num-traits/src/traits.rs

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// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Numeric traits for generic mathematics
use std::ops::{Add, Sub, Mul, Div, Rem, Neg};
use std::ops::{Not, BitAnd, BitOr, BitXor, Shl, Shr};
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use std::{usize, u8, u16, u32, u64};
use std::{isize, i8, i16, i32, i64};
use std::{f32, f64};
use std::mem::{self, size_of};
use std::num::FpCategory;
/// The base trait for numeric types
pub trait Num: PartialEq + Zero + One
+ Add<Output = Self> + Sub<Output = Self>
+ Mul<Output = Self> + Div<Output = Self> + Rem<Output = Self>
{
/// Parse error for `from_str_radix`
type FromStrRadixErr;
/// Convert from a string and radix <= 36.
fn from_str_radix(str: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr>;
}
macro_rules! int_trait_impl {
($name:ident for $($t:ty)*) => ($(
impl $name for $t {
type FromStrRadixErr = ::std::num::ParseIntError;
fn from_str_radix(s: &str, radix: u32)
-> Result<Self, ::std::num::ParseIntError>
{
<$t>::from_str_radix(s, radix)
}
}
)*)
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}
macro_rules! float_trait_impl {
($name:ident for $($t:ty)*) => ($(
impl $name for $t {
type FromStrRadixErr = ::std::num::ParseFloatError;
fn from_str_radix(s: &str, radix: u32)
-> Result<Self, ::std::num::ParseFloatError>
{
<$t>::from_str_radix(s, radix)
}
}
)*)
}
int_trait_impl!(Num for usize u8 u16 u32 u64 isize i8 i16 i32 i64);
float_trait_impl!(Num for f32 f64);
/// Defines an additive identity element for `Self`.
///
/// # Deriving
///
/// This trait can be automatically be derived using `#[deriving(Zero)]`
/// attribute. If you choose to use this, make sure that the laws outlined in
/// the documentation for `Zero::zero` still hold.
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pub trait Zero: Add<Self, Output = Self> {
/// Returns the additive identity element of `Self`, `0`.
///
/// # Laws
///
/// ```{.text}
/// a + 0 = a ∀ a ∈ Self
/// 0 + a = a ∀ a ∈ Self
/// ```
///
/// # Purity
///
/// This function should return the same result at all times regardless of
/// external mutable state, for example values stored in TLS or in
/// `static mut`s.
// FIXME (#5527): This should be an associated constant
fn zero() -> Self;
/// Returns `true` if `self` is equal to the additive identity.
#[inline]
fn is_zero(&self) -> bool;
}
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macro_rules! zero_impl {
($t:ty, $v:expr) => {
impl Zero for $t {
#[inline]
fn zero() -> $t { $v }
#[inline]
fn is_zero(&self) -> bool { *self == $v }
}
}
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}
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zero_impl!(usize, 0usize);
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zero_impl!(u8, 0u8);
zero_impl!(u16, 0u16);
zero_impl!(u32, 0u32);
zero_impl!(u64, 0u64);
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zero_impl!(isize, 0isize);
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zero_impl!(i8, 0i8);
zero_impl!(i16, 0i16);
zero_impl!(i32, 0i32);
zero_impl!(i64, 0i64);
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zero_impl!(f32, 0.0f32);
zero_impl!(f64, 0.0f64);
/// Defines a multiplicative identity element for `Self`.
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pub trait One: Mul<Self, Output = Self> {
/// Returns the multiplicative identity element of `Self`, `1`.
///
/// # Laws
///
/// ```{.text}
/// a * 1 = a ∀ a ∈ Self
/// 1 * a = a ∀ a ∈ Self
/// ```
///
/// # Purity
///
/// This function should return the same result at all times regardless of
/// external mutable state, for example values stored in TLS or in
/// `static mut`s.
// FIXME (#5527): This should be an associated constant
fn one() -> Self;
}
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macro_rules! one_impl {
($t:ty, $v:expr) => {
impl One for $t {
#[inline]
fn one() -> $t { $v }
}
}
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}
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one_impl!(usize, 1usize);
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one_impl!(u8, 1u8);
one_impl!(u16, 1u16);
one_impl!(u32, 1u32);
one_impl!(u64, 1u64);
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one_impl!(isize, 1isize);
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one_impl!(i8, 1i8);
one_impl!(i16, 1i16);
one_impl!(i32, 1i32);
one_impl!(i64, 1i64);
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one_impl!(f32, 1.0f32);
one_impl!(f64, 1.0f64);
/// Useful functions for signed numbers (i.e. numbers that can be negative).
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pub trait Signed: Num + Neg<Output = Self> {
/// Computes the absolute value.
///
/// For `f32` and `f64`, `NaN` will be returned if the number is `NaN`.
///
/// For signed integers, `::MIN` will be returned if the number is `::MIN`.
fn abs(&self) -> Self;
/// The positive difference of two numbers.
///
/// Returns `zero` if the number is less than or equal to `other`, otherwise the difference
/// between `self` and `other` is returned.
fn abs_sub(&self, other: &Self) -> Self;
/// Returns the sign of the number.
///
/// For `f32` and `f64`:
///
/// * `1.0` if the number is positive, `+0.0` or `INFINITY`
/// * `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
/// * `NaN` if the number is `NaN`
///
/// For signed integers:
///
/// * `0` if the number is zero
/// * `1` if the number is positive
/// * `-1` if the number is negative
fn signum(&self) -> Self;
/// Returns true if the number is positive and false if the number is zero or negative.
fn is_positive(&self) -> bool;
/// Returns true if the number is negative and false if the number is zero or positive.
fn is_negative(&self) -> bool;
}
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macro_rules! signed_impl {
($($t:ty)*) => ($(
impl Signed for $t {
#[inline]
fn abs(&self) -> $t {
if self.is_negative() { -*self } else { *self }
}
#[inline]
fn abs_sub(&self, other: &$t) -> $t {
if *self <= *other { 0 } else { *self - *other }
}
#[inline]
fn signum(&self) -> $t {
match *self {
n if n > 0 => 1,
0 => 0,
_ => -1,
}
}
#[inline]
fn is_positive(&self) -> bool { *self > 0 }
#[inline]
fn is_negative(&self) -> bool { *self < 0 }
}
)*)
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}
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signed_impl!(isize i8 i16 i32 i64);
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macro_rules! signed_float_impl {
($t:ty, $nan:expr, $inf:expr, $neg_inf:expr) => {
impl Signed for $t {
/// Computes the absolute value. Returns `NAN` if the number is `NAN`.
#[inline]
fn abs(&self) -> $t {
<$t>::abs(*self)
}
/// The positive difference of two numbers. Returns `0.0` if the number is
/// less than or equal to `other`, otherwise the difference between`self`
/// and `other` is returned.
#[inline]
fn abs_sub(&self, other: &$t) -> $t {
<$t>::abs_sub(*self, *other)
}
/// # Returns
///
/// - `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
#[inline]
fn signum(&self) -> $t {
<$t>::signum(*self)
}
/// Returns `true` if the number is positive, including `+0.0` and `INFINITY`
#[inline]
fn is_positive(&self) -> bool { *self > 0.0 || (1.0 / *self) == $inf }
/// Returns `true` if the number is negative, including `-0.0` and `NEG_INFINITY`
#[inline]
fn is_negative(&self) -> bool { *self < 0.0 || (1.0 / *self) == $neg_inf }
}
}
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}
signed_float_impl!(f32, f32::NAN, f32::INFINITY, f32::NEG_INFINITY);
signed_float_impl!(f64, f64::NAN, f64::INFINITY, f64::NEG_INFINITY);
/// A trait for values which cannot be negative
pub trait Unsigned: Num {}
macro_rules! empty_trait_impl {
($name:ident for $($t:ty)*) => ($(
impl $name for $t {}
)*)
}
empty_trait_impl!(Unsigned for usize u8 u16 u32 u64);
/// Numbers which have upper and lower bounds
pub trait Bounded {
// FIXME (#5527): These should be associated constants
/// returns the smallest finite number this type can represent
fn min_value() -> Self;
/// returns the largest finite number this type can represent
fn max_value() -> Self;
}
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macro_rules! bounded_impl {
($t:ty, $min:expr, $max:expr) => {
impl Bounded for $t {
#[inline]
fn min_value() -> $t { $min }
#[inline]
fn max_value() -> $t { $max }
}
}
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}
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bounded_impl!(usize, usize::MIN, usize::MAX);
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bounded_impl!(u8, u8::MIN, u8::MAX);
bounded_impl!(u16, u16::MIN, u16::MAX);
bounded_impl!(u32, u32::MIN, u32::MAX);
bounded_impl!(u64, u64::MIN, u64::MAX);
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bounded_impl!(isize, isize::MIN, isize::MAX);
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bounded_impl!(i8, i8::MIN, i8::MAX);
bounded_impl!(i16, i16::MIN, i16::MAX);
bounded_impl!(i32, i32::MIN, i32::MAX);
bounded_impl!(i64, i64::MIN, i64::MAX);
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bounded_impl!(f32, f32::MIN, f32::MAX);
bounded_impl!(f64, f64::MIN, f64::MAX);
/// Saturating math operations
pub trait Saturating {
/// Saturating addition operator.
/// Returns a+b, saturating at the numeric bounds instead of overflowing.
fn saturating_add(self, v: Self) -> Self;
/// Saturating subtraction operator.
/// Returns a-b, saturating at the numeric bounds instead of overflowing.
fn saturating_sub(self, v: Self) -> Self;
}
impl<T: CheckedAdd + CheckedSub + Zero + PartialOrd + Bounded> Saturating for T {
#[inline]
fn saturating_add(self, v: T) -> T {
match self.checked_add(&v) {
Some(x) => x,
None => if v >= Zero::zero() {
Bounded::max_value()
} else {
Bounded::min_value()
}
}
}
#[inline]
fn saturating_sub(self, v: T) -> T {
match self.checked_sub(&v) {
Some(x) => x,
None => if v >= Zero::zero() {
Bounded::min_value()
} else {
Bounded::max_value()
}
}
}
}
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/// Performs addition that returns `None` instead of wrapping around on
/// overflow.
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pub trait CheckedAdd: Add<Self, Output = Self> {
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/// Adds two numbers, checking for overflow. If overflow happens, `None` is
/// returned.
fn checked_add(&self, v: &Self) -> Option<Self>;
}
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macro_rules! checked_impl {
($trait_name:ident, $method:ident, $t:ty) => {
impl $trait_name for $t {
#[inline]
fn $method(&self, v: &$t) -> Option<$t> {
<$t>::$method(*self, *v)
}
}
}
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}
checked_impl!(CheckedAdd, checked_add, u8);
checked_impl!(CheckedAdd, checked_add, u16);
checked_impl!(CheckedAdd, checked_add, u32);
checked_impl!(CheckedAdd, checked_add, u64);
checked_impl!(CheckedAdd, checked_add, usize);
checked_impl!(CheckedAdd, checked_add, i8);
checked_impl!(CheckedAdd, checked_add, i16);
checked_impl!(CheckedAdd, checked_add, i32);
checked_impl!(CheckedAdd, checked_add, i64);
checked_impl!(CheckedAdd, checked_add, isize);
/// Performs subtraction that returns `None` instead of wrapping around on underflow.
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pub trait CheckedSub: Sub<Self, Output = Self> {
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/// Subtracts two numbers, checking for underflow. If underflow happens,
/// `None` is returned.
fn checked_sub(&self, v: &Self) -> Option<Self>;
}
checked_impl!(CheckedSub, checked_sub, u8);
checked_impl!(CheckedSub, checked_sub, u16);
checked_impl!(CheckedSub, checked_sub, u32);
checked_impl!(CheckedSub, checked_sub, u64);
checked_impl!(CheckedSub, checked_sub, usize);
checked_impl!(CheckedSub, checked_sub, i8);
checked_impl!(CheckedSub, checked_sub, i16);
checked_impl!(CheckedSub, checked_sub, i32);
checked_impl!(CheckedSub, checked_sub, i64);
checked_impl!(CheckedSub, checked_sub, isize);
/// Performs multiplication that returns `None` instead of wrapping around on underflow or
/// overflow.
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pub trait CheckedMul: Mul<Self, Output = Self> {
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/// Multiplies two numbers, checking for underflow or overflow. If underflow
/// or overflow happens, `None` is returned.
fn checked_mul(&self, v: &Self) -> Option<Self>;
}
checked_impl!(CheckedMul, checked_mul, u8);
checked_impl!(CheckedMul, checked_mul, u16);
checked_impl!(CheckedMul, checked_mul, u32);
checked_impl!(CheckedMul, checked_mul, u64);
checked_impl!(CheckedMul, checked_mul, usize);
checked_impl!(CheckedMul, checked_mul, i8);
checked_impl!(CheckedMul, checked_mul, i16);
checked_impl!(CheckedMul, checked_mul, i32);
checked_impl!(CheckedMul, checked_mul, i64);
checked_impl!(CheckedMul, checked_mul, isize);
/// Performs division that returns `None` instead of panicking on division by zero and instead of
/// wrapping around on underflow and overflow.
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pub trait CheckedDiv: Div<Self, Output = Self> {
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/// Divides two numbers, checking for underflow, overflow and division by
/// zero. If any of that happens, `None` is returned.
fn checked_div(&self, v: &Self) -> Option<Self>;
}
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macro_rules! checkeddiv_int_impl {
($t:ty, $min:expr) => {
impl CheckedDiv for $t {
#[inline]
fn checked_div(&self, v: &$t) -> Option<$t> {
if *v == 0 || (*self == $min && *v == -1) {
None
} else {
Some(*self / *v)
}
}
}
}
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}
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checkeddiv_int_impl!(isize, isize::MIN);
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checkeddiv_int_impl!(i8, i8::MIN);
checkeddiv_int_impl!(i16, i16::MIN);
checkeddiv_int_impl!(i32, i32::MIN);
checkeddiv_int_impl!(i64, i64::MIN);
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macro_rules! checkeddiv_uint_impl {
($($t:ty)*) => ($(
impl CheckedDiv for $t {
#[inline]
fn checked_div(&self, v: &$t) -> Option<$t> {
if *v == 0 {
None
} else {
Some(*self / *v)
}
}
}
)*)
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}
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checkeddiv_uint_impl!(usize u8 u16 u32 u64);
pub trait PrimInt
: Sized
+ Copy
+ Num + NumCast
+ Bounded
+ PartialOrd + Ord + Eq
+ Not<Output=Self>
+ BitAnd<Output=Self>
+ BitOr<Output=Self>
+ BitXor<Output=Self>
+ Shl<usize, Output=Self>
+ Shr<usize, Output=Self>
+ CheckedAdd<Output=Self>
+ CheckedSub<Output=Self>
+ CheckedMul<Output=Self>
+ CheckedDiv<Output=Self>
+ Saturating
{
/// Returns the number of ones in the binary representation of `self`.
///
/// # Examples
///
/// ```
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/// use num::traits::PrimInt;
///
/// let n = 0b01001100u8;
///
/// assert_eq!(n.count_ones(), 3);
/// ```
fn count_ones(self) -> u32;
/// Returns the number of zeros in the binary representation of `self`.
///
/// # Examples
///
/// ```
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/// use num::traits::PrimInt;
///
/// let n = 0b01001100u8;
///
/// assert_eq!(n.count_zeros(), 5);
/// ```
fn count_zeros(self) -> u32;
/// Returns the number of leading zeros in the binary representation
/// of `self`.
///
/// # Examples
///
/// ```
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/// use num::traits::PrimInt;
///
/// let n = 0b0101000u16;
///
/// assert_eq!(n.leading_zeros(), 10);
/// ```
fn leading_zeros(self) -> u32;
/// Returns the number of trailing zeros in the binary representation
/// of `self`.
///
/// # Examples
///
/// ```
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/// use num::traits::PrimInt;
///
/// let n = 0b0101000u16;
///
/// assert_eq!(n.trailing_zeros(), 3);
/// ```
fn trailing_zeros(self) -> u32;
/// Shifts the bits to the left by a specified amount amount, `n`, wrapping
/// the truncated bits to the end of the resulting integer.
///
/// # Examples
///
/// ```
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/// use num::traits::PrimInt;
///
/// let n = 0x0123456789ABCDEFu64;
/// let m = 0x3456789ABCDEF012u64;
///
/// assert_eq!(n.rotate_left(12), m);
/// ```
fn rotate_left(self, n: u32) -> Self;
/// Shifts the bits to the right by a specified amount amount, `n`, wrapping
/// the truncated bits to the beginning of the resulting integer.
///
/// # Examples
///
/// ```
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/// use num::traits::PrimInt;
///
/// let n = 0x0123456789ABCDEFu64;
/// let m = 0xDEF0123456789ABCu64;
///
/// assert_eq!(n.rotate_right(12), m);
/// ```
fn rotate_right(self, n: u32) -> Self;
/// Reverses the byte order of the integer.
///
/// # Examples
///
/// ```
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/// use num::traits::PrimInt;
///
/// let n = 0x0123456789ABCDEFu64;
/// let m = 0xEFCDAB8967452301u64;
///
/// assert_eq!(n.swap_bytes(), m);
/// ```
fn swap_bytes(self) -> Self;
/// Convert an integer from big endian to the target's endianness.
///
/// On big endian this is a no-op. On little endian the bytes are swapped.
///
/// # Examples
///
/// ```
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/// use num::traits::PrimInt;
///
/// let n = 0x0123456789ABCDEFu64;
///
/// if cfg!(target_endian = "big") {
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/// assert_eq!(u64::from_be(n), n)
/// } else {
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/// assert_eq!(u64::from_be(n), n.swap_bytes())
/// }
/// ```
fn from_be(x: Self) -> Self;
/// Convert an integer from little endian to the target's endianness.
///
/// On little endian this is a no-op. On big endian the bytes are swapped.
///
/// # Examples
///
/// ```
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/// use num::traits::PrimInt;
///
/// let n = 0x0123456789ABCDEFu64;
///
/// if cfg!(target_endian = "little") {
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/// assert_eq!(u64::from_le(n), n)
/// } else {
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/// assert_eq!(u64::from_le(n), n.swap_bytes())
/// }
/// ```
fn from_le(x: Self) -> Self;
/// Convert `self` to big endian from the target's endianness.
///
/// On big endian this is a no-op. On little endian the bytes are swapped.
///
/// # Examples
///
/// ```
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/// use num::traits::PrimInt;
///
/// let n = 0x0123456789ABCDEFu64;
///
/// if cfg!(target_endian = "big") {
/// assert_eq!(n.to_be(), n)
/// } else {
/// assert_eq!(n.to_be(), n.swap_bytes())
/// }
/// ```
fn to_be(self) -> Self;
/// Convert `self` to little endian from the target's endianness.
///
/// On little endian this is a no-op. On big endian the bytes are swapped.
///
/// # Examples
///
/// ```
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/// use num::traits::PrimInt;
///
/// let n = 0x0123456789ABCDEFu64;
///
/// if cfg!(target_endian = "little") {
/// assert_eq!(n.to_le(), n)
/// } else {
/// assert_eq!(n.to_le(), n.swap_bytes())
/// }
/// ```
fn to_le(self) -> Self;
/// Raises self to the power of `exp`, using exponentiation by squaring.
///
/// # Examples
///
/// ```
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/// use num::traits::PrimInt;
///
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/// assert_eq!(2i32.pow(4), 16);
/// ```
fn pow(self, mut exp: u32) -> Self;
}
macro_rules! prim_int_impl {
($($T:ty)*) => ($(
impl PrimInt for $T {
fn min_value() -> Self {
<$T>::min_value()
}
fn max_value() -> Self {
<$T>::max_value()
}
fn count_ones(self) -> u32 {
<$T>::count_ones(self)
}
fn count_zeros(self) -> u32 {
<$T>::count_zeros(self)
}
fn leading_zeros(self) -> u32 {
<$T>::leading_zeros(self)
}
fn trailing_zeros(self) -> u32 {
<$T>::trailing_zeros(self)
}
fn rotate_left(self, n: u32) -> Self {
<$T>::rotate_left(self, n)
}
fn rotate_right(self, n: u32) -> Self {
<$T>::rotate_right(self, n)
}
fn swap_bytes(self) -> Self {
<$T>::swap_bytes(self)
}
fn from_be(x: Self) -> Self {
<$T>::from_be(x)
}
fn from_le(x: Self) -> Self {
<$T>::from_le(x)
}
fn to_be(self) -> Self {
<$T>::to_be(self)
}
fn to_le(self) -> Self {
<$T>::to_le(self)
}
fn pow(self, exp: u32) -> Self {
<$T>::pow(self, exp)
}
}
)*)
}
/// A generic trait for converting a value to a number.
pub trait ToPrimitive {
/// Converts the value of `self` to an `isize`.
#[inline]
fn to_isize(&self) -> Option<isize> {
self.to_i64().and_then(|x| x.to_isize())
}
/// Converts the value of `self` to an `i8`.
#[inline]
fn to_i8(&self) -> Option<i8> {
self.to_i64().and_then(|x| x.to_i8())
}
/// Converts the value of `self` to an `i16`.
#[inline]
fn to_i16(&self) -> Option<i16> {
self.to_i64().and_then(|x| x.to_i16())
}
/// Converts the value of `self` to an `i32`.
#[inline]
fn to_i32(&self) -> Option<i32> {
self.to_i64().and_then(|x| x.to_i32())
}
/// Converts the value of `self` to an `i64`.
fn to_i64(&self) -> Option<i64>;
/// Converts the value of `self` to a `usize`.
#[inline]
fn to_usize(&self) -> Option<usize> {
self.to_u64().and_then(|x| x.to_usize())
}
/// Converts the value of `self` to an `u8`.
#[inline]
fn to_u8(&self) -> Option<u8> {
self.to_u64().and_then(|x| x.to_u8())
}
/// Converts the value of `self` to an `u16`.
#[inline]
fn to_u16(&self) -> Option<u16> {
self.to_u64().and_then(|x| x.to_u16())
}
/// Converts the value of `self` to an `u32`.
#[inline]
fn to_u32(&self) -> Option<u32> {
self.to_u64().and_then(|x| x.to_u32())
}
/// Converts the value of `self` to an `u64`.
#[inline]
fn to_u64(&self) -> Option<u64>;
/// Converts the value of `self` to an `f32`.
#[inline]
fn to_f32(&self) -> Option<f32> {
self.to_f64().and_then(|x| x.to_f32())
}
/// Converts the value of `self` to an `f64`.
#[inline]
fn to_f64(&self) -> Option<f64> {
self.to_i64().and_then(|x| x.to_f64())
}
}
macro_rules! impl_to_primitive_int_to_int {
($SrcT:ty, $DstT:ty, $slf:expr) => (
{
if size_of::<$SrcT>() <= size_of::<$DstT>() {
Some($slf as $DstT)
} else {
let n = $slf as i64;
let min_value: $DstT = Bounded::min_value();
let max_value: $DstT = Bounded::max_value();
if min_value as i64 <= n && n <= max_value as i64 {
Some($slf as $DstT)
} else {
None
}
}
}
)
}
macro_rules! impl_to_primitive_int_to_uint {
($SrcT:ty, $DstT:ty, $slf:expr) => (
{
let zero: $SrcT = Zero::zero();
let max_value: $DstT = Bounded::max_value();
if zero <= $slf && $slf as u64 <= max_value as u64 {
Some($slf as $DstT)
} else {
None
}
}
)
}
macro_rules! impl_to_primitive_int {
($T:ty) => (
impl ToPrimitive for $T {
#[inline]
fn to_isize(&self) -> Option<isize> { impl_to_primitive_int_to_int!($T, isize, *self) }
#[inline]
fn to_i8(&self) -> Option<i8> { impl_to_primitive_int_to_int!($T, i8, *self) }
#[inline]
fn to_i16(&self) -> Option<i16> { impl_to_primitive_int_to_int!($T, i16, *self) }
#[inline]
fn to_i32(&self) -> Option<i32> { impl_to_primitive_int_to_int!($T, i32, *self) }
#[inline]
fn to_i64(&self) -> Option<i64> { impl_to_primitive_int_to_int!($T, i64, *self) }
#[inline]
fn to_usize(&self) -> Option<usize> { impl_to_primitive_int_to_uint!($T, usize, *self) }
#[inline]
fn to_u8(&self) -> Option<u8> { impl_to_primitive_int_to_uint!($T, u8, *self) }
#[inline]
fn to_u16(&self) -> Option<u16> { impl_to_primitive_int_to_uint!($T, u16, *self) }
#[inline]
fn to_u32(&self) -> Option<u32> { impl_to_primitive_int_to_uint!($T, u32, *self) }
#[inline]
fn to_u64(&self) -> Option<u64> { impl_to_primitive_int_to_uint!($T, u64, *self) }
#[inline]
fn to_f32(&self) -> Option<f32> { Some(*self as f32) }
#[inline]
fn to_f64(&self) -> Option<f64> { Some(*self as f64) }
}
)
}
impl_to_primitive_int! { isize }
impl_to_primitive_int! { i8 }
impl_to_primitive_int! { i16 }
impl_to_primitive_int! { i32 }
impl_to_primitive_int! { i64 }
macro_rules! impl_to_primitive_uint_to_int {
($DstT:ty, $slf:expr) => (
{
let max_value: $DstT = Bounded::max_value();
if $slf as u64 <= max_value as u64 {
Some($slf as $DstT)
} else {
None
}
}
)
}
macro_rules! impl_to_primitive_uint_to_uint {
($SrcT:ty, $DstT:ty, $slf:expr) => (
{
if size_of::<$SrcT>() <= size_of::<$DstT>() {
Some($slf as $DstT)
} else {
let zero: $SrcT = Zero::zero();
let max_value: $DstT = Bounded::max_value();
if zero <= $slf && $slf as u64 <= max_value as u64 {
Some($slf as $DstT)
} else {
None
}
}
}
)
}
macro_rules! impl_to_primitive_uint {
($T:ty) => (
impl ToPrimitive for $T {
#[inline]
fn to_isize(&self) -> Option<isize> { impl_to_primitive_uint_to_int!(isize, *self) }
#[inline]
fn to_i8(&self) -> Option<i8> { impl_to_primitive_uint_to_int!(i8, *self) }
#[inline]
fn to_i16(&self) -> Option<i16> { impl_to_primitive_uint_to_int!(i16, *self) }
#[inline]
fn to_i32(&self) -> Option<i32> { impl_to_primitive_uint_to_int!(i32, *self) }
#[inline]
fn to_i64(&self) -> Option<i64> { impl_to_primitive_uint_to_int!(i64, *self) }
#[inline]
fn to_usize(&self) -> Option<usize> {
impl_to_primitive_uint_to_uint!($T, usize, *self)
}
#[inline]
fn to_u8(&self) -> Option<u8> { impl_to_primitive_uint_to_uint!($T, u8, *self) }
#[inline]
fn to_u16(&self) -> Option<u16> { impl_to_primitive_uint_to_uint!($T, u16, *self) }
#[inline]
fn to_u32(&self) -> Option<u32> { impl_to_primitive_uint_to_uint!($T, u32, *self) }
#[inline]
fn to_u64(&self) -> Option<u64> { impl_to_primitive_uint_to_uint!($T, u64, *self) }
#[inline]
fn to_f32(&self) -> Option<f32> { Some(*self as f32) }
#[inline]
fn to_f64(&self) -> Option<f64> { Some(*self as f64) }
}
)
}
impl_to_primitive_uint! { usize }
impl_to_primitive_uint! { u8 }
impl_to_primitive_uint! { u16 }
impl_to_primitive_uint! { u32 }
impl_to_primitive_uint! { u64 }
macro_rules! impl_to_primitive_float_to_float {
($SrcT:ident, $DstT:ident, $slf:expr) => (
if size_of::<$SrcT>() <= size_of::<$DstT>() {
Some($slf as $DstT)
} else {
let n = $slf as f64;
let max_value: $SrcT = ::std::$SrcT::MAX;
if -max_value as f64 <= n && n <= max_value as f64 {
Some($slf as $DstT)
} else {
None
}
}
)
}
macro_rules! impl_to_primitive_float {
($T:ident) => (
impl ToPrimitive for $T {
#[inline]
fn to_isize(&self) -> Option<isize> { Some(*self as isize) }
#[inline]
fn to_i8(&self) -> Option<i8> { Some(*self as i8) }
#[inline]
fn to_i16(&self) -> Option<i16> { Some(*self as i16) }
#[inline]
fn to_i32(&self) -> Option<i32> { Some(*self as i32) }
#[inline]
fn to_i64(&self) -> Option<i64> { Some(*self as i64) }
#[inline]
fn to_usize(&self) -> Option<usize> { Some(*self as usize) }
#[inline]
fn to_u8(&self) -> Option<u8> { Some(*self as u8) }
#[inline]
fn to_u16(&self) -> Option<u16> { Some(*self as u16) }
#[inline]
fn to_u32(&self) -> Option<u32> { Some(*self as u32) }
#[inline]
fn to_u64(&self) -> Option<u64> { Some(*self as u64) }
#[inline]
fn to_f32(&self) -> Option<f32> { impl_to_primitive_float_to_float!($T, f32, *self) }
#[inline]
fn to_f64(&self) -> Option<f64> { impl_to_primitive_float_to_float!($T, f64, *self) }
}
)
}
impl_to_primitive_float! { f32 }
impl_to_primitive_float! { f64 }
/// A generic trait for converting a number to a value.
pub trait FromPrimitive: Sized {
/// Convert an `isize` to return an optional value of this type. If the
/// value cannot be represented by this value, the `None` is returned.
#[inline]
fn from_isize(n: isize) -> Option<Self> {
FromPrimitive::from_i64(n as i64)
}
/// Convert an `i8` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
#[inline]
fn from_i8(n: i8) -> Option<Self> {
FromPrimitive::from_i64(n as i64)
}
/// Convert an `i16` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
#[inline]
fn from_i16(n: i16) -> Option<Self> {
FromPrimitive::from_i64(n as i64)
}
/// Convert an `i32` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
#[inline]
fn from_i32(n: i32) -> Option<Self> {
FromPrimitive::from_i64(n as i64)
}
/// Convert an `i64` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
fn from_i64(n: i64) -> Option<Self>;
/// Convert a `usize` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
#[inline]
fn from_usize(n: usize) -> Option<Self> {
FromPrimitive::from_u64(n as u64)
}
/// Convert an `u8` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
#[inline]
fn from_u8(n: u8) -> Option<Self> {
FromPrimitive::from_u64(n as u64)
}
/// Convert an `u16` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
#[inline]
fn from_u16(n: u16) -> Option<Self> {
FromPrimitive::from_u64(n as u64)
}
/// Convert an `u32` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
#[inline]
fn from_u32(n: u32) -> Option<Self> {
FromPrimitive::from_u64(n as u64)
}
/// Convert an `u64` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
fn from_u64(n: u64) -> Option<Self>;
/// Convert a `f32` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
#[inline]
fn from_f32(n: f32) -> Option<Self> {
FromPrimitive::from_f64(n as f64)
}
/// Convert a `f64` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
#[inline]
fn from_f64(n: f64) -> Option<Self> {
FromPrimitive::from_i64(n as i64)
}
}
macro_rules! impl_from_primitive {
($T:ty, $to_ty:ident) => (
#[allow(deprecated)]
impl FromPrimitive for $T {
#[inline] fn from_i8(n: i8) -> Option<$T> { n.$to_ty() }
#[inline] fn from_i16(n: i16) -> Option<$T> { n.$to_ty() }
#[inline] fn from_i32(n: i32) -> Option<$T> { n.$to_ty() }
#[inline] fn from_i64(n: i64) -> Option<$T> { n.$to_ty() }
#[inline] fn from_u8(n: u8) -> Option<$T> { n.$to_ty() }
#[inline] fn from_u16(n: u16) -> Option<$T> { n.$to_ty() }
#[inline] fn from_u32(n: u32) -> Option<$T> { n.$to_ty() }
#[inline] fn from_u64(n: u64) -> Option<$T> { n.$to_ty() }
#[inline] fn from_f32(n: f32) -> Option<$T> { n.$to_ty() }
#[inline] fn from_f64(n: f64) -> Option<$T> { n.$to_ty() }
}
)
}
impl_from_primitive! { isize, to_isize }
impl_from_primitive! { i8, to_i8 }
impl_from_primitive! { i16, to_i16 }
impl_from_primitive! { i32, to_i32 }
impl_from_primitive! { i64, to_i64 }
impl_from_primitive! { usize, to_usize }
impl_from_primitive! { u8, to_u8 }
impl_from_primitive! { u16, to_u16 }
impl_from_primitive! { u32, to_u32 }
impl_from_primitive! { u64, to_u64 }
impl_from_primitive! { f32, to_f32 }
impl_from_primitive! { f64, to_f64 }
/// Cast from one machine scalar to another.
///
/// # Examples
///
/// ```
/// use num;
///
/// let twenty: f32 = num::traits::cast(0x14).unwrap();
/// assert_eq!(twenty, 20f32);
/// ```
///
#[inline]
pub fn cast<T: NumCast,U: NumCast>(n: T) -> Option<U> {
NumCast::from(n)
}
/// An interface for casting between machine scalars.
pub trait NumCast: ToPrimitive {
/// Creates a number from another value that can be converted into
/// a primitive via the `ToPrimitive` trait.
fn from<T: ToPrimitive>(n: T) -> Option<Self>;
}
macro_rules! impl_num_cast {
($T:ty, $conv:ident) => (
impl NumCast for $T {
#[inline]
#[allow(deprecated)]
fn from<N: ToPrimitive>(n: N) -> Option<$T> {
// `$conv` could be generated using `concat_idents!`, but that
// macro seems to be broken at the moment
n.$conv()
}
}
)
}
impl_num_cast! { u8, to_u8 }
impl_num_cast! { u16, to_u16 }
impl_num_cast! { u32, to_u32 }
impl_num_cast! { u64, to_u64 }
impl_num_cast! { usize, to_usize }
impl_num_cast! { i8, to_i8 }
impl_num_cast! { i16, to_i16 }
impl_num_cast! { i32, to_i32 }
impl_num_cast! { i64, to_i64 }
impl_num_cast! { isize, to_isize }
impl_num_cast! { f32, to_f32 }
impl_num_cast! { f64, to_f64 }
pub trait Float
: Num
+ Copy
+ NumCast
+ PartialOrd
+ Neg<Output = Self>
{
/// Returns the `NaN` value.
///
/// ```
/// use num::traits::Float;
///
/// let nan: f32 = Float::nan();
///
/// assert!(nan.is_nan());
/// ```
fn nan() -> Self;
/// Returns the infinite value.
///
/// ```
/// use num::traits::Float;
/// use std::f32;
///
/// let infinity: f32 = Float::infinity();
///
/// assert!(infinity.is_infinite());
/// assert!(!infinity.is_finite());
/// assert!(infinity > f32::MAX);
/// ```
fn infinity() -> Self;
/// Returns the negative infinite value.
///
/// ```
/// use num::traits::Float;
/// use std::f32;
///
/// let neg_infinity: f32 = Float::neg_infinity();
///
/// assert!(neg_infinity.is_infinite());
/// assert!(!neg_infinity.is_finite());
/// assert!(neg_infinity < f32::MIN);
/// ```
fn neg_infinity() -> Self;
/// Returns `-0.0`.
///
/// ```
/// use num::traits::{Zero, Float};
///
/// let inf: f32 = Float::infinity();
/// let zero: f32 = Zero::zero();
/// let neg_zero: f32 = Float::neg_zero();
///
/// assert_eq!(zero, neg_zero);
/// assert_eq!(7.0f32/inf, zero);
/// assert_eq!(zero * 10.0, zero);
/// ```
fn neg_zero() -> Self;
/// Returns the smallest finite value that this type can represent.
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let x: f64 = Float::min_value();
///
/// assert_eq!(x, f64::MIN);
/// ```
fn min_value() -> Self;
/// Returns the largest finite value that this type can represent.
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let x: f64 = Float::max_value();
/// assert_eq!(x, f64::MAX);
/// ```
fn max_value() -> Self;
/// Returns `true` if this value is `NaN` and false otherwise.
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let nan = f64::NAN;
/// let f = 7.0;
///
/// assert!(nan.is_nan());
/// assert!(!f.is_nan());
/// ```
fn is_nan(self) -> bool;
/// Returns `true` if this value is positive infinity or negative infinity and
/// false otherwise.
///
/// ```
/// use num::traits::Float;
/// use std::f32;
///
/// let f = 7.0f32;
/// let inf: f32 = Float::infinity();
/// let neg_inf: f32 = Float::neg_infinity();
/// let nan: f32 = f32::NAN;
///
/// assert!(!f.is_infinite());
/// assert!(!nan.is_infinite());
///
/// assert!(inf.is_infinite());
/// assert!(neg_inf.is_infinite());
/// ```
fn is_infinite(self) -> bool;
/// Returns `true` if this number is neither infinite nor `NaN`.
///
/// ```
/// use num::traits::Float;
/// use std::f32;
///
/// let f = 7.0f32;
/// let inf: f32 = Float::infinity();
/// let neg_inf: f32 = Float::neg_infinity();
/// let nan: f32 = f32::NAN;
///
/// assert!(f.is_finite());
///
/// assert!(!nan.is_finite());
/// assert!(!inf.is_finite());
/// assert!(!neg_inf.is_finite());
/// ```
fn is_finite(self) -> bool;
/// Returns `true` if the number is neither zero, infinite,
/// [subnormal][subnormal], or `NaN`.
///
/// ```
/// use num::traits::Float;
/// use std::f32;
///
/// let min = f32::MIN_POSITIVE; // 1.17549435e-38f32
/// let max = f32::MAX;
/// let lower_than_min = 1.0e-40_f32;
/// let zero = 0.0f32;
///
/// assert!(min.is_normal());
/// assert!(max.is_normal());
///
/// assert!(!zero.is_normal());
/// assert!(!f32::NAN.is_normal());
/// assert!(!f32::INFINITY.is_normal());
/// // Values between `0` and `min` are Subnormal.
/// assert!(!lower_than_min.is_normal());
/// ```
/// [subnormal]: http://en.wikipedia.org/wiki/Denormal_number
fn is_normal(self) -> bool;
/// 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.
///
/// ```
/// # #![feature(core)]
/// use std::num::{Float, FpCategory};
/// use std::f32;
///
/// let num = 12.4f32;
/// let inf = f32::INFINITY;
///
/// assert_eq!(num.classify(), FpCategory::Normal);
/// assert_eq!(inf.classify(), FpCategory::Infinite);
/// ```
fn classify(self) -> FpCategory;
/// Returns the largest integer less than or equal to a number.
///
/// ```
/// use num::traits::Float;
///
/// let f = 3.99;
/// let g = 3.0;
///
/// assert_eq!(f.floor(), 3.0);
/// assert_eq!(g.floor(), 3.0);
/// ```
fn floor(self) -> Self;
/// Returns the smallest integer greater than or equal to a number.
///
/// ```
/// use num::traits::Float;
///
/// let f = 3.01;
/// let g = 4.0;
///
/// assert_eq!(f.ceil(), 4.0);
/// assert_eq!(g.ceil(), 4.0);
/// ```
fn ceil(self) -> Self;
/// Returns the nearest integer to a number. Round half-way cases away from
/// `0.0`.
///
/// ```
/// use num::traits::Float;
///
/// let f = 3.3;
/// let g = -3.3;
///
/// assert_eq!(f.round(), 3.0);
/// assert_eq!(g.round(), -3.0);
/// ```
fn round(self) -> Self;
/// Return the integer part of a number.
///
/// ```
/// use num::traits::Float;
///
/// let f = 3.3;
/// let g = -3.7;
///
/// assert_eq!(f.trunc(), 3.0);
/// assert_eq!(g.trunc(), -3.0);
/// ```
fn trunc(self) -> Self;
/// Returns the fractional part of a number.
///
/// ```
/// use num::traits::Float;
///
/// let x = 3.5;
/// let y = -3.5;
/// let abs_difference_x = (x.fract() - 0.5).abs();
/// let abs_difference_y = (y.fract() - (-0.5)).abs();
///
/// assert!(abs_difference_x < 1e-10);
/// assert!(abs_difference_y < 1e-10);
/// ```
fn fract(self) -> Self;
/// Computes the absolute value of `self`. Returns `Float::nan()` if the
/// number is `Float::nan()`.
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let x = 3.5;
/// let y = -3.5;
///
/// let abs_difference_x = (x.abs() - x).abs();
/// let abs_difference_y = (y.abs() - (-y)).abs();
///
/// assert!(abs_difference_x < 1e-10);
/// assert!(abs_difference_y < 1e-10);
///
/// assert!(f64::NAN.abs().is_nan());
/// ```
fn abs(self) -> Self;
/// Returns a number that represents the sign of `self`.
///
/// - `1.0` if the number is positive, `+0.0` or `Float::infinity()`
/// - `-1.0` if the number is negative, `-0.0` or `Float::neg_infinity()`
/// - `Float::nan()` if the number is `Float::nan()`
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let f = 3.5;
///
/// assert_eq!(f.signum(), 1.0);
/// assert_eq!(f64::NEG_INFINITY.signum(), -1.0);
///
/// assert!(f64::NAN.signum().is_nan());
/// ```
fn signum(self) -> Self;
/// Returns `true` if `self` is positive, including `+0.0` and
/// `Float::infinity()`.
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let nan: f64 = f64::NAN;
///
/// let f = 7.0;
/// let g = -7.0;
///
/// assert!(f.is_sign_positive());
/// assert!(!g.is_sign_positive());
/// // Requires both tests to determine if is `NaN`
/// assert!(!nan.is_sign_positive() && !nan.is_sign_negative());
/// ```
fn is_sign_positive(self) -> bool;
/// Returns `true` if `self` is negative, including `-0.0` and
/// `Float::neg_infinity()`.
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let nan = f64::NAN;
///
/// let f = 7.0;
/// let g = -7.0;
///
/// assert!(!f.is_sign_negative());
/// assert!(g.is_sign_negative());
/// // Requires both tests to determine if is `NaN`.
/// assert!(!nan.is_sign_positive() && !nan.is_sign_negative());
/// ```
fn is_sign_negative(self) -> bool;
/// Fused multiply-add. Computes `(self * a) + b` with only one rounding
/// error. This produces a more accurate result with better performance than
/// a separate multiplication operation followed by an add.
///
/// ```
/// use num::traits::Float;
///
/// let m = 10.0;
/// let x = 4.0;
/// let b = 60.0;
///
/// // 100.0
/// let abs_difference = (m.mul_add(x, b) - (m*x + b)).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn mul_add(self, a: Self, b: Self) -> Self;
/// Take the reciprocal (inverse) of a number, `1/x`.
///
/// ```
/// use num::traits::Float;
///
/// let x = 2.0;
/// let abs_difference = (x.recip() - (1.0/x)).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn recip(self) -> Self;
/// Raise a number to an integer power.
///
/// Using this function is generally faster than using `powf`
///
/// ```
/// use num::traits::Float;
///
/// let x = 2.0;
/// let abs_difference = (x.powi(2) - x*x).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn powi(self, n: i32) -> Self;
/// Raise a number to a floating point power.
///
/// ```
/// use num::traits::Float;
///
/// let x = 2.0;
/// let abs_difference = (x.powf(2.0) - x*x).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn powf(self, n: Self) -> Self;
/// Take the square root of a number.
///
/// Returns NaN if `self` is a negative number.
///
/// ```
/// use num::traits::Float;
///
/// let positive = 4.0;
/// let negative = -4.0;
///
/// let abs_difference = (positive.sqrt() - 2.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// assert!(negative.sqrt().is_nan());
/// ```
fn sqrt(self) -> Self;
/// Returns `e^(self)`, (the exponential function).
///
/// ```
/// use num::traits::Float;
///
/// let one = 1.0;
/// // e^1
/// let e = one.exp();
///
/// // ln(e) - 1 == 0
/// let abs_difference = (e.ln() - 1.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn exp(self) -> Self;
/// Returns `2^(self)`.
///
/// ```
/// use num::traits::Float;
///
/// let f = 2.0;
///
/// // 2^2 - 4 == 0
/// let abs_difference = (f.exp2() - 4.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn exp2(self) -> Self;
/// Returns the natural logarithm of the number.
///
/// ```
/// use num::traits::Float;
///
/// let one = 1.0;
/// // e^1
/// let e = one.exp();
///
/// // ln(e) - 1 == 0
/// let abs_difference = (e.ln() - 1.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn ln(self) -> Self;
/// Returns the logarithm of the number with respect to an arbitrary base.
///
/// ```
/// use num::traits::Float;
///
/// let ten = 10.0;
/// let two = 2.0;
///
/// // log10(10) - 1 == 0
/// let abs_difference_10 = (ten.log(10.0) - 1.0).abs();
///
/// // log2(2) - 1 == 0
/// let abs_difference_2 = (two.log(2.0) - 1.0).abs();
///
/// assert!(abs_difference_10 < 1e-10);
/// assert!(abs_difference_2 < 1e-10);
/// ```
fn log(self, base: Self) -> Self;
/// Returns the base 2 logarithm of the number.
///
/// ```
/// use num::traits::Float;
///
/// let two = 2.0;
///
/// // log2(2) - 1 == 0
/// let abs_difference = (two.log2() - 1.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn log2(self) -> Self;
/// Returns the base 10 logarithm of the number.
///
/// ```
/// use num::traits::Float;
///
/// let ten = 10.0;
///
/// // log10(10) - 1 == 0
/// let abs_difference = (ten.log10() - 1.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn log10(self) -> Self;
/// Returns the maximum of the two numbers.
///
/// ```
/// use num::traits::Float;
///
/// let x = 1.0;
/// let y = 2.0;
///
/// assert_eq!(x.max(y), y);
/// ```
fn max(self, other: Self) -> Self;
/// Returns the minimum of the two numbers.
///
/// ```
/// use num::traits::Float;
///
/// let x = 1.0;
/// let y = 2.0;
///
/// assert_eq!(x.min(y), x);
/// ```
fn min(self, other: Self) -> Self;
/// The positive difference of two numbers.
///
/// * If `self <= other`: `0:0`
/// * Else: `self - other`
///
/// ```
/// use num::traits::Float;
///
/// let x = 3.0;
/// let y = -3.0;
///
/// let abs_difference_x = (x.abs_sub(1.0) - 2.0).abs();
/// let abs_difference_y = (y.abs_sub(1.0) - 0.0).abs();
///
/// assert!(abs_difference_x < 1e-10);
/// assert!(abs_difference_y < 1e-10);
/// ```
fn abs_sub(self, other: Self) -> Self;
/// Take the cubic root of a number.
///
/// ```
/// use num::traits::Float;
///
/// let x = 8.0;
///
/// // x^(1/3) - 2 == 0
/// let abs_difference = (x.cbrt() - 2.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn cbrt(self) -> Self;
/// Calculate the length of the hypotenuse of a right-angle triangle given
/// legs of length `x` and `y`.
///
/// ```
/// use num::traits::Float;
///
/// let x = 2.0;
/// let y = 3.0;
///
/// // sqrt(x^2 + y^2)
/// let abs_difference = (x.hypot(y) - (x.powi(2) + y.powi(2)).sqrt()).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn hypot(self, other: Self) -> Self;
/// Computes the sine of a number (in radians).
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let x = f64::consts::PI/2.0;
///
/// let abs_difference = (x.sin() - 1.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn sin(self) -> Self;
/// Computes the cosine of a number (in radians).
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let x = 2.0*f64::consts::PI;
///
/// let abs_difference = (x.cos() - 1.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn cos(self) -> Self;
/// Computes the tangent of a number (in radians).
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let x = f64::consts::PI/4.0;
/// let abs_difference = (x.tan() - 1.0).abs();
///
/// assert!(abs_difference < 1e-14);
/// ```
fn tan(self) -> Self;
/// Computes the arcsine of a number. Return value is in radians in
/// the range [-pi/2, pi/2] or NaN if the number is outside the range
/// [-1, 1].
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let f = f64::consts::PI / 2.0;
///
/// // asin(sin(pi/2))
/// let abs_difference = (f.sin().asin() - f64::consts::PI / 2.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn asin(self) -> Self;
/// Computes the arccosine of a number. Return value is in radians in
/// the range [0, pi] or NaN if the number is outside the range
/// [-1, 1].
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let f = f64::consts::PI / 4.0;
///
/// // acos(cos(pi/4))
/// let abs_difference = (f.cos().acos() - f64::consts::PI / 4.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn acos(self) -> Self;
/// Computes the arctangent of a number. Return value is in radians in the
/// range [-pi/2, pi/2];
///
/// ```
/// use num::traits::Float;
///
/// let f = 1.0;
///
/// // atan(tan(1))
/// let abs_difference = (f.tan().atan() - 1.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn atan(self) -> Self;
/// Computes the four quadrant arctangent of `self` (`y`) and `other` (`x`).
///
/// * `x = 0`, `y = 0`: `0`
/// * `x >= 0`: `arctan(y/x)` -> `[-pi/2, pi/2]`
/// * `y >= 0`: `arctan(y/x) + pi` -> `(pi/2, pi]`
/// * `y < 0`: `arctan(y/x) - pi` -> `(-pi, -pi/2)`
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let pi = f64::consts::PI;
/// // All angles from horizontal right (+x)
/// // 45 deg counter-clockwise
/// let x1 = 3.0;
/// let y1 = -3.0;
///
/// // 135 deg clockwise
/// let x2 = -3.0;
/// let y2 = 3.0;
///
/// let abs_difference_1 = (y1.atan2(x1) - (-pi/4.0)).abs();
/// let abs_difference_2 = (y2.atan2(x2) - 3.0*pi/4.0).abs();
///
/// assert!(abs_difference_1 < 1e-10);
/// assert!(abs_difference_2 < 1e-10);
/// ```
fn atan2(self, other: Self) -> Self;
/// Simultaneously computes the sine and cosine of the number, `x`. Returns
/// `(sin(x), cos(x))`.
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let x = f64::consts::PI/4.0;
/// let f = x.sin_cos();
///
/// let abs_difference_0 = (f.0 - x.sin()).abs();
/// let abs_difference_1 = (f.1 - x.cos()).abs();
///
/// assert!(abs_difference_0 < 1e-10);
/// assert!(abs_difference_0 < 1e-10);
/// ```
fn sin_cos(self) -> (Self, Self);
/// Returns `e^(self) - 1` in a way that is accurate even if the
/// number is close to zero.
///
/// ```
/// use num::traits::Float;
///
/// let x = 7.0;
///
/// // e^(ln(7)) - 1
/// let abs_difference = (x.ln().exp_m1() - 6.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn exp_m1(self) -> Self;
/// Returns `ln(1+n)` (natural logarithm) more accurately than if
/// the operations were performed separately.
///
/// ```
/// # #![feature(std_misc, core)]
/// use num::traits::Float;
/// use std::f64;
///
/// let x = f64::consts::E - 1.0;
///
/// // ln(1 + (e - 1)) == ln(e) == 1
/// let abs_difference = (x.ln_1p() - 1.0).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn ln_1p(self) -> Self;
/// Hyperbolic sine function.
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let e = f64::consts::E;
/// let x = 1.0;
///
/// let f = x.sinh();
/// // Solving sinh() at 1 gives `(e^2-1)/(2e)`
/// let g = (e*e - 1.0)/(2.0*e);
/// let abs_difference = (f - g).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
fn sinh(self) -> Self;
/// Hyperbolic cosine function.
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let e = f64::consts::E;
/// let x = 1.0;
/// let f = x.cosh();
/// // Solving cosh() at 1 gives this result
/// let g = (e*e + 1.0)/(2.0*e);
/// let abs_difference = (f - g).abs();
///
/// // Same result
/// assert!(abs_difference < 1.0e-10);
/// ```
fn cosh(self) -> Self;
/// Hyperbolic tangent function.
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let e = f64::consts::E;
/// let x = 1.0;
///
/// let f = x.tanh();
/// // Solving tanh() at 1 gives `(1 - e^(-2))/(1 + e^(-2))`
/// let g = (1.0 - e.powi(-2))/(1.0 + e.powi(-2));
/// let abs_difference = (f - g).abs();
///
/// assert!(abs_difference < 1.0e-10);
/// ```
fn tanh(self) -> Self;
/// Inverse hyperbolic sine function.
///
/// ```
/// use num::traits::Float;
///
/// let x = 1.0;
/// let f = x.sinh().asinh();
///
/// let abs_difference = (f - x).abs();
///
/// assert!(abs_difference < 1.0e-10);
/// ```
fn asinh(self) -> Self;
/// Inverse hyperbolic cosine function.
///
/// ```
/// use num::traits::Float;
///
/// let x = 1.0;
/// let f = x.cosh().acosh();
///
/// let abs_difference = (f - x).abs();
///
/// assert!(abs_difference < 1.0e-10);
/// ```
fn acosh(self) -> Self;
/// Inverse hyperbolic tangent function.
///
/// ```
/// use num::traits::Float;
/// use std::f64;
///
/// let e = f64::consts::E;
/// let f = e.tanh().atanh();
///
/// let abs_difference = (f - e).abs();
///
/// assert!(abs_difference < 1.0e-10);
/// ```
fn atanh(self) -> Self;
/// Returns the mantissa, base 2 exponent, and sign as integers, respectively.
/// The original number can be recovered by `sign * mantissa * 2 ^ exponent`.
/// The floating point encoding is documented in the [Reference][floating-point].
///
/// ```
2015-04-03 17:26:37 +00:00
/// use num::traits::Float;
///
/// let num = 2.0f32;
///
/// // (8388608, -22, 1)
2015-04-03 17:26:37 +00:00
/// let (mantissa, exponent, sign) = Float::integer_decode(num);
/// let sign_f = sign as f32;
/// let mantissa_f = mantissa as f32;
/// let exponent_f = num.powf(exponent as f32);
///
/// // 1 * 8388608 * 2^(-22) == 2
/// let abs_difference = (sign_f * mantissa_f * exponent_f - num).abs();
///
/// assert!(abs_difference < 1e-10);
/// ```
/// [floating-point]: ../../../../../reference.html#machine-types
fn integer_decode(self) -> (u64, i16, i8);
}
macro_rules! float_impl {
($T:ident $decode:ident) => (
impl Float for $T {
fn nan() -> Self {
::std::$T::NAN
}
fn infinity() -> Self {
::std::$T::INFINITY
}
fn neg_infinity() -> Self {
::std::$T::NEG_INFINITY
}
fn neg_zero() -> Self {
-0.0
}
fn min_value() -> Self {
::std::$T::MIN
}
fn max_value() -> Self {
::std::$T::MAX
}
fn is_nan(self) -> bool {
<$T>::is_nan(self)
}
fn is_infinite(self) -> bool {
<$T>::is_infinite(self)
}
fn is_finite(self) -> bool {
<$T>::is_finite(self)
}
fn is_normal(self) -> bool {
<$T>::is_normal(self)
}
fn classify(self) -> FpCategory {
<$T>::classify(self)
}
fn floor(self) -> Self {
<$T>::floor(self)
}
fn ceil(self) -> Self {
<$T>::ceil(self)
}
fn round(self) -> Self {
<$T>::round(self)
}
fn trunc(self) -> Self {
<$T>::trunc(self)
}
fn fract(self) -> Self {
<$T>::fract(self)
}
fn abs(self) -> Self {
<$T>::abs(self)
}
fn signum(self) -> Self {
<$T>::signum(self)
}
fn is_sign_positive(self) -> bool {
<$T>::is_sign_positive(self)
}
fn is_sign_negative(self) -> bool {
<$T>::is_sign_negative(self)
}
fn mul_add(self, a: Self, b: Self) -> Self {
<$T>::mul_add(self, a, b)
}
fn recip(self) -> Self {
<$T>::recip(self)
}
fn powi(self, n: i32) -> Self {
<$T>::powi(self, n)
}
fn powf(self, n: Self) -> Self {
<$T>::powf(self, n)
}
fn sqrt(self) -> Self {
<$T>::sqrt(self)
}
fn exp(self) -> Self {
<$T>::exp(self)
}
fn exp2(self) -> Self {
<$T>::exp2(self)
}
fn ln(self) -> Self {
<$T>::ln(self)
}
fn log(self, base: Self) -> Self {
<$T>::log(self, base)
}
fn log2(self) -> Self {
<$T>::log2(self)
}
fn log10(self) -> Self {
<$T>::log10(self)
}
fn max(self, other: Self) -> Self {
<$T>::max(self, other)
}
fn min(self, other: Self) -> Self {
<$T>::min(self, other)
}
fn abs_sub(self, other: Self) -> Self {
<$T>::abs_sub(self, other)
}
fn cbrt(self) -> Self {
<$T>::cbrt(self)
}
fn hypot(self, other: Self) -> Self {
<$T>::hypot(self, other)
}
fn sin(self) -> Self {
<$T>::sin(self)
}
fn cos(self) -> Self {
<$T>::cos(self)
}
fn tan(self) -> Self {
<$T>::tan(self)
}
fn asin(self) -> Self {
<$T>::asin(self)
}
fn acos(self) -> Self {
<$T>::acos(self)
}
fn atan(self) -> Self {
<$T>::atan(self)
}
fn atan2(self, other: Self) -> Self {
<$T>::atan2(self, other)
}
fn sin_cos(self) -> (Self, Self) {
<$T>::sin_cos(self)
}
fn exp_m1(self) -> Self {
<$T>::exp_m1(self)
}
fn ln_1p(self) -> Self {
<$T>::ln_1p(self)
}
fn sinh(self) -> Self {
<$T>::sinh(self)
}
fn cosh(self) -> Self {
<$T>::cosh(self)
}
fn tanh(self) -> Self {
<$T>::tanh(self)
}
fn asinh(self) -> Self {
<$T>::asinh(self)
}
fn acosh(self) -> Self {
<$T>::acosh(self)
}
fn atanh(self) -> Self {
<$T>::atanh(self)
}
fn integer_decode(self) -> (u64, i16, i8) {
$decode(self)
}
}
)
}
fn integer_decode_f32(f: f32) -> (u64, i16, i8) {
let bits: u32 = unsafe { mem::transmute(f) };
let sign: i8 = if bits >> 31 == 0 { 1 } else { -1 };
let mut exponent: i16 = ((bits >> 23) & 0xff) as i16;
let mantissa = if exponent == 0 {
(bits & 0x7fffff) << 1
} else {
(bits & 0x7fffff) | 0x800000
};
// Exponent bias + mantissa shift
exponent -= 127 + 23;
(mantissa as u64, exponent, sign)
}
fn integer_decode_f64(f: f64) -> (u64, i16, i8) {
let bits: u64 = unsafe { mem::transmute(f) };
let sign: i8 = if bits >> 63 == 0 { 1 } else { -1 };
let mut exponent: i16 = ((bits >> 52) & 0x7ff) as i16;
let mantissa = if exponent == 0 {
(bits & 0xfffffffffffff) << 1
} else {
(bits & 0xfffffffffffff) | 0x10000000000000
};
// Exponent bias + mantissa shift
exponent -= 1023 + 52;
(mantissa, exponent, sign)
}
float_impl!(f32 integer_decode_f32);
float_impl!(f64 integer_decode_f64);