f64 - Rust
Description: A 64-bit floating point type (specifically, the “binary64” type defined in IEEE 754-2008).

# Primitive Type f64

1.0.0 ·
Expand description

A 64-bit floating point type (specifically, the “binary64” type defined in IEEE 754-2008).

This type is very similar to `f32`, but has increased precision by using twice as many bits. Please see the documentation for `f32` or Wikipedia on double precision values for more information.

See also the `std::f64::consts` module.

## Implementations§

source§

### impl f64

1.0.0 · source

#### pub fn floor(self) -> f64

Returns the largest integer less than or equal to `self`.

This function always returns the precise result.

##### §Examples

    let f = 3.7_f64;
    let g = 3.0_f64;
    let h = -3.7_f64;

    assert_eq!(f.floor(), 3.0);
    assert_eq!(g.floor(), 3.0);
    assert_eq!(h.floor(), -4.0);

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1.0.0 · source

#### pub fn ceil(self) -> f64

Returns the smallest integer greater than or equal to `self`.

This function always returns the precise result.

##### §Examples

    let f = 3.01_f64;
    let g = 4.0_f64;

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

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1.0.0 · source

#### pub fn round(self) -> f64

Returns the nearest integer to `self`. If a value is half-way between two integers, round away from `0.0`.

This function always returns the precise result.

##### §Examples

    let f = 3.3_f64;
    let g = -3.3_f64;
    let h = -3.7_f64;
    let i = 3.5_f64;
    let j = 4.5_f64;

    assert_eq!(f.round(), 3.0);
    assert_eq!(g.round(), -3.0);
    assert_eq!(h.round(), -4.0);
    assert_eq!(i.round(), 4.0);
    assert_eq!(j.round(), 5.0);

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1.77.0 · source

#### pub fn round_ties_even(self) -> f64

Returns the nearest integer to a number. Rounds half-way cases to the number with an even least significant digit.

This function always returns the precise result.

##### §Examples

    let f = 3.3_f64;
    let g = -3.3_f64;
    let h = 3.5_f64;
    let i = 4.5_f64;

    assert_eq!(f.round_ties_even(), 3.0);
    assert_eq!(g.round_ties_even(), -3.0);
    assert_eq!(h.round_ties_even(), 4.0);
    assert_eq!(i.round_ties_even(), 4.0);

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1.0.0 · source

#### pub fn trunc(self) -> f64

Returns the integer part of `self`. This means that non-integer numbers are always truncated towards zero.

This function always returns the precise result.

##### §Examples

    let f = 3.7_f64;
    let g = 3.0_f64;
    let h = -3.7_f64;

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

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1.0.0 · source

#### pub fn fract(self) -> f64

Returns the fractional part of `self`.

This function always returns the precise result.

##### §Examples

    let x = 3.6_f64;
    let y = -3.6_f64;
    let abs_difference_x = (x.fract() - 0.6).abs();
    let abs_difference_y = (y.fract() - (-0.6)).abs();

    assert!(abs_difference_x < 1e-10);
    assert!(abs_difference_y < 1e-10);

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1.0.0 · source

#### pub fn abs(self) -> f64

Computes the absolute value of `self`.

This function always returns the precise result.

##### §Examples

    let x = 3.5_f64;
    let y = -3.5_f64;

    assert_eq!(x.abs(), x);
    assert_eq!(y.abs(), -y);

    assert!(f64::NAN.abs().is_nan());

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1.0.0 · source

#### pub fn signum(self) -> f64

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_f64;

    assert_eq!(f.signum(), 1.0);
    assert_eq!(f64::NEG_INFINITY.signum(), -1.0);

    assert!(f64::NAN.signum().is_nan());

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1.35.0 · source

#### pub fn copysign(self, sign: f64) -> f64

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 bit of `sign` is returned. Note, however, that conserving the sign bit on NaN across arithmetical operations is not generally guaranteed. See explanation of NaN as a special value for more info.

##### §Examples

    let f = 3.5_f64;

    assert_eq!(f.copysign(0.42), 3.5_f64);
    assert_eq!(f.copysign(-0.42), -3.5_f64);
    assert_eq!((-f).copysign(0.42), 3.5_f64);
    assert_eq!((-f).copysign(-0.42), -3.5_f64);

    assert!(f64::NAN.copysign(1.0).is_nan());

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1.0.0 · source

#### pub fn mul_add(self, a: f64, b: f64) -> f64

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.

##### §Precision

The result of this operation is guaranteed to be the rounded infinite-precision result. It is specified by IEEE 754 as `fusedMultiplyAdd` and guaranteed not to change.

##### §Examples

    let m = 10.0_f64;
    let x = 4.0_f64;
    let b = 60.0_f64;

    assert_eq!(m.mul_add(x, b), 100.0);
    assert_eq!(m * x + b, 100.0);

    let one_plus_eps = 1.0_f64 + f64::EPSILON;
    let one_minus_eps = 1.0_f64 - f64::EPSILON;
    let minus_one = -1.0_f64;

    // The exact result (1 + eps) * (1 - eps) = 1 - eps * eps.
    assert_eq!(one_plus_eps.mul_add(one_minus_eps, minus_one), -f64::EPSILON * f64::EPSILON);
    // Different rounding with the non-fused multiply and add.
    assert_eq!(one_plus_eps * one_minus_eps + minus_one, 0.0);

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1.38.0 · source

#### pub fn div_euclid(self, rhs: f64) -> f64

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`.

##### §Precision

The result of this operation is guaranteed to be the rounded infinite-precision result.

##### §Examples

    let a: f64 = 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 · source

#### pub fn rem_euclid(self, rhs: f64) -> f64

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)` approximately.

##### §Precision

The result of this operation is guaranteed to be the rounded infinite-precision result.

##### §Examples

    let a: f64 = 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!((-f64::EPSILON).rem_euclid(3.0) != 0.0);

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1.0.0 · source

#### pub fn powi(self, n: i32) -> f64

Raises a number to an integer power.

Using this function is generally faster than using `powf`. It might have a different sequence of rounding operations than `powf`, so the results are not guaranteed to agree.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let x = 2.0_f64;
    let abs_difference = (x.powi(2) - (x * x)).abs();

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn powf(self, n: f64) -> f64

Raises a number to a floating point power.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let x = 2.0_f64;
    let abs_difference = (x.powf(2.0) - (x * x)).abs();

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn sqrt(self) -> f64

Returns the square root of a number.

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

##### §Precision

The result of this operation is guaranteed to be the rounded infinite-precision result. It is specified by IEEE 754 as `squareRoot` and guaranteed not to change.

##### §Examples

    let positive = 4.0_f64;
    let negative = -4.0_f64;
    let negative_zero = -0.0_f64;

    assert_eq!(positive.sqrt(), 2.0);
    assert!(negative.sqrt().is_nan());
    assert!(negative_zero.sqrt() == negative_zero);

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1.0.0 · source

#### pub fn exp(self) -> f64

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

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let one = 1.0_f64;
    // e^1
    let e = one.exp();

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

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn exp2(self) -> f64

Returns `2^(self)`.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let f = 2.0_f64;

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

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn ln(self) -> f64

Returns the natural logarithm of the number.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let one = 1.0_f64;
    // e^1
    let e = one.exp();

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

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn log(self, base: f64) -> f64

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.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let twenty_five = 25.0_f64;

    // log5(25) - 2 == 0
    let abs_difference = (twenty_five.log(5.0) - 2.0).abs();

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn log2(self) -> f64

Returns the base 2 logarithm of the number.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let four = 4.0_f64;

    // log2(4) - 2 == 0
    let abs_difference = (four.log2() - 2.0).abs();

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn log10(self) -> f64

Returns the base 10 logarithm of the number.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let hundred = 100.0_f64;

    // log10(100) - 2 == 0
    let abs_difference = (hundred.log10() - 2.0).abs();

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn abs_sub(self, other: f64) -> f64

👎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 `fdim` in C). If you truly need the positive difference, consider using that expression or the C function `fdim`, 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`

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `fdim` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    let x = 3.0_f64;
    let y = -3.0_f64;

    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 < 1e-10);
    assert!(abs_difference_y < 1e-10);

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1.0.0 · source

#### pub fn cbrt(self) -> f64

Returns the cube root of a number.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `cbrt` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    let x = 8.0_f64;

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

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn hypot(self, other: f64) -> f64

Compute the distance between the origin and a point (`x`, `y`) on the Euclidean plane. Equivalently, compute the length of the hypotenuse of a right-angle triangle with other sides having length `x.abs()` and `y.abs()`.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `hypot` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    let x = 2.0_f64;
    let y = 3.0_f64;

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

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn sin(self) -> f64

Computes the sine of a number (in radians).

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let x = std::f64::consts::FRAC_PI_2;

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

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn cos(self) -> f64

Computes the cosine of a number (in radians).

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let x = 2.0 * std::f64::consts::PI;

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

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn tan(self) -> f64

Computes the tangent of a number (in radians).

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `tan` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    let x = std::f64::consts::FRAC_PI_4;
    let abs_difference = (x.tan() - 1.0).abs();

    assert!(abs_difference < 1e-14);

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1.0.0 · source

#### pub fn asin(self) -> f64

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].

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `asin` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    let f = std::f64::consts::FRAC_PI_2;

    // asin(sin(pi/2))
    let abs_difference = (f.sin().asin() - std::f64::consts::FRAC_PI_2).abs();

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn acos(self) -> f64

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].

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `acos` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    let f = std::f64::consts::FRAC_PI_4;

    // acos(cos(pi/4))
    let abs_difference = (f.cos().acos() - std::f64::consts::FRAC_PI_4).abs();

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn atan(self) -> f64

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

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `atan` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    let f = 1.0_f64;

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

    assert!(abs_difference < 1e-10);

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1.0.0 · source

#### pub fn atan2(self, other: f64) -> f64

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)`

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `atan2` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    // Positive angles measured counter-clockwise
    // from positive x axis
    // -pi/4 radians (45 deg clockwise)
    let x1 = 3.0_f64;
    let y1 = -3.0_f64;

    // 3pi/4 radians (135 deg counter-clockwise)
    let x2 = -3.0_f64;
    let y2 = 3.0_f64;

    let abs_difference_1 = (y1.atan2(x1) - (-std::f64::consts::FRAC_PI_4)).abs();
    let abs_difference_2 = (y2.atan2(x2) - (3.0 * std::f64::consts::FRAC_PI_4)).abs();

    assert!(abs_difference_1 < 1e-10);
    assert!(abs_difference_2 < 1e-10);

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1.0.0 · source

#### pub fn sin_cos(self) -> (f64, f64)

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

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `(f64::sin(x), f64::cos(x))`. Note that this might change in the future.

##### §Examples

    let x = std::f64::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 < 1e-10);
    assert!(abs_difference_1 < 1e-10);

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1.0.0 · source

#### pub fn exp_m1(self) -> f64

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

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `expm1` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    let x = 1e-16_f64;

    // 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-20);

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1.0.0 · source

#### pub fn ln_1p(self) -> f64

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

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `log1p` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    let x = 1e-16_f64;

    // 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-20);

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1.0.0 · source

#### pub fn sinh(self) -> f64

Hyperbolic sine function.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `sinh` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    let e = std::f64::consts::E;
    let x = 1.0_f64;

    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 < 1e-10);

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1.0.0 · source

#### pub fn cosh(self) -> f64

Hyperbolic cosine function.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `cosh` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    let e = std::f64::consts::E;
    let x = 1.0_f64;
    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 < 1.0e-10);

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1.0.0 · source

#### pub fn tanh(self) -> f64

Hyperbolic tangent function.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `tanh` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    let e = std::f64::consts::E;
    let x = 1.0_f64;

    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 < 1.0e-10);

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1.0.0 · source

#### pub fn asinh(self) -> f64

Inverse hyperbolic sine function.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let x = 1.0_f64;
    let f = x.sinh().asinh();

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

    assert!(abs_difference < 1.0e-10);

Run
1.0.0 · source

#### pub fn acosh(self) -> f64

Inverse hyperbolic cosine function.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let x = 1.0_f64;
    let f = x.cosh().acosh();

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

    assert!(abs_difference < 1.0e-10);

Run
1.0.0 · source

#### pub fn atanh(self) -> f64

Inverse hyperbolic tangent function.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next.

##### §Examples

    let e = std::f64::consts::E;
    let f = e.tanh().atanh();

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

    assert!(abs_difference < 1.0e-10);

Run
source

#### pub fn gamma(self) -> f64

🔬This is a nightly-only experimental API. (`float_gamma` #99842)

Gamma function.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `tgamma` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    #![feature(float_gamma)]
    let x = 5.0f64;

    let abs_difference = (x.gamma() - 24.0).abs();

    assert!(abs_difference <= f64::EPSILON);

Run
source

#### pub fn ln_gamma(self) -> (f64, i32)

🔬This is a nightly-only experimental API. (`float_gamma` #99842)

Natural logarithm of the absolute value of the gamma function

The integer part of the tuple indicates the sign of the gamma function.

##### §Unspecified precision

The precision of this function is non-deterministic. This means it varies by platform, Rust version, and can even differ within the same execution from one invocation to the next. This function currently corresponds to the `lgamma_r` from libc on Unix and Windows. Note that this might change in the future.

##### §Examples

    #![feature(float_gamma)]
    let x = 2.0f64;

    let abs_difference = (x.ln_gamma().0 - 0.0).abs();

    assert!(abs_difference <= f64::EPSILON);

Run
source§

### impl f64

1.43.0 · source

#### pub const RADIX: u32 = 2u32

The radix or base of the internal representation of `f64`.

1.43.0 · source

#### pub const MANTISSA_DIGITS: u32 = 53u32

Number of significant digits in base 2.

1.43.0 · source

#### pub const DIGITS: u32 = 15u32

Approximate number of significant digits in base 10.

This is the maximum x such that any decimal number with x significant digits can be converted to `f64` and back without loss.

Equal to floor(log10 2`MANTISSA_DIGITS` − 1).

1.43.0 · source

#### pub const EPSILON: f64 = 2.2204460492503131E-16f64

Machine epsilon value for `f64`.

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

Equal to 21 − `MANTISSA_DIGITS`.

1.43.0 · source

#### pub const MIN: f64 = -1.7976931348623157E+308f64

Smallest finite `f64` value.

Equal to −`MAX`.

1.43.0 · source

#### pub const MIN_POSITIVE: f64 = 2.2250738585072014E-308f64

Smallest positive normal `f64` value.

Equal to 2`MIN_EXP` − 1.

1.43.0 · source

#### pub const MAX: f64 = 1.7976931348623157E+308f64

Largest finite `f64` value.

Equal to (1 − 2−`MANTISSA_DIGITS`) 2`MAX_EXP`.

1.43.0 · source

#### pub const MIN_EXP: i32 = -1_021i32

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

If x = `MIN_EXP`, then normal numbers ≥ 0.5 × 2x.

1.43.0 · source

#### pub const MAX_EXP: i32 = 1_024i32

Maximum possible power of 2 exponent.

If x = `MAX_EXP`, then normal numbers < 1 × 2x.

1.43.0 · source

#### pub const MIN_10_EXP: i32 = -307i32

Minimum x for which 10x is normal.

Equal to ceil(log10 `MIN_POSITIVE`).

1.43.0 · source

#### pub const MAX_10_EXP: i32 = 308i32

Maximum x for which 10x is normal.

Equal to floor(log10 `MAX`).

1.43.0 · source

#### pub const NAN: f64 = NaN_f64

Not a Number (NaN).

Note that IEEE 754 doesn’t define just a single NaN value; a plethora of bit patterns are considered to be NaN. Furthermore, the standard makes a difference between a “signaling” and a “quiet” NaN, and allows inspecting its “payload” (the unspecified bits in the bit pattern). This constant isn’t guaranteed to equal to any specific NaN bitpattern, and the stability of its representation over Rust versions and target platforms isn’t guaranteed.

1.43.0 · source

#### pub const INFINITY: f64 = +Inf_f64

Infinity (∞).

1.43.0 · source

#### pub const NEG_INFINITY: f64 = -Inf_f64

Negative infinity (−∞).

1.0.0 (const: unstable) · source

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

Returns `true` if this value is NaN.

    let nan = f64::NAN;
    let f = 7.0_f64;

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

Run
1.0.0 (const: unstable) · source

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

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

    let f = 7.0f64;
    let inf = f64::INFINITY;
    let neg_inf = f64::NEG_INFINITY;
    let nan = f64::NAN;

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

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

Run
1.0.0 (const: unstable) · source

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

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

    let f = 7.0f64;
    let inf: f64 = f64::INFINITY;
    let neg_inf: f64 = f64::NEG_INFINITY;
    let nan: f64 = f64::NAN;

    assert!(f.is_finite());

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

Run
1.53.0 (const: unstable) · source

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

Returns `true` if the number is subnormal.

    let min = f64::MIN_POSITIVE; // 2.2250738585072014e-308_f64
    let max = f64::MAX;
    let lower_than_min = 1.0e-308_f64;
    let zero = 0.0_f64;

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

    assert!(!zero.is_subnormal());
    assert!(!f64::NAN.is_subnormal());
    assert!(!f64::INFINITY.is_subnormal());
    // Values between `0` and `min` are Subnormal.
    assert!(lower_than_min.is_subnormal());

Run
1.0.0 (const: unstable) · source

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

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

    let min = f64::MIN_POSITIVE; // 2.2250738585072014e-308f64
    let max = f64::MAX;
    let lower_than_min = 1.0e-308_f64;
    let zero = 0.0f64;

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

    assert!(!zero.is_normal());
    assert!(!f64::NAN.is_normal());
    assert!(!f64::INFINITY.is_normal());
    // Values between `0` and `min` are Subnormal.
    assert!(!lower_than_min.is_normal());

Run
1.0.0 (const: unstable) · source

#### 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_f64;
    let inf = f64::INFINITY;

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

Run
1.0.0 (const: unstable) · source

#### 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. Note that IEEE 754 doesn’t assign any meaning to the sign bit in case of a NaN, and as Rust doesn’t guarantee that the bit pattern of NaNs are conserved over arithmetic operations, the result of `is_sign_positive` on a NaN might produce an unexpected result in some cases. See explanation of NaN as a special value for more info.

    let f = 7.0_f64;
    let g = -7.0_f64;

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

Run
1.0.0 (const: unstable) · source

#### 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. Note that IEEE 754 doesn’t assign any meaning to the sign bit in case of a NaN, and as Rust doesn’t guarantee that the bit pattern of NaNs are conserved over arithmetic operations, the result of `is_sign_negative` on a NaN might produce an unexpected result in some cases. See explanation of NaN as a special value for more info.

    let f = 7.0_f64;
    let g = -7.0_f64;

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

Run
source

#### pub const fn next_up(self) -> f64

🔬This is a nightly-only experimental API. (`float_next_up_down` #91399)

Returns the least number greater than `self`.

Let `TINY` be the smallest representable positive `f64`. Then,

- if `self.is_nan()`, this returns `self`;
- if `self` is `NEG_INFINITY`, this returns `MIN`;
- if `self` is `-TINY`, this returns -0.0;
- if `self` is -0.0 or +0.0, this returns `TINY`;
- if `self` is `MAX` or `INFINITY`, this returns `INFINITY`;
- otherwise the unique least value greater than `self` is returned.

The identity `x.next_up() == -(-x).next_down()` holds for all non-NaN `x`. When `x` is finite `x == x.next_up().next_down()` also holds.

    #![feature(float_next_up_down)]
    // f64::EPSILON is the difference between 1.0 and the next number up.
    assert_eq!(1.0f64.next_up(), 1.0 + f64::EPSILON);
    // But not for most numbers.
    assert!(0.1f64.next_up() < 0.1 + f64::EPSILON);
    assert_eq!(9007199254740992f64.next_up(), 9007199254740994.0);

Run
source

#### pub const fn next_down(self) -> f64

🔬This is a nightly-only experimental API. (`float_next_up_down` #91399)

Returns the greatest number less than `self`.

Let `TINY` be the smallest representable positive `f64`. Then,

- if `self.is_nan()`, this returns `self`;
- if `self` is `INFINITY`, this returns `MAX`;
- if `self` is `TINY`, this returns 0.0;
- if `self` is -0.0 or +0.0, this returns `-TINY`;
- if `self` is `MIN` or `NEG_INFINITY`, this returns `NEG_INFINITY`;
- otherwise the unique greatest value less than `self` is returned.

The identity `x.next_down() == -(-x).next_up()` holds for all non-NaN `x`. When `x` is finite `x == x.next_down().next_up()` also holds.

    #![feature(float_next_up_down)]
    let x = 1.0f64;
    // Clamp value into range [0, 1).
    let clamped = x.clamp(0.0, 1.0f64.next_down());
    assert!(clamped < 1.0);
    assert_eq!(clamped.next_up(), 1.0);

Run
1.0.0 · source

#### pub fn recip(self) -> f64

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

    let x = 2.0_f64;
    let abs_difference = (x.recip() - (1.0 / x)).abs();

    assert!(abs_difference < 1e-10);

Run
1.0.0 · source

#### pub fn to_degrees(self) -> f64

Converts radians to degrees.

    let angle = std::f64::consts::PI;

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

    assert!(abs_difference < 1e-10);

Run
1.0.0 · source

#### pub fn to_radians(self) -> f64

Converts degrees to radians.

    let angle = 180.0_f64;

    let abs_difference = (angle.to_radians() - std::f64::consts::PI).abs();

    assert!(abs_difference < 1e-10);

Run
1.0.0 · source

#### pub fn max(self, other: f64) -> f64

Returns the maximum of the two numbers, ignoring NaN.

If one of the arguments is NaN, then the other argument is returned. This follows the IEEE 754-2008 semantics for maxNum, except for handling of signaling NaNs; this function handles all NaNs the same way and avoids maxNum’s problems with associativity. This also matches the behavior of libm’s fmax.

    let x = 1.0_f64;
    let y = 2.0_f64;

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

Run
1.0.0 · source

#### pub fn min(self, other: f64) -> f64

Returns the minimum of the two numbers, ignoring NaN.

If one of the arguments is NaN, then the other argument is returned. This follows the IEEE 754-2008 semantics for minNum, except for handling of signaling NaNs; this function handles all NaNs the same way and avoids minNum’s problems with associativity. This also matches the behavior of libm’s fmin.

    let x = 1.0_f64;
    let y = 2.0_f64;

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

Run
source

#### pub fn maximum(self, other: f64) -> f64

🔬This is a nightly-only experimental API. (`float_minimum_maximum` #91079)

Returns the maximum of the two numbers, propagating NaN.

This returns NaN when either argument is NaN, as opposed to `f64::max` which only returns NaN when both arguments are NaN.

    #![feature(float_minimum_maximum)]
    let x = 1.0_f64;
    let y = 2.0_f64;

    assert_eq!(x.maximum(y), y);
    assert!(x.maximum(f64::NAN).is_nan());

Run

If one of the arguments is NaN, then NaN is returned. Otherwise this returns the greater of the two numbers. For this operation, -0.0 is considered to be less than +0.0. Note that this follows the semantics specified in IEEE 754-2019.

Also note that “propagation” of NaNs here doesn’t necessarily mean that the bitpattern of a NaN operand is conserved; see explanation of NaN as a special value for more info.

source

#### pub fn minimum(self, other: f64) -> f64

🔬This is a nightly-only experimental API. (`float_minimum_maximum` #91079)

Returns the minimum of the two numbers, propagating NaN.

This returns NaN when either argument is NaN, as opposed to `f64::min` which only returns NaN when both arguments are NaN.

    #![feature(float_minimum_maximum)]
    let x = 1.0_f64;
    let y = 2.0_f64;

    assert_eq!(x.minimum(y), x);
    assert!(x.minimum(f64::NAN).is_nan());

Run

If one of the arguments is NaN, then NaN is returned. Otherwise this returns the lesser of the two numbers. For this operation, -0.0 is considered to be less than +0.0. Note that this follows the semantics specified in IEEE 754-2019.

Also note that “propagation” of NaNs here doesn’t necessarily mean that the bitpattern of a NaN operand is conserved; see explanation of NaN as a special value for more info.

source

#### pub fn midpoint(self, other: f64) -> f64

🔬This is a nightly-only experimental API. (`num_midpoint` #110840)

Calculates the middle point of `self` and `rhs`.

This returns NaN when either argument is NaN or if a combination of +inf and -inf is provided as arguments.

##### §Examples

    #![feature(num_midpoint)]
    assert_eq!(1f64.midpoint(4.0), 2.5);
    assert_eq!((-5.5f64).midpoint(8.0), 1.25);

Run
1.44.0 · source

#### pub unsafe fn to_int_unchecked<Int>(self) -> Int
where f64: 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_f64;
    let rounded = unsafe { value.to_int_unchecked::<u16>() };
    assert_eq!(rounded, 4);

    let value = -128.9_f64;
    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) · source

#### pub fn to_bits(self) -> u64

Raw transmutation to `u64`.

This is currently identical to `transmute::<f64, u64>(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!((1f64).to_bits() != 1f64 as u64); // to_bits() is not casting!
    assert_eq!((12.5f64).to_bits(), 0x4029000000000000);

Run
1.20.0 (const: unstable) · source

#### pub fn from_bits(v: u64) -> f64

Raw transmutation from `u64`.

This is currently identical to `transmute::<u64, f64>(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 signaling-ness (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 = f64::from_bits(0x4029000000000000);
    assert_eq!(v, 12.5);

Run
1.40.0 (const: unstable) · source

#### pub fn to_be_bytes(self) -> [u8; 8]

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

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

##### §Examples

    let bytes = 12.5f64.to_be_bytes();
    assert_eq!(bytes, [0x40, 0x29, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]);

Run
1.40.0 (const: unstable) · source

#### pub fn to_le_bytes(self) -> [u8; 8]

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

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

##### §Examples

    let bytes = 12.5f64.to_le_bytes();
    assert_eq!(bytes, [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x29, 0x40]);

Run
1.40.0 (const: unstable) · source

#### pub fn to_ne_bytes(self) -> [u8; 8]

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.

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

##### §Examples

    let bytes = 12.5f64.to_ne_bytes();
    assert_eq!(
        bytes,
        if cfg!(target_endian = "big") {
            [0x40, 0x29, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
        } else {
            [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x29, 0x40]
        }
    );

Run
1.40.0 (const: unstable) · source

#### pub fn from_be_bytes(bytes: [u8; 8]) -> f64

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

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

##### §Examples

    let value = f64::from_be_bytes([0x40, 0x29, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]);
    assert_eq!(value, 12.5);

Run
1.40.0 (const: unstable) · source

#### pub fn from_le_bytes(bytes: [u8; 8]) -> f64

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

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

##### §Examples

    let value = f64::from_le_bytes([0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x29, 0x40]);
    assert_eq!(value, 12.5);

Run
1.40.0 (const: unstable) · source

#### pub fn from_ne_bytes(bytes: [u8; 8]) -> f64

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.

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

##### §Examples

    let value = f64::from_ne_bytes(if cfg!(target_endian = "big") {
        [0x40, 0x29, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
    } else {
        [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x29, 0x40]
    });
    assert_eq!(value, 12.5);

Run
1.62.0 · source

#### pub fn total_cmp(&self, other: &f64) -> Ordering

Return the ordering between `self` and `other`.

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

- negative quiet NaN
- negative signaling NaN
- negative infinity
- negative numbers
- negative subnormal numbers
- negative zero
- positive zero
- positive subnormal numbers
- positive numbers
- positive infinity
- positive signaling NaN
- positive quiet NaN.

The ordering established by this function does not always agree with the `PartialOrd` and `PartialEq` implementations of `f64`. For example, they consider negative and positive zero equal, while `total_cmp` doesn’t.

The interpretation of the signaling NaN bit follows the definition in the IEEE 754 standard, which may not match the interpretation by some of the older, non-conformant (e.g. MIPS) hardware implementations.

##### §Example

    struct GoodBoy {
        name: String,
        weight: f64,
    }

    let mut bois = vec![
        GoodBoy { name: "Pucci".to_owned(), weight: 0.1 },
        GoodBoy { name: "Woofer".to_owned(), weight: 99.0 },
        GoodBoy { name: "Yapper".to_owned(), weight: 10.0 },
        GoodBoy { name: "Chonk".to_owned(), weight: f64::INFINITY },
        GoodBoy { name: "Abs. Unit".to_owned(), weight: f64::NAN },
        GoodBoy { name: "Floaty".to_owned(), weight: -5.0 },
    ];

    bois.sort_by(|a, b| a.weight.total_cmp(&b.weight));

    // `f64::NAN` could be positive or negative, which will affect the sort order.
    if f64::NAN.is_sign_negative() {
        assert!(bois.into_iter().map(|b| b.weight)
            .zip([f64::NAN, -5.0, 0.1, 10.0, 99.0, f64::INFINITY].iter())
            .all(|(a, b)| a.to_bits() == b.to_bits()))
    } else {
        assert!(bois.into_iter().map(|b| b.weight)
            .zip([-5.0, 0.1, 10.0, 99.0, f64::INFINITY, f64::NAN].iter())
            .all(|(a, b)| a.to_bits() == b.to_bits()))
    }

Run
1.50.0 · source

#### pub fn clamp(self, min: f64, max: f64) -> f64

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!((-3.0f64).clamp(-2.0, 1.0) == -2.0);
    assert!((0.0f64).clamp(-2.0, 1.0) == 0.0);
    assert!((2.0f64).clamp(-2.0, 1.0) == 1.0);
    assert!((f64::NAN).clamp(-2.0, 1.0).is_nan());

Run

## Trait Implementations§

1.0.0 · source§

### impl Add<&f64> for &f64

§

#### type Output = <f64 as Add>::Output

The resulting type after applying the `+` operator.
source§

#### fn add(self, other: &f64) -> <f64 as Add>::Output

Performs the `+` operation. Read more
1.0.0 · source§

### impl Add<&f64> for f64

§

#### type Output = <f64 as Add>::Output

The resulting type after applying the `+` operator.
source§

#### fn add(self, other: &f64) -> <f64 as Add>::Output

Performs the `+` operation. Read more
1.0.0 · source§

### impl<'a> Add<f64> for &'a f64

§

#### type Output = <f64 as Add>::Output

The resulting type after applying the `+` operator.
source§

#### fn add(self, other: f64) -> <f64 as Add>::Output

Performs the `+` operation. Read more
1.0.0 · source§

### impl Add for f64

§

#### type Output = f64

The resulting type after applying the `+` operator.
source§

#### fn add(self, other: f64) -> f64

Performs the `+` operation. Read more
1.22.0 · source§

### impl AddAssign<&f64> for f64

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#### fn add_assign(&mut self, other: &f64)

Performs the `+=` operation. Read more
1.8.0 · source§

### impl AddAssign for f64

source§

#### fn add_assign(&mut self, other: f64)

Performs the `+=` operation. Read more
1.0.0 · source§

### impl Clone for f64

source§

#### fn clone(&self) -> f64

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from `source`. Read more
1.0.0 · source§

### impl Debug for f64

source§

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

Formats the value using the given formatter. Read more
1.0.0 · source§

### impl Default for f64

source§

#### fn default() -> f64

Returns the default value of `0.0`

1.0.0 · source§

### impl Display for f64

source§

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

Formats the value using the given formatter. Read more
1.0.0 · source§

### impl Div<&f64> for &f64

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#### type Output = <f64 as Div>::Output

The resulting type after applying the `/` operator.
source§

#### fn div(self, other: &f64) -> <f64 as Div>::Output

Performs the `/` operation. Read more
1.0.0 · source§

### impl Div<&f64> for f64

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#### type Output = <f64 as Div>::Output

The resulting type after applying the `/` operator.
source§

#### fn div(self, other: &f64) -> <f64 as Div>::Output

Performs the `/` operation. Read more
1.0.0 · source§

### impl<'a> Div<f64> for &'a f64

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#### type Output = <f64 as Div>::Output

The resulting type after applying the `/` operator.
source§

#### fn div(self, other: f64) -> <f64 as Div>::Output

Performs the `/` operation. Read more
1.0.0 · source§

### impl Div for f64

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#### type Output = f64

The resulting type after applying the `/` operator.
source§

#### fn div(self, other: f64) -> f64

Performs the `/` operation. Read more
1.22.0 · source§

### impl DivAssign<&f64> for f64

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#### fn div_assign(&mut self, other: &f64)

Performs the `/=` operation. Read more
1.8.0 · source§

### impl DivAssign for f64

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#### fn div_assign(&mut self, other: f64)

Performs the `/=` operation. Read more
1.68.0 · source§

### impl From<bool> for f64

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#### fn from(small: bool) -> f64

Converts a `bool` to `f64` losslessly. The resulting value is positive `0.0` for `false` and `1.0` for `true` values.

##### §Examples

    let x: f64 = false.into();
    assert_eq!(x, 0.0);
    assert!(x.is_sign_positive());

    let y: f64 = true.into();
    assert_eq!(y, 1.0);

Run
1.6.0 · source§

### impl From<f16> for f64

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#### fn from(small: f16) -> f64

Converts `f16` to `f64` losslessly.

1.6.0 · source§

### impl From<f32> for f64

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#### fn from(small: f32) -> f64

Converts `f32` to `f64` losslessly.

1.6.0 · source§

### impl From<f64> for f128

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#### fn from(small: f64) -> f128

Converts `f64` to `f128` losslessly.

1.6.0 · source§

### impl From<i16> for f64

source§

#### fn from(small: i16) -> f64

Converts `i16` to `f64` losslessly.

1.6.0 · source§

### impl From<i32> for f64

source§

#### fn from(small: i32) -> f64

Converts `i32` to `f64` losslessly.

1.6.0 · source§

### impl From<i8> for f64

source§

#### fn from(small: i8) -> f64

Converts `i8` to `f64` losslessly.

1.6.0 · source§

### impl From<u16> for f64

source§

#### fn from(small: u16) -> f64

Converts `u16` to `f64` losslessly.

1.6.0 · source§

### impl From<u32> for f64

source§

#### fn from(small: u32) -> f64

Converts `u32` to `f64` losslessly.

1.6.0 · source§

### impl From<u8> for f64

source§

#### fn from(small: u8) -> f64

Converts `u8` to `f64` losslessly.

1.0.0 · source§

### impl FromStr for f64

source§

#### fn from_str(src: &str) -> Result<f64, 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’, ‘+infinity’, ‘NaN’

Note that alphabetical characters are not case-sensitive.

Leading and trailing whitespace represent an error.

##### §Grammar

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

    Float  ::= Sign? ( 'inf' | 'infinity' | 'nan' | Number )
    Number ::= ( Digit+ |
                 Digit+ '.' Digit* |
                 Digit* '.' Digit+ ) Exp?
    Exp    ::= 'e' 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 closest representable floating-point number to the number represented by `src` (following the same rules for rounding as for the results of primitive operations).

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#### type Err = ParseFloatError

The associated error which can be returned from parsing.
1.0.0 · source§

### impl LowerExp for f64

source§

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

Formats the value using the given formatter. Read more
1.0.0 · source§

### impl Mul<&f64> for &f64

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#### type Output = <f64 as Mul>::Output

The resulting type after applying the `*` operator.
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#### fn mul(self, other: &f64) -> <f64 as Mul>::Output

Performs the `*` operation. Read more
1.0.0 · source§

### impl Mul<&f64> for f64

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#### type Output = <f64 as Mul>::Output

The resulting type after applying the `*` operator.
source§

#### fn mul(self, other: &f64) -> <f64 as Mul>::Output

Performs the `*` operation. Read more
1.0.0 · source§

### impl<'a> Mul<f64> for &'a f64

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#### type Output = <f64 as Mul>::Output

The resulting type after applying the `*` operator.
source§

#### fn mul(self, other: f64) -> <f64 as Mul>::Output

Performs the `*` operation. Read more
1.0.0 · source§

### impl Mul for f64

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#### type Output = f64

The resulting type after applying the `*` operator.
source§

#### fn mul(self, other: f64) -> f64

Performs the `*` operation. Read more
1.22.0 · source§

### impl MulAssign<&f64> for f64

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#### fn mul_assign(&mut self, other: &f64)

Performs the `*=` operation. Read more
1.8.0 · source§

### impl MulAssign for f64

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#### fn mul_assign(&mut self, other: f64)

Performs the `*=` operation. Read more
1.0.0 · source§

### impl Neg for &f64

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#### type Output = <f64 as Neg>::Output

The resulting type after applying the `-` operator.
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#### fn neg(self) -> <f64 as Neg>::Output

Performs the unary `-` operation. Read more
1.0.0 · source§

### impl Neg for f64

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#### type Output = f64

The resulting type after applying the `-` operator.
source§

#### fn neg(self) -> f64

Performs the unary `-` operation. Read more
1.0.0 · source§

### impl PartialEq for f64

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#### fn eq(&self, other: &f64) -> bool

This method tests for `self` and `other` values to be equal, and is used by `==`.
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#### fn ne(&self, other: &f64) -> bool

This method tests for `!=`. The default implementation is almost always sufficient, and should not be overridden without very good reason.
1.0.0 · source§

### impl PartialOrd for f64

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#### fn partial_cmp(&self, other: &f64) -> Option<Ordering>

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

#### fn lt(&self, other: &f64) -> bool

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

#### fn le(&self, other: &f64) -> bool

This method tests less than or equal to (for `self` and `other`) and is used by the `<=` operator. Read more
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#### fn ge(&self, other: &f64) -> bool

This method tests greater than or equal to (for `self` and `other`) and is used by the `>=` operator. Read more
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#### fn gt(&self, other: &f64) -> bool

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

### impl<'a> Product<&'a f64> for f64

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#### fn product<I>(iter: I) -> f64
where I: Iterator<Item = &'a f64>,

Method which takes an iterator and generates `Self` from the elements by multiplying the items.
1.12.0 · source§

### impl Product for f64

source§

#### fn product<I>(iter: I) -> f64
where I: Iterator<Item = f64>,

Method which takes an iterator and generates `Self` from the elements by multiplying the items.
1.0.0 · source§

### impl Rem<&f64> for &f64

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#### type Output = <f64 as Rem>::Output

The resulting type after applying the `%` operator.
source§

#### fn rem(self, other: &f64) -> <f64 as Rem>::Output

Performs the `%` operation. Read more
1.0.0 · source§

### impl Rem<&f64> for f64

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#### type Output = <f64 as Rem>::Output

The resulting type after applying the `%` operator.
source§

#### fn rem(self, other: &f64) -> <f64 as Rem>::Output

Performs the `%` operation. Read more
1.0.0 · source§

### impl<'a> Rem<f64> for &'a f64

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#### type Output = <f64 as Rem>::Output

The resulting type after applying the `%` operator.
source§

#### fn rem(self, other: f64) -> <f64 as Rem>::Output

Performs the `%` operation. Read more
1.0.0 · source§

### impl Rem for f64

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
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#### type Output = f64

The resulting type after applying the `%` operator.
source§

#### fn rem(self, other: f64) -> f64

Performs the `%` operation. Read more
1.22.0 · source§

### impl RemAssign<&f64> for f64

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#### fn rem_assign(&mut self, other: &f64)

Performs the `%=` operation. Read more
1.8.0 · source§

### impl RemAssign for f64

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#### fn rem_assign(&mut self, other: f64)

Performs the `%=` operation. Read more
source§

### impl SimdElement for f64

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#### type Mask = i64

🔬This is a nightly-only experimental API. (`portable_simd` #86656)
The mask element type corresponding to this element type.
1.0.0 · source§

### impl Sub<&f64> for &f64

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#### type Output = <f64 as Sub>::Output

The resulting type after applying the `-` operator.
source§

#### fn sub(self, other: &f64) -> <f64 as Sub>::Output

Performs the `-` operation. Read more
1.0.0 · source§

### impl Sub<&f64> for f64

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#### type Output = <f64 as Sub>::Output

The resulting type after applying the `-` operator.
source§

#### fn sub(self, other: &f64) -> <f64 as Sub>::Output

Performs the `-` operation. Read more
1.0.0 · source§

### impl<'a> Sub<f64> for &'a f64

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#### type Output = <f64 as Sub>::Output

The resulting type after applying the `-` operator.
source§

#### fn sub(self, other: f64) -> <f64 as Sub>::Output

Performs the `-` operation. Read more
1.0.0 · source§

### impl Sub for f64

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#### type Output = f64

The resulting type after applying the `-` operator.
source§

#### fn sub(self, other: f64) -> f64

Performs the `-` operation. Read more
1.22.0 · source§

### impl SubAssign<&f64> for f64

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#### fn sub_assign(&mut self, other: &f64)

Performs the `-=` operation. Read more
1.8.0 · source§

### impl SubAssign for f64

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#### fn sub_assign(&mut self, other: f64)

Performs the `-=` operation. Read more
1.12.0 · source§

### impl<'a> Sum<&'a f64> for f64

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#### fn sum<I>(iter: I) -> f64
where I: Iterator<Item = &'a f64>,

Method which takes an iterator and generates `Self` from the elements by “summing up” the items.
1.12.0 · source§

### impl Sum for f64

source§

#### fn sum<I>(iter: I) -> f64
where I: Iterator<Item = f64>,

Method which takes an iterator and generates `Self` from the elements by “summing up” the items.
1.0.0 · source§

### impl UpperExp for f64

source§

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

Formats the value using the given formatter. Read more
1.0.0 · source§

### impl Copy for f64

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### impl FloatToInt<i128> for f64

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### impl FloatToInt<i16> for f64

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### impl FloatToInt<i32> for f64

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### impl FloatToInt<i64> for f64

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### impl FloatToInt<i8> for f64

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### impl FloatToInt<isize> for f64

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### impl FloatToInt<u128> for f64

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### impl FloatToInt<u16> for f64

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### impl FloatToInt<u32> for f64

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### impl FloatToInt<u64> for f64

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### impl FloatToInt<u8> for f64

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### impl FloatToInt<usize> for f64

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### impl SimdCast for f64

## Auto Trait Implementations§

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### impl Freeze for f64

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### impl RefUnwindSafe for f64

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### impl Send for f64

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### impl Sync for f64

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### impl Unpin for f64

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### impl UnwindSafe for f64

## Blanket Implementations§

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

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

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

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

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

Immutably borrows from an owned value. Read more
source§

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

source§

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

Mutably borrows from an owned value. Read more
source§

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

source§

#### default unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (`clone_to_uninit` #126799)
Performs copy-assignment from `self` to `dst`. Read more
source§

### impl<T> CloneToUninit for T
where T: Copy,

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#### unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (`clone_to_uninit` #126799)
Performs copy-assignment from `self` to `dst`. Read more
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### impl<T> From<T> for T

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

Returns the argument unchanged.

source§

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

source§

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

Calls `U::from(self)`.

That is, this conversion is whatever the implementation of `From<T> for U` chooses to do.

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

§

#### type Owned = T

The resulting type after obtaining ownership.
source§

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

Creates owned data from borrowed data, usually by cloning. Read more
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#### fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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### impl<T> ToString for T
where T: Display + ?Sized,

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

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

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

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#### type Error = Infallible

The type returned in the event of a conversion error.
source§

#### 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>,

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

The type returned in the event of a conversion error.
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#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.