# Primitive Type f128

🔬This is a nightly-only experimental API. (`f128` #116909)
Expand description

A 128-bit floating point type (specifically, the “binary128” type defined in IEEE 754-2008).

This type is very similar to `f32` and `f64`, but has increased precision by using twice as many bits as `f64`. Please see [the documentation for `f32` or Wikipedia on quad-precision values for more information.

See also the `std::f128::consts` module.

## Implementations§

source§

### impl f128

source

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

🔬This is a nightly-only experimental API. (`f128` #116909)

Returns `true` if this value is NaN.

source

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

🔬This is a nightly-only experimental API. (`f128` #116909)

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.

source

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

🔬This is a nightly-only experimental API. (`f128` #116909)

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.

source

#### pub fn to_bits(self) -> u128

🔬This is a nightly-only experimental API. (`f128` #116909)

Raw transmutation to `u128`.

This is currently identical to `transmute::<f128, u128>(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.

source

#### pub fn from_bits(v: u128) -> Self

🔬This is a nightly-only experimental API. (`f128` #116909)

Raw transmutation from `u128`.

This is currently identical to `transmute::<u128, f128>(v)` on all platforms. It turns out this is incredibly portable, for two reasons:

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

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

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

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

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

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

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

## Trait Implementations§

1.0.0 · source§

### impl Add<&f128> for &f128

§

#### type Output = <f128 as Add>::Output

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

#### fn add(self, other: &f128) -> <f128 as Add<f128>>::Output

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

### impl Add<&f128> for f128

§

#### type Output = <f128 as Add>::Output

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

#### fn add(self, other: &f128) -> <f128 as Add<f128>>::Output

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

### impl<'a> Add<f128> for &'a f128

§

#### type Output = <f128 as Add>::Output

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

#### fn add(self, other: f128) -> <f128 as Add<f128>>::Output

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

### impl Add for f128

§

#### type Output = f128

The resulting type after applying the `+` operator.
const: unstable · source§

#### fn add(self, other: f128) -> f128

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

### impl AddAssign<&f128> for f128

source§

#### fn add_assign(&mut self, other: &f128)

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

### impl AddAssign for f128

source§

#### fn add_assign(&mut self, other: f128)

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

### impl Clone for f128

source§

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

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 f128

source§

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

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

### impl Default for f128

source§

#### fn default() -> f128

Returns the default value of `0.0`

1.0.0 · source§

### impl Div<&f128> for &f128

§

#### type Output = <f128 as Div>::Output

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

#### fn div(self, other: &f128) -> <f128 as Div<f128>>::Output

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

### impl Div<&f128> for f128

§

#### type Output = <f128 as Div>::Output

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

#### fn div(self, other: &f128) -> <f128 as Div<f128>>::Output

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

### impl<'a> Div<f128> for &'a f128

§

#### type Output = <f128 as Div>::Output

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

#### fn div(self, other: f128) -> <f128 as Div<f128>>::Output

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

### impl Div for f128

§

#### type Output = f128

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

#### fn div(self, other: f128) -> f128

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

### impl DivAssign<&f128> for f128

source§

#### fn div_assign(&mut self, other: &f128)

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

### impl DivAssign for f128

source§

#### fn div_assign(&mut self, other: f128)

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

### impl From<f16> for f128

source§

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

Converts `f16` to `f128` losslessly.

1.6.0 · source§

### impl From<f32> for f128

source§

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

Converts `f32` to `f128` losslessly.

1.6.0 · source§

### impl From<f64> for f128

source§

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

Converts `f64` to `f128` losslessly.

1.0.0 · source§

### impl Mul<&f128> for &f128

§

#### type Output = <f128 as Mul>::Output

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

#### fn mul(self, other: &f128) -> <f128 as Mul<f128>>::Output

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

### impl Mul<&f128> for f128

§

#### type Output = <f128 as Mul>::Output

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

#### fn mul(self, other: &f128) -> <f128 as Mul<f128>>::Output

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

### impl<'a> Mul<f128> for &'a f128

§

#### type Output = <f128 as Mul>::Output

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

#### fn mul(self, other: f128) -> <f128 as Mul<f128>>::Output

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

### impl Mul for f128

§

#### type Output = f128

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

#### fn mul(self, other: f128) -> f128

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

### impl MulAssign<&f128> for f128

source§

#### fn mul_assign(&mut self, other: &f128)

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

### impl MulAssign for f128

source§

#### fn mul_assign(&mut self, other: f128)

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

### impl Neg for &f128

§

#### type Output = <f128 as Neg>::Output

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

#### fn neg(self) -> <f128 as Neg>::Output

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

### impl Neg for f128

§

#### type Output = f128

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

#### fn neg(self) -> f128

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

### impl PartialEq for f128

const: unstable · source§

#### fn eq(&self, other: &f128) -> bool

This method tests for `self` and `other` values to be equal, and is used by `==`.
const: unstable · source§

#### fn ne(&self, other: &f128) -> 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 f128

source§

#### fn partial_cmp(&self, other: &f128) -> Option<Ordering>

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

#### fn lt(&self, other: &f128) -> bool

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

#### fn le(&self, other: &f128) -> bool

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

#### fn ge(&self, other: &f128) -> bool

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

#### fn gt(&self, other: &f128) -> bool

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

### impl Rem<&f128> for &f128

§

#### type Output = <f128 as Rem>::Output

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

#### fn rem(self, other: &f128) -> <f128 as Rem<f128>>::Output

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

### impl Rem<&f128> for f128

§

#### type Output = <f128 as Rem>::Output

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

#### fn rem(self, other: &f128) -> <f128 as Rem<f128>>::Output

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

### impl<'a> Rem<f128> for &'a f128

§

#### type Output = <f128 as Rem>::Output

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

#### fn rem(self, other: f128) -> <f128 as Rem<f128>>::Output

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

### impl Rem for f128

The remainder from the division of two floats.

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

#### §Examples

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

    // The answer to both operations is 1.75
    assert_eq!(x % y, remainder);

Run
§

#### type Output = f128

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

#### fn rem(self, other: f128) -> f128

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

### impl RemAssign<&f128> for f128

source§

#### fn rem_assign(&mut self, other: &f128)

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

### impl RemAssign for f128

source§

#### fn rem_assign(&mut self, other: f128)

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

### impl Sub<&f128> for &f128

§

#### type Output = <f128 as Sub>::Output

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

#### fn sub(self, other: &f128) -> <f128 as Sub<f128>>::Output

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

### impl Sub<&f128> for f128

§

#### type Output = <f128 as Sub>::Output

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

#### fn sub(self, other: &f128) -> <f128 as Sub<f128>>::Output

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

### impl<'a> Sub<f128> for &'a f128

§

#### type Output = <f128 as Sub>::Output

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

#### fn sub(self, other: f128) -> <f128 as Sub<f128>>::Output

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

### impl Sub for f128

§

#### type Output = f128

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

#### fn sub(self, other: f128) -> f128

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

### impl SubAssign<&f128> for f128

source§

#### fn sub_assign(&mut self, other: &f128)

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

### impl SubAssign for f128

source§

#### fn sub_assign(&mut self, other: f128)

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

### impl Copy for f128

source§

### impl FloatToInt<i128> for f128

source§

### impl FloatToInt<i16> for f128

source§

### impl FloatToInt<i32> for f128

source§

### impl FloatToInt<i64> for f128

source§

### impl FloatToInt<i8> for f128

source§

### impl FloatToInt<isize> for f128

source§

### impl FloatToInt<u128> for f128

source§

### impl FloatToInt<u16> for f128

source§

### impl FloatToInt<u32> for f128

source§

### impl FloatToInt<u64> for f128

source§

### impl FloatToInt<u8> for f128

source§

### impl FloatToInt<usize> for f128

## Auto Trait Implementations§

§

### impl Freeze for f128

§

### impl RefUnwindSafe for f128

§

### impl Send for f128

§

### impl Sync for f128

§

### impl Unpin for f128

§

### impl UnwindSafe for f128

## Blanket Implementations§

source§

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

source§

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

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

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

source§

#### 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> From<T> for T

source§

#### 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.

source§

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

§

#### 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.
source§

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

§

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

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

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

Performs the conversion.