# Primitive Type f32
1.0.0[−]

Expand description

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.

For more information on floating point numbers, see Wikipedia.

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

## Implementations

[src]

### impl f32

[src]

#### pub fn floor(self) -> f32

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);

Run
[src]

#### 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);

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[src]

#### 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);

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[src]

#### pub fn trunc(self) -> f32

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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[src]

#### pub fn fract(self) -> f32

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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[src]

#### pub fn abs(self) -> f32

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());

Run
[src]

#### 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

    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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1.35.0[src]

#### pub fn copysign(self, sign: f32) -> f32

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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[src]

#### 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` 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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1.38.0[src]

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

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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1.38.0[src]

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

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);

Run
[src]

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

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);

Run
[src]

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

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);

Run
[src]

#### pub fn sqrt(self) -> f32

Returns the square root of a number.

Returns NaN if `self` is a negative number other than `-0.0`.

# Examples

    let positive = 4.0_f32;
    let negative = -4.0_f32;
    let negative_zero = -0.0_f32;

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

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

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[src]

#### pub fn exp(self) -> f32

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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[src]

#### pub fn exp2(self) -> f32

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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[src]

#### pub fn ln(self) -> f32

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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[src]

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

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

The result might 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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[src]

#### pub fn log2(self) -> f32

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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[src]

#### pub fn log10(self) -> f32

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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[src]

#### 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

    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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[src]

#### pub fn cbrt(self) -> f32

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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[src]

#### 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

    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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[src]

#### pub fn sin(self) -> f32

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);

Run
[src]

#### pub fn cos(self) -> f32

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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[src]

#### pub fn tan(self) -> f32

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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[src]

#### 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

    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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[src]

#### 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

    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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[src]

#### pub fn atan(self) -> f32

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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[src]

#### 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

    // 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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[src]

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

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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[src]

#### 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

    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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[src]

#### pub fn ln_1p(self) -> f32

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);

Run
[src]

#### pub fn sinh(self) -> f32

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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[src]

#### pub fn cosh(self) -> f32

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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[src]

#### pub fn tanh(self) -> f32

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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[src]

#### pub fn asinh(self) -> f32

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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[src]

#### pub fn acosh(self) -> f32

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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[src]

#### pub fn atanh(self) -> f32

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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[src]

#### pub fn lerp(self, start: f32, end: f32) -> f32

🔬 This is a nightly-only experimental API. (`float_interpolation` #86269)

Linear interpolation between `start` and `end`.

This enables linear interpolation between `start` and `end`, where start is represented by `self == 0.0` and `end` is represented by `self == 1.0`. This is the basis of all “transition”, “easing”, or “step” functions; if you change `self` from 0.0 to 1.0 at a given rate, the result will change from `start` to `end` at a similar rate.

Values below 0.0 or above 1.0 are allowed, allowing you to extrapolate values outside the range from `start` to `end`. This also is useful for transition functions which might move slightly past the end or start for a desired effect. Mathematically, the values returned are equivalent to `start + self * (end - start)`, although we make a few specific guarantees that are useful specifically to linear interpolation.

These guarantees are:

- If `start` and `end` are finite, the value at 0.0 is always `start` and the value at 1.0 is always `end`. (exactness)
- If `start` and `end` are finite, the values will always move in the direction from `start` to `end` (monotonicity)
- If `self` is finite and `start == end`, the value at any point will always be `start == end`. (consistency)

[src]

### impl f32

1.43.0[src]

#### pub const RADIX: u32

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

1.43.0[src]

#### pub const MANTISSA_DIGITS: u32

Number of significant digits in base 2.

1.43.0[src]

#### pub const DIGITS: u32

Approximate number of significant digits in base 10.

1.43.0[src]

#### pub const EPSILON: f32

Machine epsilon value for `f32`.

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

1.43.0[src]

#### pub const MIN: f32

Smallest finite `f32` value.

1.43.0[src]

#### pub const MIN_POSITIVE: f32

Smallest positive normal `f32` value.

1.43.0[src]

#### pub const MAX: f32

Largest finite `f32` value.

1.43.0[src]

#### pub const MIN_EXP: i32

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

1.43.0[src]

#### pub const MAX_EXP: i32

Maximum possible power of 2 exponent.

1.43.0[src]

#### pub const MIN_10_EXP: i32

Minimum possible normal power of 10 exponent.

1.43.0[src]

#### pub const MAX_10_EXP: i32

Maximum possible power of 10 exponent.

1.43.0[src]

#### pub const NAN: f32

Not a Number (NaN).

1.43.0[src]

#### pub const INFINITY: f32

Infinity (∞).

1.43.0[src]

#### pub const NEG_INFINITY: f32

Negative infinity (−∞).

1.0.0 (const: unstable)[src]

#### pub fn is_nan(self) -> bool

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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1.0.0 (const: unstable)[src]

#### pub fn is_infinite(self) -> bool

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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1.0.0 (const: unstable)[src]

#### pub fn is_finite(self) -> bool

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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1.53.0 (const: unstable)[src]

#### pub fn is_subnormal(self) -> bool

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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1.0.0 (const: unstable)[src]

#### pub fn is_normal(self) -> bool

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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1.0.0 (const: unstable)[src]

#### 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;

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

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

Run
1.0.0 (const: unstable)[src]

#### pub fn is_sign_positive(self) -> bool

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());

Run
1.0.0 (const: unstable)[src]

#### pub fn is_sign_negative(self) -> bool

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());

Run
[src]

#### pub fn recip(self) -> f32

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);

Run
1.7.0[src]

#### pub fn to_degrees(self) -> f32

Converts radians to degrees.

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

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

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

Run
1.7.0[src]

#### pub fn to_radians(self) -> f32

Converts degrees to radians.

    let angle = 180.0f32;

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

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

Run
[src]

#### 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);

Run

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

[src]

#### 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);

Run

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

1.44.0[src]

#### pub unsafe fn to_int_unchecked<Int>(self) -> Int where
f32: FloatToInt<Int>,

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);

Run

# Safety

The value must:

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

1.20.0 (const: unstable)[src]

#### 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);

Run
1.20.0 (const: unstable)[src]

#### 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

    let v = f32::from_bits(0x41480000);
    assert_eq!(v, 12.5);

Run
1.40.0 (const: unstable)[src]

#### pub fn to_be_bytes(self) -> [u8; 4]

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]);

Run
1.40.0 (const: unstable)[src]

#### pub fn to_le_bytes(self) -> [u8; 4]

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]);

Run
1.40.0 (const: unstable)[src]

#### pub fn to_ne_bytes(self) -> [u8; 4]

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]
        }
    );

Run
1.40.0 (const: unstable)[src]

#### pub fn from_be_bytes(bytes: [u8; 4]) -> f32

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
1.40.0 (const: unstable)[src]

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

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
1.40.0 (const: unstable)[src]

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

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
[src]

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

🔬 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));

Run
1.50.0[src]

#### pub fn clamp(self, min: f32, max: f32) -> f32

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());

Run

## Trait Implementations

[src]

### impl<'_> Add<&'_ f32> for f32

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

The resulting type after applying the `+` operator.

[src]

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

Performs the `+` operation. Read more

[src]

### impl<'_, '_> Add<&'_ f32> for &'_ f32

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

The resulting type after applying the `+` operator.

[src]

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

Performs the `+` operation. Read more

[src]

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

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

The resulting type after applying the `+` operator.

[src]

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

Performs the `+` operation. Read more

[src]

### impl Add<f32> for f32

#### type Output = f32

The resulting type after applying the `+` operator.

[src]

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

Performs the `+` operation. Read more

1.22.0[src]

### impl<'_> AddAssign<&'_ f32> for f32

[src]

#### pub fn add_assign(&mut self, other: &f32)

Performs the `+=` operation. Read more

1.8.0[src]

### impl AddAssign<f32> for f32

[src]

#### pub fn add_assign(&mut self, other: f32)

Performs the `+=` operation. Read more

[src]

### impl Clone for f32

[src]

#### pub fn clone(&self) -> f32

Returns a copy of the value. Read more

[src]

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

Performs copy-assignment from `source`. Read more

[src]

### impl Debug for f32

[src]

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

Formats the value using the given formatter. Read more

1.0.0 (const: unstable)[src]

### impl Default for f32

[src]

#### pub fn default() -> f32

Returns the default value of `0.0`

[src]

### impl Display for f32

[src]

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

Formats the value using the given formatter. Read more

[src]

### impl<'_> Div<&'_ f32> for f32

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

The resulting type after applying the `/` operator.

[src]

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

Performs the `/` operation. Read more

[src]

### impl<'_, '_> Div<&'_ f32> for &'_ f32

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

The resulting type after applying the `/` operator.

[src]

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

Performs the `/` operation. Read more

[src]

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

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

The resulting type after applying the `/` operator.

[src]

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

Performs the `/` operation. Read more

[src]

### impl Div<f32> for f32

#### type Output = f32

The resulting type after applying the `/` operator.

[src]

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

Performs the `/` operation. Read more

1.22.0[src]

### impl<'_> DivAssign<&'_ f32> for f32

[src]

#### pub fn div_assign(&mut self, other: &f32)

Performs the `/=` operation. Read more

1.8.0[src]

### impl DivAssign<f32> for f32

[src]

#### pub fn div_assign(&mut self, other: f32)

Performs the `/=` operation. Read more

1.6.0 (const: unstable)[src]

### impl From<i16> for f32

[src]

#### pub fn from(small: i16) -> f32

Converts `i16` to `f32` losslessly.

1.6.0 (const: unstable)[src]

### impl From<i8> for f32

[src]

#### pub fn from(small: i8) -> f32

Converts `i8` to `f32` losslessly.

1.6.0 (const: unstable)[src]

### impl From<u16> for f32

[src]

#### pub fn from(small: u16) -> f32

Converts `u16` to `f32` losslessly.

1.6.0 (const: unstable)[src]

### impl From<u8> for f32

[src]

#### pub fn from(small: u8) -> f32

Converts `u8` to `f32` losslessly.

[src]

### impl FromStr for f32

[src]

#### pub 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]

# 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`.

#### type Err = ParseFloatError

The associated error which can be returned from parsing.

[src]

### impl LowerExp for f32

[src]

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

Formats the value using the given formatter.

[src]

### impl<'_> Mul<&'_ f32> for f32

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

The resulting type after applying the `*` operator.

[src]

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

Performs the `*` operation. Read more

[src]

### impl<'_, '_> Mul<&'_ f32> for &'_ f32

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

The resulting type after applying the `*` operator.

[src]

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

Performs the `*` operation. Read more

[src]

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

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

The resulting type after applying the `*` operator.

[src]

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

Performs the `*` operation. Read more

[src]

### impl Mul<f32> for f32

#### type Output = f32

The resulting type after applying the `*` operator.

[src]

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

Performs the `*` operation. Read more

1.22.0[src]

### impl<'_> MulAssign<&'_ f32> for f32

[src]

#### pub fn mul_assign(&mut self, other: &f32)

Performs the `*=` operation. Read more

1.8.0[src]

### impl MulAssign<f32> for f32

[src]

#### pub fn mul_assign(&mut self, other: f32)

Performs the `*=` operation. Read more

[src]

### impl<'_> Neg for &'_ f32

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

The resulting type after applying the `-` operator.

[src]

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

Performs the unary `-` operation. Read more

[src]

### impl Neg for f32

#### type Output = f32

The resulting type after applying the `-` operator.

[src]

#### pub fn neg(self) -> f32

Performs the unary `-` operation. Read more

[src]

### impl PartialEq<f32> for f32

[src]

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

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

[src]

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

This method tests for `!=`.

[src]

### impl PartialOrd<f32> for f32

[src]

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

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

[src]

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

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

[src]

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

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

[src]

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

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

[src]

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

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

1.12.0[src]

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

[src]

#### pub 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. Read more

1.12.0[src]

### impl Product<f32> for f32

[src]

#### pub 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. Read more

[src]

### impl<'_, '_> Rem<&'_ f32> for &'_ f32

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

The resulting type after applying the `%` operator.

[src]

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

Performs the `%` operation. Read more

[src]

### impl<'_> Rem<&'_ f32> for f32

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

The resulting type after applying the `%` operator.

[src]

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

Performs the `%` operation. Read more

[src]

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

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

The resulting type after applying the `%` operator.

[src]

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

Performs the `%` operation. Read more

[src]

### impl Rem<f32> for f32

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);

Run

#### type Output = f32

The resulting type after applying the `%` operator.

[src]

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

Performs the `%` operation. Read more

1.22.0[src]

### impl<'_> RemAssign<&'_ f32> for f32

[src]

#### pub fn rem_assign(&mut self, other: &f32)

Performs the `%=` operation. Read more

1.8.0[src]

### impl RemAssign<f32> for f32

[src]

#### pub fn rem_assign(&mut self, other: f32)

Performs the `%=` operation. Read more

[src]

### impl<'_> Sub<&'_ f32> for f32

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

The resulting type after applying the `-` operator.

[src]

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

Performs the `-` operation. Read more

[src]

### impl<'_, '_> Sub<&'_ f32> for &'_ f32

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

The resulting type after applying the `-` operator.

[src]

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

Performs the `-` operation. Read more

[src]

### impl Sub<f32> for f32

#### type Output = f32

The resulting type after applying the `-` operator.

[src]

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

Performs the `-` operation. Read more

[src]

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

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

The resulting type after applying the `-` operator.

[src]

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

Performs the `-` operation. Read more

1.22.0[src]

### impl<'_> SubAssign<&'_ f32> for f32

[src]

#### pub fn sub_assign(&mut self, other: &f32)

Performs the `-=` operation. Read more

1.8.0[src]

### impl SubAssign<f32> for f32

[src]

#### pub fn sub_assign(&mut self, other: f32)

Performs the `-=` operation. Read more

1.12.0[src]

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

[src]

#### pub 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. Read more

1.12.0[src]

### impl Sum<f32> for f32

[src]

#### pub 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. Read more

[src]

### impl UpperExp for f32

[src]

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

Formats the value using the given formatter.

[src]

### impl Copy for f32

[src]

### impl FloatToInt<i128> for f32

[src]

### impl FloatToInt<i16> for f32

[src]

### impl FloatToInt<i32> for f32

[src]

### impl FloatToInt<i64> for f32

[src]

### impl FloatToInt<i8> for f32

[src]

### impl FloatToInt<isize> for f32

[src]

### impl FloatToInt<u128> for f32

[src]

### impl FloatToInt<u16> for f32

[src]

### impl FloatToInt<u32> for f32

[src]

### impl FloatToInt<u64> for f32

[src]

### impl FloatToInt<u8> for f32

[src]

### impl FloatToInt<usize> for f32

## Auto Trait Implementations

### impl RefUnwindSafe for f32

### impl Send for f32

### impl Sync for f32

### impl Unpin for f32

### impl UnwindSafe for f32

## Blanket Implementations

[src]

### impl<T> Any for T where
T: 'static + ?Sized,

[src]

#### pub fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more

[src]

### impl<T> Borrow<T> for T where
T: ?Sized,

[src]

#### pub fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

[src]

### impl<T> BorrowMut<T> for T where
T: ?Sized,

[src]

#### pub fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

[src]

### impl<T> From<T> for T

[src]

#### pub fn from(t: T) -> T

Performs the conversion.

[src]

### impl<T, U> Into<U> for T where
U: From<T>,

[src]

#### pub fn into(self) -> U

Performs the conversion.

[src]

### impl<T> ToOwned for T where
T: Clone,

#### type Owned = T

The resulting type after obtaining ownership.

[src]

#### pub fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more

[src]

#### pub fn clone_into(&self, target: &mut T)

🔬 This is a nightly-only experimental API. (`toowned_clone_into` #41263)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

[src]

### impl<T> ToString for T where
T: Display + ?Sized,

[src]

#### pub default fn to_string(&self) -> String

Converts the given value to a `String`. Read more

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### impl<T, U> TryFrom<U> for T where
U: Into<T>,

#### type Error = Infallible

The type returned in the event of a conversion error.

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#### pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.

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### impl<T, U> TryInto<U> for T where
U: TryFrom<T>,

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

The type returned in the event of a conversion error.

[src]

#### pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.