macro_rules! int_impl { ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $BITS_MINUS_ONE:expr, $Min:expr, $Max:expr, $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr, $reversed:expr, $le_bytes:expr, $be_bytes:expr, $to_xe_bytes_doc:expr, $from_xe_bytes_doc:expr, $bound_condition:expr) => { /// The smallest value that can be represented by this integer type #[doc = concat!("(−2^{", $BITS_MINUS_ONE, "}", $bound_condition, ")")] /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN, ", stringify!($Min), ");")] /// ``` #[stable(feature = "assoc_int_consts", since = "1.43.0")] pub const MIN: Self = !0 ^ ((!0 as $UnsignedT) >> 1) as Self; /// The largest value that can be represented by this integer type #[doc = concat!("(2^{", $BITS_MINUS_ONE, "} − 1", $bound_condition, ")")] /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX, ", stringify!($Max), ");")] /// ``` #[stable(feature = "assoc_int_consts", since = "1.43.0")] pub const MAX: Self = !Self::MIN; /// The size of this integer type in bits. /// /// # Examples /// /// ``` #[doc = concat!("assert_eq!(", stringify!($SelfT), "::BITS, ", stringify!($BITS), ");")] /// ``` #[stable(feature = "int_bits_const", since = "1.53.0")] pub const BITS: u32 = $BITS; /// Converts a string slice in a given base to an integer. /// /// The string is expected to be an optional `+` or `-` sign followed by digits. /// Leading and trailing whitespace represent an error. Digits are a subset of these characters, /// depending on `radix`: /// /// * `0-9` /// * `a-z` /// * `A-Z` /// /// # Panics /// /// This function panics if `radix` is not in the range from 2 to 36. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(", stringify!($SelfT), "::from_str_radix(\"A\", 16), Ok(10));")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] pub fn from_str_radix(src: &str, radix: u32) -> Result { from_str_radix(src, radix) } /// Returns the number of ones in the binary representation of `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = 0b100_0000", stringify!($SelfT), ";")] /// /// assert_eq!(n.count_ones(), 1); /// ``` /// #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[doc(alias = "popcount")] #[doc(alias = "popcnt")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn count_ones(self) -> u32 { (self as $UnsignedT).count_ones() } /// Returns the number of zeros in the binary representation of `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.count_zeros(), 1);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn count_zeros(self) -> u32 { (!self).count_ones() } /// Returns the number of leading zeros in the binary representation of `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = -1", stringify!($SelfT), ";")] /// /// assert_eq!(n.leading_zeros(), 0); /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn leading_zeros(self) -> u32 { (self as $UnsignedT).leading_zeros() } /// Returns the number of trailing zeros in the binary representation of `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = -4", stringify!($SelfT), ";")] /// /// assert_eq!(n.trailing_zeros(), 2); /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn trailing_zeros(self) -> u32 { (self as $UnsignedT).trailing_zeros() } /// Returns the number of leading ones in the binary representation of `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = -1", stringify!($SelfT), ";")] /// #[doc = concat!("assert_eq!(n.leading_ones(), ", stringify!($BITS), ");")] /// ``` #[stable(feature = "leading_trailing_ones", since = "1.46.0")] #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn leading_ones(self) -> u32 { (self as $UnsignedT).leading_ones() } /// Returns the number of trailing ones in the binary representation of `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = 3", stringify!($SelfT), ";")] /// /// assert_eq!(n.trailing_ones(), 2); /// ``` #[stable(feature = "leading_trailing_ones", since = "1.46.0")] #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn trailing_ones(self) -> u32 { (self as $UnsignedT).trailing_ones() } /// Shifts the bits to the left by a specified amount, `n`, /// wrapping the truncated bits to the end of the resulting integer. /// /// Please note this isn't the same operation as the `<<` shifting operator! /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = ", $rot_op, stringify!($SelfT), ";")] #[doc = concat!("let m = ", $rot_result, ";")] /// #[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn rotate_left(self, n: u32) -> Self { (self as $UnsignedT).rotate_left(n) as Self } /// Shifts the bits to the right by a specified amount, `n`, /// wrapping the truncated bits to the beginning of the resulting /// integer. /// /// Please note this isn't the same operation as the `>>` shifting operator! /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = ", $rot_result, stringify!($SelfT), ";")] #[doc = concat!("let m = ", $rot_op, ";")] /// #[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn rotate_right(self, n: u32) -> Self { (self as $UnsignedT).rotate_right(n) as Self } /// Reverses the byte order of the integer. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")] /// /// let m = n.swap_bytes(); /// #[doc = concat!("assert_eq!(m, ", $swapped, ");")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn swap_bytes(self) -> Self { (self as $UnsignedT).swap_bytes() as Self } /// Reverses the order of bits in the integer. The least significant bit becomes the most significant bit, /// second least-significant bit becomes second most-significant bit, etc. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")] /// let m = n.reverse_bits(); /// #[doc = concat!("assert_eq!(m, ", $reversed, ");")] #[doc = concat!("assert_eq!(0, 0", stringify!($SelfT), ".reverse_bits());")] /// ``` #[stable(feature = "reverse_bits", since = "1.37.0")] #[rustc_const_stable(feature = "reverse_bits", since = "1.37.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn reverse_bits(self) -> Self { (self as $UnsignedT).reverse_bits() as Self } /// Converts an integer from big endian to the target's endianness. /// /// On big endian this is a no-op. On little endian the bytes are swapped. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")] /// /// if cfg!(target_endian = "big") { #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n)")] /// } else { #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n.swap_bytes())")] /// } /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")] #[must_use] #[inline] pub const fn from_be(x: Self) -> Self { #[cfg(target_endian = "big")] { x } #[cfg(not(target_endian = "big"))] { 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 /// /// Basic usage: /// /// ``` #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")] /// /// if cfg!(target_endian = "little") { #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n)")] /// } else { #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n.swap_bytes())")] /// } /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")] #[must_use] #[inline] pub const fn from_le(x: Self) -> Self { #[cfg(target_endian = "little")] { x } #[cfg(not(target_endian = "little"))] { x.swap_bytes() } } /// Converts `self` to big endian from the target's endianness. /// /// On big endian this is a no-op. On little endian the bytes are swapped. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")] /// /// 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")] #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn to_be(self) -> Self { // or not to be? #[cfg(target_endian = "big")] { self } #[cfg(not(target_endian = "big"))] { 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 /// /// Basic usage: /// /// ``` #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")] /// /// if cfg!(target_endian = "little") { /// assert_eq!(n.to_le(), n) /// } else { /// assert_eq!(n.to_le(), n.swap_bytes()) /// } /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn to_le(self) -> Self { #[cfg(target_endian = "little")] { self } #[cfg(not(target_endian = "little"))] { self.swap_bytes() } } /// Checked integer addition. Computes `self + rhs`, returning `None` /// if overflow occurred. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(1), Some(", stringify!($SelfT), "::MAX - 1));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(3), None);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_add(self, rhs: Self) -> Option { let (a, b) = self.overflowing_add(rhs); if unlikely!(b) {None} else {Some(a)} } /// Unchecked integer addition. Computes `self + rhs`, assuming overflow /// cannot occur. /// /// # Safety /// /// This results in undefined behavior when #[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX` or `self + rhs < ", stringify!($SelfT), "::MIN`,")] /// i.e. when [`checked_add`] would return `None`. /// #[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")] #[unstable( feature = "unchecked_math", reason = "niche optimization path", issue = "85122", )] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_add(self, rhs: Self) -> Self { // SAFETY: the caller must uphold the safety contract for // `unchecked_add`. unsafe { intrinsics::unchecked_add(self, rhs) } } /// Checked addition with an unsigned integer. Computes `self + rhs`, /// returning `None` if overflow occurred. /// /// # Examples /// /// Basic usage: /// /// ``` /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_unsigned(2), Some(3));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add_unsigned(3), None);")] /// ``` #[unstable(feature = "mixed_integer_ops", issue = "87840")] #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_add_unsigned(self, rhs: $UnsignedT) -> Option { let (a, b) = self.overflowing_add_unsigned(rhs); if unlikely!(b) {None} else {Some(a)} } /// Checked integer subtraction. Computes `self - rhs`, returning `None` if /// overflow occurred. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub(1), Some(", stringify!($SelfT), "::MIN + 1));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub(3), None);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_sub(self, rhs: Self) -> Option { let (a, b) = self.overflowing_sub(rhs); if unlikely!(b) {None} else {Some(a)} } /// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow /// cannot occur. /// /// # Safety /// /// This results in undefined behavior when #[doc = concat!("`self - rhs > ", stringify!($SelfT), "::MAX` or `self - rhs < ", stringify!($SelfT), "::MIN`,")] /// i.e. when [`checked_sub`] would return `None`. /// #[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")] #[unstable( feature = "unchecked_math", reason = "niche optimization path", issue = "85122", )] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self { // SAFETY: the caller must uphold the safety contract for // `unchecked_sub`. unsafe { intrinsics::unchecked_sub(self, rhs) } } /// Checked subtraction with an unsigned integer. Computes `self - rhs`, /// returning `None` if overflow occurred. /// /// # Examples /// /// Basic usage: /// /// ``` /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_unsigned(2), Some(-1));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub_unsigned(3), None);")] /// ``` #[unstable(feature = "mixed_integer_ops", issue = "87840")] #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_sub_unsigned(self, rhs: $UnsignedT) -> Option { let (a, b) = self.overflowing_sub_unsigned(rhs); if unlikely!(b) {None} else {Some(a)} } /// Checked integer multiplication. Computes `self * rhs`, returning `None` if /// overflow occurred. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(1), Some(", stringify!($SelfT), "::MAX));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(2), None);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_mul(self, rhs: Self) -> Option { let (a, b) = self.overflowing_mul(rhs); if unlikely!(b) {None} else {Some(a)} } /// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow /// cannot occur. /// /// # Safety /// /// This results in undefined behavior when #[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX` or `self * rhs < ", stringify!($SelfT), "::MIN`,")] /// i.e. when [`checked_mul`] would return `None`. /// #[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")] #[unstable( feature = "unchecked_math", reason = "niche optimization path", issue = "85122", )] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self { // SAFETY: the caller must uphold the safety contract for // `unchecked_mul`. unsafe { intrinsics::unchecked_mul(self, rhs) } } /// Checked integer division. Computes `self / rhs`, returning `None` if `rhs == 0` /// or the division results in overflow. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div(-1), Some(", stringify!($Max), "));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div(-1), None);")] #[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div(0), None);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_div(self, rhs: Self) -> Option { if unlikely!(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) { None } else { // SAFETY: div by zero and by INT_MIN have been checked above Some(unsafe { intrinsics::unchecked_div(self, rhs) }) } } /// Checked Euclidean division. Computes `self.div_euclid(rhs)`, /// returning `None` if `rhs == 0` or the division results in overflow. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div_euclid(-1), Some(", stringify!($Max), "));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div_euclid(-1), None);")] #[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div_euclid(0), None);")] /// ``` #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_div_euclid(self, rhs: Self) -> Option { // Using `&` helps LLVM see that it is the same check made in division. if unlikely!(rhs == 0 || ((self == Self::MIN) & (rhs == -1))) { None } else { Some(self.div_euclid(rhs)) } } /// Checked integer remainder. Computes `self % rhs`, returning `None` if /// `rhs == 0` or the division results in overflow. /// /// # Examples /// /// Basic usage: /// /// ``` /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(2), Some(1));")] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(0), None);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem(-1), None);")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_rem(self, rhs: Self) -> Option { if unlikely!(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) { None } else { // SAFETY: div by zero and by INT_MIN have been checked above Some(unsafe { intrinsics::unchecked_rem(self, rhs) }) } } /// Checked Euclidean remainder. Computes `self.rem_euclid(rhs)`, returning `None` /// if `rhs == 0` or the division results in overflow. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(2), Some(1));")] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(0), None);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem_euclid(-1), None);")] /// ``` #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_rem_euclid(self, rhs: Self) -> Option { // Using `&` helps LLVM see that it is the same check made in division. if unlikely!(rhs == 0 || ((self == Self::MIN) & (rhs == -1))) { None } else { Some(self.rem_euclid(rhs)) } } /// Checked negation. Computes `-self`, returning `None` if `self == MIN`. /// /// # Examples /// /// Basic usage: /// /// ``` /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_neg(), Some(-5));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_neg(), None);")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_neg(self) -> Option { let (a, b) = self.overflowing_neg(); if unlikely!(b) {None} else {Some(a)} } /// Checked shift left. Computes `self << rhs`, returning `None` if `rhs` is larger /// than or equal to the number of bits in `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(4), Some(0x10));")] #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(129), None);")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_shl(self, rhs: u32) -> Option { let (a, b) = self.overflowing_shl(rhs); if unlikely!(b) {None} else {Some(a)} } /// Unchecked shift left. Computes `self << rhs`, assuming that /// `rhs` is less than the number of bits in `self`. /// /// # Safety /// /// This results in undefined behavior if `rhs` is larger than /// or equal to the number of bits in `self`, /// i.e. when [`checked_shl`] would return `None`. /// #[doc = concat!("[`checked_shl`]: ", stringify!($SelfT), "::checked_shl")] #[unstable( feature = "unchecked_math", reason = "niche optimization path", issue = "85122", )] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_shl(self, rhs: Self) -> Self { // SAFETY: the caller must uphold the safety contract for // `unchecked_shl`. unsafe { intrinsics::unchecked_shl(self, rhs) } } /// Checked shift right. Computes `self >> rhs`, returning `None` if `rhs` is /// larger than or equal to the number of bits in `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(4), Some(0x1));")] #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(128), None);")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_shr(self, rhs: u32) -> Option { let (a, b) = self.overflowing_shr(rhs); if unlikely!(b) {None} else {Some(a)} } /// Unchecked shift right. Computes `self >> rhs`, assuming that /// `rhs` is less than the number of bits in `self`. /// /// # Safety /// /// This results in undefined behavior if `rhs` is larger than /// or equal to the number of bits in `self`, /// i.e. when [`checked_shr`] would return `None`. /// #[doc = concat!("[`checked_shr`]: ", stringify!($SelfT), "::checked_shr")] #[unstable( feature = "unchecked_math", reason = "niche optimization path", issue = "85122", )] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_shr(self, rhs: Self) -> Self { // SAFETY: the caller must uphold the safety contract for // `unchecked_shr`. unsafe { intrinsics::unchecked_shr(self, rhs) } } /// Checked absolute value. Computes `self.abs()`, returning `None` if /// `self == MIN`. /// /// # Examples /// /// Basic usage: /// /// ``` /// #[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").checked_abs(), Some(5));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_abs(), None);")] /// ``` #[stable(feature = "no_panic_abs", since = "1.13.0")] #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_abs(self) -> Option { if self.is_negative() { self.checked_neg() } else { Some(self) } } /// Checked exponentiation. Computes `self.pow(exp)`, returning `None` if /// overflow occurred. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(8", stringify!($SelfT), ".checked_pow(2), Some(64));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_pow(2), None);")] /// ``` #[stable(feature = "no_panic_pow", since = "1.34.0")] #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_pow(self, mut exp: u32) -> Option { if exp == 0 { return Some(1); } let mut base = self; let mut acc: Self = 1; while exp > 1 { if (exp & 1) == 1 { acc = try_opt!(acc.checked_mul(base)); } exp /= 2; base = try_opt!(base.checked_mul(base)); } // since exp!=0, finally the exp must be 1. // Deal with the final bit of the exponent separately, since // squaring the base afterwards is not necessary and may cause a // needless overflow. Some(try_opt!(acc.checked_mul(base))) } /// Saturating integer addition. Computes `self + rhs`, saturating at the numeric /// bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_add(1), 101);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add(100), ", stringify!($SelfT), "::MAX);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_add(-1), ", stringify!($SelfT), "::MIN);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn saturating_add(self, rhs: Self) -> Self { intrinsics::saturating_add(self, rhs) } /// Saturating addition with an unsigned integer. Computes `self + rhs`, /// saturating at the numeric bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_unsigned(2), 3);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add_unsigned(100), ", stringify!($SelfT), "::MAX);")] /// ``` #[unstable(feature = "mixed_integer_ops", issue = "87840")] #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn saturating_add_unsigned(self, rhs: $UnsignedT) -> Self { // Overflow can only happen at the upper bound // We cannot use `unwrap_or` here because it is not `const` match self.checked_add_unsigned(rhs) { Some(x) => x, None => Self::MAX, } } /// Saturating integer subtraction. Computes `self - rhs`, saturating at the /// numeric bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub(127), -27);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub(100), ", stringify!($SelfT), "::MIN);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_sub(-1), ", stringify!($SelfT), "::MAX);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn saturating_sub(self, rhs: Self) -> Self { intrinsics::saturating_sub(self, rhs) } /// Saturating subtraction with an unsigned integer. Computes `self - rhs`, /// saturating at the numeric bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub_unsigned(127), -27);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub_unsigned(100), ", stringify!($SelfT), "::MIN);")] /// ``` #[unstable(feature = "mixed_integer_ops", issue = "87840")] #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn saturating_sub_unsigned(self, rhs: $UnsignedT) -> Self { // Overflow can only happen at the lower bound // We cannot use `unwrap_or` here because it is not `const` match self.checked_sub_unsigned(rhs) { Some(x) => x, None => Self::MIN, } } /// Saturating integer negation. Computes `-self`, returning `MAX` if `self == MIN` /// instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_neg(), -100);")] #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").saturating_neg(), 100);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_neg(), ", stringify!($SelfT), "::MAX);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_neg(), ", stringify!($SelfT), "::MIN + 1);")] /// ``` #[stable(feature = "saturating_neg", since = "1.45.0")] #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn saturating_neg(self) -> Self { intrinsics::saturating_sub(0, self) } /// Saturating absolute value. Computes `self.abs()`, returning `MAX` if `self == /// MIN` instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_abs(), 100);")] #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").saturating_abs(), 100);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_abs(), ", stringify!($SelfT), "::MAX);")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).saturating_abs(), ", stringify!($SelfT), "::MAX);")] /// ``` #[stable(feature = "saturating_neg", since = "1.45.0")] #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn saturating_abs(self) -> Self { if self.is_negative() { self.saturating_neg() } else { self } } /// Saturating integer multiplication. Computes `self * rhs`, saturating at the /// numeric bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` /// #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".saturating_mul(12), 120);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_mul(10), ", stringify!($SelfT), "::MAX);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_mul(10), ", stringify!($SelfT), "::MIN);")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn saturating_mul(self, rhs: Self) -> Self { match self.checked_mul(rhs) { Some(x) => x, None => if (self < 0) == (rhs < 0) { Self::MAX } else { Self::MIN } } } /// Saturating integer division. Computes `self / rhs`, saturating at the /// numeric bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".saturating_div(2), 2);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_div(-1), ", stringify!($SelfT), "::MIN + 1);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_div(-1), ", stringify!($SelfT), "::MAX);")] /// /// ``` /// /// ```should_panic #[doc = concat!("let _ = 1", stringify!($SelfT), ".saturating_div(0);")] /// /// ``` #[stable(feature = "saturating_div", since = "1.58.0")] #[rustc_const_stable(feature = "saturating_div", since = "1.58.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn saturating_div(self, rhs: Self) -> Self { match self.overflowing_div(rhs) { (result, false) => result, (_result, true) => Self::MAX, // MIN / -1 is the only possible saturating overflow } } /// Saturating integer exponentiation. Computes `self.pow(exp)`, /// saturating at the numeric bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` /// #[doc = concat!("assert_eq!((-4", stringify!($SelfT), ").saturating_pow(3), -64);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(2), ", stringify!($SelfT), "::MAX);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(3), ", stringify!($SelfT), "::MIN);")] /// ``` #[stable(feature = "no_panic_pow", since = "1.34.0")] #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn saturating_pow(self, exp: u32) -> Self { match self.checked_pow(exp) { Some(x) => x, None if self < 0 && exp % 2 == 1 => Self::MIN, None => Self::MAX, } } /// Wrapping (modular) addition. Computes `self + rhs`, wrapping around at the /// boundary of the type. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add(27), 127);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add(2), ", stringify!($SelfT), "::MIN + 1);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn wrapping_add(self, rhs: Self) -> Self { intrinsics::wrapping_add(self, rhs) } /// Wrapping (modular) addition with an unsigned integer. Computes /// `self + rhs`, wrapping around at the boundary of the type. /// /// # Examples /// /// Basic usage: /// /// ``` /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add_unsigned(27), 127);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add_unsigned(2), ", stringify!($SelfT), "::MIN + 1);")] /// ``` #[unstable(feature = "mixed_integer_ops", issue = "87840")] #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn wrapping_add_unsigned(self, rhs: $UnsignedT) -> Self { self.wrapping_add(rhs as Self) } /// Wrapping (modular) subtraction. Computes `self - rhs`, wrapping around at the /// boundary of the type. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub(127), -127);")] #[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub(", stringify!($SelfT), "::MAX), ", stringify!($SelfT), "::MAX);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn wrapping_sub(self, rhs: Self) -> Self { intrinsics::wrapping_sub(self, rhs) } /// Wrapping (modular) subtraction with an unsigned integer. Computes /// `self - rhs`, wrapping around at the boundary of the type. /// /// # Examples /// /// Basic usage: /// /// ``` /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub_unsigned(127), -127);")] #[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub_unsigned(", stringify!($UnsignedT), "::MAX), -1);")] /// ``` #[unstable(feature = "mixed_integer_ops", issue = "87840")] #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn wrapping_sub_unsigned(self, rhs: $UnsignedT) -> Self { self.wrapping_sub(rhs as Self) } /// Wrapping (modular) multiplication. Computes `self * rhs`, wrapping around at /// the boundary of the type. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".wrapping_mul(12), 120);")] /// assert_eq!(11i8.wrapping_mul(12), -124); /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn wrapping_mul(self, rhs: Self) -> Self { intrinsics::wrapping_mul(self, rhs) } /// Wrapping (modular) division. Computes `self / rhs`, 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. /// /// # Panics /// /// This function will panic if `rhs` is 0. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div(10), 10);")] /// assert_eq!((-128i8).wrapping_div(-1), -128); /// ``` #[stable(feature = "num_wrapping", since = "1.2.0")] #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn wrapping_div(self, rhs: Self) -> Self { self.overflowing_div(rhs).0 } /// Wrapping Euclidean division. Computes `self.div_euclid(rhs)`, /// wrapping around at the boundary of the type. /// /// Wrapping will only occur in `MIN / -1` on a signed type (where `MIN` is the negative minimal value /// for the type). This is equivalent to `-MIN`, a positive value that is too large to represent in the /// type. In this case, this method returns `MIN` itself. /// /// # Panics /// /// This function will panic if `rhs` is 0. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div_euclid(10), 10);")] /// assert_eq!((-128i8).wrapping_div_euclid(-1), -128); /// ``` #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn wrapping_div_euclid(self, rhs: Self) -> Self { self.overflowing_div_euclid(rhs).0 } /// Wrapping (modular) remainder. Computes `self % rhs`, wrapping around at the /// boundary of the type. /// /// Such wrap-around never actually occurs mathematically; implementation artifacts make `x % y` /// invalid for `MIN / -1` on a signed type (where `MIN` is the negative minimal value). In such a case, /// this function returns `0`. /// /// # Panics /// /// This function will panic if `rhs` is 0. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem(10), 0);")] /// assert_eq!((-128i8).wrapping_rem(-1), 0); /// ``` #[stable(feature = "num_wrapping", since = "1.2.0")] #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn wrapping_rem(self, rhs: Self) -> Self { self.overflowing_rem(rhs).0 } /// Wrapping Euclidean remainder. Computes `self.rem_euclid(rhs)`, wrapping around /// at the boundary of the type. /// /// Wrapping will only occur in `MIN % -1` on a signed type (where `MIN` is the negative minimal value /// for the type). In this case, this method returns 0. /// /// # Panics /// /// This function will panic if `rhs` is 0. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem_euclid(10), 0);")] /// assert_eq!((-128i8).wrapping_rem_euclid(-1), 0); /// ``` #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn wrapping_rem_euclid(self, rhs: Self) -> Self { self.overflowing_rem_euclid(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. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_neg(), -100);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.wrapping_neg(), ", stringify!($SelfT), "::MIN);")] /// ``` #[stable(feature = "num_wrapping", since = "1.2.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn wrapping_neg(self) -> Self { (0 as $SelfT).wrapping_sub(self) } /// Panic-free bitwise shift-left; yields `self << mask(rhs)`, where `mask` removes /// any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type. /// /// Note that this is *not* the same as a rotate-left; the RHS of a wrapping shift-left is restricted to /// the range of the type, rather than the bits shifted out of the LHS being returned to the other end. /// The primitive integer types all implement a [`rotate_left`](Self::rotate_left) function, /// which may be what you want instead. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!((-1", stringify!($SelfT), ").wrapping_shl(7), -128);")] #[doc = concat!("assert_eq!((-1", stringify!($SelfT), ").wrapping_shl(128), -1);")] /// ``` #[stable(feature = "num_wrapping", since = "1.2.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn wrapping_shl(self, rhs: u32) -> Self { // SAFETY: the masking by the bitsize of the type ensures that we do not shift // out of bounds unsafe { intrinsics::unchecked_shl(self, (rhs & ($BITS - 1)) as $SelfT) } } /// Panic-free bitwise shift-right; yields `self >> mask(rhs)`, where `mask` /// removes any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type. /// /// Note that this is *not* the same as a rotate-right; the RHS of a wrapping shift-right is restricted /// to the range of the type, rather than the bits shifted out of the LHS being returned to the other /// end. The primitive integer types all implement a [`rotate_right`](Self::rotate_right) function, /// which may be what you want instead. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!((-128", stringify!($SelfT), ").wrapping_shr(7), -1);")] /// assert_eq!((-128i16).wrapping_shr(64), -128); /// ``` #[stable(feature = "num_wrapping", since = "1.2.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn wrapping_shr(self, rhs: u32) -> Self { // SAFETY: the masking by the bitsize of the type ensures that we do not shift // out of bounds unsafe { intrinsics::unchecked_shr(self, (rhs & ($BITS - 1)) as $SelfT) } } /// Wrapping (modular) absolute value. Computes `self.abs()`, wrapping around at /// the boundary of the type. /// /// The only case where such wrapping can occur is when one takes the absolute value of the negative /// minimal value for the type; this is a positive value that is too large to represent in the type. In /// such a case, this function returns `MIN` itself. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_abs(), 100);")] #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").wrapping_abs(), 100);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.wrapping_abs(), ", stringify!($SelfT), "::MIN);")] /// assert_eq!((-128i8).wrapping_abs() as u8, 128); /// ``` #[stable(feature = "no_panic_abs", since = "1.13.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[allow(unused_attributes)] #[inline] pub const fn wrapping_abs(self) -> Self { if self.is_negative() { self.wrapping_neg() } else { self } } /// Computes the absolute value of `self` without any wrapping /// or panicking. /// /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".unsigned_abs(), 100", stringify!($UnsignedT), ");")] #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").unsigned_abs(), 100", stringify!($UnsignedT), ");")] /// assert_eq!((-128i8).unsigned_abs(), 128u8); /// ``` #[stable(feature = "unsigned_abs", since = "1.51.0")] #[rustc_const_stable(feature = "unsigned_abs", since = "1.51.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn unsigned_abs(self) -> $UnsignedT { self.wrapping_abs() as $UnsignedT } /// Wrapping (modular) exponentiation. Computes `self.pow(exp)`, /// wrapping around at the boundary of the type. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_pow(4), 81);")] /// assert_eq!(3i8.wrapping_pow(5), -13); /// assert_eq!(3i8.wrapping_pow(6), -39); /// ``` #[stable(feature = "no_panic_pow", since = "1.34.0")] #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn wrapping_pow(self, mut exp: u32) -> Self { if exp == 0 { return 1; } let mut base = self; let mut acc: Self = 1; while exp > 1 { if (exp & 1) == 1 { acc = acc.wrapping_mul(base); } exp /= 2; base = base.wrapping_mul(base); } // since exp!=0, finally the exp must be 1. // Deal with the final bit of the exponent separately, since // squaring the base afterwards is not necessary and may cause a // needless overflow. acc.wrapping_mul(base) } /// Calculates `self` + `rhs` /// /// Returns a tuple of the addition along with a boolean indicating whether an arithmetic overflow would /// occur. If an overflow would have occurred then the wrapped value is returned. /// /// # Examples /// /// Basic usage: /// /// ``` /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (", stringify!($SelfT), "::MIN, true));")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn overflowing_add(self, rhs: Self) -> (Self, bool) { let (a, b) = intrinsics::add_with_overflow(self as $ActualT, rhs as $ActualT); (a as Self, b) } /// Calculates `self + rhs + carry` without the ability to overflow. /// /// Performs "signed ternary addition" which takes in an extra bit to add, and may return an /// additional bit of overflow. This signed function is used only on the highest-ordered data, /// for which the signed overflow result indicates whether the big integer overflowed or not. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(bigint_helper_methods)] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".carrying_add(2, false), (7, false));")] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".carrying_add(2, true), (8, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, false), (", stringify!($SelfT), "::MIN, true));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(0, true), (", stringify!($SelfT), "::MIN, true));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, true), (", stringify!($SelfT), "::MIN + 1, true));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(", stringify!($SelfT), "::MAX, true), ", "(-1, true));" )] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.carrying_add(-1, true), (", stringify!($SelfT), "::MIN, false));")] #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".carrying_add(", stringify!($SelfT), "::MAX, true), (", stringify!($SelfT), "::MIN, true));")] /// ``` /// /// If `carry` is false, this method is equivalent to [`overflowing_add`](Self::overflowing_add): /// /// ``` /// #![feature(bigint_helper_methods)] #[doc = concat!("assert_eq!(5_", stringify!($SelfT), ".carrying_add(2, false), 5_", stringify!($SelfT), ".overflowing_add(2));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, false), ", stringify!($SelfT), "::MAX.overflowing_add(1));")] /// ``` #[unstable(feature = "bigint_helper_methods", issue = "85532")] #[rustc_const_unstable(feature = "const_bigint_helper_methods", issue = "85532")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn carrying_add(self, rhs: Self, carry: bool) -> (Self, bool) { // note: longer-term this should be done via an intrinsic. // note: no intermediate overflow is required (https://github.com/rust-lang/rust/issues/85532#issuecomment-1032214946). let (a, b) = self.overflowing_add(rhs); let (c, d) = a.overflowing_add(carry as $SelfT); (c, b != d) } /// Calculates `self` + `rhs` with an unsigned `rhs` /// /// Returns a tuple of the addition along with a boolean indicating /// whether an arithmetic overflow would occur. If an overflow would /// have occurred then the wrapped value is returned. /// /// # Examples /// /// Basic usage: /// /// ``` /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_unsigned(2), (3, false));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_add_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MAX, false));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_add_unsigned(3), (", stringify!($SelfT), "::MIN, true));")] /// ``` #[unstable(feature = "mixed_integer_ops", issue = "87840")] #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn overflowing_add_unsigned(self, rhs: $UnsignedT) -> (Self, bool) { let rhs = rhs as Self; let (res, overflowed) = self.overflowing_add(rhs); (res, overflowed ^ (rhs < 0)) } /// Calculates `self` - `rhs` /// /// Returns a tuple of the subtraction along with a boolean indicating whether an arithmetic overflow /// would occur. If an overflow would have occurred then the wrapped value is returned. /// /// # Examples /// /// Basic usage: /// /// ``` /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_sub(1), (", stringify!($SelfT), "::MAX, true));")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn overflowing_sub(self, rhs: Self) -> (Self, bool) { let (a, b) = intrinsics::sub_with_overflow(self as $ActualT, rhs as $ActualT); (a as Self, b) } /// Calculates `self - rhs - borrow` without the ability to overflow. /// /// Performs "signed ternary subtraction" which takes in an extra bit to subtract, and may return an /// additional bit of overflow. This signed function is used only on the highest-ordered data, /// for which the signed overflow result indicates whether the big integer overflowed or not. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(bigint_helper_methods)] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".borrowing_sub(2, false), (3, false));")] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".borrowing_sub(2, true), (2, false));")] #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".borrowing_sub(1, false), (-1, false));")] #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".borrowing_sub(1, true), (-2, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.borrowing_sub(1, true), (", stringify!($SelfT), "::MAX - 1, true));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.borrowing_sub(-1, false), (", stringify!($SelfT), "::MIN, true));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.borrowing_sub(-1, true), (", stringify!($SelfT), "::MAX, false));")] /// ``` #[unstable(feature = "bigint_helper_methods", issue = "85532")] #[rustc_const_unstable(feature = "const_bigint_helper_methods", issue = "85532")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn borrowing_sub(self, rhs: Self, borrow: bool) -> (Self, bool) { // note: longer-term this should be done via an intrinsic. // note: no intermediate overflow is required (https://github.com/rust-lang/rust/issues/85532#issuecomment-1032214946). let (a, b) = self.overflowing_sub(rhs); let (c, d) = a.overflowing_sub(borrow as $SelfT); (c, b != d) } /// Calculates `self` - `rhs` with an unsigned `rhs` /// /// Returns a tuple of the subtraction along with a boolean indicating /// whether an arithmetic overflow would occur. If an overflow would /// have occurred then the wrapped value is returned. /// /// # Examples /// /// Basic usage: /// /// ``` /// # #![feature(mixed_integer_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_unsigned(2), (-1, false));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX).overflowing_sub_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MIN, false));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).overflowing_sub_unsigned(3), (", stringify!($SelfT), "::MAX, true));")] /// ``` #[unstable(feature = "mixed_integer_ops", issue = "87840")] #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn overflowing_sub_unsigned(self, rhs: $UnsignedT) -> (Self, bool) { let rhs = rhs as Self; let (res, overflowed) = self.overflowing_sub(rhs); (res, overflowed ^ (rhs < 0)) } /// Calculates the multiplication of `self` and `rhs`. /// /// Returns a tuple of the multiplication along with a boolean indicating whether an arithmetic overflow /// would occur. If an overflow would have occurred then the wrapped value is returned. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_mul(2), (10, false));")] /// assert_eq!(1_000_000_000i32.overflowing_mul(10), (1410065408, true)); /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn overflowing_mul(self, rhs: Self) -> (Self, bool) { let (a, b) = intrinsics::mul_with_overflow(self as $ActualT, rhs as $ActualT); (a as Self, b) } /// Calculates the divisor when `self` is divided by `rhs`. /// /// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would /// occur. If an overflow would occur then self is returned. /// /// # Panics /// /// This function will panic if `rhs` is 0. /// /// # Examples /// /// Basic usage: /// /// ``` /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div(-1), (", stringify!($SelfT), "::MIN, true));")] /// ``` #[inline] #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] pub const fn overflowing_div(self, rhs: Self) -> (Self, bool) { // Using `&` helps LLVM see that it is the same check made in division. if unlikely!((self == Self::MIN) & (rhs == -1)) { (self, true) } else { (self / rhs, false) } } /// Calculates the quotient of Euclidean division `self.div_euclid(rhs)`. /// /// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would /// occur. If an overflow would occur then `self` is returned. /// /// # Panics /// /// This function will panic if `rhs` is 0. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div_euclid(2), (2, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div_euclid(-1), (", stringify!($SelfT), "::MIN, true));")] /// ``` #[inline] #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] pub const fn overflowing_div_euclid(self, rhs: Self) -> (Self, bool) { // Using `&` helps LLVM see that it is the same check made in division. if unlikely!((self == Self::MIN) & (rhs == -1)) { (self, true) } else { (self.div_euclid(rhs), false) } } /// Calculates the remainder when `self` is divided by `rhs`. /// /// Returns a tuple of the remainder after dividing along with a boolean indicating whether an /// arithmetic overflow would occur. If an overflow would occur then 0 is returned. /// /// # Panics /// /// This function will panic if `rhs` is 0. /// /// # Examples /// /// Basic usage: /// /// ``` /// #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem(2), (1, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem(-1), (0, true));")] /// ``` #[inline] #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) { if unlikely!(rhs == -1) { (0, self == Self::MIN) } else { (self % rhs, false) } } /// Overflowing Euclidean remainder. Calculates `self.rem_euclid(rhs)`. /// /// Returns a tuple of the remainder after dividing along with a boolean indicating whether an /// arithmetic overflow would occur. If an overflow would occur then 0 is returned. /// /// # Panics /// /// This function will panic if `rhs` is 0. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem_euclid(2), (1, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem_euclid(-1), (0, true));")] /// ``` #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) { if unlikely!(rhs == -1) { (0, self == Self::MIN) } else { (self.rem_euclid(rhs), false) } } /// Negates self, overflowing if this is equal to the minimum value. /// /// Returns a tuple of the negated version of self along with a boolean indicating whether an overflow /// happened. If `self` is the minimum value (e.g., `i32::MIN` for values of type `i32`), then the /// minimum value will be returned again and `true` will be returned for an overflow happening. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2, false));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_neg(), (", stringify!($SelfT), "::MIN, true));")] /// ``` #[inline] #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[allow(unused_attributes)] pub const fn overflowing_neg(self) -> (Self, bool) { if unlikely!(self == Self::MIN) { (Self::MIN, true) } else { (-self, false) } } /// Shifts self left by `rhs` bits. /// /// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift /// value was larger than or equal to the number of bits. If the shift value is too large, then value is /// masked (N-1) where N is the number of bits, and this value is then used to perform the shift. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(0x1", stringify!($SelfT),".overflowing_shl(4), (0x10, false));")] /// assert_eq!(0x1i32.overflowing_shl(36), (0x10, true)); /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn overflowing_shl(self, rhs: u32) -> (Self, bool) { (self.wrapping_shl(rhs), (rhs > ($BITS - 1))) } /// Shifts self right by `rhs` bits. /// /// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift /// value was larger than or equal to the number of bits. If the shift value is too large, then value is /// masked (N-1) where N is the number of bits, and this value is then used to perform the shift. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(4), (0x1, false));")] /// assert_eq!(0x10i32.overflowing_shr(36), (0x1, true)); /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) { (self.wrapping_shr(rhs), (rhs > ($BITS - 1))) } /// Computes the absolute value of `self`. /// /// Returns a tuple of the absolute version of self along with a boolean indicating whether an overflow /// happened. If self is the minimum value #[doc = concat!("(e.g., ", stringify!($SelfT), "::MIN for values of type ", stringify!($SelfT), "),")] /// then the minimum value will be returned again and true will be returned /// for an overflow happening. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".overflowing_abs(), (10, false));")] #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").overflowing_abs(), (10, false));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_abs(), (", stringify!($SelfT), "::MIN, true));")] /// ``` #[stable(feature = "no_panic_abs", since = "1.13.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn overflowing_abs(self) -> (Self, bool) { (self.wrapping_abs(), self == Self::MIN) } /// Raises self to the power of `exp`, using exponentiation by squaring. /// /// Returns a tuple of the exponentiation along with a bool indicating /// whether an overflow happened. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".overflowing_pow(4), (81, false));")] /// assert_eq!(3i8.overflowing_pow(5), (-13, true)); /// ``` #[stable(feature = "no_panic_pow", since = "1.34.0")] #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) { if exp == 0 { return (1,false); } let mut base = self; let mut acc: Self = 1; let mut overflown = false; // Scratch space for storing results of overflowing_mul. let mut r; while exp > 1 { if (exp & 1) == 1 { r = acc.overflowing_mul(base); acc = r.0; overflown |= r.1; } exp /= 2; r = base.overflowing_mul(base); base = r.0; overflown |= r.1; } // since exp!=0, finally the exp must be 1. // Deal with the final bit of the exponent separately, since // squaring the base afterwards is not necessary and may cause a // needless overflow. r = acc.overflowing_mul(base); r.1 |= overflown; r } /// Raises self to the power of `exp`, using exponentiation by squaring. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let x: ", stringify!($SelfT), " = 2; // or any other integer type")] /// /// assert_eq!(x.pow(5), 32); /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[rustc_inherit_overflow_checks] pub const fn pow(self, mut exp: u32) -> Self { if exp == 0 { return 1; } let mut base = self; let mut acc = 1; while exp > 1 { if (exp & 1) == 1 { acc = acc * base; } exp /= 2; base = base * base; } // since exp!=0, finally the exp must be 1. // Deal with the final bit of the exponent separately, since // squaring the base afterwards is not necessary and may cause a // needless overflow. acc * base } /// Calculates the quotient of Euclidean division of `self` by `rhs`. /// /// This computes the integer `q` such that `self = q * rhs + r`, with /// `r = self.rem_euclid(rhs)` and `0 <= r < abs(rhs)`. /// /// In other words, the result is `self / rhs` rounded to the integer `q` /// such that `self >= q * rhs`. /// If `self > 0`, this is equal to round towards zero (the default in Rust); /// if `self < 0`, this is equal to round towards +/- infinity. /// /// # Panics /// /// This function will panic if `rhs` is 0 or the division results in overflow. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")] /// let b = 4; /// /// assert_eq!(a.div_euclid(b), 1); // 7 >= 4 * 1 /// assert_eq!(a.div_euclid(-b), -1); // 7 >= -4 * -1 /// assert_eq!((-a).div_euclid(b), -2); // -7 >= 4 * -2 /// assert_eq!((-a).div_euclid(-b), 2); // -7 >= -4 * 2 /// ``` #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[rustc_inherit_overflow_checks] pub const fn div_euclid(self, rhs: Self) -> Self { let q = self / rhs; if self % rhs < 0 { return if rhs > 0 { q - 1 } else { q + 1 } } q } /// Calculates the least nonnegative remainder of `self (mod rhs)`. /// /// This is done as if by the Euclidean division algorithm -- given /// `r = self.rem_euclid(rhs)`, `self = rhs * self.div_euclid(rhs) + r`, and /// `0 <= r < abs(rhs)`. /// /// # Panics /// /// This function will panic if `rhs` is 0 or the division results in overflow. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")] /// let b = 4; /// /// assert_eq!(a.rem_euclid(b), 3); /// assert_eq!((-a).rem_euclid(b), 1); /// assert_eq!(a.rem_euclid(-b), 3); /// assert_eq!((-a).rem_euclid(-b), 1); /// ``` #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[rustc_inherit_overflow_checks] pub const fn rem_euclid(self, rhs: Self) -> Self { let r = self % rhs; if r < 0 { if rhs < 0 { r - rhs } else { r + rhs } } else { r } } /// Calculates the quotient of `self` and `rhs`, rounding the result towards negative infinity. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// ## Overflow behavior /// /// On overflow, this function will panic if overflow checks are enabled (default in debug /// mode) and wrap if overflow checks are disabled (default in release mode). /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(int_roundings)] #[doc = concat!("let a: ", stringify!($SelfT)," = 8;")] /// let b = 3; /// /// assert_eq!(a.div_floor(b), 2); /// assert_eq!(a.div_floor(-b), -3); /// assert_eq!((-a).div_floor(b), -3); /// assert_eq!((-a).div_floor(-b), 2); /// ``` #[unstable(feature = "int_roundings", issue = "88581")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[rustc_inherit_overflow_checks] pub const fn div_floor(self, rhs: Self) -> Self { let d = self / rhs; let r = self % rhs; if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) { d - 1 } else { d } } /// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// ## Overflow behavior /// /// On overflow, this function will panic if overflow checks are enabled (default in debug /// mode) and wrap if overflow checks are disabled (default in release mode). /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(int_roundings)] #[doc = concat!("let a: ", stringify!($SelfT)," = 8;")] /// let b = 3; /// /// assert_eq!(a.div_ceil(b), 3); /// assert_eq!(a.div_ceil(-b), -2); /// assert_eq!((-a).div_ceil(b), -2); /// assert_eq!((-a).div_ceil(-b), 3); /// ``` #[unstable(feature = "int_roundings", issue = "88581")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[rustc_inherit_overflow_checks] pub const fn div_ceil(self, rhs: Self) -> Self { let d = self / rhs; let r = self % rhs; if (r > 0 && rhs > 0) || (r < 0 && rhs < 0) { d + 1 } else { d } } /// If `rhs` is positive, calculates the smallest value greater than or /// equal to `self` that is a multiple of `rhs`. If `rhs` is negative, /// calculates the largest value less than or equal to `self` that is a /// multiple of `rhs`. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// ## Overflow behavior /// /// On overflow, this function will panic if overflow checks are enabled (default in debug /// mode) and wrap if overflow checks are disabled (default in release mode). /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(int_roundings)] #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(8), 16);")] #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(8), 24);")] #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(-8), 16);")] #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(-8), 16);")] #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(8), -16);")] #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(8), -16);")] #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(-8), -16);")] #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(-8), -24);")] /// ``` #[unstable(feature = "int_roundings", issue = "88581")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[rustc_inherit_overflow_checks] pub const fn next_multiple_of(self, rhs: Self) -> Self { // This would otherwise fail when calculating `r` when self == T::MIN. if rhs == -1 { return self; } let r = self % rhs; let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) { r + rhs } else { r }; if m == 0 { self } else { self + (rhs - m) } } /// If `rhs` is positive, calculates the smallest value greater than or /// equal to `self` that is a multiple of `rhs`. If `rhs` is negative, /// calculates the largest value less than or equal to `self` that is a /// multiple of `rhs`. Returns `None` if `rhs` is zero or the operation /// would result in overflow. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(int_roundings)] #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(16));")] #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(24));")] #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")] #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")] #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")] #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")] #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-16));")] #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-24));")] #[doc = concat!("assert_eq!(1_", stringify!($SelfT), ".checked_next_multiple_of(0), None);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_multiple_of(2), None);")] /// ``` #[unstable(feature = "int_roundings", issue = "88581")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_next_multiple_of(self, rhs: Self) -> Option { // This would otherwise fail when calculating `r` when self == T::MIN. if rhs == -1 { return Some(self); } let r = try_opt!(self.checked_rem(rhs)); let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) { // r + rhs cannot overflow because they have opposite signs r + rhs } else { r }; if m == 0 { Some(self) } else { // rhs - m cannot overflow because m has the same sign as rhs self.checked_add(rhs - m) } } /// Returns the logarithm of the number with respect to an arbitrary base, /// rounded down. /// /// This method might not be optimized owing to implementation details; /// `ilog2` can produce results more efficiently for base 2, and `ilog10` /// can produce results more efficiently for base 10. /// /// # Panics /// /// When the number is negative, zero, or if the base is not at least 2; it /// panics in debug mode and the return value is 0 in release /// mode. /// /// # Examples /// /// ``` /// #![feature(int_log)] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".ilog(5), 1);")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] #[rustc_inherit_overflow_checks] #[allow(arithmetic_overflow)] pub const fn ilog(self, base: Self) -> u32 { match self.checked_ilog(base) { Some(n) => n, None => { // In debug builds, trigger a panic on None. // This should optimize completely out in release builds. let _ = Self::MAX + 1; 0 }, } } /// Returns the base 2 logarithm of the number, rounded down. /// /// # Panics /// /// When the number is negative or zero it panics in debug mode and the return value /// is 0 in release mode. /// /// # Examples /// /// ``` /// #![feature(int_log)] #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".ilog2(), 1);")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] #[rustc_inherit_overflow_checks] #[allow(arithmetic_overflow)] pub const fn ilog2(self) -> u32 { match self.checked_ilog2() { Some(n) => n, None => { // In debug builds, trigger a panic on None. // This should optimize completely out in release builds. let _ = Self::MAX + 1; 0 }, } } /// Returns the base 10 logarithm of the number, rounded down. /// /// # Panics /// /// When the number is negative or zero it panics in debug mode and the return value /// is 0 in release mode. /// /// # Example /// /// ``` /// #![feature(int_log)] #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".ilog10(), 1);")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] #[rustc_inherit_overflow_checks] #[allow(arithmetic_overflow)] pub const fn ilog10(self) -> u32 { match self.checked_ilog10() { Some(n) => n, None => { // In debug builds, trigger a panic on None. // This should optimize completely out in release builds. let _ = Self::MAX + 1; 0 }, } } /// Returns the logarithm of the number with respect to an arbitrary base, /// rounded down. /// /// Returns `None` if the number is negative or zero, or if the base is not at least 2. /// /// This method might not be optimized owing to implementation details; /// `checked_ilog2` can produce results more efficiently for base 2, and /// `checked_ilog10` can produce results more efficiently for base 10. /// /// # Examples /// /// ``` /// #![feature(int_log)] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(5), Some(1));")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_ilog(self, base: Self) -> Option { if self <= 0 || base <= 1 { None } else { let mut n = 0; let mut r = self; // Optimization for 128 bit wide integers. if Self::BITS == 128 { let b = Self::ilog2(self) / (Self::ilog2(base) + 1); n += b; r /= base.pow(b as u32); } while r >= base { r /= base; n += 1; } Some(n) } } /// Returns the base 2 logarithm of the number, rounded down. /// /// Returns `None` if the number is negative or zero. /// /// # Examples /// /// ``` /// #![feature(int_log)] #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_ilog2(), Some(1));")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_ilog2(self) -> Option { if self <= 0 { None } else { // SAFETY: We just checked that this number is positive let log = (Self::BITS - 1) - unsafe { intrinsics::ctlz_nonzero(self) as u32 }; Some(log) } } /// Returns the base 10 logarithm of the number, rounded down. /// /// Returns `None` if the number is negative or zero. /// /// # Example /// /// ``` /// #![feature(int_log)] #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_ilog10(), Some(1));")] /// ``` #[unstable(feature = "int_log", issue = "70887")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_ilog10(self) -> Option { if self > 0 { Some(int_log10::$ActualT(self as $ActualT)) } else { None } } /// Computes the absolute value of `self`. /// /// # Overflow behavior /// /// The absolute value of #[doc = concat!("`", stringify!($SelfT), "::MIN`")] /// cannot be represented as an #[doc = concat!("`", stringify!($SelfT), "`,")] /// and attempting to calculate it will cause an overflow. This means /// that code in debug mode will trigger a panic on this case and /// optimized code will return #[doc = concat!("`", stringify!($SelfT), "::MIN`")] /// without a panic. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".abs(), 10);")] #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").abs(), 10);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[allow(unused_attributes)] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[rustc_inherit_overflow_checks] pub const fn abs(self) -> Self { // Note that the #[rustc_inherit_overflow_checks] and #[inline] // above mean that the overflow semantics of the subtraction // depend on the crate we're being called from. if self.is_negative() { -self } else { self } } /// Computes the absolute difference between `self` and `other`. /// /// This function always returns the correct answer without overflow or /// panics by returning an unsigned integer. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(80), 20", stringify!($UnsignedT), ");")] #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(110), 10", stringify!($UnsignedT), ");")] #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(80), 180", stringify!($UnsignedT), ");")] #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(-120), 20", stringify!($UnsignedT), ");")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.abs_diff(", stringify!($SelfT), "::MAX), ", stringify!($UnsignedT), "::MAX);")] /// ``` #[stable(feature = "int_abs_diff", since = "1.60.0")] #[rustc_const_stable(feature = "int_abs_diff", since = "1.60.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn abs_diff(self, other: Self) -> $UnsignedT { if self < other { // Converting a non-negative x from signed to unsigned by using // `x as U` is left unchanged, but a negative x is converted // to value x + 2^N. Thus if `s` and `o` are binary variables // respectively indicating whether `self` and `other` are // negative, we are computing the mathematical value: // // (other + o*2^N) - (self + s*2^N) mod 2^N // other - self + (o-s)*2^N mod 2^N // other - self mod 2^N // // Finally, taking the mod 2^N of the mathematical value of // `other - self` does not change it as it already is // in the range [0, 2^N). (other as $UnsignedT).wrapping_sub(self as $UnsignedT) } else { (self as $UnsignedT).wrapping_sub(other as $UnsignedT) } } /// Returns a number representing sign of `self`. /// /// - `0` if the number is zero /// - `1` if the number is positive /// - `-1` if the number is negative /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".signum(), 1);")] #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".signum(), 0);")] #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").signum(), -1);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_sign", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn signum(self) -> Self { 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. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert!(10", stringify!($SelfT), ".is_positive());")] #[doc = concat!("assert!(!(-10", stringify!($SelfT), ").is_positive());")] /// ``` #[must_use] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[inline(always)] pub const fn is_positive(self) -> bool { self > 0 } /// Returns `true` if `self` is negative and `false` if the number is zero or /// positive. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert!((-10", stringify!($SelfT), ").is_negative());")] #[doc = concat!("assert!(!10", stringify!($SelfT), ".is_negative());")] /// ``` #[must_use] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] #[inline(always)] pub const fn is_negative(self) -> bool { self < 0 } /// Return the memory representation of this integer as a byte array in /// big-endian (network) byte order. /// #[doc = $to_xe_bytes_doc] /// /// # Examples /// /// ``` #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_be_bytes();")] #[doc = concat!("assert_eq!(bytes, ", $be_bytes, ");")] /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn to_be_bytes(self) -> [u8; mem::size_of::()] { self.to_be().to_ne_bytes() } /// Return the memory representation of this integer as a byte array in /// little-endian byte order. /// #[doc = $to_xe_bytes_doc] /// /// # Examples /// /// ``` #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_le_bytes();")] #[doc = concat!("assert_eq!(bytes, ", $le_bytes, ");")] /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn to_le_bytes(self) -> [u8; mem::size_of::()] { self.to_le().to_ne_bytes() } /// Return the memory representation of this integer as a byte array in /// native byte order. /// /// As the target platform's native endianness is used, portable code /// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate, /// instead. /// #[doc = $to_xe_bytes_doc] /// /// [`to_be_bytes`]: Self::to_be_bytes /// [`to_le_bytes`]: Self::to_le_bytes /// /// # Examples /// /// ``` #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_ne_bytes();")] /// assert_eq!( /// bytes, /// if cfg!(target_endian = "big") { #[doc = concat!(" ", $be_bytes)] /// } else { #[doc = concat!(" ", $le_bytes)] /// } /// ); /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] // SAFETY: const sound because integers are plain old datatypes so we can always // transmute them to arrays of bytes #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn to_ne_bytes(self) -> [u8; mem::size_of::()] { // SAFETY: integers are plain old datatypes so we can always transmute them to // arrays of bytes unsafe { mem::transmute(self) } } /// Create an integer value from its representation as a byte array in /// big endian. /// #[doc = $from_xe_bytes_doc] /// /// # Examples /// /// ``` #[doc = concat!("let value = ", stringify!($SelfT), "::from_be_bytes(", $be_bytes, ");")] #[doc = concat!("assert_eq!(value, ", $swap_op, ");")] /// ``` /// /// When starting from a slice rather than an array, fallible conversion APIs can be used: /// /// ``` #[doc = concat!("fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")] #[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")] /// *input = rest; #[doc = concat!(" ", stringify!($SelfT), "::from_be_bytes(int_bytes.try_into().unwrap())")] /// } /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] #[must_use] #[inline] pub const fn from_be_bytes(bytes: [u8; mem::size_of::()]) -> Self { Self::from_be(Self::from_ne_bytes(bytes)) } /// Create an integer value from its representation as a byte array in /// little endian. /// #[doc = $from_xe_bytes_doc] /// /// # Examples /// /// ``` #[doc = concat!("let value = ", stringify!($SelfT), "::from_le_bytes(", $le_bytes, ");")] #[doc = concat!("assert_eq!(value, ", $swap_op, ");")] /// ``` /// /// When starting from a slice rather than an array, fallible conversion APIs can be used: /// /// ``` #[doc = concat!("fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")] #[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")] /// *input = rest; #[doc = concat!(" ", stringify!($SelfT), "::from_le_bytes(int_bytes.try_into().unwrap())")] /// } /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] #[must_use] #[inline] pub const fn from_le_bytes(bytes: [u8; mem::size_of::()]) -> Self { Self::from_le(Self::from_ne_bytes(bytes)) } /// Create an integer value from its memory representation as a byte /// array in native endianness. /// /// As the target platform's native endianness is used, portable code /// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as /// appropriate instead. /// /// [`from_be_bytes`]: Self::from_be_bytes /// [`from_le_bytes`]: Self::from_le_bytes /// #[doc = $from_xe_bytes_doc] /// /// # Examples /// /// ``` #[doc = concat!("let value = ", stringify!($SelfT), "::from_ne_bytes(if cfg!(target_endian = \"big\") {")] #[doc = concat!(" ", $be_bytes)] /// } else { #[doc = concat!(" ", $le_bytes)] /// }); #[doc = concat!("assert_eq!(value, ", $swap_op, ");")] /// ``` /// /// When starting from a slice rather than an array, fallible conversion APIs can be used: /// /// ``` #[doc = concat!("fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")] #[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")] /// *input = rest; #[doc = concat!(" ", stringify!($SelfT), "::from_ne_bytes(int_bytes.try_into().unwrap())")] /// } /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] #[must_use] // SAFETY: const sound because integers are plain old datatypes so we can always // transmute to them #[inline] pub const fn from_ne_bytes(bytes: [u8; mem::size_of::()]) -> Self { // SAFETY: integers are plain old datatypes so we can always transmute to them unsafe { mem::transmute(bytes) } } /// New code should prefer to use #[doc = concat!("[`", stringify!($SelfT), "::MIN", "`] instead.")] /// /// Returns the smallest value that can be represented by this integer type. #[stable(feature = "rust1", since = "1.0.0")] #[inline(always)] #[rustc_promotable] #[rustc_const_stable(feature = "const_min_value", since = "1.32.0")] #[deprecated(since = "TBD", note = "replaced by the `MIN` associated constant on this type")] pub const fn min_value() -> Self { Self::MIN } /// New code should prefer to use #[doc = concat!("[`", stringify!($SelfT), "::MAX", "`] instead.")] /// /// Returns the largest value that can be represented by this integer type. #[stable(feature = "rust1", since = "1.0.0")] #[inline(always)] #[rustc_promotable] #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")] #[deprecated(since = "TBD", note = "replaced by the `MAX` associated constant on this type")] pub const fn max_value() -> Self { Self::MAX } } }