| // 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 the built-in numeric types. |
| |
| #![stable(feature = "rust1", since = "1.0.0")] |
| #![allow(missing_docs)] |
| |
| use self::wrapping::OverflowingOps; |
| |
| use char::CharExt; |
| use cmp::{Eq, PartialOrd}; |
| use fmt; |
| use intrinsics; |
| use marker::Copy; |
| use mem::size_of; |
| use option::Option::{self, Some, None}; |
| use result::Result::{self, Ok, Err}; |
| use str::{FromStr, StrExt}; |
| |
| /// Provides intentionally-wrapped arithmetic on `T`. |
| /// |
| /// Operations like `+` on `u32` values is intended to never overflow, |
| /// and in some debug configurations overflow is detected and results |
| /// in a panic. While most arithmetic falls into this category, some |
| /// code explicitly expects and relies upon modular arithmetic (e.g., |
| /// hashing). |
| /// |
| /// Wrapping arithmetic can be achieved either through methods like |
| /// `wrapping_add`, or through the `Wrapping<T>` type, which says that |
| /// all standard arithmetic operations on the underlying value are |
| /// intended to have wrapping semantics. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Debug)] |
| pub struct Wrapping<T>(#[stable(feature = "rust1", since = "1.0.0")] pub T); |
| |
| #[unstable(feature = "core", reason = "may be removed or relocated")] |
| pub mod wrapping; |
| |
| /// Types that have a "zero" value. |
| /// |
| /// This trait is intended for use in conjunction with `Add`, as an identity: |
| /// `x + T::zero() == x`. |
| #[unstable(feature = "zero_one", |
| reason = "unsure of placement, wants to use associated constants")] |
| pub trait Zero { |
| /// The "zero" (usually, additive identity) for this type. |
| fn zero() -> Self; |
| } |
| |
| /// Types that have a "one" value. |
| /// |
| /// This trait is intended for use in conjunction with `Mul`, as an identity: |
| /// `x * T::one() == x`. |
| #[unstable(feature = "zero_one", |
| reason = "unsure of placement, wants to use associated constants")] |
| pub trait One { |
| /// The "one" (usually, multiplicative identity) for this type. |
| fn one() -> Self; |
| } |
| |
| macro_rules! zero_one_impl { |
| ($($t:ty)*) => ($( |
| impl Zero for $t { |
| #[inline] |
| fn zero() -> $t { 0 } |
| } |
| impl One for $t { |
| #[inline] |
| fn one() -> $t { 1 } |
| } |
| )*) |
| } |
| zero_one_impl! { u8 u16 u32 u64 usize i8 i16 i32 i64 isize } |
| |
| macro_rules! zero_one_impl_float { |
| ($($t:ty)*) => ($( |
| impl Zero for $t { |
| #[inline] |
| fn zero() -> $t { 0.0 } |
| } |
| impl One for $t { |
| #[inline] |
| fn one() -> $t { 1.0 } |
| } |
| )*) |
| } |
| zero_one_impl_float! { f32 f64 } |
| |
| macro_rules! checked_op { |
| ($T:ty, $U:ty, $op:path, $x:expr, $y:expr) => {{ |
| let (result, overflowed) = unsafe { $op($x as $U, $y as $U) }; |
| if overflowed { None } else { Some(result as $T) } |
| }} |
| } |
| |
| /// Swapping a single byte is a no-op. This is marked as `unsafe` for |
| /// consistency with the other `bswap` intrinsics. |
| unsafe fn bswap8(x: u8) -> u8 { x } |
| |
| // `Int` + `SignedInt` implemented for signed integers |
| macro_rules! int_impl { |
| ($T:ident = $ActualT:ty, $UnsignedT:ty, $BITS:expr, |
| $add_with_overflow:path, |
| $sub_with_overflow:path, |
| $mul_with_overflow:path) => { |
| /// Returns the smallest value that can be represented by this integer type. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn min_value() -> $T { |
| (-1 as $T) << ($BITS - 1) |
| } |
| |
| /// Returns the largest value that can be represented by this integer type. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn max_value() -> $T { |
| let min = $T::min_value(); !min |
| } |
| |
| /// Converts a string slice in a given base to an integer. |
| /// |
| /// Leading and trailing whitespace represent an error. |
| /// |
| /// # Arguments |
| /// |
| /// * src - A string slice |
| /// * radix - The base to use. Must lie in the range [2 .. 36] |
| /// |
| /// # Return value |
| /// |
| /// `Err(ParseIntError)` if the string did not represent a valid number. |
| /// Otherwise, `Ok(n)` where `n` is the integer represented by `src`. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[allow(deprecated)] |
| pub fn from_str_radix(src: &str, radix: u32) -> Result<$T, ParseIntError> { |
| from_str_radix(src, radix) |
| } |
| |
| /// Returns the number of ones in the binary representation of `self`. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0b01001100u8; |
| /// |
| /// assert_eq!(n.count_ones(), 3); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn count_ones(self) -> u32 { (self as $UnsignedT).count_ones() } |
| |
| /// Returns the number of zeros in the binary representation of `self`. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0b01001100u8; |
| /// |
| /// assert_eq!(n.count_zeros(), 5); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn count_zeros(self) -> u32 { |
| (!self).count_ones() |
| } |
| |
| /// Returns the number of leading zeros in the binary representation |
| /// of `self`. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0b0101000u16; |
| /// |
| /// assert_eq!(n.leading_zeros(), 10); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn leading_zeros(self) -> u32 { |
| (self as $UnsignedT).leading_zeros() |
| } |
| |
| /// Returns the number of trailing zeros in the binary representation |
| /// of `self`. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0b0101000u16; |
| /// |
| /// assert_eq!(n.trailing_zeros(), 3); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn trailing_zeros(self) -> u32 { |
| (self as $UnsignedT).trailing_zeros() |
| } |
| |
| /// Shifts the bits to the left by a specified amount, `n`, |
| /// wrapping the truncated bits to the end of the resulting integer. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// let m = 0x3456789ABCDEF012u64; |
| /// |
| /// assert_eq!(n.rotate_left(12), m); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn rotate_left(self, n: u32) -> $T { |
| (self as $UnsignedT).rotate_left(n) as $T |
| } |
| |
| /// Shifts the bits to the right by a specified amount, `n`, |
| /// wrapping the truncated bits to the beginning of the resulting |
| /// integer. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// let m = 0xDEF0123456789ABCu64; |
| /// |
| /// assert_eq!(n.rotate_right(12), m); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn rotate_right(self, n: u32) -> $T { |
| (self as $UnsignedT).rotate_right(n) as $T |
| } |
| |
| /// Reverses the byte order of the integer. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// let m = 0xEFCDAB8967452301u64; |
| /// |
| /// assert_eq!(n.swap_bytes(), m); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn swap_bytes(self) -> $T { |
| (self as $UnsignedT).swap_bytes() as $T |
| } |
| |
| /// Converts 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 |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// |
| /// if cfg!(target_endian = "big") { |
| /// assert_eq!(u64::from_be(n), n) |
| /// } else { |
| /// assert_eq!(u64::from_be(n), n.swap_bytes()) |
| /// } |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn from_be(x: $T) -> $T { |
| if cfg!(target_endian = "big") { x } else { x.swap_bytes() } |
| } |
| |
| /// Converts 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 |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// |
| /// if cfg!(target_endian = "little") { |
| /// assert_eq!(u64::from_le(n), n) |
| /// } else { |
| /// assert_eq!(u64::from_le(n), n.swap_bytes()) |
| /// } |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn from_le(x: $T) -> $T { |
| if cfg!(target_endian = "little") { x } else { x.swap_bytes() } |
| } |
| |
| /// Converts `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 |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// |
| /// if cfg!(target_endian = "big") { |
| /// assert_eq!(n.to_be(), n) |
| /// } else { |
| /// assert_eq!(n.to_be(), n.swap_bytes()) |
| /// } |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn to_be(self) -> $T { // or not to be? |
| if cfg!(target_endian = "big") { self } else { self.swap_bytes() } |
| } |
| |
| /// Converts `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 |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// |
| /// if cfg!(target_endian = "little") { |
| /// assert_eq!(n.to_le(), n) |
| /// } else { |
| /// assert_eq!(n.to_le(), n.swap_bytes()) |
| /// } |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn to_le(self) -> $T { |
| if cfg!(target_endian = "little") { self } else { self.swap_bytes() } |
| } |
| |
| /// Checked integer addition. Computes `self + other`, returning `None` |
| /// if overflow occurred. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// assert_eq!(5u16.checked_add(65530), Some(65535)); |
| /// assert_eq!(6u16.checked_add(65530), None); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn checked_add(self, other: $T) -> Option<$T> { |
| checked_op!($T, $ActualT, $add_with_overflow, self, other) |
| } |
| |
| /// Checked integer subtraction. Computes `self - other`, returning |
| /// `None` if underflow occurred. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// assert_eq!((-127i8).checked_sub(1), Some(-128)); |
| /// assert_eq!((-128i8).checked_sub(1), None); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn checked_sub(self, other: $T) -> Option<$T> { |
| checked_op!($T, $ActualT, $sub_with_overflow, self, other) |
| } |
| |
| /// Checked integer multiplication. Computes `self * other`, returning |
| /// `None` if underflow or overflow occurred. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// assert_eq!(5u8.checked_mul(51), Some(255)); |
| /// assert_eq!(5u8.checked_mul(52), None); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn checked_mul(self, other: $T) -> Option<$T> { |
| checked_op!($T, $ActualT, $mul_with_overflow, self, other) |
| } |
| |
| /// Checked integer division. Computes `self / other`, returning `None` |
| /// if `other == 0` or the operation results in underflow or overflow. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// assert_eq!((-127i8).checked_div(-1), Some(127)); |
| /// assert_eq!((-128i8).checked_div(-1), None); |
| /// assert_eq!((1i8).checked_div(0), None); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn checked_div(self, v: $T) -> Option<$T> { |
| match v { |
| 0 => None, |
| -1 if self == <$T>::min_value() |
| => None, |
| v => Some(self / v), |
| } |
| } |
| |
| /// Saturating integer addition. Computes `self + other`, saturating at |
| /// the numeric bounds instead of overflowing. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn saturating_add(self, other: $T) -> $T { |
| match self.checked_add(other) { |
| Some(x) => x, |
| None if other >= <$T as Zero>::zero() => <$T>::max_value(), |
| None => <$T>::min_value(), |
| } |
| } |
| |
| /// Saturating integer subtraction. Computes `self - other`, saturating |
| /// at the numeric bounds instead of overflowing. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn saturating_sub(self, other: $T) -> $T { |
| match self.checked_sub(other) { |
| Some(x) => x, |
| None if other >= <$T as Zero>::zero() => <$T>::min_value(), |
| None => <$T>::max_value(), |
| } |
| } |
| |
| /// Wrapping (modular) addition. Computes `self + other`, |
| /// wrapping around at the boundary of the type. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn wrapping_add(self, rhs: $T) -> $T { |
| unsafe { |
| intrinsics::overflowing_add(self, rhs) |
| } |
| } |
| |
| /// Wrapping (modular) subtraction. Computes `self - other`, |
| /// wrapping around at the boundary of the type. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn wrapping_sub(self, rhs: $T) -> $T { |
| unsafe { |
| intrinsics::overflowing_sub(self, rhs) |
| } |
| } |
| |
| /// Wrapping (modular) multiplication. Computes `self * |
| /// other`, wrapping around at the boundary of the type. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn wrapping_mul(self, rhs: $T) -> $T { |
| unsafe { |
| intrinsics::overflowing_mul(self, rhs) |
| } |
| } |
| |
| /// Wrapping (modular) division. Computes `floor(self / other)`, |
| /// wrapping around at the boundary of the type. |
| /// |
| /// The only case where such wrapping can occur is when one |
| /// divides `MIN / -1` on a signed type (where `MIN` is the |
| /// negative minimal value for the type); this is equivalent |
| /// to `-MIN`, a positive value that is too large to represent |
| /// in the type. In such a case, this function returns `MIN` |
| /// itself.. |
| #[unstable(feature = "core", since = "1.0.0")] |
| #[inline(always)] |
| pub fn wrapping_div(self, rhs: $T) -> $T { |
| self.overflowing_div(rhs).0 |
| } |
| |
| /// Wrapping (modular) remainder. Computes `self % other`, |
| /// wrapping around at the boundary of the type. |
| /// |
| /// Such wrap-around never actually occurs mathematically; |
| /// implementation artifacts make `x % y` illegal for `MIN / |
| /// -1` on a signed type illegal (where `MIN` is the negative |
| /// minimal value). In such a case, this function returns `0`. |
| #[unstable(feature = "core", since = "1.0.0")] |
| #[inline(always)] |
| pub fn wrapping_rem(self, rhs: $T) -> $T { |
| self.overflowing_rem(rhs).0 |
| } |
| |
| /// Wrapping (modular) negation. Computes `-self`, |
| /// wrapping around at the boundary of the type. |
| /// |
| /// The only case where such wrapping can occur is when one |
| /// negates `MIN` on a signed type (where `MIN` is the |
| /// negative minimal value for the type); this is a positive |
| /// value that is too large to represent in the type. In such |
| /// a case, this function returns `MIN` itself. |
| #[unstable(feature = "core", since = "1.0.0")] |
| #[inline(always)] |
| pub fn wrapping_neg(self) -> $T { |
| self.overflowing_neg().0 |
| } |
| |
| /// Panic-free bitwise shift-left; yields `self << mask(rhs)`, |
| /// where `mask` removes any high-order bits of `rhs` that |
| /// would cause the shift to exceed the bitwidth of the type. |
| #[unstable(feature = "core", since = "1.0.0")] |
| #[inline(always)] |
| pub fn wrapping_shl(self, rhs: u32) -> $T { |
| self.overflowing_shl(rhs).0 |
| } |
| |
| /// Panic-free bitwise shift-left; yields `self >> mask(rhs)`, |
| /// where `mask` removes any high-order bits of `rhs` that |
| /// would cause the shift to exceed the bitwidth of the type. |
| #[unstable(feature = "core", since = "1.0.0")] |
| #[inline(always)] |
| pub fn wrapping_shr(self, rhs: u32) -> $T { |
| self.overflowing_shr(rhs).0 |
| } |
| |
| /// Raises self to the power of `exp`, using exponentiation by squaring. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// let x: i32 = 2; // or any other integer type |
| /// |
| /// assert_eq!(x.pow(4), 16); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn pow(self, mut exp: u32) -> $T { |
| let mut base = self; |
| let mut acc = <$T as One>::one(); |
| |
| let mut prev_base = self; |
| let mut base_oflo = false; |
| while exp > 0 { |
| if (exp & 1) == 1 { |
| if base_oflo { |
| // ensure overflow occurs in the same manner it |
| // would have otherwise (i.e. signal any exception |
| // it would have otherwise). |
| acc = acc * (prev_base * prev_base); |
| } else { |
| acc = acc * base; |
| } |
| } |
| prev_base = base; |
| let (new_base, new_base_oflo) = base.overflowing_mul(base); |
| base = new_base; |
| base_oflo = new_base_oflo; |
| exp /= 2; |
| } |
| acc |
| } |
| |
| /// Computes the absolute value of `self`. `Int::min_value()` will be |
| /// returned if the number is `Int::min_value()`. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn abs(self) -> $T { |
| if self.is_negative() { |
| self.wrapping_neg() |
| } else { |
| self |
| } |
| } |
| |
| /// Returns a number representing sign of `self`. |
| /// |
| /// - `0` if the number is zero |
| /// - `1` if the number is positive |
| /// - `-1` if the number is negative |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn signum(self) -> $T { |
| match self { |
| n if n > 0 => 1, |
| 0 => 0, |
| _ => -1, |
| } |
| } |
| |
| /// Returns `true` if `self` is positive and `false` if the number |
| /// is zero or negative. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn is_positive(self) -> bool { self > 0 } |
| |
| /// Returns `true` if `self` is negative and `false` if the number |
| /// is zero or positive. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn is_negative(self) -> bool { self < 0 } |
| } |
| } |
| |
| #[lang = "i8"] |
| impl i8 { |
| int_impl! { i8 = i8, u8, 8, |
| intrinsics::i8_add_with_overflow, |
| intrinsics::i8_sub_with_overflow, |
| intrinsics::i8_mul_with_overflow } |
| } |
| |
| #[lang = "i16"] |
| impl i16 { |
| int_impl! { i16 = i16, u16, 16, |
| intrinsics::i16_add_with_overflow, |
| intrinsics::i16_sub_with_overflow, |
| intrinsics::i16_mul_with_overflow } |
| } |
| |
| #[lang = "i32"] |
| impl i32 { |
| int_impl! { i32 = i32, u32, 32, |
| intrinsics::i32_add_with_overflow, |
| intrinsics::i32_sub_with_overflow, |
| intrinsics::i32_mul_with_overflow } |
| } |
| |
| #[lang = "i64"] |
| impl i64 { |
| int_impl! { i64 = i64, u64, 64, |
| intrinsics::i64_add_with_overflow, |
| intrinsics::i64_sub_with_overflow, |
| intrinsics::i64_mul_with_overflow } |
| } |
| |
| #[cfg(target_pointer_width = "32")] |
| #[lang = "isize"] |
| impl isize { |
| int_impl! { isize = i32, u32, 32, |
| intrinsics::i32_add_with_overflow, |
| intrinsics::i32_sub_with_overflow, |
| intrinsics::i32_mul_with_overflow } |
| } |
| |
| #[cfg(target_pointer_width = "64")] |
| #[lang = "isize"] |
| impl isize { |
| int_impl! { isize = i64, u64, 64, |
| intrinsics::i64_add_with_overflow, |
| intrinsics::i64_sub_with_overflow, |
| intrinsics::i64_mul_with_overflow } |
| } |
| |
| // `Int` + `UnsignedInt` implemented for signed integers |
| macro_rules! uint_impl { |
| ($T:ty = $ActualT:ty, $BITS:expr, |
| $ctpop:path, |
| $ctlz:path, |
| $cttz:path, |
| $bswap:path, |
| $add_with_overflow:path, |
| $sub_with_overflow:path, |
| $mul_with_overflow:path) => { |
| /// Returns the smallest value that can be represented by this integer type. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn min_value() -> $T { 0 } |
| |
| /// Returns the largest value that can be represented by this integer type. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn max_value() -> $T { !0 } |
| |
| /// Converts a string slice in a given base to an integer. |
| /// |
| /// Leading and trailing whitespace represent an error. |
| /// |
| /// # Arguments |
| /// |
| /// * src - A string slice |
| /// * radix - The base to use. Must lie in the range [2 .. 36] |
| /// |
| /// # Return value |
| /// |
| /// `Err(ParseIntError)` if the string did not represent a valid number. |
| /// Otherwise, `Ok(n)` where `n` is the integer represented by `src`. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[allow(deprecated)] |
| pub fn from_str_radix(src: &str, radix: u32) -> Result<$T, ParseIntError> { |
| from_str_radix(src, radix) |
| } |
| |
| /// Returns the number of ones in the binary representation of `self`. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0b01001100u8; |
| /// |
| /// assert_eq!(n.count_ones(), 3); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn count_ones(self) -> u32 { |
| unsafe { $ctpop(self as $ActualT) as u32 } |
| } |
| |
| /// Returns the number of zeros in the binary representation of `self`. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0b01001100u8; |
| /// |
| /// assert_eq!(n.count_zeros(), 5); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn count_zeros(self) -> u32 { |
| (!self).count_ones() |
| } |
| |
| /// Returns the number of leading zeros in the binary representation |
| /// of `self`. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0b0101000u16; |
| /// |
| /// assert_eq!(n.leading_zeros(), 10); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn leading_zeros(self) -> u32 { |
| unsafe { $ctlz(self as $ActualT) as u32 } |
| } |
| |
| /// Returns the number of trailing zeros in the binary representation |
| /// of `self`. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0b0101000u16; |
| /// |
| /// assert_eq!(n.trailing_zeros(), 3); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn trailing_zeros(self) -> u32 { |
| // As of LLVM 3.6 the codegen for the zero-safe cttz8 intrinsic |
| // emits two conditional moves on x86_64. By promoting the value to |
| // u16 and setting bit 8, we get better code without any conditional |
| // operations. |
| // FIXME: There's a LLVM patch (http://reviews.llvm.org/D9284) |
| // pending, remove this workaround once LLVM generates better code |
| // for cttz8. |
| unsafe { |
| if $BITS == 8 { |
| intrinsics::cttz16(self as u16 | 0x100) as u32 |
| } else { |
| $cttz(self as $ActualT) as u32 |
| } |
| } |
| } |
| |
| /// Shifts the bits to the left by a specified amount, `n`, |
| /// wrapping the truncated bits to the end of the resulting integer. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// let m = 0x3456789ABCDEF012u64; |
| /// |
| /// assert_eq!(n.rotate_left(12), m); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn rotate_left(self, n: u32) -> $T { |
| // Protect against undefined behaviour for over-long bit shifts |
| let n = n % $BITS; |
| (self << n) | (self >> (($BITS - n) % $BITS)) |
| } |
| |
| /// Shifts the bits to the right by a specified amount, `n`, |
| /// wrapping the truncated bits to the beginning of the resulting |
| /// integer. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// let m = 0xDEF0123456789ABCu64; |
| /// |
| /// assert_eq!(n.rotate_right(12), m); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn rotate_right(self, n: u32) -> $T { |
| // Protect against undefined behaviour for over-long bit shifts |
| let n = n % $BITS; |
| (self >> n) | (self << (($BITS - n) % $BITS)) |
| } |
| |
| /// Reverses the byte order of the integer. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// let m = 0xEFCDAB8967452301u64; |
| /// |
| /// assert_eq!(n.swap_bytes(), m); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn swap_bytes(self) -> $T { |
| unsafe { $bswap(self as $ActualT) as $T } |
| } |
| |
| /// Converts 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 |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// |
| /// if cfg!(target_endian = "big") { |
| /// assert_eq!(u64::from_be(n), n) |
| /// } else { |
| /// assert_eq!(u64::from_be(n), n.swap_bytes()) |
| /// } |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn from_be(x: $T) -> $T { |
| if cfg!(target_endian = "big") { x } else { x.swap_bytes() } |
| } |
| |
| /// Converts 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 |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// |
| /// if cfg!(target_endian = "little") { |
| /// assert_eq!(u64::from_le(n), n) |
| /// } else { |
| /// assert_eq!(u64::from_le(n), n.swap_bytes()) |
| /// } |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn from_le(x: $T) -> $T { |
| if cfg!(target_endian = "little") { x } else { x.swap_bytes() } |
| } |
| |
| /// Converts `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 |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// |
| /// if cfg!(target_endian = "big") { |
| /// assert_eq!(n.to_be(), n) |
| /// } else { |
| /// assert_eq!(n.to_be(), n.swap_bytes()) |
| /// } |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn to_be(self) -> $T { // or not to be? |
| if cfg!(target_endian = "big") { self } else { self.swap_bytes() } |
| } |
| |
| /// Converts `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 |
| /// |
| /// ```rust |
| /// let n = 0x0123456789ABCDEFu64; |
| /// |
| /// if cfg!(target_endian = "little") { |
| /// assert_eq!(n.to_le(), n) |
| /// } else { |
| /// assert_eq!(n.to_le(), n.swap_bytes()) |
| /// } |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn to_le(self) -> $T { |
| if cfg!(target_endian = "little") { self } else { self.swap_bytes() } |
| } |
| |
| /// Checked integer addition. Computes `self + other`, returning `None` |
| /// if overflow occurred. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// assert_eq!(5u16.checked_add(65530), Some(65535)); |
| /// assert_eq!(6u16.checked_add(65530), None); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn checked_add(self, other: $T) -> Option<$T> { |
| checked_op!($T, $ActualT, $add_with_overflow, self, other) |
| } |
| |
| /// Checked integer subtraction. Computes `self - other`, returning |
| /// `None` if underflow occurred. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// assert_eq!((-127i8).checked_sub(1), Some(-128)); |
| /// assert_eq!((-128i8).checked_sub(1), None); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn checked_sub(self, other: $T) -> Option<$T> { |
| checked_op!($T, $ActualT, $sub_with_overflow, self, other) |
| } |
| |
| /// Checked integer multiplication. Computes `self * other`, returning |
| /// `None` if underflow or overflow occurred. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// assert_eq!(5u8.checked_mul(51), Some(255)); |
| /// assert_eq!(5u8.checked_mul(52), None); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn checked_mul(self, other: $T) -> Option<$T> { |
| checked_op!($T, $ActualT, $mul_with_overflow, self, other) |
| } |
| |
| /// Checked integer division. Computes `self / other`, returning `None` |
| /// if `other == 0` or the operation results in underflow or overflow. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// assert_eq!((-127i8).checked_div(-1), Some(127)); |
| /// assert_eq!((-128i8).checked_div(-1), None); |
| /// assert_eq!((1i8).checked_div(0), None); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn checked_div(self, v: $T) -> Option<$T> { |
| match v { |
| 0 => None, |
| v => Some(self / v), |
| } |
| } |
| |
| /// Saturating integer addition. Computes `self + other`, saturating at |
| /// the numeric bounds instead of overflowing. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn saturating_add(self, other: $T) -> $T { |
| match self.checked_add(other) { |
| Some(x) => x, |
| None if other >= <$T as Zero>::zero() => <$T>::max_value(), |
| None => <$T>::min_value(), |
| } |
| } |
| |
| /// Saturating integer subtraction. Computes `self - other`, saturating |
| /// at the numeric bounds instead of overflowing. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn saturating_sub(self, other: $T) -> $T { |
| match self.checked_sub(other) { |
| Some(x) => x, |
| None if other >= <$T as Zero>::zero() => <$T>::min_value(), |
| None => <$T>::max_value(), |
| } |
| } |
| |
| /// Wrapping (modular) addition. Computes `self + other`, |
| /// wrapping around at the boundary of the type. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn wrapping_add(self, rhs: $T) -> $T { |
| unsafe { |
| intrinsics::overflowing_add(self, rhs) |
| } |
| } |
| |
| /// Wrapping (modular) subtraction. Computes `self - other`, |
| /// wrapping around at the boundary of the type. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn wrapping_sub(self, rhs: $T) -> $T { |
| unsafe { |
| intrinsics::overflowing_sub(self, rhs) |
| } |
| } |
| |
| /// Wrapping (modular) multiplication. Computes `self * |
| /// other`, wrapping around at the boundary of the type. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn wrapping_mul(self, rhs: $T) -> $T { |
| unsafe { |
| intrinsics::overflowing_mul(self, rhs) |
| } |
| } |
| |
| /// Wrapping (modular) division. Computes `floor(self / other)`, |
| /// wrapping around at the boundary of the type. |
| /// |
| /// The only case where such wrapping can occur is when one |
| /// divides `MIN / -1` on a signed type (where `MIN` is the |
| /// negative minimal value for the type); this is equivalent |
| /// to `-MIN`, a positive value that is too large to represent |
| /// in the type. In such a case, this function returns `MIN` |
| /// itself.. |
| #[unstable(feature = "core", since = "1.0.0")] |
| #[inline(always)] |
| pub fn wrapping_div(self, rhs: $T) -> $T { |
| self.overflowing_div(rhs).0 |
| } |
| |
| /// Wrapping (modular) remainder. Computes `self % other`, |
| /// wrapping around at the boundary of the type. |
| /// |
| /// Such wrap-around never actually occurs mathematically; |
| /// implementation artifacts make `x % y` illegal for `MIN / |
| /// -1` on a signed type illegal (where `MIN` is the negative |
| /// minimal value). In such a case, this function returns `0`. |
| #[unstable(feature = "core", since = "1.0.0")] |
| #[inline(always)] |
| pub fn wrapping_rem(self, rhs: $T) -> $T { |
| self.overflowing_rem(rhs).0 |
| } |
| |
| /// Wrapping (modular) negation. Computes `-self`, |
| /// wrapping around at the boundary of the type. |
| /// |
| /// The only case where such wrapping can occur is when one |
| /// negates `MIN` on a signed type (where `MIN` is the |
| /// negative minimal value for the type); this is a positive |
| /// value that is too large to represent in the type. In such |
| /// a case, this function returns `MIN` itself. |
| #[unstable(feature = "core", since = "1.0.0")] |
| #[inline(always)] |
| pub fn wrapping_neg(self) -> $T { |
| self.overflowing_neg().0 |
| } |
| |
| /// Panic-free bitwise shift-left; yields `self << mask(rhs)`, |
| /// where `mask` removes any high-order bits of `rhs` that |
| /// would cause the shift to exceed the bitwidth of the type. |
| #[unstable(feature = "core", since = "1.0.0")] |
| #[inline(always)] |
| pub fn wrapping_shl(self, rhs: u32) -> $T { |
| self.overflowing_shl(rhs).0 |
| } |
| |
| /// Panic-free bitwise shift-left; yields `self >> mask(rhs)`, |
| /// where `mask` removes any high-order bits of `rhs` that |
| /// would cause the shift to exceed the bitwidth of the type. |
| #[unstable(feature = "core", since = "1.0.0")] |
| #[inline(always)] |
| pub fn wrapping_shr(self, rhs: u32) -> $T { |
| self.overflowing_shr(rhs).0 |
| } |
| |
| /// Raises self to the power of `exp`, using exponentiation by squaring. |
| /// |
| /// # Examples |
| /// |
| /// ```rust |
| /// assert_eq!(2i32.pow(4), 16); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn pow(self, mut exp: u32) -> $T { |
| let mut base = self; |
| let mut acc = <$T as One>::one(); |
| |
| let mut prev_base = self; |
| let mut base_oflo = false; |
| while exp > 0 { |
| if (exp & 1) == 1 { |
| if base_oflo { |
| // ensure overflow occurs in the same manner it |
| // would have otherwise (i.e. signal any exception |
| // it would have otherwise). |
| acc = acc * (prev_base * prev_base); |
| } else { |
| acc = acc * base; |
| } |
| } |
| prev_base = base; |
| let (new_base, new_base_oflo) = base.overflowing_mul(base); |
| base = new_base; |
| base_oflo = new_base_oflo; |
| exp /= 2; |
| } |
| acc |
| } |
| |
| /// Returns `true` iff `self == 2^k` for some `k`. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn is_power_of_two(self) -> bool { |
| (self.wrapping_sub(<$T as One>::one())) & self == <$T as Zero>::zero() && |
| !(self == <$T as Zero>::zero()) |
| } |
| |
| /// Returns the smallest power of two greater than or equal to `self`. |
| /// Unspecified behavior on overflow. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn next_power_of_two(self) -> $T { |
| let bits = size_of::<$T>() * 8; |
| let one: $T = <$T as One>::one(); |
| one << ((bits - self.wrapping_sub(one).leading_zeros() as usize) % bits) |
| } |
| |
| /// Returns the smallest power of two 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 two is wrapped in `Some`. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn checked_next_power_of_two(self) -> Option<$T> { |
| let npot = self.next_power_of_two(); |
| if npot >= self { |
| Some(npot) |
| } else { |
| None |
| } |
| } |
| } |
| } |
| |
| #[lang = "u8"] |
| impl u8 { |
| uint_impl! { u8 = u8, 8, |
| intrinsics::ctpop8, |
| intrinsics::ctlz8, |
| intrinsics::cttz8, |
| bswap8, |
| intrinsics::u8_add_with_overflow, |
| intrinsics::u8_sub_with_overflow, |
| intrinsics::u8_mul_with_overflow } |
| } |
| |
| #[lang = "u16"] |
| impl u16 { |
| uint_impl! { u16 = u16, 16, |
| intrinsics::ctpop16, |
| intrinsics::ctlz16, |
| intrinsics::cttz16, |
| intrinsics::bswap16, |
| intrinsics::u16_add_with_overflow, |
| intrinsics::u16_sub_with_overflow, |
| intrinsics::u16_mul_with_overflow } |
| } |
| |
| #[lang = "u32"] |
| impl u32 { |
| uint_impl! { u32 = u32, 32, |
| intrinsics::ctpop32, |
| intrinsics::ctlz32, |
| intrinsics::cttz32, |
| intrinsics::bswap32, |
| intrinsics::u32_add_with_overflow, |
| intrinsics::u32_sub_with_overflow, |
| intrinsics::u32_mul_with_overflow } |
| } |
| |
| |
| #[lang = "u64"] |
| impl u64 { |
| uint_impl! { u64 = u64, 64, |
| intrinsics::ctpop64, |
| intrinsics::ctlz64, |
| intrinsics::cttz64, |
| intrinsics::bswap64, |
| intrinsics::u64_add_with_overflow, |
| intrinsics::u64_sub_with_overflow, |
| intrinsics::u64_mul_with_overflow } |
| } |
| |
| #[cfg(target_pointer_width = "32")] |
| #[lang = "usize"] |
| impl usize { |
| uint_impl! { usize = u32, 32, |
| intrinsics::ctpop32, |
| intrinsics::ctlz32, |
| intrinsics::cttz32, |
| intrinsics::bswap32, |
| intrinsics::u32_add_with_overflow, |
| intrinsics::u32_sub_with_overflow, |
| intrinsics::u32_mul_with_overflow } |
| } |
| |
| #[cfg(target_pointer_width = "64")] |
| #[lang = "usize"] |
| impl usize { |
| uint_impl! { usize = u64, 64, |
| intrinsics::ctpop64, |
| intrinsics::ctlz64, |
| intrinsics::cttz64, |
| intrinsics::bswap64, |
| intrinsics::u64_add_with_overflow, |
| intrinsics::u64_sub_with_overflow, |
| intrinsics::u64_mul_with_overflow } |
| } |
| |
| /// Used for representing the classification of floating point numbers |
| #[derive(Copy, Clone, PartialEq, Debug)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub enum FpCategory { |
| /// "Not a Number", often obtained by dividing by zero |
| #[stable(feature = "rust1", since = "1.0.0")] |
| Nan, |
| |
| /// Positive or negative infinity |
| #[stable(feature = "rust1", since = "1.0.0")] |
| Infinite , |
| |
| /// Positive or negative zero |
| #[stable(feature = "rust1", since = "1.0.0")] |
| Zero, |
| |
| /// De-normalized floating point representation (less precise than `Normal`) |
| #[stable(feature = "rust1", since = "1.0.0")] |
| Subnormal, |
| |
| /// A regular floating point number |
| #[stable(feature = "rust1", since = "1.0.0")] |
| Normal, |
| } |
| |
| /// A built-in floating point number. |
| #[doc(hidden)] |
| pub trait Float { |
| /// 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 0.0. |
| fn zero() -> Self; |
| /// Returns 1.0. |
| fn one() -> Self; |
| /// Parses the string `s` with the radix `r` as a float. |
| fn from_str_radix(s: &str, r: u32) -> Result<Self, ParseFloatError>; |
| |
| /// 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 mantissa, exponent and sign as integers, respectively. |
| fn integer_decode(self) -> (u64, i16, i8); |
| |
| /// 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; |
| |
| /// Computes the absolute value of `self`. Returns `Float::nan()` if the |
| /// number is `Float::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()` |
| fn signum(self) -> Self; |
| /// Returns `true` if `self` is positive, including `+0.0` and |
| /// `Float::infinity()`. |
| fn is_positive(self) -> bool; |
| /// Returns `true` if `self` is negative, including `-0.0` and |
| /// `Float::neg_infinity()`. |
| fn is_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. |
| fn mul_add(self, a: Self, b: Self) -> Self; |
| /// Take the reciprocal (inverse) of a number, `1/x`. |
| fn recip(self) -> Self; |
| |
| /// Raise a number to an integer power. |
| /// |
| /// Using this function is generally faster than using `powf` |
| fn powi(self, n: i32) -> Self; |
| /// Raise a number to a floating point power. |
| fn powf(self, n: Self) -> Self; |
| |
| /// Take the square root of a number. |
| /// |
| /// Returns NaN if `self` is a negative number. |
| fn sqrt(self) -> Self; |
| /// Take the reciprocal (inverse) square root of a number, `1/sqrt(x)`. |
| fn rsqrt(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; |
| |
| /// Convert radians to degrees. |
| fn to_degrees(self) -> Self; |
| /// Convert degrees to radians. |
| fn to_radians(self) -> Self; |
| } |
| |
| macro_rules! from_str_float_impl { |
| ($T:ident) => { |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl FromStr for $T { |
| type Err = ParseFloatError; |
| |
| /// Converts a string in base 10 to a float. |
| /// Accepts an optional decimal exponent. |
| /// |
| /// This function accepts strings such as |
| /// |
| /// * '3.14' |
| /// * '+3.14', equivalent to '3.14' |
| /// * '-3.14' |
| /// * '2.5E10', or equivalently, '2.5e10' |
| /// * '2.5E-10' |
| /// * '.' (understood as 0) |
| /// * '5.' |
| /// * '.5', or, equivalently, '0.5' |
| /// * '+inf', 'inf', '-inf', 'NaN' |
| /// |
| /// Leading and trailing whitespace represent an error. |
| /// |
| /// # Arguments |
| /// |
| /// * src - A string |
| /// |
| /// # Return value |
| /// |
| /// `Err(ParseFloatError)` if the string did not represent a valid |
| /// number. Otherwise, `Ok(n)` where `n` is the floating-point |
| /// number represented by `src`. |
| #[inline] |
| #[allow(deprecated)] |
| fn from_str(src: &str) -> Result<$T, ParseFloatError> { |
| $T::from_str_radix(src, 10) |
| } |
| } |
| } |
| } |
| from_str_float_impl!(f32); |
| from_str_float_impl!(f64); |
| |
| macro_rules! from_str_radix_int_impl { |
| ($($T:ident)*) => {$( |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[allow(deprecated)] |
| impl FromStr for $T { |
| type Err = ParseIntError; |
| fn from_str(src: &str) -> Result<$T, ParseIntError> { |
| from_str_radix(src, 10) |
| } |
| } |
| )*} |
| } |
| from_str_radix_int_impl! { isize i8 i16 i32 i64 usize u8 u16 u32 u64 } |
| |
| #[doc(hidden)] |
| trait FromStrRadixHelper: PartialOrd + Copy { |
| fn min_value() -> Self; |
| fn from_u32(u: u32) -> Self; |
| fn checked_mul(&self, other: u32) -> Option<Self>; |
| fn checked_sub(&self, other: u32) -> Option<Self>; |
| fn checked_add(&self, other: u32) -> Option<Self>; |
| } |
| |
| macro_rules! doit { |
| ($($t:ident)*) => ($(impl FromStrRadixHelper for $t { |
| fn min_value() -> Self { <$t>::min_value() } |
| fn from_u32(u: u32) -> Self { u as $t } |
| fn checked_mul(&self, other: u32) -> Option<Self> { |
| <$t>::checked_mul(*self, other as $t) |
| } |
| fn checked_sub(&self, other: u32) -> Option<Self> { |
| <$t>::checked_sub(*self, other as $t) |
| } |
| fn checked_add(&self, other: u32) -> Option<Self> { |
| <$t>::checked_add(*self, other as $t) |
| } |
| })*) |
| } |
| doit! { i8 i16 i32 i64 isize u8 u16 u32 u64 usize } |
| |
| fn from_str_radix<T: FromStrRadixHelper>(src: &str, radix: u32) |
| -> Result<T, ParseIntError> { |
| use self::IntErrorKind::*; |
| use self::ParseIntError as PIE; |
| assert!(radix >= 2 && radix <= 36, |
| "from_str_radix_int: must lie in the range `[2, 36]` - found {}", |
| radix); |
| |
| let is_signed_ty = T::from_u32(0) > T::min_value(); |
| |
| match src.slice_shift_char() { |
| Some(('-', "")) => Err(PIE { kind: Empty }), |
| Some(('-', src)) if is_signed_ty => { |
| // The number is negative |
| let mut result = T::from_u32(0); |
| for c in src.chars() { |
| let x = match c.to_digit(radix) { |
| Some(x) => x, |
| None => return Err(PIE { kind: InvalidDigit }), |
| }; |
| result = match result.checked_mul(radix) { |
| Some(result) => result, |
| None => return Err(PIE { kind: Underflow }), |
| }; |
| result = match result.checked_sub(x) { |
| Some(result) => result, |
| None => return Err(PIE { kind: Underflow }), |
| }; |
| } |
| Ok(result) |
| }, |
| Some((_, _)) => { |
| // The number is signed |
| let mut result = T::from_u32(0); |
| for c in src.chars() { |
| let x = match c.to_digit(radix) { |
| Some(x) => x, |
| None => return Err(PIE { kind: InvalidDigit }), |
| }; |
| result = match result.checked_mul(radix) { |
| Some(result) => result, |
| None => return Err(PIE { kind: Overflow }), |
| }; |
| result = match result.checked_add(x) { |
| Some(result) => result, |
| None => return Err(PIE { kind: Overflow }), |
| }; |
| } |
| Ok(result) |
| }, |
| None => Err(ParseIntError { kind: Empty }), |
| } |
| } |
| |
| /// An error which can be returned when parsing an integer. |
| #[derive(Debug, Clone, PartialEq)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct ParseIntError { kind: IntErrorKind } |
| |
| #[derive(Debug, Clone, PartialEq)] |
| enum IntErrorKind { |
| Empty, |
| InvalidDigit, |
| Overflow, |
| Underflow, |
| } |
| |
| impl ParseIntError { |
| #[unstable(feature = "core", reason = "available through Error trait")] |
| pub fn description(&self) -> &str { |
| match self.kind { |
| IntErrorKind::Empty => "cannot parse integer from empty string", |
| IntErrorKind::InvalidDigit => "invalid digit found in string", |
| IntErrorKind::Overflow => "number too large to fit in target type", |
| IntErrorKind::Underflow => "number too small to fit in target type", |
| } |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl fmt::Display for ParseIntError { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| self.description().fmt(f) |
| } |
| } |
| |
| /// An error which can be returned when parsing a float. |
| #[derive(Debug, Clone, PartialEq)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct ParseFloatError { |
| #[doc(hidden)] |
| pub __kind: FloatErrorKind |
| } |
| |
| #[derive(Debug, Clone, PartialEq)] |
| pub enum FloatErrorKind { |
| Empty, |
| Invalid, |
| } |
| |
| impl ParseFloatError { |
| #[doc(hidden)] |
| pub fn __description(&self) -> &str { |
| match self.__kind { |
| FloatErrorKind::Empty => "cannot parse float from empty string", |
| FloatErrorKind::Invalid => "invalid float literal", |
| } |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl fmt::Display for ParseFloatError { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| self.__description().fmt(f) |
| } |
| } |
