//! This module provides constants which are specific to the implementation
//! of the `f64` floating point data type.
//!
//! *[See also the `f64` primitive type](../../std/primitive.f64.html).*
//!
//! Mathematically significant numbers are provided in the `consts` sub-module.
//!
//! Although using these constants won’t cause compilation warnings,
//! new code should use the associated constants directly on the primitive type.
#![stable(feature = "rust1", since = "1.0.0")]
use crate::convert::FloatToInt;
#[cfg(not(test))]
use crate::intrinsics;
use crate::mem;
use crate::num::FpCategory;
/// The radix or base of the internal representation of `f64`.
/// Use [`f64::RADIX`](../../std/primitive.f64.html#associatedconstant.RADIX) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let r = std::f64::RADIX;
///
/// // intended way
/// let r = f64::RADIX;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const RADIX: u32 = f64::RADIX;
/// Number of significant digits in base 2.
/// Use [`f64::MANTISSA_DIGITS`](../../std/primitive.f64.html#associatedconstant.MANTISSA_DIGITS) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let d = std::f64::MANTISSA_DIGITS;
///
/// // intended way
/// let d = f64::MANTISSA_DIGITS;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const MANTISSA_DIGITS: u32 = f64::MANTISSA_DIGITS;
/// Approximate number of significant digits in base 10.
/// Use [`f64::DIGITS`](../../std/primitive.f64.html#associatedconstant.DIGITS) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let d = std::f64::DIGITS;
///
/// // intended way
/// let d = f64::DIGITS;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const DIGITS: u32 = f64::DIGITS;
/// [Machine epsilon] value for `f64`.
/// Use [`f64::EPSILON`](../../std/primitive.f64.html#associatedconstant.EPSILON) instead.
///
/// This is the difference between `1.0` and the next larger representable number.
///
/// [Machine epsilon]: https://en.wikipedia.org/wiki/Machine_epsilon
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let e = std::f64::EPSILON;
///
/// // intended way
/// let e = f64::EPSILON;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const EPSILON: f64 = f64::EPSILON;
/// Smallest finite `f64` value.
/// Use [`f64::MIN`](../../std/primitive.f64.html#associatedconstant.MIN) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let min = std::f64::MIN;
///
/// // intended way
/// let min = f64::MIN;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const MIN: f64 = f64::MIN;
/// Smallest positive normal `f64` value.
/// Use [`f64::MIN_POSITIVE`](../../std/primitive.f64.html#associatedconstant.MIN_POSITIVE) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let min = std::f64::MIN_POSITIVE;
///
/// // intended way
/// let min = f64::MIN_POSITIVE;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const MIN_POSITIVE: f64 = f64::MIN_POSITIVE;
/// Largest finite `f64` value.
/// Use [`f64::MAX`](../../std/primitive.f64.html#associatedconstant.MAX) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let max = std::f64::MAX;
///
/// // intended way
/// let max = f64::MAX;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const MAX: f64 = f64::MAX;
/// One greater than the minimum possible normal power of 2 exponent.
/// Use [`f64::MIN_EXP`](../../std/primitive.f64.html#associatedconstant.MIN_EXP) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let min = std::f64::MIN_EXP;
///
/// // intended way
/// let min = f64::MIN_EXP;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const MIN_EXP: i32 = f64::MIN_EXP;
/// Maximum possible power of 2 exponent.
/// Use [`f64::MAX_EXP`](../../std/primitive.f64.html#associatedconstant.MAX_EXP) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let max = std::f64::MAX_EXP;
///
/// // intended way
/// let max = f64::MAX_EXP;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const MAX_EXP: i32 = f64::MAX_EXP;
/// Minimum possible normal power of 10 exponent.
/// Use [`f64::MIN_10_EXP`](../../std/primitive.f64.html#associatedconstant.MIN_10_EXP) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let min = std::f64::MIN_10_EXP;
///
/// // intended way
/// let min = f64::MIN_10_EXP;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const MIN_10_EXP: i32 = f64::MIN_10_EXP;
/// Maximum possible power of 10 exponent.
/// Use [`f64::MAX_10_EXP`](../../std/primitive.f64.html#associatedconstant.MAX_10_EXP) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let max = std::f64::MAX_10_EXP;
///
/// // intended way
/// let max = f64::MAX_10_EXP;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const MAX_10_EXP: i32 = f64::MAX_10_EXP;
/// Not a Number (NaN).
/// Use [`f64::NAN`](../../std/primitive.f64.html#associatedconstant.NAN) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let nan = std::f64::NAN;
///
/// // intended way
/// let nan = f64::NAN;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const NAN: f64 = f64::NAN;
/// Infinity (∞).
/// Use [`f64::INFINITY`](../../std/primitive.f64.html#associatedconstant.INFINITY) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let inf = std::f64::INFINITY;
///
/// // intended way
/// let inf = f64::INFINITY;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const INFINITY: f64 = f64::INFINITY;
/// Negative infinity (−∞).
/// Use [`f64::NEG_INFINITY`](../../std/primitive.f64.html#associatedconstant.NEG_INFINITY) instead.
///
/// # Examples
///
/// ```rust
/// // deprecated way
/// let ninf = std::f64::NEG_INFINITY;
///
/// // intended way
/// let ninf = f64::NEG_INFINITY;
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub const NEG_INFINITY: f64 = f64::NEG_INFINITY;
/// Basic mathematical constants.
#[stable(feature = "rust1", since = "1.0.0")]
pub mod consts {
// FIXME: replace with mathematical constants from cmath.
/// Archimedes' constant (π)
#[stable(feature = "rust1", since = "1.0.0")]
pub const PI: f64 = 3.14159265358979323846264338327950288_f64;
/// The full circle constant (τ)
///
/// Equal to 2π.
#[unstable(feature = "tau_constant", issue = "66770")]
pub const TAU: f64 = 6.28318530717958647692528676655900577_f64;
/// π/2
#[stable(feature = "rust1", since = "1.0.0")]
pub const FRAC_PI_2: f64 = 1.57079632679489661923132169163975144_f64;
/// π/3
#[stable(feature = "rust1", since = "1.0.0")]
pub const FRAC_PI_3: f64 = 1.04719755119659774615421446109316763_f64;
/// π/4
#[stable(feature = "rust1", since = "1.0.0")]
pub const FRAC_PI_4: f64 = 0.785398163397448309615660845819875721_f64;
/// π/6
#[stable(feature = "rust1", since = "1.0.0")]
pub const FRAC_PI_6: f64 = 0.52359877559829887307710723054658381_f64;
/// π/8
#[stable(feature = "rust1", since = "1.0.0")]
pub const FRAC_PI_8: f64 = 0.39269908169872415480783042290993786_f64;
/// 1/π
#[stable(feature = "rust1", since = "1.0.0")]
pub const FRAC_1_PI: f64 = 0.318309886183790671537767526745028724_f64;
/// 2/π
#[stable(feature = "rust1", since = "1.0.0")]
pub const FRAC_2_PI: f64 = 0.636619772367581343075535053490057448_f64;
/// 2/sqrt(π)
#[stable(feature = "rust1", since = "1.0.0")]
pub const FRAC_2_SQRT_PI: f64 = 1.12837916709551257389615890312154517_f64;
/// sqrt(2)
#[stable(feature = "rust1", since = "1.0.0")]
pub const SQRT_2: f64 = 1.41421356237309504880168872420969808_f64;
/// 1/sqrt(2)
#[stable(feature = "rust1", since = "1.0.0")]
pub const FRAC_1_SQRT_2: f64 = 0.707106781186547524400844362104849039_f64;
/// Euler's number (e)
#[stable(feature = "rust1", since = "1.0.0")]
pub const E: f64 = 2.71828182845904523536028747135266250_f64;
/// log2(10)
#[stable(feature = "extra_log_consts", since = "1.43.0")]
pub const LOG2_10: f64 = 3.32192809488736234787031942948939018_f64;
/// log2(e)
#[stable(feature = "rust1", since = "1.0.0")]
pub const LOG2_E: f64 = 1.44269504088896340735992468100189214_f64;
/// log10(2)
#[stable(feature = "extra_log_consts", since = "1.43.0")]
pub const LOG10_2: f64 = 0.301029995663981195213738894724493027_f64;
/// log10(e)
#[stable(feature = "rust1", since = "1.0.0")]
pub const LOG10_E: f64 = 0.434294481903251827651128918916605082_f64;
/// ln(2)
#[stable(feature = "rust1", since = "1.0.0")]
pub const LN_2: f64 = 0.693147180559945309417232121458176568_f64;
/// ln(10)
#[stable(feature = "rust1", since = "1.0.0")]
pub const LN_10: f64 = 2.30258509299404568401799145468436421_f64;
}
#[lang = "f64"]
#[cfg(not(test))]
impl f64 {
/// The radix or base of the internal representation of `f64`.
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const RADIX: u32 = 2;
/// Number of significant digits in base 2.
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MANTISSA_DIGITS: u32 = 53;
/// Approximate number of significant digits in base 10.
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const DIGITS: u32 = 15;
/// [Machine epsilon] value for `f64`.
///
/// This is the difference between `1.0` and the next larger representable number.
///
/// [Machine epsilon]: https://en.wikipedia.org/wiki/Machine_epsilon
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const EPSILON: f64 = 2.2204460492503131e-16_f64;
/// Smallest finite `f64` value.
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MIN: f64 = -1.7976931348623157e+308_f64;
/// Smallest positive normal `f64` value.
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MIN_POSITIVE: f64 = 2.2250738585072014e-308_f64;
/// Largest finite `f64` value.
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MAX: f64 = 1.7976931348623157e+308_f64;
/// One greater than the minimum possible normal power of 2 exponent.
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MIN_EXP: i32 = -1021;
/// Maximum possible power of 2 exponent.
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MAX_EXP: i32 = 1024;
/// Minimum possible normal power of 10 exponent.
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MIN_10_EXP: i32 = -307;
/// Maximum possible power of 10 exponent.
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MAX_10_EXP: i32 = 308;
/// Not a Number (NaN).
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const NAN: f64 = 0.0_f64 / 0.0_f64;
/// Infinity (∞).
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const INFINITY: f64 = 1.0_f64 / 0.0_f64;
/// Negative infinity (-∞).
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const NEG_INFINITY: f64 = -1.0_f64 / 0.0_f64;
/// Returns `true` if this value is `NaN`.
///
/// ```
/// let nan = f64::NAN;
/// let f = 7.0_f64;
///
/// assert!(nan.is_nan());
/// assert!(!f.is_nan());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn is_nan(self) -> bool {
self != self
}
// FIXME(#50145): `abs` is publicly unavailable in libcore due to
// concerns about portability, so this implementation is for
// private use internally.
#[inline]
fn abs_private(self) -> f64 {
f64::from_bits(self.to_bits() & 0x7fff_ffff_ffff_ffff)
}
/// 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());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn is_infinite(self) -> bool {
self.abs_private() == Self::INFINITY
}
/// 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());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn is_finite(self) -> bool {
// There's no need to handle NaN separately: if self is NaN,
// the comparison is not true, exactly as desired.
self.abs_private() < Self::INFINITY
}
/// 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());
/// ```
/// [subnormal]: https://en.wikipedia.org/wiki/Denormal_number
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn is_normal(self) -> bool {
self.classify() == FpCategory::Normal
}
/// 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);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn classify(self) -> FpCategory {
const EXP_MASK: u64 = 0x7ff0000000000000;
const MAN_MASK: u64 = 0x000fffffffffffff;
let bits = self.to_bits();
match (bits & MAN_MASK, bits & EXP_MASK) {
(0, 0) => FpCategory::Zero,
(_, 0) => FpCategory::Subnormal,
(0, EXP_MASK) => FpCategory::Infinite,
(_, EXP_MASK) => FpCategory::Nan,
_ => FpCategory::Normal,
}
}
/// Returns `true` if `self` has a positive sign, including `+0.0`, `NaN`s with
/// positive sign bit and positive infinity.
///
/// ```
/// let f = 7.0_f64;
/// let g = -7.0_f64;
///
/// assert!(f.is_sign_positive());
/// assert!(!g.is_sign_positive());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn is_sign_positive(self) -> bool {
!self.is_sign_negative()
}
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_deprecated(since = "1.0.0", reason = "renamed to is_sign_positive")]
#[inline]
#[doc(hidden)]
pub fn is_positive(self) -> bool {
self.is_sign_positive()
}
/// Returns `true` if `self` has a negative sign, including `-0.0`, `NaN`s with
/// negative sign bit and negative infinity.
///
/// ```
/// let f = 7.0_f64;
/// let g = -7.0_f64;
///
/// assert!(!f.is_sign_negative());
/// assert!(g.is_sign_negative());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn is_sign_negative(self) -> bool {
self.to_bits() & 0x8000_0000_0000_0000 != 0
}
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_deprecated(since = "1.0.0", reason = "renamed to is_sign_negative")]
#[inline]
#[doc(hidden)]
pub fn is_negative(self) -> bool {
self.is_sign_negative()
}
/// 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);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn recip(self) -> f64 {
1.0 / self
}
/// Converts radians to degrees.
///
/// ```
/// let angle = std::f64::consts::PI;
///
/// let abs_difference = (angle.to_degrees() - 180.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn to_degrees(self) -> f64 {
// The division here is correctly rounded with respect to the true
// value of 180/π. (This differs from f32, where a constant must be
// used to ensure a correctly rounded result.)
self * (180.0f64 / consts::PI)
}
/// Converts degrees to radians.
///
/// ```
/// let angle = 180.0_f64;
///
/// let abs_difference = (angle.to_radians() - std::f64::consts::PI).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn to_radians(self) -> f64 {
let value: f64 = consts::PI;
self * (value / 180.0)
}
/// Returns the maximum of the two numbers.
///
/// ```
/// let x = 1.0_f64;
/// let y = 2.0_f64;
///
/// assert_eq!(x.max(y), y);
/// ```
///
/// If one of the arguments is NaN, then the other argument is returned.
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn max(self, other: f64) -> f64 {
intrinsics::maxnumf64(self, other)
}
/// Returns the minimum of the two numbers.
///
/// ```
/// let x = 1.0_f64;
/// let y = 2.0_f64;
///
/// assert_eq!(x.min(y), x);
/// ```
///
/// If one of the arguments is NaN, then the other argument is returned.
#[stable(feature = "rust1", since = "1.0.0")]
#[inline]
pub fn min(self, other: f64) -> f64 {
intrinsics::minnumf64(self, other)
}
/// 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::() };
/// assert_eq!(rounded, 4);
///
/// let value = -128.9_f64;
/// let rounded = unsafe { value.to_int_unchecked::() };
/// 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
#[stable(feature = "float_approx_unchecked_to", since = "1.44.0")]
#[inline]
pub unsafe fn to_int_unchecked(self) -> Int
where
Self: FloatToInt,
{
FloatToInt::::to_int_unchecked(self)
}
/// Raw transmutation to `u64`.
///
/// This is currently identical to `transmute::(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);
///
/// ```
#[stable(feature = "float_bits_conv", since = "1.20.0")]
#[inline]
pub fn to_bits(self) -> u64 {
// SAFETY: `u64` is a plain old datatype so we can always transmute to it
unsafe { mem::transmute(self) }
}
/// Raw transmutation from `u64`.
///
/// This is currently identical to `transmute::(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 favours 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.
///
/// # Examples
///
/// ```
/// let v = f64::from_bits(0x4029000000000000);
/// assert_eq!(v, 12.5);
/// ```
#[stable(feature = "float_bits_conv", since = "1.20.0")]
#[inline]
pub fn from_bits(v: u64) -> Self {
// SAFETY: `u64` is a plain old datatype so we can always transmute from it
// It turns out the safety issues with sNaN were overblown! Hooray!
unsafe { mem::transmute(v) }
}
/// Return the memory representation of this floating point number as a byte array in
/// big-endian (network) byte order.
///
/// # Examples
///
/// ```
/// let bytes = 12.5f64.to_be_bytes();
/// assert_eq!(bytes, [0x40, 0x29, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]);
/// ```
#[stable(feature = "float_to_from_bytes", since = "1.40.0")]
#[inline]
pub fn to_be_bytes(self) -> [u8; 8] {
self.to_bits().to_be_bytes()
}
/// Return the memory representation of this floating point number as a byte array in
/// little-endian byte order.
///
/// # Examples
///
/// ```
/// let bytes = 12.5f64.to_le_bytes();
/// assert_eq!(bytes, [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x29, 0x40]);
/// ```
#[stable(feature = "float_to_from_bytes", since = "1.40.0")]
#[inline]
pub fn to_le_bytes(self) -> [u8; 8] {
self.to_bits().to_le_bytes()
}
/// Return the memory representation of this floating point number as a byte array in
/// native byte order.
///
/// As the target platform's native endianness is used, portable code
/// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate, instead.
///
/// [`to_be_bytes`]: #method.to_be_bytes
/// [`to_le_bytes`]: #method.to_le_bytes
///
/// # 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]
/// }
/// );
/// ```
#[stable(feature = "float_to_from_bytes", since = "1.40.0")]
#[inline]
pub fn to_ne_bytes(self) -> [u8; 8] {
self.to_bits().to_ne_bytes()
}
/// Create a floating point value from its representation as a byte array in big endian.
///
/// # Examples
///
/// ```
/// let value = f64::from_be_bytes([0x40, 0x29, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]);
/// assert_eq!(value, 12.5);
/// ```
#[stable(feature = "float_to_from_bytes", since = "1.40.0")]
#[inline]
pub fn from_be_bytes(bytes: [u8; 8]) -> Self {
Self::from_bits(u64::from_be_bytes(bytes))
}
/// Create a floating point value from its representation as a byte array in little endian.
///
/// # Examples
///
/// ```
/// let value = f64::from_le_bytes([0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x29, 0x40]);
/// assert_eq!(value, 12.5);
/// ```
#[stable(feature = "float_to_from_bytes", since = "1.40.0")]
#[inline]
pub fn from_le_bytes(bytes: [u8; 8]) -> Self {
Self::from_bits(u64::from_le_bytes(bytes))
}
/// Create a floating point value from its representation as a byte array in native endian.
///
/// As the target platform's native endianness is used, portable code
/// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as
/// appropriate instead.
///
/// [`from_be_bytes`]: #method.from_be_bytes
/// [`from_le_bytes`]: #method.from_le_bytes
///
/// # 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);
/// ```
#[stable(feature = "float_to_from_bytes", since = "1.40.0")]
#[inline]
pub fn from_ne_bytes(bytes: [u8; 8]) -> Self {
Self::from_bits(u64::from_ne_bytes(bytes))
}
}