Struct Float64 

#[repr(C, align(8))]
pub struct Float64(pub f64);

A wire-encoded f64

Tuple Fields

0: f64

Methods from Deref<Target = f64>

pub const RADIX: u32 = 2

pub const BITS: u32 = 64

pub const MANTISSA_DIGITS: u32 = 53

pub const DIGITS: u32 = 15

pub const EPSILON: f64 = 2.2204460492503131e-16_f64

pub const MIN: f64 = -1.7976931348623157e+308_f64

pub const MIN_POSITIVE: f64 = 2.2250738585072014e-308_f64

pub const MAX: f64 = 1.7976931348623157e+308_f64

pub const MIN_EXP: i32 = -1021

pub const MAX_EXP: i32 = 1024

pub const MIN_10_EXP: i32 = -307

pub const MAX_10_EXP: i32 = 308

pub const NAN: f64

pub const INFINITY: f64

pub const NEG_INFINITY: f64

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

Trait Implementations

impl Add<&Float64> for &Float64

type Output = f64

The resulting type after applying the + operator.

fn add(self, other: &Float64) -> Self::Output

Performs the + operation.

impl Add<&Float64> for &f64

type Output = f64

The resulting type after applying the + operator.

fn add(self, other: &Float64) -> Self::Output

Performs the + operation.

impl Add<&Float64> for Float64

type Output = f64

The resulting type after applying the + operator.

fn add(self, other: &Float64) -> Self::Output

Performs the + operation.

impl Add<&Float64> for f64

type Output = f64

The resulting type after applying the + operator.

fn add(self, other: &Float64) -> Self::Output

Performs the + operation.

impl Add<&f64> for &Float64

type Output = f64

The resulting type after applying the + operator.

fn add(self, other: &f64) -> Self::Output

Performs the + operation.

impl Add<&f64> for Float64

type Output = f64

The resulting type after applying the + operator.

fn add(self, other: &f64) -> Self::Output

Performs the + operation.

impl Add<Float64> for &Float64

type Output = f64

The resulting type after applying the + operator.

fn add(self, other: Float64) -> Self::Output

Performs the + operation.

impl Add<Float64> for &f64

type Output = f64

The resulting type after applying the + operator.

fn add(self, other: Float64) -> Self::Output

Performs the + operation.

impl Add<Float64> for f64

type Output = f64

The resulting type after applying the + operator.

fn add(self, other: Float64) -> Self::Output

Performs the + operation.

impl Add<f64> for &Float64

type Output = f64

The resulting type after applying the + operator.

fn add(self, other: f64) -> Self::Output

Performs the + operation.

impl Add<f64> for Float64

type Output = f64

The resulting type after applying the + operator.

fn add(self, other: f64) -> Self::Output

Performs the + operation.

impl Add for Float64

type Output = f64

The resulting type after applying the + operator.

fn add(self, other: Float64) -> Self::Output

Performs the + operation.

impl AddAssign<&Float64> for Float64

fn add_assign(&mut self, other: &Float64)

Performs the += operation.

impl AddAssign<&f64> for Float64

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

Performs the += operation.

impl AddAssign<f64> for Float64

fn add_assign(&mut self, other: f64)

Performs the += operation.

impl AddAssign for Float64

fn add_assign(&mut self, other: Float64)

Performs the += operation.

impl Clone for Float64

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Constrained for Float64

type Constraint = ()

Type of constraint information for this type.

fn validate( _: Slot<'_, Self>, _: Self::Constraint, ) -> Result<(), ValidationError>

Validate a slot of this type against a constraint. Can be called when pointers/envelopes are just presence markers.

impl Debug for Float64

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

Formats the value using the given formatter.

impl<D: ?Sized> Decode<D> for Float64

fn decode(_: Slot<'_, Self>, _: &mut D, _: ()) -> Result<(), DecodeError>

Decodes a value into a slot using a decoder.

impl Default for Float64

fn default() -> Self

Returns the “default value” for a type.

impl Deref for Float64

type Target = f64

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl DerefMut for Float64

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl Display for Float64

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

Formats the value using the given formatter.

impl Div<&Float64> for &Float64

type Output = f64

The resulting type after applying the / operator.

fn div(self, other: &Float64) -> Self::Output

Performs the / operation.

impl Div<&Float64> for &f64

type Output = f64

The resulting type after applying the / operator.

fn div(self, other: &Float64) -> Self::Output

Performs the / operation.

impl Div<&Float64> for Float64

type Output = f64

The resulting type after applying the / operator.

fn div(self, other: &Float64) -> Self::Output

Performs the / operation.

impl Div<&Float64> for f64

type Output = f64

The resulting type after applying the / operator.

fn div(self, other: &Float64) -> Self::Output

Performs the / operation.

impl Div<&f64> for &Float64

type Output = f64

The resulting type after applying the / operator.

fn div(self, other: &f64) -> Self::Output

Performs the / operation.

impl Div<&f64> for Float64

type Output = f64

The resulting type after applying the / operator.

fn div(self, other: &f64) -> Self::Output

Performs the / operation.

impl Div<Float64> for &Float64

type Output = f64

The resulting type after applying the / operator.

fn div(self, other: Float64) -> Self::Output

Performs the / operation.

impl Div<Float64> for &f64

type Output = f64

The resulting type after applying the / operator.

fn div(self, other: Float64) -> Self::Output

Performs the / operation.

impl Div<Float64> for f64

type Output = f64

The resulting type after applying the / operator.

fn div(self, other: Float64) -> Self::Output

Performs the / operation.

impl Div<f64> for &Float64

type Output = f64

The resulting type after applying the / operator.

fn div(self, other: f64) -> Self::Output

Performs the / operation.

impl Div<f64> for Float64

type Output = f64

The resulting type after applying the / operator.

fn div(self, other: f64) -> Self::Output

Performs the / operation.

impl Div for Float64

type Output = f64

The resulting type after applying the / operator.

fn div(self, other: Float64) -> Self::Output

Performs the / operation.

impl DivAssign<&Float64> for Float64

fn div_assign(&mut self, other: &Float64)

Performs the /= operation.

impl DivAssign<&f64> for Float64

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

Performs the /= operation.

impl DivAssign<f64> for Float64

fn div_assign(&mut self, other: f64)

Performs the /= operation.

impl DivAssign for Float64

fn div_assign(&mut self, other: Float64)

Performs the /= operation.

impl<E: ?Sized> Encode<Float64, E> for &Float64

fn encode( self, _: &mut E, out: &mut MaybeUninit<Float64>, _: <Float64 as Constrained>::Constraint, ) -> Result<(), EncodeError>

Encodes this value into an encoder and output.

const COPY_OPTIMIZATION: CopyOptimization<Self, W> = _

Whether the conversion from Self to W is equivalent to copying the raw bytes of Self.

impl<E: ?Sized> Encode<Float64, E> for &f64

fn encode( self, _: &mut E, out: &mut MaybeUninit<Float64>, _: <Float64 as Constrained>::Constraint, ) -> Result<(), EncodeError>

Encodes this value into an encoder and output.

const COPY_OPTIMIZATION: CopyOptimization<Self, W> = _

Whether the conversion from Self to W is equivalent to copying the raw bytes of Self.

impl<E: ?Sized> Encode<Float64, E> for Float64

const COPY_OPTIMIZATION: CopyOptimization<Float64, Float64> = crate::CopyOptimization<Float64, Float64>::PRIMITIVE

Whether the conversion from Self to W is equivalent to copying the raw bytes of Self.

fn encode( self, encoder: &mut E, out: &mut MaybeUninit<Float64>, constraint: <Float64 as Constrained>::Constraint, ) -> Result<(), EncodeError>

Encodes this value into an encoder and output.

impl<E: ?Sized> Encode<Float64, E> for f64

const COPY_OPTIMIZATION: CopyOptimization<f64, Float64> = crate::CopyOptimization<f64, Float64>::PRIMITIVE

Whether the conversion from Self to W is equivalent to copying the raw bytes of Self.

fn encode( self, encoder: &mut E, out: &mut MaybeUninit<Float64>, constraint: <Float64 as Constrained>::Constraint, ) -> Result<(), EncodeError>

Encodes this value into an encoder and output.

impl<E> EncodeOption<Box<'static, Float64>, E> for &Float64

where E: Encoder + ?Sized,

fn encode_option( this: Option<Self>, encoder: &mut E, out: &mut MaybeUninit<Box<'static, Float64>>, constraint: <Float64 as Constrained>::Constraint, ) -> Result<(), EncodeError>

Encodes this optional value into an encoder and output.

impl<E> EncodeOption<Box<'static, Float64>, E> for Float64

where E: Encoder + ?Sized,

fn encode_option( this: Option<Self>, encoder: &mut E, out: &mut MaybeUninit<Box<'static, Float64>>, constraint: <Float64 as Constrained>::Constraint, ) -> Result<(), EncodeError>

Encodes this optional value into an encoder and output.

impl<'a> From<&'a Float64> for f64

fn from(value: &'a Float64) -> Self

Converts to this type from the input type.

impl<'a> From<&'a f64> for Float64

fn from(value: &'a f64) -> Self

Converts to this type from the input type.

impl From<Float64> for f64

fn from(value: Float64) -> Self

Converts to this type from the input type.

impl From<f64> for Float64

fn from(value: f64) -> Self

Converts to this type from the input type.

impl FromBytes for Float64

where f64: FromBytes,

fn read_from_bytes(source: &[u8]) -> Result<Self, SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the given source.

fn read_from_prefix( source: &[u8], ) -> Result<(Self, &[u8]), SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the prefix of the given source.

fn read_from_suffix( source: &[u8], ) -> Result<(&[u8], Self), SizeError<&[u8], Self>>

where Self: Sized,

Reads a copy of Self from the suffix of the given source.

impl FromWire<Float64> for f64

const COPY_OPTIMIZATION: CopyOptimization<Float64, f64> = crate::CopyOptimization<Float64, f64>::PRIMITIVE

Whether the conversion from W to Self is equivalent to copying the raw bytes of W.

fn from_wire(wire: Float64) -> Self

Converts the given owned value to this type.

impl FromWireRef<Float64> for f64

fn from_wire_ref(wire: &Float64) -> Self

Converts the given reference to this type.

impl FromZeros for Float64

where f64: FromZeros,

fn zero(&mut self)

Overwrites self with zeros.

fn new_zeroed() -> Self

where Self: Sized,

Creates an instance of Self from zeroed bytes.

fn new_box_zeroed() -> Result<Box<Self>, AllocError>

where Self: Sized,

Creates a Box<Self> from zeroed bytes.

fn new_vec_zeroed(len: usize) -> Result<Vec<Self>, AllocError>

where Self: Sized,

Creates a Vec<Self> from zeroed bytes.

fn extend_vec_zeroed( v: &mut Vec<Self>, additional: usize, ) -> Result<(), AllocError>

where Self: Sized,

Extends a Vec<Self> by pushing additional new items onto the end of the vector. The new items are initialized with zeros.

fn insert_vec_zeroed( v: &mut Vec<Self>, position: usize, additional: usize, ) -> Result<(), AllocError>

where Self: Sized,

Inserts additional new items into Vec<Self> at position. The new items are initialized with zeros.

impl IntoBytes for Float64

where f64: IntoBytes, (): PaddingFree<Self, { _ }>,

fn as_mut_bytes(&mut self) -> &mut [u8]

where Self: FromBytes,

Gets the bytes of this value mutably.

impl IntoNatural for Float64

type Natural = f64

A good default type for this wire type to convert into.

fn into_natural(self) -> Self::Natural

Converts this type into its natural equivalent.

impl LowerExp for Float64

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

Formats the value using the given formatter.

impl Mul<&Float64> for &Float64

type Output = f64

The resulting type after applying the * operator.

fn mul(self, other: &Float64) -> Self::Output

Performs the * operation.

impl Mul<&Float64> for &f64

type Output = f64

The resulting type after applying the * operator.

fn mul(self, other: &Float64) -> Self::Output

Performs the * operation.

impl Mul<&Float64> for Float64

type Output = f64

The resulting type after applying the * operator.

fn mul(self, other: &Float64) -> Self::Output

Performs the * operation.

impl Mul<&Float64> for f64

type Output = f64

The resulting type after applying the * operator.

fn mul(self, other: &Float64) -> Self::Output

Performs the * operation.

impl Mul<&f64> for &Float64

type Output = f64

The resulting type after applying the * operator.

fn mul(self, other: &f64) -> Self::Output

Performs the * operation.

impl Mul<&f64> for Float64

type Output = f64

The resulting type after applying the * operator.

fn mul(self, other: &f64) -> Self::Output

Performs the * operation.

impl Mul<Float64> for &Float64

type Output = f64

The resulting type after applying the * operator.

fn mul(self, other: Float64) -> Self::Output

Performs the * operation.

impl Mul<Float64> for &f64

type Output = f64

The resulting type after applying the * operator.

fn mul(self, other: Float64) -> Self::Output

Performs the * operation.

impl Mul<Float64> for f64

type Output = f64

The resulting type after applying the * operator.

fn mul(self, other: Float64) -> Self::Output

Performs the * operation.

impl Mul<f64> for &Float64

type Output = f64

The resulting type after applying the * operator.

fn mul(self, other: f64) -> Self::Output

Performs the * operation.

impl Mul<f64> for Float64

type Output = f64

The resulting type after applying the * operator.

fn mul(self, other: f64) -> Self::Output

Performs the * operation.

impl Mul for Float64

type Output = f64

The resulting type after applying the * operator.

fn mul(self, other: Float64) -> Self::Output

Performs the * operation.

impl MulAssign<&Float64> for Float64

fn mul_assign(&mut self, other: &Float64)

Performs the *= operation.

impl MulAssign<&f64> for Float64

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

Performs the *= operation.

impl MulAssign<f64> for Float64

fn mul_assign(&mut self, other: f64)

Performs the *= operation.

impl MulAssign for Float64

fn mul_assign(&mut self, other: Float64)

Performs the *= operation.

impl Neg for Float64

type Output = <f64 as Neg>::Output

The resulting type after applying the - operator.

fn neg(self) -> Self::Output

Performs the unary - operation.

impl PartialEq<f64> for Float64

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

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq for Float64

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

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd<f64> for Float64

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl PartialOrd for Float64

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl Product for Float64

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

Takes an iterator and generates Self from the elements by multiplying the items.

impl Rem<&Float64> for &Float64

type Output = f64

The resulting type after applying the % operator.

fn rem(self, other: &Float64) -> Self::Output

Performs the % operation.

impl Rem<&Float64> for &f64

type Output = f64

The resulting type after applying the % operator.

fn rem(self, other: &Float64) -> Self::Output

Performs the % operation.

impl Rem<&Float64> for Float64

type Output = f64

The resulting type after applying the % operator.

fn rem(self, other: &Float64) -> Self::Output

Performs the % operation.

impl Rem<&Float64> for f64

type Output = f64

The resulting type after applying the % operator.

fn rem(self, other: &Float64) -> Self::Output

Performs the % operation.

impl Rem<&f64> for &Float64

type Output = f64

The resulting type after applying the % operator.

fn rem(self, other: &f64) -> Self::Output

Performs the % operation.

impl Rem<&f64> for Float64

type Output = f64

The resulting type after applying the % operator.

fn rem(self, other: &f64) -> Self::Output

Performs the % operation.

impl Rem<Float64> for &Float64

type Output = f64

The resulting type after applying the % operator.

fn rem(self, other: Float64) -> Self::Output

Performs the % operation.

impl Rem<Float64> for &f64

type Output = f64

The resulting type after applying the % operator.

fn rem(self, other: Float64) -> Self::Output

Performs the % operation.

impl Rem<Float64> for f64

type Output = f64

The resulting type after applying the % operator.

fn rem(self, other: Float64) -> Self::Output

Performs the % operation.

impl Rem<f64> for &Float64

type Output = f64

The resulting type after applying the % operator.

fn rem(self, other: f64) -> Self::Output

Performs the % operation.

impl Rem<f64> for Float64

type Output = f64

The resulting type after applying the % operator.

fn rem(self, other: f64) -> Self::Output

Performs the % operation.

impl Rem for Float64

type Output = f64

The resulting type after applying the % operator.

fn rem(self, other: Float64) -> Self::Output

Performs the % operation.

impl RemAssign<&Float64> for Float64

fn rem_assign(&mut self, other: &Float64)

Performs the %= operation.

impl RemAssign<&f64> for Float64

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

Performs the %= operation.

impl RemAssign<f64> for Float64

fn rem_assign(&mut self, other: f64)

Performs the %= operation.

impl RemAssign for Float64

fn rem_assign(&mut self, other: Float64)

Performs the %= operation.

impl Sub<&Float64> for &Float64

type Output = f64

The resulting type after applying the - operator.

fn sub(self, other: &Float64) -> Self::Output

Performs the - operation.

impl Sub<&Float64> for &f64

type Output = f64

The resulting type after applying the - operator.

fn sub(self, other: &Float64) -> Self::Output

Performs the - operation.

impl Sub<&Float64> for Float64

type Output = f64

The resulting type after applying the - operator.

fn sub(self, other: &Float64) -> Self::Output

Performs the - operation.

impl Sub<&Float64> for f64

type Output = f64

The resulting type after applying the - operator.

fn sub(self, other: &Float64) -> Self::Output

Performs the - operation.

impl Sub<&f64> for &Float64

type Output = f64

The resulting type after applying the - operator.

fn sub(self, other: &f64) -> Self::Output

Performs the - operation.

impl Sub<&f64> for Float64

type Output = f64

The resulting type after applying the - operator.

fn sub(self, other: &f64) -> Self::Output

Performs the - operation.

impl Sub<Float64> for &Float64

type Output = f64

The resulting type after applying the - operator.

fn sub(self, other: Float64) -> Self::Output

Performs the - operation.

impl Sub<Float64> for &f64

type Output = f64

The resulting type after applying the - operator.

fn sub(self, other: Float64) -> Self::Output

Performs the - operation.

impl Sub<Float64> for f64

type Output = f64

The resulting type after applying the - operator.

fn sub(self, other: Float64) -> Self::Output

Performs the - operation.

impl Sub<f64> for &Float64

type Output = f64

The resulting type after applying the - operator.

fn sub(self, other: f64) -> Self::Output

Performs the - operation.

impl Sub<f64> for Float64

type Output = f64

The resulting type after applying the - operator.

fn sub(self, other: f64) -> Self::Output

Performs the - operation.

impl Sub for Float64

type Output = f64

The resulting type after applying the - operator.

fn sub(self, other: Float64) -> Self::Output

Performs the - operation.

impl SubAssign<&Float64> for Float64

fn sub_assign(&mut self, other: &Float64)

Performs the -= operation.

impl SubAssign<&f64> for Float64

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

Performs the -= operation.

impl SubAssign<f64> for Float64

fn sub_assign(&mut self, other: f64)

Performs the -= operation.

impl SubAssign for Float64

fn sub_assign(&mut self, other: Float64)

Performs the -= operation.

impl Sum for Float64

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

Takes an iterator and generates Self from the elements by “summing up” the items.

impl TryFromBytes for Float64

where f64: TryFromBytes,

fn try_read_from_bytes( source: &[u8], ) -> Result<Self, ConvertError<Infallible, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read the given source as a Self.

fn try_read_from_prefix( source: &[u8], ) -> Result<(Self, &[u8]), ConvertError<Infallible, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read a Self from the prefix of the given source.

fn try_read_from_suffix( source: &[u8], ) -> Result<(&[u8], Self), ConvertError<Infallible, SizeError<&[u8], Self>, ValidityError<&[u8], Self>>>

where Self: Sized,

Attempts to read a Self from the suffix of the given source.

impl UpperExp for Float64

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

Formats the value using the given formatter.

impl Wire for Float64

type Narrowed<'de> = Float64

The narrowed wire type, restricted to the 'de lifetime.

fn zero_padding(_: &mut MaybeUninit<Self>)

Writes zeroes to the padding for this type, if any.

impl Copy for Float64

impl Eq for Float64