Primitive Type f32

The 32-bit floating point type.

See also the std::f32 module.

Methods

impl f32

pub fn floor(self) -> f32

Returns the largest integer less than or equal to a number.

Examples

let f = 3.99_f32;
let g = 3.0_f32;

assert_eq!(f.floor(), 3.0);
assert_eq!(g.floor(), 3.0);

pub fn ceil(self) -> f32

Returns the smallest integer greater than or equal to a number.

Examples

let f = 3.01_f32;
let g = 4.0_f32;

assert_eq!(f.ceil(), 4.0);
assert_eq!(g.ceil(), 4.0);

pub fn round(self) -> f32

Returns the nearest integer to a number. Round half-way cases away from 0.0.

Examples

let f = 3.3_f32;
let g = -3.3_f32;

assert_eq!(f.round(), 3.0);
assert_eq!(g.round(), -3.0);

pub fn trunc(self) -> f32

Returns the integer part of a number.

Examples

let f = 3.3_f32;
let g = -3.7_f32;

assert_eq!(f.trunc(), 3.0);
assert_eq!(g.trunc(), -3.0);

pub fn fract(self) -> f32

Returns the fractional part of a number.

Examples

use std::f32;

let x = 3.5_f32;
let y = -3.5_f32;
let abs_difference_x = (x.fract() - 0.5).abs();
let abs_difference_y = (y.fract() - (-0.5)).abs();

assert!(abs_difference_x <= f32::EPSILON);
assert!(abs_difference_y <= f32::EPSILON);

pub fn abs(self) -> f32

Computes the absolute value of self. Returns NAN if the number is NAN.

Examples

use std::f32;

let x = 3.5_f32;
let y = -3.5_f32;

let abs_difference_x = (x.abs() - x).abs();
let abs_difference_y = (y.abs() - (-y)).abs();

assert!(abs_difference_x <= f32::EPSILON);
assert!(abs_difference_y <= f32::EPSILON);

assert!(f32::NAN.abs().is_nan());

pub fn signum(self) -> f32

Returns a number that represents the sign of self.

• 1.0 if the number is positive, +0.0 or INFINITY
• -1.0 if the number is negative, -0.0 or NEG_INFINITY
• NAN if the number is NAN

Examples

use std::f32;

let f = 3.5_f32;

assert_eq!(f.signum(), 1.0);
assert_eq!(f32::NEG_INFINITY.signum(), -1.0);

assert!(f32::NAN.signum().is_nan());

#[must_use]

pub fn copysign(self, y: f32) -> f32

🔬 This is a nightly-only experimental API. (copysign #55169)

Returns a number composed of the magnitude of self and the sign of y.

Equal to self if the sign of self and y are the same, otherwise equal to -self. If self is a NAN, then a NAN with the sign of y is returned.

Examples

#![feature(copysign)]
use std::f32;

let f = 3.5_f32;

assert_eq!(f.copysign(0.42), 3.5_f32);
assert_eq!(f.copysign(-0.42), -3.5_f32);
assert_eq!((-f).copysign(0.42), 3.5_f32);
assert_eq!((-f).copysign(-0.42), -3.5_f32);

assert!(f32::NAN.copysign(1.0).is_nan());

pub fn mul_add(self, a: f32, b: f32) -> f32

Fused multiply-add. Computes (self * a) + b with only one rounding error, yielding a more accurate result than an unfused multiply-add.

Using mul_add can be more performant than an unfused multiply-add if the target architecture has a dedicated fma CPU instruction.

Examples

use std::f32;

let m = 10.0_f32;
let x = 4.0_f32;
let b = 60.0_f32;

// 100.0
let abs_difference = (m.mul_add(x, b) - (m*x + b)).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn div_euclid(self, rhs: f32) -> f32

🔬 This is a nightly-only experimental API. (euclidean_division #49048)

Calculates Euclidean division, the matching method for rem_euclid.

This computes the integer n such that self = n * rhs + self.rem_euclid(rhs). In other words, the result is self / rhs rounded to the integer n such that self >= n * rhs.

Examples

#![feature(euclidean_division)]
let a: f32 = 7.0;
let b = 4.0;
assert_eq!(a.div_euclid(b), 1.0); // 7.0 > 4.0 * 1.0
assert_eq!((-a).div_euclid(b), -2.0); // -7.0 >= 4.0 * -2.0
assert_eq!(a.div_euclid(-b), -1.0); // 7.0 >= -4.0 * -1.0
assert_eq!((-a).div_euclid(-b), 2.0); // -7.0 >= -4.0 * 2.0

pub fn rem_euclid(self, rhs: f32) -> f32

🔬 This is a nightly-only experimental API. (euclidean_division #49048)

Calculates the least nonnegative remainder of self (mod rhs).

In particular, the return value r satisfies 0.0 <= r < rhs.abs() in most cases. However, due to a floating point round-off error it can result in r == rhs.abs(), violating the mathematical definition, if self is much smaller than rhs.abs() in magnitude and self < 0.0. This result is not an element of the function's codomain, but it is the closest floating point number in the real numbers and thus fulfills the property self == self.div_euclid(rhs) * rhs + self.rem_euclid(rhs) approximatively.

Examples

#![feature(euclidean_division)]
let a: f32 = 7.0;
let b = 4.0;
assert_eq!(a.rem_euclid(b), 3.0);
assert_eq!((-a).rem_euclid(b), 1.0);
assert_eq!(a.rem_euclid(-b), 3.0);
assert_eq!((-a).rem_euclid(-b), 1.0);
// limitation due to round-off error
assert!((-std::f32::EPSILON).rem_euclid(3.0) != 0.0);

pub fn powi(self, n: i32) -> f32

Raises a number to an integer power.

Using this function is generally faster than using powf

Examples

use std::f32;

let x = 2.0_f32;
let abs_difference = (x.powi(2) - x*x).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn powf(self, n: f32) -> f32

Raises a number to a floating point power.

Examples

use std::f32;

let x = 2.0_f32;
let abs_difference = (x.powf(2.0) - x*x).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn sqrt(self) -> f32

Takes the square root of a number.

Returns NaN if self is a negative number.

Examples

use std::f32;

let positive = 4.0_f32;
let negative = -4.0_f32;

let abs_difference = (positive.sqrt() - 2.0).abs();

assert!(abs_difference <= f32::EPSILON);
assert!(negative.sqrt().is_nan());

pub fn exp(self) -> f32

Returns e^(self), (the exponential function).

Examples

use std::f32;

let one = 1.0f32;
// e^1
let e = one.exp();

// ln(e) - 1 == 0
let abs_difference = (e.ln() - 1.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn exp2(self) -> f32

Returns 2^(self).

Examples

use std::f32;

let f = 2.0f32;

// 2^2 - 4 == 0
let abs_difference = (f.exp2() - 4.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn ln(self) -> f32

Returns the natural logarithm of the number.

Examples

use std::f32;

let one = 1.0f32;
// e^1
let e = one.exp();

// ln(e) - 1 == 0
let abs_difference = (e.ln() - 1.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn log(self, base: f32) -> f32

Returns the logarithm of the number with respect to an arbitrary base.

The result may not be correctly rounded owing to implementation details; self.log2() can produce more accurate results for base 2, and self.log10() can produce more accurate results for base 10.

Examples

use std::f32;

let five = 5.0f32;

// log5(5) - 1 == 0
let abs_difference = (five.log(5.0) - 1.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn log2(self) -> f32

Returns the base 2 logarithm of the number.

Examples

use std::f32;

let two = 2.0f32;

// log2(2) - 1 == 0
let abs_difference = (two.log2() - 1.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn log10(self) -> f32

Returns the base 10 logarithm of the number.

Examples

use std::f32;

let ten = 10.0f32;

// log10(10) - 1 == 0
let abs_difference = (ten.log10() - 1.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn abs_sub(self, other: f32) -> f32

Deprecated since 1.10.0:

you probably meant (self - other).abs(): this operation is (self - other).max(0.0) except that abs_sub also propagates NaNs (also known as fdimf in C). If you truly need the positive difference, consider using that expression or the C function fdimf, depending on how you wish to handle NaN (please consider filing an issue describing your use-case too).

The positive difference of two numbers.

• If self <= other: 0:0
• Else: self - other

Examples

use std::f32;

let x = 3.0f32;
let y = -3.0f32;

let abs_difference_x = (x.abs_sub(1.0) - 2.0).abs();
let abs_difference_y = (y.abs_sub(1.0) - 0.0).abs();

assert!(abs_difference_x <= f32::EPSILON);
assert!(abs_difference_y <= f32::EPSILON);

pub fn cbrt(self) -> f32

Takes the cubic root of a number.

Examples

use std::f32;

let x = 8.0f32;

// x^(1/3) - 2 == 0
let abs_difference = (x.cbrt() - 2.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn hypot(self, other: f32) -> f32

Calculates the length of the hypotenuse of a right-angle triangle given legs of length x and y.

Examples

use std::f32;

let x = 2.0f32;
let y = 3.0f32;

// sqrt(x^2 + y^2)
let abs_difference = (x.hypot(y) - (x.powi(2) + y.powi(2)).sqrt()).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn sin(self) -> f32

Computes the sine of a number (in radians).

Examples

use std::f32;

let x = f32::consts::PI/2.0;

let abs_difference = (x.sin() - 1.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn cos(self) -> f32

Computes the cosine of a number (in radians).

Examples

use std::f32;

let x = 2.0*f32::consts::PI;

let abs_difference = (x.cos() - 1.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn tan(self) -> f32

Computes the tangent of a number (in radians).

Examples

use std::f32;

let x = f32::consts::PI / 4.0;
let abs_difference = (x.tan() - 1.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn asin(self) -> f32

Computes the arcsine of a number. Return value is in radians in the range [-pi/2, pi/2] or NaN if the number is outside the range [-1, 1].

Examples

use std::f32;

let f = f32::consts::PI / 2.0;

// asin(sin(pi/2))
let abs_difference = (f.sin().asin() - f32::consts::PI / 2.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn acos(self) -> f32

Computes the arccosine of a number. Return value is in radians in the range [0, pi] or NaN if the number is outside the range [-1, 1].

Examples

use std::f32;

let f = f32::consts::PI / 4.0;

// acos(cos(pi/4))
let abs_difference = (f.cos().acos() - f32::consts::PI / 4.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn atan(self) -> f32

Computes the arctangent of a number. Return value is in radians in the range [-pi/2, pi/2];

Examples

use std::f32;

let f = 1.0f32;

// atan(tan(1))
let abs_difference = (f.tan().atan() - 1.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn atan2(self, other: f32) -> f32

Computes the four quadrant arctangent of self (y) and other (x) in radians.

• x = 0, y = 0: 0
• x >= 0: arctan(y/x) -> [-pi/2, pi/2]
• y >= 0: arctan(y/x) + pi -> (pi/2, pi]
• y < 0: arctan(y/x) - pi -> (-pi, -pi/2)

Examples

use std::f32;

let pi = f32::consts::PI;
// Positive angles measured counter-clockwise
// from positive x axis
// -pi/4 radians (45 deg clockwise)
let x1 = 3.0f32;
let y1 = -3.0f32;

// 3pi/4 radians (135 deg counter-clockwise)
let x2 = -3.0f32;
let y2 = 3.0f32;

let abs_difference_1 = (y1.atan2(x1) - (-pi/4.0)).abs();
let abs_difference_2 = (y2.atan2(x2) - 3.0*pi/4.0).abs();

assert!(abs_difference_1 <= f32::EPSILON);
assert!(abs_difference_2 <= f32::EPSILON);

pub fn sin_cos(self) -> (f32, f32)

Simultaneously computes the sine and cosine of the number, x. Returns (sin(x), cos(x)).

Examples

use std::f32;

let x = f32::consts::PI/4.0;
let f = x.sin_cos();

let abs_difference_0 = (f.0 - x.sin()).abs();
let abs_difference_1 = (f.1 - x.cos()).abs();

assert!(abs_difference_0 <= f32::EPSILON);
assert!(abs_difference_1 <= f32::EPSILON);

pub fn exp_m1(self) -> f32

Returns e^(self) - 1 in a way that is accurate even if the number is close to zero.

Examples

use std::f32;

let x = 6.0f32;

// e^(ln(6)) - 1
let abs_difference = (x.ln().exp_m1() - 5.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn ln_1p(self) -> f32

Returns ln(1+n) (natural logarithm) more accurately than if the operations were performed separately.

Examples

use std::f32;

let x = f32::consts::E - 1.0;

// ln(1 + (e - 1)) == ln(e) == 1
let abs_difference = (x.ln_1p() - 1.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn sinh(self) -> f32

Hyperbolic sine function.

Examples

use std::f32;

let e = f32::consts::E;
let x = 1.0f32;

let f = x.sinh();
// Solving sinh() at 1 gives `(e^2-1)/(2e)`
let g = (e*e - 1.0)/(2.0*e);
let abs_difference = (f - g).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn cosh(self) -> f32

Hyperbolic cosine function.

Examples

use std::f32;

let e = f32::consts::E;
let x = 1.0f32;
let f = x.cosh();
// Solving cosh() at 1 gives this result
let g = (e*e + 1.0)/(2.0*e);
let abs_difference = (f - g).abs();

// Same result
assert!(abs_difference <= f32::EPSILON);

pub fn tanh(self) -> f32

Hyperbolic tangent function.

Examples

use std::f32;

let e = f32::consts::E;
let x = 1.0f32;

let f = x.tanh();
// Solving tanh() at 1 gives `(1 - e^(-2))/(1 + e^(-2))`
let g = (1.0 - e.powi(-2))/(1.0 + e.powi(-2));
let abs_difference = (f - g).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn asinh(self) -> f32

Inverse hyperbolic sine function.

Examples

use std::f32;

let x = 1.0f32;
let f = x.sinh().asinh();

let abs_difference = (f - x).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn acosh(self) -> f32

Inverse hyperbolic cosine function.

Examples

use std::f32;

let x = 1.0f32;
let f = x.cosh().acosh();

let abs_difference = (f - x).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn atanh(self) -> f32

Inverse hyperbolic tangent function.

Examples

use std::f32;

let e = f32::consts::E;
let f = e.tanh().atanh();

let abs_difference = (f - e).abs();

assert!(abs_difference <= 1e-5);

impl f32

pub fn is_nan(self) -> bool

Returns true if this value is NaN.

use std::f32;

let nan = f32::NAN;
let f = 7.0_f32;

assert!(nan.is_nan());
assert!(!f.is_nan());

pub fn is_infinite(self) -> bool

Returns true if this value is positive infinity or negative infinity, and false otherwise.

use std::f32;

let f = 7.0f32;
let inf = f32::INFINITY;
let neg_inf = f32::NEG_INFINITY;
let nan = f32::NAN;

assert!(!f.is_infinite());
assert!(!nan.is_infinite());

assert!(inf.is_infinite());
assert!(neg_inf.is_infinite());

pub fn is_finite(self) -> bool

Returns true if this number is neither infinite nor NaN.

use std::f32;

let f = 7.0f32;
let inf = f32::INFINITY;
let neg_inf = f32::NEG_INFINITY;
let nan = f32::NAN;

assert!(f.is_finite());

assert!(!nan.is_finite());
assert!(!inf.is_finite());
assert!(!neg_inf.is_finite());

pub fn is_normal(self) -> bool

Returns true if the number is neither zero, infinite, subnormal, or NaN.

use std::f32;

let min = f32::MIN_POSITIVE; // 1.17549435e-38f32
let max = f32::MAX;
let lower_than_min = 1.0e-40_f32;
let zero = 0.0_f32;

assert!(min.is_normal());
assert!(max.is_normal());

assert!(!zero.is_normal());
assert!(!f32::NAN.is_normal());
assert!(!f32::INFINITY.is_normal());
// Values between `0` and `min` are Subnormal.
assert!(!lower_than_min.is_normal());

pub fn classify(self) -> FpCategory

Returns the floating point category of the number. If only one property is going to be tested, it is generally faster to use the specific predicate instead.

use std::num::FpCategory;
use std::f32;

let num = 12.4_f32;
let inf = f32::INFINITY;

assert_eq!(num.classify(), FpCategory::Normal);
assert_eq!(inf.classify(), FpCategory::Infinite);

pub fn is_sign_positive(self) -> bool

Returns true if self has a positive sign, including +0.0, NaNs with positive sign bit and positive infinity.

let f = 7.0_f32;
let g = -7.0_f32;

assert!(f.is_sign_positive());
assert!(!g.is_sign_positive());

pub fn is_sign_negative(self) -> bool

Returns true if self has a negative sign, including -0.0, NaNs with negative sign bit and negative infinity.

let f = 7.0f32;
let g = -7.0f32;

assert!(!f.is_sign_negative());
assert!(g.is_sign_negative());

pub fn recip(self) -> f32

Takes the reciprocal (inverse) of a number, 1/x.

use std::f32;

let x = 2.0_f32;
let abs_difference = (x.recip() - (1.0/x)).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn to_degrees(self) -> f32

Converts radians to degrees.

use std::f32::{self, consts};

let angle = consts::PI;

let abs_difference = (angle.to_degrees() - 180.0).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn to_radians(self) -> f32

Converts degrees to radians.

use std::f32::{self, consts};

let angle = 180.0f32;

let abs_difference = (angle.to_radians() - consts::PI).abs();

assert!(abs_difference <= f32::EPSILON);

pub fn max(self, other: f32) -> f32

Returns the maximum of the two numbers.

let x = 1.0f32;
let y = 2.0f32;

assert_eq!(x.max(y), y);

If one of the arguments is NaN, then the other argument is returned.

pub fn min(self, other: f32) -> f32

Returns the minimum of the two numbers.

let x = 1.0f32;
let y = 2.0f32;

assert_eq!(x.min(y), x);

If one of the arguments is NaN, then the other argument is returned.

pub fn to_bits(self) -> u32

Raw transmutation to u32.

This is currently identical to transmute::<f32, u32>(self) on all platforms.

See from_bits for some discussion of the portability of this operation (there are almost no issues).

Note that this function is distinct from as casting, which attempts to preserve the numeric value, and not the bitwise value.

Examples

assert_ne!((1f32).to_bits(), 1f32 as u32); // to_bits() is not casting!
assert_eq!((12.5f32).to_bits(), 0x41480000);

pub fn from_bits(v: u32) -> f32

Raw transmutation from u32.

This is currently identical to transmute::<u32, f32>(v) on all platforms. It turns out this is incredibly portable, for two reasons:

• Floats and Ints have the same endianness on all supported platforms.
• IEEE-754 very precisely specifies the bit layout of floats.

However there is one caveat: prior to the 2008 version of IEEE-754, how to interpret the NaN signaling bit wasn't actually specified. Most platforms (notably x86 and ARM) picked the interpretation that was ultimately standardized in 2008, but some didn't (notably MIPS). As a result, all signaling NaNs on MIPS are quiet NaNs on x86, and vice-versa.

Rather than trying to preserve signaling-ness cross-platform, this implementation favors preserving the exact bits. This means that any payloads encoded in NaNs will be preserved even if the result of this method is sent over the network from an x86 machine to a MIPS one.

If the results of this method are only manipulated by the same architecture that produced them, then there is no portability concern.

If the input isn't NaN, then there is no portability concern.

If you don't care about signalingness (very likely), then there is no portability concern.

Note that this function is distinct from as casting, which attempts to preserve the numeric value, and not the bitwise value.

Examples

use std::f32;
let v = f32::from_bits(0x41480000);
let difference = (v - 12.5).abs();
assert!(difference <= 1e-5);

Trait Implementations

impl<'a, 'b> Div<&'a f32> for &'b f32

type Output = <f32 as Div<f32>>::Output

The resulting type after applying the / operator.

fn div(self, other: &'a f32) -> <f32 as Div<f32>>::Output

Performs the / operation.

impl<'a> Div<&'a f32> for f32

type Output = <f32 as Div<f32>>::Output

The resulting type after applying the / operator.

fn div(self, other: &'a f32) -> <f32 as Div<f32>>::Output

Performs the / operation.

impl Div<f32> for f32

type Output = f32

The resulting type after applying the / operator.

fn div(self, other: f32) -> f32

Performs the / operation.

impl<'a> Div<f32> for &'a f32

type Output = <f32 as Div<f32>>::Output

The resulting type after applying the / operator.

fn div(self, other: f32) -> <f32 as Div<f32>>::Output

Performs the / operation.

impl Display for f32

fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.

impl<'a> Add<f32> for &'a f32

type Output = <f32 as Add<f32>>::Output

The resulting type after applying the + operator.

fn add(self, other: f32) -> <f32 as Add<f32>>::Output

Performs the + operation.

impl<'a> Add<&'a f32> for f32

type Output = <f32 as Add<f32>>::Output

The resulting type after applying the + operator.

fn add(self, other: &'a f32) -> <f32 as Add<f32>>::Output

Performs the + operation.

impl Add<f32> for f32

type Output = f32

The resulting type after applying the + operator.

fn add(self, other: f32) -> f32

Performs the + operation.

impl<'a, 'b> Add<&'a f32> for &'b f32

type Output = <f32 as Add<f32>>::Output

The resulting type after applying the + operator.

fn add(self, other: &'a f32) -> <f32 as Add<f32>>::Output

Performs the + operation.

impl<'a> RemAssign<&'a f32> for f32

fn rem_assign(&mut self, other: &'a f32)

Performs the %= operation.

impl RemAssign<f32> for f32

fn rem_assign(&mut self, other: f32)

Performs the %= operation.

impl<'a> DivAssign<&'a f32> for f32

fn div_assign(&mut self, other: &'a f32)

Performs the /= operation.

impl DivAssign<f32> for f32

fn div_assign(&mut self, other: f32)

Performs the /= operation.

impl<'a> MulAssign<&'a f32> for f32

fn mul_assign(&mut self, other: &'a f32)

Performs the *= operation.

impl MulAssign<f32> for f32

fn mul_assign(&mut self, other: f32)

Performs the *= operation.

impl<'a> SubAssign<&'a f32> for f32

fn sub_assign(&mut self, other: &'a f32)

Performs the -= operation.

impl SubAssign<f32> for f32

fn sub_assign(&mut self, other: f32)

Performs the -= operation.

impl Clone for f32

fn clone(&self) -> f32

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a> AddAssign<&'a f32> for f32

fn add_assign(&mut self, other: &'a f32)

Performs the += operation.

impl AddAssign<f32> for f32

fn add_assign(&mut self, other: f32)

Performs the += operation.

impl PartialOrd<f32> for f32

fn partial_cmp(&self, other: &f32) -> Option<Ordering>

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

fn lt(&self, other: &f32) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &f32) -> bool

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

fn ge(&self, other: &f32) -> bool

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

fn gt(&self, other: &f32) -> bool

This method tests greater than (for self and other) and is used by the > operator.

impl Neg for f32

type Output = f32

The resulting type after applying the - operator.

fn neg(self) -> f32

Performs the unary - operation.

impl<'_> Neg for &'_ f32

type Output = <f32 as Neg>::Output

The resulting type after applying the - operator.

fn neg(self) -> <f32 as Neg>::Output

Performs the unary - operation.

impl<'a> Sub<f32> for &'a f32

type Output = <f32 as Sub<f32>>::Output

The resulting type after applying the - operator.

fn sub(self, other: f32) -> <f32 as Sub<f32>>::Output

Performs the - operation.

impl<'a> Sub<&'a f32> for f32

type Output = <f32 as Sub<f32>>::Output

The resulting type after applying the - operator.

fn sub(self, other: &'a f32) -> <f32 as Sub<f32>>::Output

Performs the - operation.

impl Sub<f32> for f32

type Output = f32

The resulting type after applying the - operator.

fn sub(self, other: f32) -> f32

Performs the - operation.

impl<'a, 'b> Sub<&'a f32> for &'b f32

type Output = <f32 as Sub<f32>>::Output

The resulting type after applying the - operator.

fn sub(self, other: &'a f32) -> <f32 as Sub<f32>>::Output

Performs the - operation.

impl Debug for f32

fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.

impl PartialEq<f32> for f32

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

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

fn ne(&self, other: &f32) -> bool

This method tests for !=.

impl Product<f32> for f32

fn product<I>(iter: I) -> f32 where
    I: Iterator<Item = f32>, 

Method which takes an iterator and generates Self from the elements by multiplying the items.

impl<'a> Product<&'a f32> for f32

fn product<I>(iter: I) -> f32 where
    I: Iterator<Item = &'a f32>, 

Method which takes an iterator and generates Self from the elements by multiplying the items.

impl Copy for f32

impl Rem<f32> for f32

type Output = f32

The resulting type after applying the % operator.

fn rem(self, other: f32) -> f32

Performs the % operation.

impl<'a> Rem<&'a f32> for f32

type Output = <f32 as Rem<f32>>::Output

The resulting type after applying the % operator.

fn rem(self, other: &'a f32) -> <f32 as Rem<f32>>::Output

Performs the % operation.

impl<'a, 'b> Rem<&'a f32> for &'b f32

type Output = <f32 as Rem<f32>>::Output

The resulting type after applying the % operator.

fn rem(self, other: &'a f32) -> <f32 as Rem<f32>>::Output

Performs the % operation.

impl<'a> Rem<f32> for &'a f32

type Output = <f32 as Rem<f32>>::Output

The resulting type after applying the % operator.

fn rem(self, other: f32) -> <f32 as Rem<f32>>::Output

Performs the % operation.

impl UpperExp for f32

fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.

impl Mul<f32> for f32

type Output = f32

The resulting type after applying the * operator.

fn mul(self, other: f32) -> f32

Performs the * operation.

impl<'a> Mul<f32> for &'a f32

type Output = <f32 as Mul<f32>>::Output

The resulting type after applying the * operator.

fn mul(self, other: f32) -> <f32 as Mul<f32>>::Output

Performs the * operation.

impl<'a, 'b> Mul<&'a f32> for &'b f32

type Output = <f32 as Mul<f32>>::Output

The resulting type after applying the * operator.

fn mul(self, other: &'a f32) -> <f32 as Mul<f32>>::Output

Performs the * operation.

impl<'a> Mul<&'a f32> for f32

type Output = <f32 as Mul<f32>>::Output

The resulting type after applying the * operator.

fn mul(self, other: &'a f32) -> <f32 as Mul<f32>>::Output

Performs the * operation.

impl From<u8> for f32

Converts u8 to f32 losslessly.

fn from(small: u8) -> f32

Performs the conversion.

impl From<u16> for f32

Converts u16 to f32 losslessly.

fn from(small: u16) -> f32

Performs the conversion.

impl From<i8> for f32

Converts i8 to f32 losslessly.

fn from(small: i8) -> f32

Performs the conversion.

impl From<i16> for f32

Converts i16 to f32 losslessly.

fn from(small: i16) -> f32

Performs the conversion.

impl Default for f32

fn default() -> f32

Returns the default value of 0.0

impl FromStr for f32

type Err = ParseFloatError

The associated error which can be returned from parsing.

fn from_str(src: &str) -> Result<f32, ParseFloatError>

Converts a string in base 10 to a float. Accepts an optional decimal exponent.

This function accepts strings such as

• '3.14'
• '-3.14'
• '2.5E10', or equivalently, '2.5e10'
• '2.5E-10'
• '5.'
• '.5', or, equivalently, '0.5'
• 'inf', '-inf', 'NaN'

Leading and trailing whitespace represent an error.

Grammar

All strings that adhere to the following EBNF grammar will result in an Ok being returned:

Float  ::= Sign? ( 'inf' | 'NaN' | Number )
Number ::= ( Digit+ |
             Digit+ '.' Digit* |
             Digit* '.' Digit+ ) Exp?
Exp    ::= [eE] Sign? Digit+
Sign   ::= [+-]
Digit  ::= [0-9]

Known bugs

In some situations, some strings that should create a valid float instead return an error. See issue #31407 for details.

Arguments

• src - A string

Return value

Err(ParseFloatError) if the string did not represent a valid number. Otherwise, Ok(n) where n is the floating-point number represented by src.

impl<'a> Sum<&'a f32> for f32

fn sum<I>(iter: I) -> f32 where
    I: Iterator<Item = &'a f32>, 

Method which takes an iterator and generates Self from the elements by "summing up" the items.

impl Sum<f32> for f32

fn sum<I>(iter: I) -> f32 where
    I: Iterator<Item = f32>, 

Method which takes an iterator and generates Self from the elements by "summing up" the items.

impl LowerExp for f32

fn fmt(&self, fmt: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.