresentation for FullF32

const REGEX: &'static str

Matches any floating point number, including nan, inf, 2.0e5, …

See FromStr on f32 for details

impl StructuralPartialEq for FullF32