Primitive Type f128

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

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

impl f128

pub const fn is_nan(self) -> bool

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

Returns true if this value is NaN.

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.

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.

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.

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

impl Add<&f128> for &f128

type Output = <f128 as Add>::Output

The resulting type after applying the + operator.

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

Performs the + operation.

impl Add<&f128> for f128

type Output = <f128 as Add>::Output

The resulting type after applying the + operator.

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

Performs the + operation.

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

type Output = <f128 as Add>::Output

The resulting type after applying the + operator.

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

Performs the + operation.

impl Add for f128

type Output = f128

The resulting type after applying the + operator.

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

Performs the + operation.

impl AddAssign<&f128> for f128

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

Performs the += operation.

impl AddAssign for f128

fn add_assign(&mut self, other: f128)

Performs the += operation.

impl Clone for f128

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for f128

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

Formats the value using the given formatter.

impl Default for f128

fn default() -> f128

Returns the default value of 0.0

impl Div<&f128> for &f128

type Output = <f128 as Div>::Output

The resulting type after applying the / operator.

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

Performs the / operation.

impl Div<&f128> for f128

type Output = <f128 as Div>::Output

The resulting type after applying the / operator.

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

Performs the / operation.

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

type Output = <f128 as Div>::Output

The resulting type after applying the / operator.

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

Performs the / operation.

impl Div for f128

type Output = f128

The resulting type after applying the / operator.

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

Performs the / operation.

impl DivAssign<&f128> for f128

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

Performs the /= operation.

impl DivAssign for f128

fn div_assign(&mut self, other: f128)

Performs the /= operation.

impl From<f16> for f128

fn from(small: f16) -> Self

Converts f16 to f128 losslessly.

impl From<f32> for f128

fn from(small: f32) -> Self

Converts f32 to f128 losslessly.

impl From<f64> for f128

fn from(small: f64) -> Self

Converts f64 to f128 losslessly.

impl Mul<&f128> for &f128

type Output = <f128 as Mul>::Output

The resulting type after applying the * operator.

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

Performs the * operation.

impl Mul<&f128> for f128

type Output = <f128 as Mul>::Output

The resulting type after applying the * operator.

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

Performs the * operation.

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

type Output = <f128 as Mul>::Output

The resulting type after applying the * operator.

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

Performs the * operation.

impl Mul for f128

type Output = f128

The resulting type after applying the * operator.

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

Performs the * operation.

impl MulAssign<&f128> for f128

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

Performs the *= operation.

impl MulAssign for f128

fn mul_assign(&mut self, other: f128)

Performs the *= operation.

impl Neg for &f128

type Output = <f128 as Neg>::Output

The resulting type after applying the - operator.

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

Performs the unary - operation.

impl Neg for f128

type Output = f128

The resulting type after applying the - operator.

fn neg(self) -> f128

Performs the unary - operation.

impl PartialEq for f128

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

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

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.

impl PartialOrd for f128

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

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

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

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

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

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

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

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

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

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

impl Rem<&f128> for &f128

type Output = <f128 as Rem>::Output

The resulting type after applying the % operator.

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

Performs the % operation.

impl Rem<&f128> for f128

type Output = <f128 as Rem>::Output

The resulting type after applying the % operator.

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

Performs the % operation.

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

type Output = <f128 as Rem>::Output

The resulting type after applying the % operator.

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

Performs the % operation.

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);

type Output = f128

The resulting type after applying the % operator.

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

Performs the % operation.

impl RemAssign<&f128> for f128

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

Performs the %= operation.

impl RemAssign for f128

fn rem_assign(&mut self, other: f128)

Performs the %= operation.

impl Sub<&f128> for &f128

type Output = <f128 as Sub>::Output

The resulting type after applying the - operator.

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

Performs the - operation.

impl Sub<&f128> for f128

type Output = <f128 as Sub>::Output

The resulting type after applying the - operator.

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

Performs the - operation.

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

type Output = <f128 as Sub>::Output

The resulting type after applying the - operator.

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

Performs the - operation.

impl Sub for f128

type Output = f128

The resulting type after applying the - operator.

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

Performs the - operation.

impl SubAssign<&f128> for f128

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

Performs the -= operation.

impl SubAssign for f128

fn sub_assign(&mut self, other: f128)

Performs the -= operation.

impl Copy for f128

impl FloatToInt<i128> for f128

impl FloatToInt<i16> for f128

impl FloatToInt<i32> for f128

impl FloatToInt<i64> for f128

impl FloatToInt<i8> for f128

impl FloatToInt<isize> for f128

impl FloatToInt<u128> for f128

impl FloatToInt<u16> for f128

impl FloatToInt<u32> for f128

impl FloatToInt<u64> for f128

impl FloatToInt<u8> for f128

impl FloatToInt<usize> for f128