# Primitive Type f321.0.0[−]

A 32-bit floating point type (specifically, the “binary32” type defined in IEEE 754-2008).

This type can represent a wide range of decimal numbers, like `3.5`, `27`, `-113.75`, `0.0078125`, `34359738368`, `0`, `-1`. So unlike integer types (such as `i32`), floating point types can represent non-integer numbers, too.

However, being able to represent this wide range of numbers comes at the cost of precision: floats can only represent some of the real numbers and calculation with floats round to a nearby representable number. For example, `5.0` and `1.0` can be exactly represented as `f32`, but `1.0 / 5.0` results in `0.20000000298023223876953125` since `0.2` cannot be exactly represented as `f32`. Note, however, that printing floats with `println` and friends will often discard insignificant digits: `println!("{}", 1.0f32 / 5.0f32)` will print `0.2`.

Additionally, `f32` can represent some special values:

• −0.0: IEEE 754 floating point numbers have a bit that indicates their sign, so −0.0 is a possible value. For comparison −0.0 = +0.0, but floating point operations can carry the sign bit through arithmetic operations. This means −0.0 × +0.0 produces −0.0 and a negative number rounded to a value smaller than a float can represent also produces −0.0.
• and −∞: these result from calculations like `1.0 / 0.0`.
• NaN (not a number): this value results from calculations like `(-1.0).sqrt()`. NaN has some potentially unexpected behavior: it is unequal to any float, including itself! It is also neither smaller nor greater than any float, making it impossible to sort. Lastly, it is considered infectious as almost all calculations where one of the operands is NaN will also result in NaN.

See also the `std::f32::consts` module.

## Implementations

### `impl f32`[src]

#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn floor(self) -> f32`[src]

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

# Examples

```let f = 3.7_f32;
let g = 3.0_f32;
let h = -3.7_f32;

assert_eq!(f.floor(), 3.0);
assert_eq!(g.floor(), 3.0);
assert_eq!(h.floor(), -4.0);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn ceil(self) -> f32`[src]

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);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn round(self) -> f32`[src]

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);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn trunc(self) -> f32`[src]

Returns the integer part of a number.

# Examples

```let f = 3.7_f32;
let g = 3.0_f32;
let h = -3.7_f32;

assert_eq!(f.trunc(), 3.0);
assert_eq!(g.trunc(), 3.0);
assert_eq!(h.trunc(), -3.0);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn fract(self) -> f32`[src]

Returns the fractional part of a number.

# Examples

```let x = 3.6_f32;
let y = -3.6_f32;
let abs_difference_x = (x.fract() - 0.6).abs();
let abs_difference_y = (y.fract() - (-0.6)).abs();

assert!(abs_difference_x <= f32::EPSILON);
assert!(abs_difference_y <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn abs(self) -> f32`[src]

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

# Examples

```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());```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn signum(self) -> f32`[src]

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

```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());```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn copysign(self, sign: f32) -> f32`1.35.0[src]

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

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

# Examples

```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());```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn mul_add(self, a: f32, b: f32) -> f32`[src]

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` may be more performant than an unfused multiply-add if the target architecture has a dedicated `fma` CPU instruction. However, this is not always true, and will be heavily dependant on designing algorithms with specific target hardware in mind.

# Examples

```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);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn div_euclid(self, rhs: f32) -> f32`1.38.0[src]

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

```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```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn rem_euclid(self, rhs: f32) -> f32`1.38.0[src]

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

```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!((-f32::EPSILON).rem_euclid(3.0) != 0.0);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn powi(self, n: i32) -> f32`[src]

Raises a number to an integer power.

Using this function is generally faster than using `powf`

# Examples

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

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn powf(self, n: f32) -> f32`[src]

Raises a number to a floating point power.

# Examples

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

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn sqrt(self) -> f32`[src]

Returns the square root of a number.

Returns NaN if `self` is a negative number.

# Examples

```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());```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn exp(self) -> f32`[src]

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

# Examples

```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);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn exp2(self) -> f32`[src]

Returns `2^(self)`.

# Examples

```let f = 2.0f32;

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

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn ln(self) -> f32`[src]

Returns the natural logarithm of the number.

# Examples

```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);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn log(self, base: f32) -> f32`[src]

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

```let five = 5.0f32;

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

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn log2(self) -> f32`[src]

Returns the base 2 logarithm of the number.

# Examples

```let two = 2.0f32;

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

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn log10(self) -> f32`[src]

Returns the base 10 logarithm of the number.

# Examples

```let ten = 10.0f32;

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

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn abs_sub(self, other: f32) -> f32`[src]

👎 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

```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);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn cbrt(self) -> f32`[src]

Returns the cube root of a number.

# Examples

```let x = 8.0f32;

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

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn hypot(self, other: f32) -> f32`[src]

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

# Examples

```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);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn sin(self) -> f32`[src]

Computes the sine of a number (in radians).

# Examples

```let x = std::f32::consts::FRAC_PI_2;

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

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn cos(self) -> f32`[src]

Computes the cosine of a number (in radians).

# Examples

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

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

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn tan(self) -> f32`[src]

Computes the tangent of a number (in radians).

# Examples

```let x = std::f32::consts::FRAC_PI_4;
let abs_difference = (x.tan() - 1.0).abs();

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn asin(self) -> f32`[src]

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

```let f = std::f32::consts::FRAC_PI_2;

// asin(sin(pi/2))
let abs_difference = (f.sin().asin() - std::f32::consts::FRAC_PI_2).abs();

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn acos(self) -> f32`[src]

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

```let f = std::f32::consts::FRAC_PI_4;

// acos(cos(pi/4))
let abs_difference = (f.cos().acos() - std::f32::consts::FRAC_PI_4).abs();

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn atan(self) -> f32`[src]

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

# Examples

```let f = 1.0f32;

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

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn atan2(self, other: f32) -> f32`[src]

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

```// 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) - (-std::f32::consts::FRAC_PI_4)).abs();
let abs_difference_2 = (y2.atan2(x2) - (3.0 * std::f32::consts::FRAC_PI_4)).abs();

assert!(abs_difference_1 <= f32::EPSILON);
assert!(abs_difference_2 <= f32::EPSILON);```
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#### `pub fn sin_cos(self) -> (f32, f32)`[src]

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

# Examples

```let x = std::f32::consts::FRAC_PI_4;
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);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn exp_m1(self) -> f32`[src]

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

# Examples

```let x = 1e-8_f32;

// for very small x, e^x is approximately 1 + x + x^2 / 2
let approx = x + x * x / 2.0;
let abs_difference = (x.exp_m1() - approx).abs();

assert!(abs_difference < 1e-10);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn ln_1p(self) -> f32`[src]

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

# Examples

```let x = 1e-8_f32;

// for very small x, ln(1 + x) is approximately x - x^2 / 2
let approx = x - x * x / 2.0;
let abs_difference = (x.ln_1p() - approx).abs();

assert!(abs_difference < 1e-10);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn sinh(self) -> f32`[src]

Hyperbolic sine function.

# Examples

```let e = std::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);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn cosh(self) -> f32`[src]

Hyperbolic cosine function.

# Examples

```let e = std::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);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn tanh(self) -> f32`[src]

Hyperbolic tangent function.

# Examples

```let e = std::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);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn asinh(self) -> f32`[src]

Inverse hyperbolic sine function.

# Examples

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

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

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn acosh(self) -> f32`[src]

Inverse hyperbolic cosine function.

# Examples

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

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

assert!(abs_difference <= f32::EPSILON);```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn atanh(self) -> f32`[src]

Inverse hyperbolic tangent function.

# Examples

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

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

assert!(abs_difference <= 1e-5);```
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### `impl f32`[src]

#### `pub const RADIX: u32`1.43.0[src]

The radix or base of the internal representation of `f32`.

#### `pub const MANTISSA_DIGITS: u32`1.43.0[src]

Number of significant digits in base 2.

#### `pub const DIGITS: u32`1.43.0[src]

Approximate number of significant digits in base 10.

#### `pub const EPSILON: f32`1.43.0[src]

Machine epsilon value for `f32`.

This is the difference between `1.0` and the next larger representable number.

#### `pub const MIN: f32`1.43.0[src]

Smallest finite `f32` value.

#### `pub const MIN_POSITIVE: f32`1.43.0[src]

Smallest positive normal `f32` value.

#### `pub const MAX: f32`1.43.0[src]

Largest finite `f32` value.

#### `pub const MIN_EXP: i32`1.43.0[src]

One greater than the minimum possible normal power of 2 exponent.

#### `pub const MAX_EXP: i32`1.43.0[src]

Maximum possible power of 2 exponent.

#### `pub const MIN_10_EXP: i32`1.43.0[src]

Minimum possible normal power of 10 exponent.

#### `pub const MAX_10_EXP: i32`1.43.0[src]

Maximum possible power of 10 exponent.

#### `pub const NAN: f32`1.43.0[src]

Not a Number (NaN).

Infinity (∞).

#### `pub const NEG_INFINITY: f32`1.43.0[src]

Negative infinity (−∞).

#### `pub const fn is_nan(self) -> bool`[src]

Returns `true` if this value is `NaN`.

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

assert!(nan.is_nan());
assert!(!f.is_nan());```
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#### `pub const fn is_infinite(self) -> bool`[src]

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

```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());```
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#### `pub const fn is_finite(self) -> bool`[src]

Returns `true` if this number is neither infinite nor `NaN`.

```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());```
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#### `pub const fn is_subnormal(self) -> bool`1.53.0[src]

Returns `true` if the number is subnormal.

```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_subnormal());
assert!(!max.is_subnormal());

assert!(!zero.is_subnormal());
assert!(!f32::NAN.is_subnormal());
assert!(!f32::INFINITY.is_subnormal());
// Values between `0` and `min` are Subnormal.
assert!(lower_than_min.is_subnormal());```
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#### `pub const fn is_normal(self) -> bool`[src]

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

```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());```
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#### `pub const fn classify(self) -> FpCategory`[src]

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;

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

assert_eq!(num.classify(), FpCategory::Normal);
assert_eq!(inf.classify(), FpCategory::Infinite);```
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#### `pub const fn is_sign_positive(self) -> bool`[src]

Returns `true` if `self` has a positive sign, including `+0.0`, `NaN`s 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());```
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#### `pub const fn is_sign_negative(self) -> bool`[src]

Returns `true` if `self` has a negative sign, including `-0.0`, `NaN`s 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());```
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#### `pub fn recip(self) -> f32`[src]

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

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

assert!(abs_difference <= f32::EPSILON);```
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#### `pub fn to_degrees(self) -> f32`1.7.0[src]

```let angle = std::f32::consts::PI;

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

assert!(abs_difference <= f32::EPSILON);```
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#### `pub fn to_radians(self) -> f32`1.7.0[src]

```let angle = 180.0f32;

let abs_difference = (angle.to_radians() - std::f32::consts::PI).abs();

assert!(abs_difference <= f32::EPSILON);```
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#### `pub fn max(self, other: f32) -> f32`[src]

Returns the maximum of the two numbers.

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

assert_eq!(x.max(y), y);```
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If one of the arguments is NaN, then the other argument is returned.

#### `pub fn min(self, other: f32) -> f32`[src]

Returns the minimum of the two numbers.

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

assert_eq!(x.min(y), x);```
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If one of the arguments is NaN, then the other argument is returned.

#### `pub unsafe fn to_int_unchecked<Int>(self) -> Int where    f32: FloatToInt<Int>, `1.44.0[src]

Rounds toward zero and converts to any primitive integer type, assuming that the value is finite and fits in that type.

```let value = 4.6_f32;
let rounded = unsafe { value.to_int_unchecked::<u16>() };
assert_eq!(rounded, 4);

let value = -128.9_f32;
let rounded = unsafe { value.to_int_unchecked::<i8>() };
assert_eq!(rounded, i8::MIN);```
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# Safety

The value must:

• Not be `NaN`
• Not be infinite
• Be representable in the return type `Int`, after truncating off its fractional part

#### `pub const fn to_bits(self) -> u32`1.20.0[src]

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);
```
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#### `pub const fn from_bits(v: u32) -> f32`1.20.0[src]

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

```let v = f32::from_bits(0x41480000);
assert_eq!(v, 12.5);```
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#### `pub const fn to_be_bytes(self) -> [u8; 4]`1.40.0[src]

Return the memory representation of this floating point number as a byte array in big-endian (network) byte order.

# Examples

```let bytes = 12.5f32.to_be_bytes();
assert_eq!(bytes, [0x41, 0x48, 0x00, 0x00]);```
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#### `pub const fn to_le_bytes(self) -> [u8; 4]`1.40.0[src]

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

# Examples

```let bytes = 12.5f32.to_le_bytes();
assert_eq!(bytes, [0x00, 0x00, 0x48, 0x41]);```
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#### `pub const fn to_ne_bytes(self) -> [u8; 4]`1.40.0[src]

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

As the target platform’s native endianness is used, portable code should use `to_be_bytes` or `to_le_bytes`, as appropriate, instead.

# Examples

```let bytes = 12.5f32.to_ne_bytes();
assert_eq!(
bytes,
if cfg!(target_endian = "big") {
[0x41, 0x48, 0x00, 0x00]
} else {
[0x00, 0x00, 0x48, 0x41]
}
);```
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#### `pub fn as_ne_bytes(&self) -> &[u8; 4]`[src]

🔬 This is a nightly-only experimental API. (`num_as_ne_bytes` #76976)

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]
}
);```
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#### `pub const fn from_be_bytes(bytes: [u8; 4]) -> f32`1.40.0[src]

Create a floating point value from its representation as a byte array in big endian.

# Examples

```let value = f32::from_be_bytes([0x41, 0x48, 0x00, 0x00]);
assert_eq!(value, 12.5);```
Run

#### `pub const fn from_le_bytes(bytes: [u8; 4]) -> f32`1.40.0[src]

Create a floating point value from its representation as a byte array in little endian.

# Examples

```let value = f32::from_le_bytes([0x00, 0x00, 0x48, 0x41]);
assert_eq!(value, 12.5);```
Run

#### `pub const fn from_ne_bytes(bytes: [u8; 4]) -> f32`1.40.0[src]

Create a floating point value from its representation as a byte array in native endian.

As the target platform’s native endianness is used, portable code likely wants to use `from_be_bytes` or `from_le_bytes`, as appropriate instead.

# Examples

```let value = f32::from_ne_bytes(if cfg!(target_endian = "big") {
[0x41, 0x48, 0x00, 0x00]
} else {
[0x00, 0x00, 0x48, 0x41]
});
assert_eq!(value, 12.5);```
Run

#### `pub fn total_cmp(&self, other: &f32) -> Ordering`[src]

🔬 This is a nightly-only experimental API. (`total_cmp` #72599)

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));```
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#### `#[must_use = "method returns a new number and does not mutate the original value"]pub fn clamp(self, min: f32, max: f32) -> f32`1.50.0[src]

Restrict a value to a certain interval unless it is NaN.

Returns `max` if `self` is greater than `max`, and `min` if `self` is less than `min`. Otherwise this returns `self`.

Note that this function returns NaN if the initial value was NaN as well.

# Panics

Panics if `min > max`, `min` is NaN, or `max` is NaN.

# Examples

```assert!((-3.0f32).clamp(-2.0, 1.0) == -2.0);
assert!((0.0f32).clamp(-2.0, 1.0) == 0.0);
assert!((2.0f32).clamp(-2.0, 1.0) == 1.0);
assert!((f32::NAN).clamp(-2.0, 1.0).is_nan());```
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## Trait Implementations

### `impl<'_, '_> Add<&'_ f32> for &'_ f32`[src]

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

The resulting type after applying the `+` operator.

### `impl<'_> Add<&'_ f32> for f32`[src]

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

The resulting type after applying the `+` operator.

### `impl Add<f32> for f32`[src]

#### `type Output = f32`

The resulting type after applying the `+` operator.

### `impl<'a> Add<f32> for &'a f32`[src]

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

The resulting type after applying the `+` operator.

### `impl Default for f32`[src]

#### `pub fn default() -> f32`[src]

Returns the default value of `0.0`

### `impl<'_, '_> Div<&'_ f32> for &'_ f32`[src]

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

The resulting type after applying the `/` operator.

### `impl<'_> Div<&'_ f32> for f32`[src]

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

The resulting type after applying the `/` operator.

### `impl<'a> Div<f32> for &'a f32`[src]

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

The resulting type after applying the `/` operator.

### `impl Div<f32> for f32`[src]

#### `type Output = f32`

The resulting type after applying the `/` operator.

### `impl From<i16> for f32`1.6.0[src]

#### `pub fn from(small: i16) -> f32`[src]

Converts `i16` to `f32` losslessly.

### `impl From<i8> for f32`1.6.0[src]

#### `pub fn from(small: i8) -> f32`[src]

Converts `i8` to `f32` losslessly.

### `impl From<u16> for f32`1.6.0[src]

#### `pub fn from(small: u16) -> f32`[src]

Converts `u16` to `f32` losslessly.

### `impl From<u8> for f32`1.6.0[src]

#### `pub fn from(small: u8) -> f32`[src]

Converts `u8` to `f32` losslessly.

### `impl FromStr for f32`[src]

#### `type Err = ParseFloatError`

The associated error which can be returned from parsing.

#### `pub fn from_str(src: &str) -> Result<f32, ParseFloatError>`[src]

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<'_, '_> Mul<&'_ f32> for &'_ f32`[src]

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

The resulting type after applying the `*` operator.

### `impl<'_> Mul<&'_ f32> for f32`[src]

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

The resulting type after applying the `*` operator.

### `impl Mul<f32> for f32`[src]

#### `type Output = f32`

The resulting type after applying the `*` operator.

### `impl<'a> Mul<f32> for &'a f32`[src]

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

The resulting type after applying the `*` operator.

### `impl Neg for f32`[src]

#### `type Output = f32`

The resulting type after applying the `-` operator.

### `impl<'_> Neg for &'_ f32`[src]

#### `type Output = <f32 as Neg>::Output`

The resulting type after applying the `-` operator.

### `impl<'_, '_> Rem<&'_ f32> for &'_ f32`[src]

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

The resulting type after applying the `%` operator.

### `impl<'_> Rem<&'_ f32> for f32`[src]

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

The resulting type after applying the `%` operator.

### `impl<'a> Rem<f32> for &'a f32`[src]

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

The resulting type after applying the `%` operator.

### `impl Rem<f32> for f32`[src]

The remainder from the division of two floats.

The remainder has the same sign as the dividend and is computed as: `x - (x / y).trunc() * y`.

# Examples

```let x: f32 = 50.50;
let y: f32 = 8.125;
let remainder = x - (x / y).trunc() * y;

// The answer to both operations is 1.75
assert_eq!(x % y, remainder);```
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#### `type Output = f32`

The resulting type after applying the `%` operator.

### `impl<'_> Sub<&'_ f32> for f32`[src]

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

The resulting type after applying the `-` operator.

### `impl<'_, '_> Sub<&'_ f32> for &'_ f32`[src]

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

The resulting type after applying the `-` operator.

### `impl Sub<f32> for f32`[src]

#### `type Output = f32`

The resulting type after applying the `-` operator.

### `impl<'a> Sub<f32> for &'a f32`[src]

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

The resulting type after applying the `-` operator.

## Blanket Implementations

### `impl<T> ToOwned for T where    T: Clone, `[src]

#### `type Owned = T`

The resulting type after obtaining ownership.

### `impl<T, U> TryFrom<U> for T where    U: Into<T>, `[src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

### `impl<T, U> TryInto<U> for T where    U: TryFrom<T>, `[src]

#### `type Error = <U as TryFrom<T>>::Error`

The type returned in the event of a conversion error.