rust/src/libstd/num/mod.rs
2014-04-04 20:32:50 -04:00

1787 lines
60 KiB
Rust

// Copyright 2012-2014 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 and functions for generic mathematics
//!
//! These are implemented for the primitive numeric types in `std::{u8, u16,
//! u32, u64, uint, i8, i16, i32, i64, int, f32, f64, float}`.
#![allow(missing_doc)]
use clone::Clone;
use cmp::{Eq, Ord};
use kinds::Copy;
use mem::size_of;
use ops::{Add, Sub, Mul, Div, Rem, Neg};
use ops::{Not, BitAnd, BitOr, BitXor, Shl, Shr};
use option::{Option, Some, None};
use fmt::{Show, Binary, Octal, LowerHex, UpperHex};
pub mod strconv;
/// The base trait for numeric types
pub trait Num: Eq + Zero + One
+ Neg<Self>
+ Add<Self,Self>
+ Sub<Self,Self>
+ Mul<Self,Self>
+ Div<Self,Self>
+ Rem<Self,Self> {}
/// Simultaneous division and remainder
#[inline]
pub fn div_rem<T: Div<T, T> + Rem<T, T>>(x: T, y: T) -> (T, T) {
(x / y, x % y)
}
/// 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.
pub trait Zero: Add<Self, Self> {
/// Returns the additive identity element of `Self`, `0`.
///
/// # Laws
///
/// ~~~notrust
/// 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.
fn is_zero(&self) -> bool;
}
/// Returns the additive identity, `0`.
#[inline(always)] pub fn zero<T: Zero>() -> T { Zero::zero() }
/// Defines a multiplicative identity element for `Self`.
pub trait One: Mul<Self, Self> {
/// Returns the multiplicative identity element of `Self`, `1`.
///
/// # Laws
///
/// ~~~notrust
/// 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;
}
/// Returns the multiplicative identity, `1`.
#[inline(always)] pub fn one<T: One>() -> T { One::one() }
/// Useful functions for signed numbers (i.e. numbers that can be negative).
pub trait Signed: Num + Neg<Self> {
/// Computes the absolute value.
///
/// For float, f32, and f64, `NaN` will be returned if the number is `NaN`.
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 `float`, `f32`, `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 `int`:
/// * `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;
}
/// Computes the absolute value.
///
/// For float, f32, and f64, `NaN` will be returned if the number is `NaN`
#[inline(always)]
pub fn abs<T: Signed>(value: T) -> T {
value.abs()
}
/// 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.
#[inline(always)]
pub fn abs_sub<T: Signed>(x: T, y: T) -> T {
x.abs_sub(&y)
}
/// Returns the sign of the number.
///
/// For float, f32, 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 int:
/// - `0` if the number is zero
/// - `1` if the number is positive
/// - `-1` if the number is negative
#[inline(always)] pub fn signum<T: Signed>(value: T) -> T { value.signum() }
pub trait Unsigned: Num {}
/// A collection of rounding operations.
pub trait Round {
/// Return the largest integer less than or equal to a number.
fn floor(&self) -> Self;
/// Return the smallest integer greater than or equal to a number.
fn ceil(&self) -> Self;
/// Return the nearest integer to a number. Round half-way cases away from
/// `0.0`.
fn round(&self) -> Self;
/// Return the integer part of a number.
fn trunc(&self) -> Self;
/// Return the fractional part of a number.
fn fract(&self) -> Self;
}
/// Raises a value to the power of exp, using exponentiation by squaring.
///
/// # Example
///
/// ```rust
/// use std::num;
///
/// assert_eq!(num::pow(2, 4), 16);
/// ```
#[inline]
pub fn pow<T: One + Mul<T, T>>(mut base: T, mut exp: uint) -> T {
if exp == 1 { base }
else {
let mut acc = one::<T>();
while exp > 0 {
if (exp & 1) == 1 {
acc = acc * base;
}
base = base * base;
exp = exp >> 1;
}
acc
}
}
pub trait Bounded {
// FIXME (#5527): These should be associated constants
fn min_value() -> Self;
fn max_value() -> Self;
}
/// Numbers with a fixed binary representation.
pub trait Bitwise: Bounded
+ Not<Self>
+ BitAnd<Self,Self>
+ BitOr<Self,Self>
+ BitXor<Self,Self>
+ Shl<Self,Self>
+ Shr<Self,Self> {
/// Returns the number of ones in the binary representation of the number.
///
/// # Example
///
/// ```rust
/// use std::num::Bitwise;
///
/// let n = 0b01001100u8;
/// assert_eq!(n.count_ones(), 3);
/// ```
fn count_ones(&self) -> Self;
/// Returns the number of zeros in the binary representation of the number.
///
/// # Example
///
/// ```rust
/// use std::num::Bitwise;
///
/// let n = 0b01001100u8;
/// assert_eq!(n.count_zeros(), 5);
/// ```
#[inline]
fn count_zeros(&self) -> Self {
(!*self).count_ones()
}
/// Returns the number of leading zeros in the in the binary representation
/// of the number.
///
/// # Example
///
/// ```rust
/// use std::num::Bitwise;
///
/// let n = 0b0101000u16;
/// assert_eq!(n.leading_zeros(), 10);
/// ```
fn leading_zeros(&self) -> Self;
/// Returns the number of trailing zeros in the in the binary representation
/// of the number.
///
/// # Example
///
/// ```rust
/// use std::num::Bitwise;
///
/// let n = 0b0101000u16;
/// assert_eq!(n.trailing_zeros(), 3);
/// ```
fn trailing_zeros(&self) -> Self;
}
/// Specifies the available operations common to all of Rust's core numeric primitives.
/// These may not always make sense from a purely mathematical point of view, but
/// may be useful for systems programming.
pub trait Primitive: Copy
+ Clone
+ Num
+ NumCast
+ Ord
+ Bounded {}
/// A collection of traits relevant to primitive signed and unsigned integers
pub trait Int: Primitive
+ Bitwise
+ CheckedAdd
+ CheckedSub
+ CheckedMul
+ CheckedDiv
+ Show
+ Binary
+ Octal
+ LowerHex
+ UpperHex {}
/// Returns the smallest power of 2 greater than or equal to `n`.
#[inline]
pub fn next_power_of_two<T: Unsigned + Int>(n: T) -> T {
let halfbits: T = cast(size_of::<T>() * 4).unwrap();
let mut tmp: T = n - one();
let mut shift: T = one();
while shift <= halfbits {
tmp = tmp | (tmp >> shift);
shift = shift << one();
}
tmp + one()
}
/// Returns the smallest power of 2 greater than or equal to `n`. If the next
/// power of two is greater than the type's maximum value, `None` is returned,
/// otherwise the power of 2 is wrapped in `Some`.
#[inline]
pub fn checked_next_power_of_two<T: Unsigned + Int>(n: T) -> Option<T> {
let halfbits: T = cast(size_of::<T>() * 4).unwrap();
let mut tmp: T = n - one();
let mut shift: T = one();
while shift <= halfbits {
tmp = tmp | (tmp >> shift);
shift = shift << one();
}
tmp.checked_add(&one())
}
/// Used for representing the classification of floating point numbers
#[deriving(Eq, Show)]
pub enum FPCategory {
/// "Not a Number", often obtained by dividing by zero
FPNaN,
/// Positive or negative infinity
FPInfinite ,
/// Positive or negative zero
FPZero,
/// De-normalized floating point representation (less precise than `FPNormal`)
FPSubnormal,
/// A regular floating point number
FPNormal,
}
/// Operations on primitive floating point numbers.
// FIXME(#5527): In a future version of Rust, many of these functions will
// become constants.
//
// FIXME(#8888): Several of these functions have a parameter named
// `unused_self`. Removing it requires #8888 to be fixed.
pub trait Float: Signed + Round + Primitive {
/// Returns the maximum of the two numbers.
fn max(self, other: Self) -> Self;
/// Returns the minimum of the two numbers.
fn min(self, other: Self) -> Self;
/// Returns the NaN value.
fn nan() -> Self;
/// Returns the infinite value.
fn infinity() -> Self;
/// Returns the negative infinite value.
fn neg_infinity() -> Self;
/// Returns -0.0.
fn neg_zero() -> Self;
/// Returns true if this value is NaN and false otherwise.
fn is_nan(&self) -> bool;
/// Returns true if this value is positive infinity or negative infinity and false otherwise.
fn is_infinite(&self) -> bool;
/// Returns true if this number is neither infinite nor NaN.
fn is_finite(&self) -> bool;
/// Returns true if this number is neither zero, infinite, denormal, or NaN.
fn is_normal(&self) -> bool;
/// Returns the category that this number falls into.
fn classify(&self) -> FPCategory;
/// Returns the number of binary digits of mantissa that this type supports.
fn mantissa_digits(unused_self: Option<Self>) -> uint;
/// Returns the number of binary digits of exponent that this type supports.
fn digits(unused_self: Option<Self>) -> uint;
/// Returns the smallest positive number that this type can represent.
fn epsilon() -> Self;
/// Returns the minimum binary exponent that this type can represent.
fn min_exp(unused_self: Option<Self>) -> int;
/// Returns the maximum binary exponent that this type can represent.
fn max_exp(unused_self: Option<Self>) -> int;
/// Returns the minimum base-10 exponent that this type can represent.
fn min_10_exp(unused_self: Option<Self>) -> int;
/// Returns the maximum base-10 exponent that this type can represent.
fn max_10_exp(unused_self: Option<Self>) -> int;
/// Constructs a floating point number created by multiplying `x` by 2 raised to the power of
/// `exp`.
fn ldexp(x: Self, exp: int) -> Self;
/// Breaks the number into a normalized fraction and a base-2 exponent, satisfying:
///
/// * `self = x * pow(2, exp)`
///
/// * `0.5 <= abs(x) < 1.0`
fn frexp(&self) -> (Self, int);
/// Returns the exponential of the number, minus 1, in a way that is accurate even if the
/// number is close to zero.
fn exp_m1(&self) -> Self;
/// Returns the natural logarithm of the number plus 1 (`ln(1+n)`) more accurately than if the
/// operations were performed separately.
fn ln_1p(&self) -> Self;
/// 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.
fn mul_add(&self, a: Self, b: Self) -> Self;
/// Returns the next representable floating-point value in the direction of `other`.
fn next_after(&self, other: Self) -> Self;
/// Returns the mantissa, exponent and sign as integers, respectively.
fn integer_decode(&self) -> (u64, i16, i8);
/// Archimedes' constant.
fn pi() -> Self;
/// 2.0 * pi.
fn two_pi() -> Self;
/// pi / 2.0.
fn frac_pi_2() -> Self;
/// pi / 3.0.
fn frac_pi_3() -> Self;
/// pi / 4.0.
fn frac_pi_4() -> Self;
/// pi / 6.0.
fn frac_pi_6() -> Self;
/// pi / 8.0.
fn frac_pi_8() -> Self;
/// 1.0 / pi.
fn frac_1_pi() -> Self;
/// 2.0 / pi.
fn frac_2_pi() -> Self;
/// 2.0 / sqrt(pi).
fn frac_2_sqrtpi() -> Self;
/// sqrt(2.0).
fn sqrt2() -> Self;
/// 1.0 / sqrt(2.0).
fn frac_1_sqrt2() -> Self;
/// Euler's number.
fn e() -> Self;
/// log2(e).
fn log2_e() -> Self;
/// log10(e).
fn log10_e() -> Self;
/// ln(2.0).
fn ln_2() -> Self;
/// ln(10.0).
fn ln_10() -> Self;
/// Take the reciprocal (inverse) of a number, `1/x`.
fn recip(&self) -> Self;
/// Raise a number to a power.
fn powf(&self, n: &Self) -> Self;
/// Raise a number to an integer power.
///
/// Using this function is generally faster than using `powf`
fn powi(&self, n: i32) -> Self;
/// Take the square root of a number.
fn sqrt(&self) -> Self;
/// Take the reciprocal (inverse) square root of a number, `1/sqrt(x)`.
fn rsqrt(&self) -> Self;
/// Take the cubic root of a number.
fn cbrt(&self) -> Self;
/// Calculate the length of the hypotenuse of a right-angle triangle given
/// legs of length `x` and `y`.
fn hypot(&self, other: &Self) -> Self;
/// Computes the sine of a number (in radians).
fn sin(&self) -> Self;
/// Computes the cosine of a number (in radians).
fn cos(&self) -> Self;
/// Computes the tangent of a number (in radians).
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].
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].
fn acos(&self) -> Self;
/// Computes the arctangent of a number. Return value is in radians in the
/// range [-pi/2, pi/2];
fn atan(&self) -> Self;
/// Computes the four quadrant arctangent of a number, `y`, and another
/// number `x`. Return value is in radians in the range [-pi, pi].
fn atan2(&self, other: &Self) -> Self;
/// Simultaneously computes the sine and cosine of the number, `x`. Returns
/// `(sin(x), cos(x))`.
fn sin_cos(&self) -> (Self, Self);
/// Returns `e^(self)`, (the exponential function).
fn exp(&self) -> Self;
/// Returns 2 raised to the power of the number, `2^(self)`.
fn exp2(&self) -> Self;
/// Returns the natural logarithm of the number.
fn ln(&self) -> Self;
/// Returns the logarithm of the number with respect to an arbitrary base.
fn log(&self, base: &Self) -> Self;
/// Returns the base 2 logarithm of the number.
fn log2(&self) -> Self;
/// Returns the base 10 logarithm of the number.
fn log10(&self) -> Self;
/// Hyperbolic sine function.
fn sinh(&self) -> Self;
/// Hyperbolic cosine function.
fn cosh(&self) -> Self;
/// Hyperbolic tangent function.
fn tanh(&self) -> Self;
/// Inverse hyperbolic sine function.
fn asinh(&self) -> Self;
/// Inverse hyperbolic cosine function.
fn acosh(&self) -> Self;
/// Inverse hyperbolic tangent function.
fn atanh(&self) -> Self;
/// Convert radians to degrees.
fn to_degrees(&self) -> Self;
/// Convert degrees to radians.
fn to_radians(&self) -> Self;
}
/// A generic trait for converting a value to a number.
pub trait ToPrimitive {
/// Converts the value of `self` to an `int`.
#[inline]
fn to_int(&self) -> Option<int> {
self.to_i64().and_then(|x| x.to_int())
}
/// 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 an `uint`.
#[inline]
fn to_uint(&self) -> Option<uint> {
self.to_u64().and_then(|x| x.to_uint())
}
/// 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, $DstT:ty) => (
{
if size_of::<$SrcT>() <= size_of::<$DstT>() {
Some(*self as $DstT)
} else {
let n = *self 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(*self as $DstT)
} else {
None
}
}
}
)
)
macro_rules! impl_to_primitive_int_to_uint(
($SrcT:ty, $DstT:ty) => (
{
let zero: $SrcT = Zero::zero();
let max_value: $DstT = Bounded::max_value();
if zero <= *self && *self as u64 <= max_value as u64 {
Some(*self as $DstT)
} else {
None
}
}
)
)
macro_rules! impl_to_primitive_int(
($T:ty) => (
impl ToPrimitive for $T {
#[inline]
fn to_int(&self) -> Option<int> { impl_to_primitive_int_to_int!($T, int) }
#[inline]
fn to_i8(&self) -> Option<i8> { impl_to_primitive_int_to_int!($T, i8) }
#[inline]
fn to_i16(&self) -> Option<i16> { impl_to_primitive_int_to_int!($T, i16) }
#[inline]
fn to_i32(&self) -> Option<i32> { impl_to_primitive_int_to_int!($T, i32) }
#[inline]
fn to_i64(&self) -> Option<i64> { impl_to_primitive_int_to_int!($T, i64) }
#[inline]
fn to_uint(&self) -> Option<uint> { impl_to_primitive_int_to_uint!($T, uint) }
#[inline]
fn to_u8(&self) -> Option<u8> { impl_to_primitive_int_to_uint!($T, u8) }
#[inline]
fn to_u16(&self) -> Option<u16> { impl_to_primitive_int_to_uint!($T, u16) }
#[inline]
fn to_u32(&self) -> Option<u32> { impl_to_primitive_int_to_uint!($T, u32) }
#[inline]
fn to_u64(&self) -> Option<u64> { impl_to_primitive_int_to_uint!($T, u64) }
#[inline]
fn to_f32(&self) -> Option<f32> { Some(*self as f32) }
#[inline]
fn to_f64(&self) -> Option<f64> { Some(*self as f64) }
}
)
)
impl_to_primitive_int!(int)
impl_to_primitive_int!(i8)
impl_to_primitive_int!(i16)
impl_to_primitive_int!(i32)
impl_to_primitive_int!(i64)
macro_rules! impl_to_primitive_uint_to_int(
($DstT:ty) => (
{
let max_value: $DstT = Bounded::max_value();
if *self as u64 <= max_value as u64 {
Some(*self as $DstT)
} else {
None
}
}
)
)
macro_rules! impl_to_primitive_uint_to_uint(
($SrcT:ty, $DstT:ty) => (
{
if size_of::<$SrcT>() <= size_of::<$DstT>() {
Some(*self as $DstT)
} else {
let zero: $SrcT = Zero::zero();
let max_value: $DstT = Bounded::max_value();
if zero <= *self && *self as u64 <= max_value as u64 {
Some(*self as $DstT)
} else {
None
}
}
}
)
)
macro_rules! impl_to_primitive_uint(
($T:ty) => (
impl ToPrimitive for $T {
#[inline]
fn to_int(&self) -> Option<int> { impl_to_primitive_uint_to_int!(int) }
#[inline]
fn to_i8(&self) -> Option<i8> { impl_to_primitive_uint_to_int!(i8) }
#[inline]
fn to_i16(&self) -> Option<i16> { impl_to_primitive_uint_to_int!(i16) }
#[inline]
fn to_i32(&self) -> Option<i32> { impl_to_primitive_uint_to_int!(i32) }
#[inline]
fn to_i64(&self) -> Option<i64> { impl_to_primitive_uint_to_int!(i64) }
#[inline]
fn to_uint(&self) -> Option<uint> { impl_to_primitive_uint_to_uint!($T, uint) }
#[inline]
fn to_u8(&self) -> Option<u8> { impl_to_primitive_uint_to_uint!($T, u8) }
#[inline]
fn to_u16(&self) -> Option<u16> { impl_to_primitive_uint_to_uint!($T, u16) }
#[inline]
fn to_u32(&self) -> Option<u32> { impl_to_primitive_uint_to_uint!($T, u32) }
#[inline]
fn to_u64(&self) -> Option<u64> { impl_to_primitive_uint_to_uint!($T, u64) }
#[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!(uint)
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:ty, $DstT:ty) => (
if size_of::<$SrcT>() <= size_of::<$DstT>() {
Some(*self as $DstT)
} else {
let n = *self as f64;
let max_value: $SrcT = Bounded::max_value();
if -max_value as f64 <= n && n <= max_value as f64 {
Some(*self as $DstT)
} else {
None
}
}
)
)
macro_rules! impl_to_primitive_float(
($T:ty) => (
impl ToPrimitive for $T {
#[inline]
fn to_int(&self) -> Option<int> { Some(*self as int) }
#[inline]
fn to_i8(&self) -> Option<i8> { Some(*self as i8) }
#[inline]
fn to_i16(&self) -> Option<i16> { Some(*self as i16) }
#[inline]
fn to_i32(&self) -> Option<i32> { Some(*self as i32) }
#[inline]
fn to_i64(&self) -> Option<i64> { Some(*self as i64) }
#[inline]
fn to_uint(&self) -> Option<uint> { Some(*self as uint) }
#[inline]
fn to_u8(&self) -> Option<u8> { Some(*self as u8) }
#[inline]
fn to_u16(&self) -> Option<u16> { Some(*self as u16) }
#[inline]
fn to_u32(&self) -> Option<u32> { Some(*self as u32) }
#[inline]
fn to_u64(&self) -> Option<u64> { Some(*self as u64) }
#[inline]
fn to_f32(&self) -> Option<f32> { impl_to_primitive_float_to_float!($T, f32) }
#[inline]
fn to_f64(&self) -> Option<f64> { impl_to_primitive_float_to_float!($T, f64) }
}
)
)
impl_to_primitive_float!(f32)
impl_to_primitive_float!(f64)
/// A generic trait for converting a number to a value.
pub trait FromPrimitive {
/// Convert an `int` to return an optional value of this type. If the
/// value cannot be represented by this value, the `None` is returned.
#[inline]
fn from_int(n: int) -> 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 an `uint` to return an optional value of this type. If the
/// type cannot be represented by this value, the `None` is returned.
#[inline]
fn from_uint(n: uint) -> 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)
}
}
/// A utility function that just calls `FromPrimitive::from_int`.
pub fn from_int<A: FromPrimitive>(n: int) -> Option<A> {
FromPrimitive::from_int(n)
}
/// A utility function that just calls `FromPrimitive::from_i8`.
pub fn from_i8<A: FromPrimitive>(n: i8) -> Option<A> {
FromPrimitive::from_i8(n)
}
/// A utility function that just calls `FromPrimitive::from_i16`.
pub fn from_i16<A: FromPrimitive>(n: i16) -> Option<A> {
FromPrimitive::from_i16(n)
}
/// A utility function that just calls `FromPrimitive::from_i32`.
pub fn from_i32<A: FromPrimitive>(n: i32) -> Option<A> {
FromPrimitive::from_i32(n)
}
/// A utility function that just calls `FromPrimitive::from_i64`.
pub fn from_i64<A: FromPrimitive>(n: i64) -> Option<A> {
FromPrimitive::from_i64(n)
}
/// A utility function that just calls `FromPrimitive::from_uint`.
pub fn from_uint<A: FromPrimitive>(n: uint) -> Option<A> {
FromPrimitive::from_uint(n)
}
/// A utility function that just calls `FromPrimitive::from_u8`.
pub fn from_u8<A: FromPrimitive>(n: u8) -> Option<A> {
FromPrimitive::from_u8(n)
}
/// A utility function that just calls `FromPrimitive::from_u16`.
pub fn from_u16<A: FromPrimitive>(n: u16) -> Option<A> {
FromPrimitive::from_u16(n)
}
/// A utility function that just calls `FromPrimitive::from_u32`.
pub fn from_u32<A: FromPrimitive>(n: u32) -> Option<A> {
FromPrimitive::from_u32(n)
}
/// A utility function that just calls `FromPrimitive::from_u64`.
pub fn from_u64<A: FromPrimitive>(n: u64) -> Option<A> {
FromPrimitive::from_u64(n)
}
/// A utility function that just calls `FromPrimitive::from_f32`.
pub fn from_f32<A: FromPrimitive>(n: f32) -> Option<A> {
FromPrimitive::from_f32(n)
}
/// A utility function that just calls `FromPrimitive::from_f64`.
pub fn from_f64<A: FromPrimitive>(n: f64) -> Option<A> {
FromPrimitive::from_f64(n)
}
macro_rules! impl_from_primitive(
($T:ty, $to_ty:expr) => (
impl FromPrimitive for $T {
#[inline] fn from_int(n: int) -> Option<$T> { $to_ty }
#[inline] fn from_i8(n: i8) -> Option<$T> { $to_ty }
#[inline] fn from_i16(n: i16) -> Option<$T> { $to_ty }
#[inline] fn from_i32(n: i32) -> Option<$T> { $to_ty }
#[inline] fn from_i64(n: i64) -> Option<$T> { $to_ty }
#[inline] fn from_uint(n: uint) -> Option<$T> { $to_ty }
#[inline] fn from_u8(n: u8) -> Option<$T> { $to_ty }
#[inline] fn from_u16(n: u16) -> Option<$T> { $to_ty }
#[inline] fn from_u32(n: u32) -> Option<$T> { $to_ty }
#[inline] fn from_u64(n: u64) -> Option<$T> { $to_ty }
#[inline] fn from_f32(n: f32) -> Option<$T> { $to_ty }
#[inline] fn from_f64(n: f64) -> Option<$T> { $to_ty }
}
)
)
impl_from_primitive!(int, n.to_int())
impl_from_primitive!(i8, n.to_i8())
impl_from_primitive!(i16, n.to_i16())
impl_from_primitive!(i32, n.to_i32())
impl_from_primitive!(i64, n.to_i64())
impl_from_primitive!(uint, n.to_uint())
impl_from_primitive!(u8, n.to_u8())
impl_from_primitive!(u16, n.to_u16())
impl_from_primitive!(u32, n.to_u32())
impl_from_primitive!(u64, n.to_u64())
impl_from_primitive!(f32, n.to_f32())
impl_from_primitive!(f64, n.to_f64())
/// Cast from one machine scalar to another.
///
/// # Example
///
/// ```
/// use std::num;
///
/// let twenty: f32 = num::cast(0x14).unwrap();
/// assert_eq!(twenty, 20f32);
/// ```
///
#[inline]
pub fn cast<T: NumCast,U: NumCast>(n: T) -> Option<U> {
NumCast::from(n)
}
/// An interface for casting between machine scalars.
pub trait NumCast: ToPrimitive {
/// Creates a number from another value that can be converted into a primitive via the
/// `ToPrimitive` trait.
fn from<T: ToPrimitive>(n: T) -> Option<Self>;
}
macro_rules! impl_num_cast(
($T:ty, $conv:ident) => (
impl NumCast for $T {
#[inline]
fn from<N: ToPrimitive>(n: N) -> Option<$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!(uint, to_uint)
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!(int, to_int)
impl_num_cast!(f32, to_f32)
impl_num_cast!(f64, to_f64)
pub trait ToStrRadix {
fn to_str_radix(&self, radix: uint) -> ~str;
}
pub trait FromStrRadix {
fn from_str_radix(str: &str, radix: uint) -> Option<Self>;
}
/// A utility function that just calls FromStrRadix::from_str_radix.
pub fn from_str_radix<T: FromStrRadix>(str: &str, radix: uint) -> Option<T> {
FromStrRadix::from_str_radix(str, radix)
}
/// 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 + Ord + 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()
}
}
}
}
/// Performs addition that returns `None` instead of wrapping around on overflow.
pub trait CheckedAdd: Add<Self, Self> {
/// Adds two numbers, checking for overflow. If overflow happens, `None` is returned.
fn checked_add(&self, v: &Self) -> Option<Self>;
}
/// Performs subtraction that returns `None` instead of wrapping around on underflow.
pub trait CheckedSub: Sub<Self, Self> {
/// Subtracts two numbers, checking for underflow. If underflow happens, `None` is returned.
fn checked_sub(&self, v: &Self) -> Option<Self>;
}
/// Performs multiplication that returns `None` instead of wrapping around on underflow or
/// overflow.
pub trait CheckedMul: Mul<Self, Self> {
/// Multiplies two numbers, checking for underflow or overflow. If underflow or overflow
/// happens, `None` is returned.
fn checked_mul(&self, v: &Self) -> Option<Self>;
}
/// Performs division that returns `None` instead of wrapping around on underflow or overflow.
pub trait CheckedDiv: Div<Self, Self> {
/// Divides two numbers, checking for underflow or overflow. If underflow or overflow happens,
/// `None` is returned.
fn checked_div(&self, v: &Self) -> Option<Self>;
}
/// Helper function for testing numeric operations
#[cfg(test)]
pub fn test_num<T:Num + NumCast + Show>(ten: T, two: T) {
assert_eq!(ten.add(&two), cast(12).unwrap());
assert_eq!(ten.sub(&two), cast(8).unwrap());
assert_eq!(ten.mul(&two), cast(20).unwrap());
assert_eq!(ten.div(&two), cast(5).unwrap());
assert_eq!(ten.rem(&two), cast(0).unwrap());
assert_eq!(ten.add(&two), ten + two);
assert_eq!(ten.sub(&two), ten - two);
assert_eq!(ten.mul(&two), ten * two);
assert_eq!(ten.div(&two), ten / two);
assert_eq!(ten.rem(&two), ten % two);
}
#[cfg(test)]
mod tests {
use prelude::*;
use super::*;
use i8;
use i16;
use i32;
use i64;
use int;
use u8;
use u16;
use u32;
use u64;
use uint;
macro_rules! test_cast_20(
($_20:expr) => ({
let _20 = $_20;
assert_eq!(20u, _20.to_uint().unwrap());
assert_eq!(20u8, _20.to_u8().unwrap());
assert_eq!(20u16, _20.to_u16().unwrap());
assert_eq!(20u32, _20.to_u32().unwrap());
assert_eq!(20u64, _20.to_u64().unwrap());
assert_eq!(20i, _20.to_int().unwrap());
assert_eq!(20i8, _20.to_i8().unwrap());
assert_eq!(20i16, _20.to_i16().unwrap());
assert_eq!(20i32, _20.to_i32().unwrap());
assert_eq!(20i64, _20.to_i64().unwrap());
assert_eq!(20f32, _20.to_f32().unwrap());
assert_eq!(20f64, _20.to_f64().unwrap());
assert_eq!(_20, NumCast::from(20u).unwrap());
assert_eq!(_20, NumCast::from(20u8).unwrap());
assert_eq!(_20, NumCast::from(20u16).unwrap());
assert_eq!(_20, NumCast::from(20u32).unwrap());
assert_eq!(_20, NumCast::from(20u64).unwrap());
assert_eq!(_20, NumCast::from(20i).unwrap());
assert_eq!(_20, NumCast::from(20i8).unwrap());
assert_eq!(_20, NumCast::from(20i16).unwrap());
assert_eq!(_20, NumCast::from(20i32).unwrap());
assert_eq!(_20, NumCast::from(20i64).unwrap());
assert_eq!(_20, NumCast::from(20f32).unwrap());
assert_eq!(_20, NumCast::from(20f64).unwrap());
assert_eq!(_20, cast(20u).unwrap());
assert_eq!(_20, cast(20u8).unwrap());
assert_eq!(_20, cast(20u16).unwrap());
assert_eq!(_20, cast(20u32).unwrap());
assert_eq!(_20, cast(20u64).unwrap());
assert_eq!(_20, cast(20i).unwrap());
assert_eq!(_20, cast(20i8).unwrap());
assert_eq!(_20, cast(20i16).unwrap());
assert_eq!(_20, cast(20i32).unwrap());
assert_eq!(_20, cast(20i64).unwrap());
assert_eq!(_20, cast(20f32).unwrap());
assert_eq!(_20, cast(20f64).unwrap());
})
)
#[test] fn test_u8_cast() { test_cast_20!(20u8) }
#[test] fn test_u16_cast() { test_cast_20!(20u16) }
#[test] fn test_u32_cast() { test_cast_20!(20u32) }
#[test] fn test_u64_cast() { test_cast_20!(20u64) }
#[test] fn test_uint_cast() { test_cast_20!(20u) }
#[test] fn test_i8_cast() { test_cast_20!(20i8) }
#[test] fn test_i16_cast() { test_cast_20!(20i16) }
#[test] fn test_i32_cast() { test_cast_20!(20i32) }
#[test] fn test_i64_cast() { test_cast_20!(20i64) }
#[test] fn test_int_cast() { test_cast_20!(20i) }
#[test] fn test_f32_cast() { test_cast_20!(20f32) }
#[test] fn test_f64_cast() { test_cast_20!(20f64) }
#[test]
fn test_cast_range_int_min() {
assert_eq!(int::MIN.to_int(), Some(int::MIN as int));
assert_eq!(int::MIN.to_i8(), None);
assert_eq!(int::MIN.to_i16(), None);
// int::MIN.to_i32() is word-size specific
assert_eq!(int::MIN.to_i64(), Some(int::MIN as i64));
assert_eq!(int::MIN.to_uint(), None);
assert_eq!(int::MIN.to_u8(), None);
assert_eq!(int::MIN.to_u16(), None);
assert_eq!(int::MIN.to_u32(), None);
assert_eq!(int::MIN.to_u64(), None);
#[cfg(target_word_size = "32")]
fn check_word_size() {
assert_eq!(int::MIN.to_i32(), Some(int::MIN as i32));
}
#[cfg(target_word_size = "64")]
fn check_word_size() {
assert_eq!(int::MIN.to_i32(), None);
}
check_word_size();
}
#[test]
fn test_cast_range_i8_min() {
assert_eq!(i8::MIN.to_int(), Some(i8::MIN as int));
assert_eq!(i8::MIN.to_i8(), Some(i8::MIN as i8));
assert_eq!(i8::MIN.to_i16(), Some(i8::MIN as i16));
assert_eq!(i8::MIN.to_i32(), Some(i8::MIN as i32));
assert_eq!(i8::MIN.to_i64(), Some(i8::MIN as i64));
assert_eq!(i8::MIN.to_uint(), None);
assert_eq!(i8::MIN.to_u8(), None);
assert_eq!(i8::MIN.to_u16(), None);
assert_eq!(i8::MIN.to_u32(), None);
assert_eq!(i8::MIN.to_u64(), None);
}
#[test]
fn test_cast_range_i16_min() {
assert_eq!(i16::MIN.to_int(), Some(i16::MIN as int));
assert_eq!(i16::MIN.to_i8(), None);
assert_eq!(i16::MIN.to_i16(), Some(i16::MIN as i16));
assert_eq!(i16::MIN.to_i32(), Some(i16::MIN as i32));
assert_eq!(i16::MIN.to_i64(), Some(i16::MIN as i64));
assert_eq!(i16::MIN.to_uint(), None);
assert_eq!(i16::MIN.to_u8(), None);
assert_eq!(i16::MIN.to_u16(), None);
assert_eq!(i16::MIN.to_u32(), None);
assert_eq!(i16::MIN.to_u64(), None);
}
#[test]
fn test_cast_range_i32_min() {
assert_eq!(i32::MIN.to_int(), Some(i32::MIN as int));
assert_eq!(i32::MIN.to_i8(), None);
assert_eq!(i32::MIN.to_i16(), None);
assert_eq!(i32::MIN.to_i32(), Some(i32::MIN as i32));
assert_eq!(i32::MIN.to_i64(), Some(i32::MIN as i64));
assert_eq!(i32::MIN.to_uint(), None);
assert_eq!(i32::MIN.to_u8(), None);
assert_eq!(i32::MIN.to_u16(), None);
assert_eq!(i32::MIN.to_u32(), None);
assert_eq!(i32::MIN.to_u64(), None);
}
#[test]
fn test_cast_range_i64_min() {
// i64::MIN.to_int() is word-size specific
assert_eq!(i64::MIN.to_i8(), None);
assert_eq!(i64::MIN.to_i16(), None);
assert_eq!(i64::MIN.to_i32(), None);
assert_eq!(i64::MIN.to_i64(), Some(i64::MIN as i64));
assert_eq!(i64::MIN.to_uint(), None);
assert_eq!(i64::MIN.to_u8(), None);
assert_eq!(i64::MIN.to_u16(), None);
assert_eq!(i64::MIN.to_u32(), None);
assert_eq!(i64::MIN.to_u64(), None);
#[cfg(target_word_size = "32")]
fn check_word_size() {
assert_eq!(i64::MIN.to_int(), None);
}
#[cfg(target_word_size = "64")]
fn check_word_size() {
assert_eq!(i64::MIN.to_int(), Some(i64::MIN as int));
}
check_word_size();
}
#[test]
fn test_cast_range_int_max() {
assert_eq!(int::MAX.to_int(), Some(int::MAX as int));
assert_eq!(int::MAX.to_i8(), None);
assert_eq!(int::MAX.to_i16(), None);
// int::MAX.to_i32() is word-size specific
assert_eq!(int::MAX.to_i64(), Some(int::MAX as i64));
assert_eq!(int::MAX.to_u8(), None);
assert_eq!(int::MAX.to_u16(), None);
// int::MAX.to_u32() is word-size specific
assert_eq!(int::MAX.to_u64(), Some(int::MAX as u64));
#[cfg(target_word_size = "32")]
fn check_word_size() {
assert_eq!(int::MAX.to_i32(), Some(int::MAX as i32));
assert_eq!(int::MAX.to_u32(), Some(int::MAX as u32));
}
#[cfg(target_word_size = "64")]
fn check_word_size() {
assert_eq!(int::MAX.to_i32(), None);
assert_eq!(int::MAX.to_u32(), None);
}
check_word_size();
}
#[test]
fn test_cast_range_i8_max() {
assert_eq!(i8::MAX.to_int(), Some(i8::MAX as int));
assert_eq!(i8::MAX.to_i8(), Some(i8::MAX as i8));
assert_eq!(i8::MAX.to_i16(), Some(i8::MAX as i16));
assert_eq!(i8::MAX.to_i32(), Some(i8::MAX as i32));
assert_eq!(i8::MAX.to_i64(), Some(i8::MAX as i64));
assert_eq!(i8::MAX.to_uint(), Some(i8::MAX as uint));
assert_eq!(i8::MAX.to_u8(), Some(i8::MAX as u8));
assert_eq!(i8::MAX.to_u16(), Some(i8::MAX as u16));
assert_eq!(i8::MAX.to_u32(), Some(i8::MAX as u32));
assert_eq!(i8::MAX.to_u64(), Some(i8::MAX as u64));
}
#[test]
fn test_cast_range_i16_max() {
assert_eq!(i16::MAX.to_int(), Some(i16::MAX as int));
assert_eq!(i16::MAX.to_i8(), None);
assert_eq!(i16::MAX.to_i16(), Some(i16::MAX as i16));
assert_eq!(i16::MAX.to_i32(), Some(i16::MAX as i32));
assert_eq!(i16::MAX.to_i64(), Some(i16::MAX as i64));
assert_eq!(i16::MAX.to_uint(), Some(i16::MAX as uint));
assert_eq!(i16::MAX.to_u8(), None);
assert_eq!(i16::MAX.to_u16(), Some(i16::MAX as u16));
assert_eq!(i16::MAX.to_u32(), Some(i16::MAX as u32));
assert_eq!(i16::MAX.to_u64(), Some(i16::MAX as u64));
}
#[test]
fn test_cast_range_i32_max() {
assert_eq!(i32::MAX.to_int(), Some(i32::MAX as int));
assert_eq!(i32::MAX.to_i8(), None);
assert_eq!(i32::MAX.to_i16(), None);
assert_eq!(i32::MAX.to_i32(), Some(i32::MAX as i32));
assert_eq!(i32::MAX.to_i64(), Some(i32::MAX as i64));
assert_eq!(i32::MAX.to_uint(), Some(i32::MAX as uint));
assert_eq!(i32::MAX.to_u8(), None);
assert_eq!(i32::MAX.to_u16(), None);
assert_eq!(i32::MAX.to_u32(), Some(i32::MAX as u32));
assert_eq!(i32::MAX.to_u64(), Some(i32::MAX as u64));
}
#[test]
fn test_cast_range_i64_max() {
// i64::MAX.to_int() is word-size specific
assert_eq!(i64::MAX.to_i8(), None);
assert_eq!(i64::MAX.to_i16(), None);
assert_eq!(i64::MAX.to_i32(), None);
assert_eq!(i64::MAX.to_i64(), Some(i64::MAX as i64));
// i64::MAX.to_uint() is word-size specific
assert_eq!(i64::MAX.to_u8(), None);
assert_eq!(i64::MAX.to_u16(), None);
assert_eq!(i64::MAX.to_u32(), None);
assert_eq!(i64::MAX.to_u64(), Some(i64::MAX as u64));
#[cfg(target_word_size = "32")]
fn check_word_size() {
assert_eq!(i64::MAX.to_int(), None);
assert_eq!(i64::MAX.to_uint(), None);
}
#[cfg(target_word_size = "64")]
fn check_word_size() {
assert_eq!(i64::MAX.to_int(), Some(i64::MAX as int));
assert_eq!(i64::MAX.to_uint(), Some(i64::MAX as uint));
}
check_word_size();
}
#[test]
fn test_cast_range_uint_min() {
assert_eq!(uint::MIN.to_int(), Some(uint::MIN as int));
assert_eq!(uint::MIN.to_i8(), Some(uint::MIN as i8));
assert_eq!(uint::MIN.to_i16(), Some(uint::MIN as i16));
assert_eq!(uint::MIN.to_i32(), Some(uint::MIN as i32));
assert_eq!(uint::MIN.to_i64(), Some(uint::MIN as i64));
assert_eq!(uint::MIN.to_uint(), Some(uint::MIN as uint));
assert_eq!(uint::MIN.to_u8(), Some(uint::MIN as u8));
assert_eq!(uint::MIN.to_u16(), Some(uint::MIN as u16));
assert_eq!(uint::MIN.to_u32(), Some(uint::MIN as u32));
assert_eq!(uint::MIN.to_u64(), Some(uint::MIN as u64));
}
#[test]
fn test_cast_range_u8_min() {
assert_eq!(u8::MIN.to_int(), Some(u8::MIN as int));
assert_eq!(u8::MIN.to_i8(), Some(u8::MIN as i8));
assert_eq!(u8::MIN.to_i16(), Some(u8::MIN as i16));
assert_eq!(u8::MIN.to_i32(), Some(u8::MIN as i32));
assert_eq!(u8::MIN.to_i64(), Some(u8::MIN as i64));
assert_eq!(u8::MIN.to_uint(), Some(u8::MIN as uint));
assert_eq!(u8::MIN.to_u8(), Some(u8::MIN as u8));
assert_eq!(u8::MIN.to_u16(), Some(u8::MIN as u16));
assert_eq!(u8::MIN.to_u32(), Some(u8::MIN as u32));
assert_eq!(u8::MIN.to_u64(), Some(u8::MIN as u64));
}
#[test]
fn test_cast_range_u16_min() {
assert_eq!(u16::MIN.to_int(), Some(u16::MIN as int));
assert_eq!(u16::MIN.to_i8(), Some(u16::MIN as i8));
assert_eq!(u16::MIN.to_i16(), Some(u16::MIN as i16));
assert_eq!(u16::MIN.to_i32(), Some(u16::MIN as i32));
assert_eq!(u16::MIN.to_i64(), Some(u16::MIN as i64));
assert_eq!(u16::MIN.to_uint(), Some(u16::MIN as uint));
assert_eq!(u16::MIN.to_u8(), Some(u16::MIN as u8));
assert_eq!(u16::MIN.to_u16(), Some(u16::MIN as u16));
assert_eq!(u16::MIN.to_u32(), Some(u16::MIN as u32));
assert_eq!(u16::MIN.to_u64(), Some(u16::MIN as u64));
}
#[test]
fn test_cast_range_u32_min() {
assert_eq!(u32::MIN.to_int(), Some(u32::MIN as int));
assert_eq!(u32::MIN.to_i8(), Some(u32::MIN as i8));
assert_eq!(u32::MIN.to_i16(), Some(u32::MIN as i16));
assert_eq!(u32::MIN.to_i32(), Some(u32::MIN as i32));
assert_eq!(u32::MIN.to_i64(), Some(u32::MIN as i64));
assert_eq!(u32::MIN.to_uint(), Some(u32::MIN as uint));
assert_eq!(u32::MIN.to_u8(), Some(u32::MIN as u8));
assert_eq!(u32::MIN.to_u16(), Some(u32::MIN as u16));
assert_eq!(u32::MIN.to_u32(), Some(u32::MIN as u32));
assert_eq!(u32::MIN.to_u64(), Some(u32::MIN as u64));
}
#[test]
fn test_cast_range_u64_min() {
assert_eq!(u64::MIN.to_int(), Some(u64::MIN as int));
assert_eq!(u64::MIN.to_i8(), Some(u64::MIN as i8));
assert_eq!(u64::MIN.to_i16(), Some(u64::MIN as i16));
assert_eq!(u64::MIN.to_i32(), Some(u64::MIN as i32));
assert_eq!(u64::MIN.to_i64(), Some(u64::MIN as i64));
assert_eq!(u64::MIN.to_uint(), Some(u64::MIN as uint));
assert_eq!(u64::MIN.to_u8(), Some(u64::MIN as u8));
assert_eq!(u64::MIN.to_u16(), Some(u64::MIN as u16));
assert_eq!(u64::MIN.to_u32(), Some(u64::MIN as u32));
assert_eq!(u64::MIN.to_u64(), Some(u64::MIN as u64));
}
#[test]
fn test_cast_range_uint_max() {
assert_eq!(uint::MAX.to_int(), None);
assert_eq!(uint::MAX.to_i8(), None);
assert_eq!(uint::MAX.to_i16(), None);
assert_eq!(uint::MAX.to_i32(), None);
// uint::MAX.to_i64() is word-size specific
assert_eq!(uint::MAX.to_u8(), None);
assert_eq!(uint::MAX.to_u16(), None);
// uint::MAX.to_u32() is word-size specific
assert_eq!(uint::MAX.to_u64(), Some(uint::MAX as u64));
#[cfg(target_word_size = "32")]
fn check_word_size() {
assert_eq!(uint::MAX.to_u32(), Some(uint::MAX as u32));
assert_eq!(uint::MAX.to_i64(), Some(uint::MAX as i64));
}
#[cfg(target_word_size = "64")]
fn check_word_size() {
assert_eq!(uint::MAX.to_u32(), None);
assert_eq!(uint::MAX.to_i64(), None);
}
check_word_size();
}
#[test]
fn test_cast_range_u8_max() {
assert_eq!(u8::MAX.to_int(), Some(u8::MAX as int));
assert_eq!(u8::MAX.to_i8(), None);
assert_eq!(u8::MAX.to_i16(), Some(u8::MAX as i16));
assert_eq!(u8::MAX.to_i32(), Some(u8::MAX as i32));
assert_eq!(u8::MAX.to_i64(), Some(u8::MAX as i64));
assert_eq!(u8::MAX.to_uint(), Some(u8::MAX as uint));
assert_eq!(u8::MAX.to_u8(), Some(u8::MAX as u8));
assert_eq!(u8::MAX.to_u16(), Some(u8::MAX as u16));
assert_eq!(u8::MAX.to_u32(), Some(u8::MAX as u32));
assert_eq!(u8::MAX.to_u64(), Some(u8::MAX as u64));
}
#[test]
fn test_cast_range_u16_max() {
assert_eq!(u16::MAX.to_int(), Some(u16::MAX as int));
assert_eq!(u16::MAX.to_i8(), None);
assert_eq!(u16::MAX.to_i16(), None);
assert_eq!(u16::MAX.to_i32(), Some(u16::MAX as i32));
assert_eq!(u16::MAX.to_i64(), Some(u16::MAX as i64));
assert_eq!(u16::MAX.to_uint(), Some(u16::MAX as uint));
assert_eq!(u16::MAX.to_u8(), None);
assert_eq!(u16::MAX.to_u16(), Some(u16::MAX as u16));
assert_eq!(u16::MAX.to_u32(), Some(u16::MAX as u32));
assert_eq!(u16::MAX.to_u64(), Some(u16::MAX as u64));
}
#[test]
fn test_cast_range_u32_max() {
// u32::MAX.to_int() is word-size specific
assert_eq!(u32::MAX.to_i8(), None);
assert_eq!(u32::MAX.to_i16(), None);
assert_eq!(u32::MAX.to_i32(), None);
assert_eq!(u32::MAX.to_i64(), Some(u32::MAX as i64));
assert_eq!(u32::MAX.to_uint(), Some(u32::MAX as uint));
assert_eq!(u32::MAX.to_u8(), None);
assert_eq!(u32::MAX.to_u16(), None);
assert_eq!(u32::MAX.to_u32(), Some(u32::MAX as u32));
assert_eq!(u32::MAX.to_u64(), Some(u32::MAX as u64));
#[cfg(target_word_size = "32")]
fn check_word_size() {
assert_eq!(u32::MAX.to_int(), None);
}
#[cfg(target_word_size = "64")]
fn check_word_size() {
assert_eq!(u32::MAX.to_int(), Some(u32::MAX as int));
}
check_word_size();
}
#[test]
fn test_cast_range_u64_max() {
assert_eq!(u64::MAX.to_int(), None);
assert_eq!(u64::MAX.to_i8(), None);
assert_eq!(u64::MAX.to_i16(), None);
assert_eq!(u64::MAX.to_i32(), None);
assert_eq!(u64::MAX.to_i64(), None);
// u64::MAX.to_uint() is word-size specific
assert_eq!(u64::MAX.to_u8(), None);
assert_eq!(u64::MAX.to_u16(), None);
assert_eq!(u64::MAX.to_u32(), None);
assert_eq!(u64::MAX.to_u64(), Some(u64::MAX as u64));
#[cfg(target_word_size = "32")]
fn check_word_size() {
assert_eq!(u64::MAX.to_uint(), None);
}
#[cfg(target_word_size = "64")]
fn check_word_size() {
assert_eq!(u64::MAX.to_uint(), Some(u64::MAX as uint));
}
check_word_size();
}
#[test]
fn test_saturating_add_uint() {
use uint::MAX;
assert_eq!(3u.saturating_add(5u), 8u);
assert_eq!(3u.saturating_add(MAX-1), MAX);
assert_eq!(MAX.saturating_add(MAX), MAX);
assert_eq!((MAX-2).saturating_add(1), MAX-1);
}
#[test]
fn test_saturating_sub_uint() {
use uint::MAX;
assert_eq!(5u.saturating_sub(3u), 2u);
assert_eq!(3u.saturating_sub(5u), 0u);
assert_eq!(0u.saturating_sub(1u), 0u);
assert_eq!((MAX-1).saturating_sub(MAX), 0);
}
#[test]
fn test_saturating_add_int() {
use int::{MIN,MAX};
assert_eq!(3i.saturating_add(5i), 8i);
assert_eq!(3i.saturating_add(MAX-1), MAX);
assert_eq!(MAX.saturating_add(MAX), MAX);
assert_eq!((MAX-2).saturating_add(1), MAX-1);
assert_eq!(3i.saturating_add(-5i), -2i);
assert_eq!(MIN.saturating_add(-1i), MIN);
assert_eq!((-2i).saturating_add(-MAX), MIN);
}
#[test]
fn test_saturating_sub_int() {
use int::{MIN,MAX};
assert_eq!(3i.saturating_sub(5i), -2i);
assert_eq!(MIN.saturating_sub(1i), MIN);
assert_eq!((-2i).saturating_sub(MAX), MIN);
assert_eq!(3i.saturating_sub(-5i), 8i);
assert_eq!(3i.saturating_sub(-(MAX-1)), MAX);
assert_eq!(MAX.saturating_sub(-MAX), MAX);
assert_eq!((MAX-2).saturating_sub(-1), MAX-1);
}
#[test]
fn test_checked_add() {
let five_less = uint::MAX - 5;
assert_eq!(five_less.checked_add(&0), Some(uint::MAX - 5));
assert_eq!(five_less.checked_add(&1), Some(uint::MAX - 4));
assert_eq!(five_less.checked_add(&2), Some(uint::MAX - 3));
assert_eq!(five_less.checked_add(&3), Some(uint::MAX - 2));
assert_eq!(five_less.checked_add(&4), Some(uint::MAX - 1));
assert_eq!(five_less.checked_add(&5), Some(uint::MAX));
assert_eq!(five_less.checked_add(&6), None);
assert_eq!(five_less.checked_add(&7), None);
}
#[test]
fn test_checked_sub() {
assert_eq!(5u.checked_sub(&0), Some(5));
assert_eq!(5u.checked_sub(&1), Some(4));
assert_eq!(5u.checked_sub(&2), Some(3));
assert_eq!(5u.checked_sub(&3), Some(2));
assert_eq!(5u.checked_sub(&4), Some(1));
assert_eq!(5u.checked_sub(&5), Some(0));
assert_eq!(5u.checked_sub(&6), None);
assert_eq!(5u.checked_sub(&7), None);
}
#[test]
fn test_checked_mul() {
let third = uint::MAX / 3;
assert_eq!(third.checked_mul(&0), Some(0));
assert_eq!(third.checked_mul(&1), Some(third));
assert_eq!(third.checked_mul(&2), Some(third * 2));
assert_eq!(third.checked_mul(&3), Some(third * 3));
assert_eq!(third.checked_mul(&4), None);
}
macro_rules! test_next_power_of_two(
($test_name:ident, $T:ident) => (
fn $test_name() {
#![test]
assert_eq!(next_power_of_two::<$T>(0), 0);
let mut next_power = 1;
for i in range::<$T>(1, 40) {
assert_eq!(next_power_of_two(i), next_power);
if i == next_power { next_power *= 2 }
}
}
)
)
test_next_power_of_two!(test_next_power_of_two_u8, u8)
test_next_power_of_two!(test_next_power_of_two_u16, u16)
test_next_power_of_two!(test_next_power_of_two_u32, u32)
test_next_power_of_two!(test_next_power_of_two_u64, u64)
test_next_power_of_two!(test_next_power_of_two_uint, uint)
macro_rules! test_checked_next_power_of_two(
($test_name:ident, $T:ident) => (
fn $test_name() {
#![test]
assert_eq!(checked_next_power_of_two::<$T>(0), None);
let mut next_power = 1;
for i in range::<$T>(1, 40) {
assert_eq!(checked_next_power_of_two(i), Some(next_power));
if i == next_power { next_power *= 2 }
}
assert!(checked_next_power_of_two::<$T>($T::MAX / 2).is_some());
assert_eq!(checked_next_power_of_two::<$T>($T::MAX - 1), None);
assert_eq!(checked_next_power_of_two::<$T>($T::MAX), None);
}
)
)
test_checked_next_power_of_two!(test_checked_next_power_of_two_u8, u8)
test_checked_next_power_of_two!(test_checked_next_power_of_two_u16, u16)
test_checked_next_power_of_two!(test_checked_next_power_of_two_u32, u32)
test_checked_next_power_of_two!(test_checked_next_power_of_two_u64, u64)
test_checked_next_power_of_two!(test_checked_next_power_of_two_uint, uint)
#[deriving(Eq, Show)]
struct Value { x: int }
impl ToPrimitive for Value {
fn to_i64(&self) -> Option<i64> { self.x.to_i64() }
fn to_u64(&self) -> Option<u64> { self.x.to_u64() }
}
impl FromPrimitive for Value {
fn from_i64(n: i64) -> Option<Value> { Some(Value { x: n as int }) }
fn from_u64(n: u64) -> Option<Value> { Some(Value { x: n as int }) }
}
#[test]
fn test_to_primitive() {
let value = Value { x: 5 };
assert_eq!(value.to_int(), Some(5));
assert_eq!(value.to_i8(), Some(5));
assert_eq!(value.to_i16(), Some(5));
assert_eq!(value.to_i32(), Some(5));
assert_eq!(value.to_i64(), Some(5));
assert_eq!(value.to_uint(), Some(5));
assert_eq!(value.to_u8(), Some(5));
assert_eq!(value.to_u16(), Some(5));
assert_eq!(value.to_u32(), Some(5));
assert_eq!(value.to_u64(), Some(5));
assert_eq!(value.to_f32(), Some(5f32));
assert_eq!(value.to_f64(), Some(5f64));
}
#[test]
fn test_from_primitive() {
assert_eq!(from_int(5), Some(Value { x: 5 }));
assert_eq!(from_i8(5), Some(Value { x: 5 }));
assert_eq!(from_i16(5), Some(Value { x: 5 }));
assert_eq!(from_i32(5), Some(Value { x: 5 }));
assert_eq!(from_i64(5), Some(Value { x: 5 }));
assert_eq!(from_uint(5), Some(Value { x: 5 }));
assert_eq!(from_u8(5), Some(Value { x: 5 }));
assert_eq!(from_u16(5), Some(Value { x: 5 }));
assert_eq!(from_u32(5), Some(Value { x: 5 }));
assert_eq!(from_u64(5), Some(Value { x: 5 }));
assert_eq!(from_f32(5f32), Some(Value { x: 5 }));
assert_eq!(from_f64(5f64), Some(Value { x: 5 }));
}
#[test]
fn test_pow() {
fn naive_pow<T: One + Mul<T, T>>(base: T, exp: uint) -> T {
range(0, exp).fold(one::<T>(), |acc, _| acc * base)
}
macro_rules! assert_pow(
(($num:expr, $exp:expr) => $expected:expr) => {{
let result = pow($num, $exp);
assert_eq!(result, $expected);
assert_eq!(result, naive_pow($num, $exp));
}}
)
assert_pow!((3, 0 ) => 1);
assert_pow!((5, 1 ) => 5);
assert_pow!((-4, 2 ) => 16);
assert_pow!((0.5, 5 ) => 0.03125);
assert_pow!((8, 3 ) => 512);
assert_pow!((8.0, 5 ) => 32768.0);
assert_pow!((8.5, 5 ) => 44370.53125);
assert_pow!((2u64, 50) => 1125899906842624);
}
}
#[cfg(test)]
mod bench {
extern crate test;
use self::test::BenchHarness;
use num;
use slice;
use prelude::*;
#[bench]
fn bench_pow_function(b: &mut BenchHarness) {
let v = slice::from_fn(1024, |n| n);
b.iter(|| {v.iter().fold(0, |old, new| num::pow(old, *new));});
}
}