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

## f64

# 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

1.43.0 · Source

#### pub const RADIX: u32 = 2

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

1.43.0 · Source

#### pub const MANTISSA_DIGITS: u32 = 53

Number of significant digits in base 2.

Note that the size of the mantissa in the bitwise representation is one smaller than this since the leading 1 is not stored explicitly.

1.43.0 · Source

#### pub const DIGITS: u32 = 15

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-16_f64

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+308_f64

Smallest finite `f64` value.

Equal to −`MAX`.

1.43.0 · Source

#### pub const MIN_POSITIVE: f64 = 2.2250738585072014e-308_f64

Smallest positive normal `f64` value.

Equal to 2`MIN_EXP` − 1.

1.43.0 · Source

#### pub const MAX: f64 = 1.7976931348623157e+308_f64

Largest finite `f64` value.

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

1.43.0 · Source

#### pub const MIN_EXP: i32 = -1021

One greater than the minimum possible normal power of 2 exponent for a significand bounded by 1 ≤ x < 2 (i.e. the IEEE definition).

This corresponds to the exact minimum possible normal power of 2 exponent for a significand bounded by 0.5 ≤ x < 1 (i.e. the C definition). In other words, all normal numbers representable by this type are greater than or equal to 0.5 × 2MIN_EXP.

1.43.0 · Source

#### pub const MAX_EXP: i32 = 1024

One greater than the maximum possible power of 2 exponent for a significand bounded by 1 ≤ x < 2 (i.e. the IEEE definition).

This corresponds to the exact maximum possible power of 2 exponent for a significand bounded by 0.5 ≤ x < 1 (i.e. the C definition). In other words, all numbers representable by this type are strictly less than 2MAX_EXP.

1.43.0 · Source

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

Minimum x for which 10x is normal.

Equal to ceil(log10 `MIN_POSITIVE`).

1.43.0 · Source

#### pub const MAX_10_EXP: i32 = 308

Maximum x for which 10x is normal.

Equal to floor(log10 `MAX`).

1.43.0 · Source

#### pub const 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) and its sign. See the specification of NaN bit patterns for more info.

This constant is guaranteed to be a quiet NaN (on targets that follow the Rust assumptions that the quiet/signaling bit being set to 1 indicates a quiet NaN). Beyond that, nothing is guaranteed about the specific bit pattern chosen here: both payload and sign are arbitrary. The concrete bit pattern may change across Rust versions and target platforms.

1.43.0 · Source

#### pub const INFINITY: f64

Infinity (∞).

1.43.0 · Source

#### pub const NEG_INFINITY: f64

Negative infinity (−∞).

1.0.0 (const: 1.83.0) · Source

#### pub const 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());

1.0.0 (const: 1.83.0) · Source

#### pub const 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());

1.0.0 (const: 1.83.0) · Source

#### pub const 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());

1.53.0 (const: 1.83.0) · Source

#### pub const 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());

1.0.0 (const: 1.83.0) · Source

#### pub const 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());

1.0.0 (const: 1.83.0) · Source

#### pub const 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);

1.0.0 (const: 1.83.0) · Source

#### pub const 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 or non-portable result. See the specification of NaN bit patterns for more info. Use `self.signum() == 1.0` if you need fully portable behavior (will return `false` for all NaNs).

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

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

1.0.0 (const: 1.83.0) · Source

#### pub const 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 or non-portable result. See the specification of NaN bit patterns for more info. Use `self.signum() == -1.0` if you need fully portable behavior (will return `false` for all NaNs).

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

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

1.86.0 (const: 1.86.0) · Source

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

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.

    // 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);

This operation corresponds to IEEE-754 `nextUp`.

1.86.0 (const: 1.86.0) · Source

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

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.

    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);

This operation corresponds to IEEE-754 `nextDown`.

1.0.0 (const: 1.85.0) · Source

#### pub const 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);

1.0.0 (const: 1.85.0) · Source

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

Converts radians to degrees.

##### §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 angle = std::f64::consts::PI;

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

    assert!(abs_difference < 1e-10);

1.0.0 (const: 1.85.0) · Source

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

Converts degrees to 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 angle = 180.0_f64;

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

    assert!(abs_difference < 1e-10);

1.0.0 (const: 1.85.0) · Source

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

Returns the maximum of the two numbers, ignoring NaN.

If exactly one of the arguments is NaN (quiet or signaling), then the other argument is returned. If both arguments are NaN, the return value is NaN, with the bit pattern picked using the usual rules for arithmetic operations. If the inputs compare equal (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.

The handling of NaNs follows the IEEE 754-2019 semantics for `maximumNumber`, treating all NaNs the same way to ensure the operation is associative. The handling of signed zeros follows the IEEE 754-2008 semantics for `maxNum`.

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

    assert_eq!(x.max(y), y);
    assert_eq!(x.max(f64::NAN), x);

1.0.0 (const: 1.85.0) · Source

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

Returns the minimum of the two numbers, ignoring NaN.

If exactly one of the arguments is NaN (quiet or signaling), then the other argument is returned. If both arguments are NaN, the return value is NaN, with the bit pattern picked using the usual rules for arithmetic operations. If the inputs compare equal (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.

The handling of NaNs follows the IEEE 754-2019 semantics for `minimumNumber`, treating all NaNs the same way to ensure the operation is associative. The handling of signed zeros follows the IEEE 754-2008 semantics for `minNum`.

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

    assert_eq!(x.min(y), x);
    assert_eq!(x.min(f64::NAN), x);

Source

#### pub const 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.

If at least one of the arguments is NaN, the return value is NaN, with the bit pattern picked using the usual rules for arithmetic operations. Furthermore, `-0.0` is considered to be less than `+0.0`, making this function fully deterministic for non-NaN inputs.

This is in contrast to `f64::max` which only returns NaN when both arguments are NaN, and which does not reliably order `-0.0` and `+0.0`.

This follows the IEEE 754-2019 semantics for `maximum`.

    #![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());

Source

#### pub const 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.

If at least one of the arguments is NaN, the return value is NaN, with the bit pattern picked using the usual rules for arithmetic operations. Furthermore, `-0.0` is considered to be less than `+0.0`, making this function fully deterministic for non-NaN inputs.

This is in contrast to `f64::min` which only returns NaN when both arguments are NaN, and which does not reliably order `-0.0` and `+0.0`.

This follows the IEEE 754-2019 semantics for `minimum`.

    #![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());

1.85.0 (const: 1.85.0) · Source

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

Calculates the midpoint (average) between `self` and `rhs`.

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

##### §Examples

    assert_eq!(1f64.midpoint(4.0), 2.5);
    assert_eq!((-5.5f64).midpoint(8.0), 1.25);

1.44.0 · Source

#### pub unsafe fn to_int_unchecked<Int>(self) -> Int
where Self: 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);

##### §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: 1.83.0) · Source

#### pub const 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);

1.20.0 (const: 1.83.0) · Source

#### pub const fn from_bits(v: u64) -> Self

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);

1.40.0 (const: 1.83.0) · Source

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

Returns 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]);

1.40.0 (const: 1.83.0) · Source

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

Returns 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]);

1.40.0 (const: 1.83.0) · Source

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

Returns 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]
        }
    );

1.40.0 (const: 1.83.0) · Source

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

Creates 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);

1.40.0 (const: 1.83.0) · Source

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

Creates 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);

1.40.0 (const: 1.83.0) · Source

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

Creates 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);

1.62.0 (const: unstable) · Source

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

Returns 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()))
    }

1.50.0 (const: 1.85.0) · Source

#### pub const 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. If the result is zero and among the three inputs `self`, `min`, and `max` there are zeros with different sign, either `0.0` or `-0.0` is returned non-deterministically.

##### §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());

    // These always returns zero, but the sign (which is ignored by `==`) is non-deterministic.
    assert!((0.0f64).clamp(-0.0, -0.0) == 0.0);
    assert!((1.0f64).clamp(-0.0, 0.0) == 0.0);
    // This is definitely a negative zero.
    assert!((-1.0f64).clamp(-0.0, 1.0).is_sign_negative());

Source

#### pub fn clamp_magnitude(self, limit: f64) -> f64

🔬This is a nightly-only experimental API. (`clamp_magnitude` #148519)

Clamps this number to a symmetric range centered around zero.

The method clamps the number’s magnitude (absolute value) to be at most `limit`.

This is functionally equivalent to `self.clamp(-limit, limit)`, but is more explicit about the intent.

##### §Panics

Panics if `limit` is negative or NaN, as this indicates a logic error.

##### §Examples

    #![feature(clamp_magnitude)]
    assert_eq!(5.0f64.clamp_magnitude(3.0), 3.0);
    assert_eq!((-5.0f64).clamp_magnitude(3.0), -3.0);
    assert_eq!(2.0f64.clamp_magnitude(3.0), 2.0);
    assert_eq!((-2.0f64).clamp_magnitude(3.0), -2.0);

1.0.0 (const: 1.85.0) · Source

#### pub const 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());

1.0.0 (const: 1.85.0) · Source

#### pub const 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());

1.35.0 (const: 1.85.0) · Source

#### pub const 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 same payload as `self` and the sign bit of `sign` is returned.

If `sign` is a NaN, then this operation will still carry over its sign into the result. 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 `copysign` with `sign` being a NaN might produce an unexpected or non-portable result. See the specification of NaN bit patterns 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());

Source

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

🔬This is a nightly-only experimental API. (`float_algebraic` #136469)

Float addition that allows optimizations based on algebraic rules.

See algebraic operators for more info.

Source

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

🔬This is a nightly-only experimental API. (`float_algebraic` #136469)

Float subtraction that allows optimizations based on algebraic rules.

See algebraic operators for more info.

Source

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

🔬This is a nightly-only experimental API. (`float_algebraic` #136469)

Float multiplication that allows optimizations based on algebraic rules.

See algebraic operators for more info.

Source

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

🔬This is a nightly-only experimental API. (`float_algebraic` #136469)

Float division that allows optimizations based on algebraic rules.

See algebraic operators for more info.

Source

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

🔬This is a nightly-only experimental API. (`float_algebraic` #136469)

Float remainder that allows optimizations based on algebraic rules.

See algebraic operators for more info.

## Trait Implementations§

1.0.0 (const: unstable) · Source§

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

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

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

Performs the `+` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Add<&f64> for f64

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

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

Performs the `+` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Add<f64> for &f64

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

The resulting type after applying the `+` operator.
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#### fn add(self, other: f64) -> <f64 as Add<f64>>::Output

Performs the `+` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Add for f64

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#### type Output = f64

The resulting type after applying the `+` operator.
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#### fn add(self, other: f64) -> f64

Performs the `+` operation. Read more
1.22.0 (const: unstable) · 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 (const: unstable) · Source§

### impl AddAssign for f64

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

Performs the `+=` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Clone for f64

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

Returns a duplicate of the value. Read more
1.0.0 · Source§

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

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

### impl Debug for f64

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

Formats the value using the given formatter. Read more
1.0.0 (const: unstable) · Source§

### impl Default for f64

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#### fn default() -> f64

Returns the default value of `0.0`

1.0.0 · Source§

### impl Display for f64

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

Formats the value using the given formatter. Read more
1.0.0 (const: unstable) · Source§

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

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

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

Performs the `/` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Div<&f64> for f64

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

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

Performs the `/` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Div<f64> for &f64

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

The resulting type after applying the `/` operator.
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#### fn div(self, other: f64) -> <f64 as Div<f64>>::Output

Performs the `/` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Div for f64

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#### type Output = f64

The resulting type after applying the `/` operator.
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#### fn div(self, other: f64) -> f64

Performs the `/` operation. Read more
1.22.0 (const: unstable) · 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 (const: unstable) · Source§

### impl DivAssign for f64

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

Performs the `/=` operation. Read more
1.68.0 (const: unstable) · Source§

### impl From<bool> for f64

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

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);

1.6.0 (const: unstable) · Source§

### impl From<f16> for f64

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

Converts `f16` to `f64` losslessly.

1.6.0 (const: unstable) · Source§

### impl From<f32> for f64

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

Converts `f32` to `f64` losslessly.

1.6.0 (const: unstable) · Source§

### impl From<f64> for f128

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

Converts `f64` to `f128` losslessly.

1.6.0 (const: unstable) · Source§

### impl From<i16> for f64

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

Converts `i16` to `f64` losslessly.

1.6.0 (const: unstable) · Source§

### impl From<i32> for f64

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

Converts `i32` to `f64` losslessly.

1.6.0 (const: unstable) · Source§

### impl From<i8> for f64

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

Converts `i8` to `f64` losslessly.

1.6.0 (const: unstable) · Source§

### impl From<u16> for f64

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

Converts `u16` to `f64` losslessly.

1.6.0 (const: unstable) · Source§

### impl From<u32> for f64

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

Converts `u32` to `f64` losslessly.

1.6.0 (const: unstable) · Source§

### impl From<u8> for f64

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

Converts `u8` to `f64` losslessly.

1.0.0 · Source§

### impl FromStr for f64

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#### fn from_str(src: &str) -> Result<Self, 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’
- ‘7’
- ‘007’
- ‘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

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

Formats the value using the given formatter. Read more
1.0.0 (const: unstable) · 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<f64>>::Output

Performs the `*` operation. Read more
1.0.0 (const: unstable) · 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<f64>>::Output

Performs the `*` operation. Read more
1.0.0 (const: unstable) · 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<f64>>::Output

Performs the `*` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Mul for f64

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#### type Output = f64

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

Performs the `*` operation. Read more
1.22.0 (const: unstable) · 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 (const: unstable) · Source§

### impl MulAssign for f64

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

Performs the `*=` operation. Read more
1.0.0 (const: unstable) · 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 (const: unstable) · Source§

### impl Neg for f64

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#### type Output = f64

The resulting type after applying the `-` operator.
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#### fn neg(self) -> f64

Performs the unary `-` operation. Read more
1.0.0 (const: unstable) · Source§

### impl PartialEq for f64

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

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

Tests for `!=`. The default implementation is almost always sufficient, and should not be overridden without very good reason.
1.0.0 (const: unstable) · Source§

### impl PartialOrd for f64

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

This method returns an ordering between `self` and `other` values if one exists. Read more
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#### fn lt(&self, other: &Self) -> bool

Tests less than (for `self` and `other`) and is used by the `<` operator. Read more
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#### fn le(&self, other: &Self) -> bool

Tests less than or equal to (for `self` and `other`) and is used by the `<=` operator. Read more
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#### fn gt(&self, other: &Self) -> bool

Tests greater than (for `self` and `other`) and is used by the `>` operator. Read more
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#### fn ge(&self, other: &Self) -> bool

Tests greater than or equal to (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: Iterator<Item = &'a Self>>(iter: I) -> Self

Takes an iterator and generates `Self` from the elements by multiplying the items.
1.12.0 · Source§

### impl Product for f64

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#### fn product<I: Iterator<Item = Self>>(iter: I) -> Self

Takes an iterator and generates `Self` from the elements by multiplying the items.
1.0.0 (const: unstable) · Source§

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

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

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

Performs the `%` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Rem<&f64> for f64

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

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

Performs the `%` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Rem<f64> for &f64

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

The resulting type after applying the `%` operator.
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#### fn rem(self, other: f64) -> <f64 as Rem<f64>>::Output

Performs the `%` operation. Read more
1.0.0 (const: unstable) · 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);

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#### type Output = f64

The resulting type after applying the `%` operator.
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#### fn rem(self, other: f64) -> f64

Performs the `%` operation. Read more
1.22.0 (const: unstable) · 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 (const: unstable) · Source§

### impl RemAssign for f64

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

Performs the `%=` operation. Read more
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### 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 (const: unstable) · Source§

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

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

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

Performs the `-` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Sub<&f64> for f64

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

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

Performs the `-` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Sub<f64> for &f64

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

The resulting type after applying the `-` operator.
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#### fn sub(self, other: f64) -> <f64 as Sub<f64>>::Output

Performs the `-` operation. Read more
1.0.0 (const: unstable) · Source§

### impl Sub for f64

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#### type Output = f64

The resulting type after applying the `-` operator.
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#### fn sub(self, other: f64) -> f64

Performs the `-` operation. Read more
1.22.0 (const: unstable) · 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 (const: unstable) · 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: Iterator<Item = &'a Self>>(iter: I) -> Self

Takes an iterator and generates `Self` from the elements by “summing up” the items.
1.12.0 · Source§

### impl Sum for f64

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#### fn sum<I: Iterator<Item = Self>>(iter: I) -> Self

Takes an iterator and generates `Self` from the elements by “summing up” the items.
1.0.0 · Source§

### impl UpperExp for f64

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

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

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### impl UseCloned for f64

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### impl VaArgSafe for f64

## Auto Trait Implementations§

§

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

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

Mutably borrows from an owned value. Read more
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### impl<T> CloneToUninit for T
where T: Clone,

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#### unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (`clone_to_uninit` #126799)
Performs copy-assignment from `self` to `dest`. 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.

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

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#### 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, 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.
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#### 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.