macro_rules! uint_impl { ( Self = $SelfT:ty, ActualT = $ActualT:ident, SignedT = $SignedT:ident, // These are all for use *only* in doc comments. // As such, they're all passed as literals -- passing them as a string // literal is fine if they need to be multiple code tokens. // In non-comments, use the associated constants rather than these. BITS = $BITS:literal, BITS_MINUS_ONE = $BITS_MINUS_ONE:literal, MAX = $MaxV:literal, rot = $rot:literal, rot_op = $rot_op:literal, rot_result = $rot_result:literal, swap_op = $swap_op:literal, swapped = $swapped:literal, reversed = $reversed:literal, le_bytes = $le_bytes:literal, be_bytes = $be_bytes:literal, to_xe_bytes_doc = $to_xe_bytes_doc:expr, from_xe_bytes_doc = $from_xe_bytes_doc:expr, bound_condition = $bound_condition:literal, ) => { /// The smallest value that can be represented by this integer type. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN, 0);")] /// ``` #[stable(feature = "assoc_int_consts", since = "1.43.0")] pub const MIN: Self = 0; /// The largest value that can be represented by this integer type #[doc = concat!("(2", $BITS, " − 1", $bound_condition, ").")] /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX, ", stringify!($MaxV), ");")] /// ``` #[stable(feature = "assoc_int_consts", since = "1.43.0")] pub const MAX: Self = !0; /// The size of this integer type in bits. /// /// # Examples /// /// ``` #[doc = concat!("assert_eq!(", stringify!($SelfT), "::BITS, ", stringify!($BITS), ");")] /// ``` #[stable(feature = "int_bits_const", since = "1.53.0")] pub const BITS: u32 = Self::MAX.count_ones(); /// Returns the number of ones in the binary representation of `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = 0b01001100", stringify!($SelfT), ";")] /// assert_eq!(n.count_ones(), 3); /// #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")] #[doc = concat!("assert_eq!(max.count_ones(), ", stringify!($BITS), ");")] /// #[doc = concat!("let zero = 0", stringify!($SelfT), ";")] /// assert_eq!(zero.count_ones(), 0); /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_math", since = "1.32.0")] #[doc(alias = "popcount")] #[doc(alias = "popcnt")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn count_ones(self) -> u32 { return intrinsics::ctpop(self); } /// Returns the number of zeros in the binary representation of `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let zero = 0", stringify!($SelfT), ";")] #[doc = concat!("assert_eq!(zero.count_zeros(), ", stringify!($BITS), ");")] /// #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")] /// assert_eq!(max.count_zeros(), 0); /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_math", 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`. /// /// Depending on what you're doing with the value, you might also be interested in the /// [`ilog2`] function which returns a consistent number, even if the type widens. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = ", stringify!($SelfT), "::MAX >> 2;")] /// assert_eq!(n.leading_zeros(), 2); /// #[doc = concat!("let zero = 0", stringify!($SelfT), ";")] #[doc = concat!("assert_eq!(zero.leading_zeros(), ", stringify!($BITS), ");")] /// #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")] /// assert_eq!(max.leading_zeros(), 0); /// ``` #[doc = concat!("[`ilog2`]: ", stringify!($SelfT), "::ilog2")] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_math", 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 { return intrinsics::ctlz(self as $ActualT); } /// Returns the number of trailing zeros in the binary representation /// of `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = 0b0101000", stringify!($SelfT), ";")] /// assert_eq!(n.trailing_zeros(), 3); /// #[doc = concat!("let zero = 0", stringify!($SelfT), ";")] #[doc = concat!("assert_eq!(zero.trailing_zeros(), ", stringify!($BITS), ");")] /// #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")] #[doc = concat!("assert_eq!(max.trailing_zeros(), 0);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_math", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn trailing_zeros(self) -> u32 { return intrinsics::cttz(self); } /// Returns the number of leading ones in the binary representation of `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = !(", stringify!($SelfT), "::MAX >> 2);")] /// assert_eq!(n.leading_ones(), 2); /// #[doc = concat!("let zero = 0", stringify!($SelfT), ";")] /// assert_eq!(zero.leading_ones(), 0); /// #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")] #[doc = concat!("assert_eq!(max.leading_ones(), ", stringify!($BITS), ");")] /// ``` #[stable(feature = "leading_trailing_ones", since = "1.46.0")] #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn leading_ones(self) -> u32 { (!self).leading_zeros() } /// Returns the number of trailing ones in the binary representation /// of `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = 0b1010111", stringify!($SelfT), ";")] /// assert_eq!(n.trailing_ones(), 3); /// #[doc = concat!("let zero = 0", stringify!($SelfT), ";")] /// assert_eq!(zero.trailing_ones(), 0); /// #[doc = concat!("let max = ", stringify!($SelfT),"::MAX;")] #[doc = concat!("assert_eq!(max.trailing_ones(), ", stringify!($BITS), ");")] /// ``` #[stable(feature = "leading_trailing_ones", since = "1.46.0")] #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn trailing_ones(self) -> u32 { (!self).trailing_zeros() } /// Returns `self` with only the most significant bit set, or `0` if /// the input is `0`. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(isolate_most_least_significant_one)] /// #[doc = concat!("let n: ", stringify!($SelfT), " = 0b_01100100;")] /// /// assert_eq!(n.isolate_most_significant_one(), 0b_01000000); #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".isolate_most_significant_one(), 0);")] /// ``` #[unstable(feature = "isolate_most_least_significant_one", issue = "136909")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn isolate_most_significant_one(self) -> Self { self & (((1 as $SelfT) << (<$SelfT>::BITS - 1)).wrapping_shr(self.leading_zeros())) } /// Returns `self` with only the least significant bit set, or `0` if /// the input is `0`. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(isolate_most_least_significant_one)] /// #[doc = concat!("let n: ", stringify!($SelfT), " = 0b_01100100;")] /// /// assert_eq!(n.isolate_least_significant_one(), 0b_00000100); #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".isolate_least_significant_one(), 0);")] /// ``` #[unstable(feature = "isolate_most_least_significant_one", issue = "136909")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn isolate_least_significant_one(self) -> Self { self & self.wrapping_neg() } /// Returns the bit pattern of `self` reinterpreted as a signed integer of the same size. /// /// This produces the same result as an `as` cast, but ensures that the bit-width remains /// the same. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = ", stringify!($SelfT), "::MAX;")] /// #[doc = concat!("assert_eq!(n.cast_signed(), -1", stringify!($SignedT), ");")] /// ``` #[stable(feature = "integer_sign_cast", since = "1.87.0")] #[rustc_const_stable(feature = "integer_sign_cast", since = "1.87.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn cast_signed(self) -> $SignedT { self as $SignedT } /// 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_math", 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 { return intrinsics::rotate_left(self, n); } /// 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_math", 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 { return intrinsics::rotate_right(self, n); } /// 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_math", 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 { intrinsics::bswap(self as $ActualT) 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 { intrinsics::bitreverse(self as $ActualT) as Self } /// Converts an integer from big endian to the target's endianness. /// /// On big endian this is a no-op. On little endian the bytes are /// swapped. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = 0x1A", stringify!($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_math", since = "1.32.0")] #[must_use] #[inline(always)] 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!($SelfT), "::from_le(n), n.swap_bytes())")] /// } /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_math", since = "1.32.0")] #[must_use] #[inline(always)] pub const fn from_le(x: Self) -> Self { #[cfg(target_endian = "little")] { x } #[cfg(not(target_endian = "little"))] { x.swap_bytes() } } /// Converts `self` to big endian from the target's endianness. /// /// On big endian this is a no-op. On little endian the bytes are /// swapped. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("let n = 0x1A", stringify!($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_math", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] 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!($SelfT), ";")] /// /// if cfg!(target_endian = "little") { /// assert_eq!(n.to_le(), n) /// } else { /// assert_eq!(n.to_le(), n.swap_bytes()) /// } /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_math", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn to_le(self) -> Self { #[cfg(target_endian = "little")] { self } #[cfg(not(target_endian = "little"))] { self.swap_bytes() } } /// Checked integer addition. Computes `self + rhs`, returning `None` /// if overflow occurred. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!( "assert_eq!((", stringify!($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 { // This used to use `overflowing_add`, but that means it ends up being // a `wrapping_add`, losing some optimization opportunities. Notably, // phrasing it this way helps `.checked_add(1)` optimize to a check // against `MAX` and a `add nuw`. // Per , // LLVM is happy to re-form the intrinsic later if useful. if intrinsics::unlikely(intrinsics::add_with_overflow(self, rhs).1) { None } else { // SAFETY: Just checked it doesn't overflow Some(unsafe { intrinsics::unchecked_add(self, rhs) }) } } /// Strict integer addition. Computes `self + rhs`, panicking /// if overflow occurred. /// /// # Panics /// /// ## Overflow behavior /// /// This function will always panic on overflow, regardless of whether overflow checks are enabled. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(strict_overflow_ops)] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).strict_add(1), ", stringify!($SelfT), "::MAX - 1);")] /// ``` /// /// The following panics because of overflow: /// /// ```should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add(3);")] /// ``` #[unstable(feature = "strict_overflow_ops", issue = "118260")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn strict_add(self, rhs: Self) -> Self { let (a, b) = self.overflowing_add(rhs); if b { overflow_panic::add() } else { a } } /// Unchecked integer addition. Computes `self + rhs`, assuming overflow /// cannot occur. /// /// Calling `x.unchecked_add(y)` is semantically equivalent to calling /// `x.`[`checked_add`]`(y).`[`unwrap_unchecked`]`()`. /// /// If you're just trying to avoid the panic in debug mode, then **do not** /// use this. Instead, you're looking for [`wrapping_add`]. /// /// # Safety /// /// This results in undefined behavior when #[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX` or `self + rhs < ", stringify!($SelfT), "::MIN`,")] /// i.e. when [`checked_add`] would return `None`. /// /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked #[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")] #[doc = concat!("[`wrapping_add`]: ", stringify!($SelfT), "::wrapping_add")] #[stable(feature = "unchecked_math", since = "1.79.0")] #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_add(self, rhs: Self) -> Self { assert_unsafe_precondition!( check_language_ub, concat!(stringify!($SelfT), "::unchecked_add cannot overflow"), ( lhs: $SelfT = self, rhs: $SelfT = rhs, ) => !lhs.overflowing_add(rhs).1, ); // SAFETY: this is guaranteed to be safe by the caller. unsafe { intrinsics::unchecked_add(self, rhs) } } /// Checked addition with a signed integer. Computes `self + rhs`, /// returning `None` if overflow occurred. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_signed(2), Some(3));")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_signed(-2), None);")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add_signed(3), None);")] /// ``` #[stable(feature = "mixed_integer_ops", since = "1.66.0")] #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_add_signed(self, rhs: $SignedT) -> Option { let (a, b) = self.overflowing_add_signed(rhs); if intrinsics::unlikely(b) { None } else { Some(a) } } /// Strict addition with a signed integer. Computes `self + rhs`, /// panicking if overflow occurred. /// /// # Panics /// /// ## Overflow behavior /// /// This function will always panic on overflow, regardless of whether overflow checks are enabled. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(strict_overflow_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_add_signed(2), 3);")] /// ``` /// /// The following panic because of overflow: /// /// ```should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = 1", stringify!($SelfT), ".strict_add_signed(-2);")] /// ``` /// /// ```should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = (", stringify!($SelfT), "::MAX - 2).strict_add_signed(3);")] /// ``` #[unstable(feature = "strict_overflow_ops", issue = "118260")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn strict_add_signed(self, rhs: $SignedT) -> Self { let (a, b) = self.overflowing_add_signed(rhs); if b { overflow_panic::add() } else { a } } /// Checked integer subtraction. Computes `self - rhs`, returning /// `None` if overflow occurred. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub(1), Some(0));")] #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".checked_sub(1), None);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_sub(self, rhs: Self) -> Option { // Per PR#103299, there's no advantage to the `overflowing` intrinsic // for *unsigned* subtraction and we just emit the manual check anyway. // Thus, rather than using `overflowing_sub` that produces a wrapping // subtraction, check it ourself so we can use an unchecked one. if self < rhs { None } else { // SAFETY: just checked this can't overflow Some(unsafe { intrinsics::unchecked_sub(self, rhs) }) } } /// Strict integer subtraction. Computes `self - rhs`, panicking if /// overflow occurred. /// /// # Panics /// /// ## Overflow behavior /// /// This function will always panic on overflow, regardless of whether overflow checks are enabled. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(strict_overflow_ops)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".strict_sub(1), 0);")] /// ``` /// /// The following panics because of overflow: /// /// ```should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = 0", stringify!($SelfT), ".strict_sub(1);")] /// ``` #[unstable(feature = "strict_overflow_ops", issue = "118260")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn strict_sub(self, rhs: Self) -> Self { let (a, b) = self.overflowing_sub(rhs); if b { overflow_panic::sub() } else { a } } /// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow /// cannot occur. /// /// Calling `x.unchecked_sub(y)` is semantically equivalent to calling /// `x.`[`checked_sub`]`(y).`[`unwrap_unchecked`]`()`. /// /// If you're just trying to avoid the panic in debug mode, then **do not** /// use this. Instead, you're looking for [`wrapping_sub`]. /// /// If you find yourself writing code like this: /// /// ``` /// # let foo = 30_u32; /// # let bar = 20; /// if foo >= bar { /// // SAFETY: just checked it will not overflow /// let diff = unsafe { foo.unchecked_sub(bar) }; /// // ... use diff ... /// } /// ``` /// /// Consider changing it to /// /// ``` /// # let foo = 30_u32; /// # let bar = 20; /// if let Some(diff) = foo.checked_sub(bar) { /// // ... use diff ... /// } /// ``` /// /// As that does exactly the same thing -- including telling the optimizer /// that the subtraction cannot overflow -- but avoids needing `unsafe`. /// /// # Safety /// /// This results in undefined behavior when #[doc = concat!("`self - rhs > ", stringify!($SelfT), "::MAX` or `self - rhs < ", stringify!($SelfT), "::MIN`,")] /// i.e. when [`checked_sub`] would return `None`. /// /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked #[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")] #[doc = concat!("[`wrapping_sub`]: ", stringify!($SelfT), "::wrapping_sub")] #[stable(feature = "unchecked_math", since = "1.79.0")] #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self { assert_unsafe_precondition!( check_language_ub, concat!(stringify!($SelfT), "::unchecked_sub cannot overflow"), ( lhs: $SelfT = self, rhs: $SelfT = rhs, ) => !lhs.overflowing_sub(rhs).1, ); // SAFETY: this is guaranteed to be safe by the caller. unsafe { intrinsics::unchecked_sub(self, rhs) } } /// Checked subtraction with a signed integer. Computes `self - rhs`, /// returning `None` if overflow occurred. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(mixed_integer_ops_unsigned_sub)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_signed(2), None);")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_signed(-2), Some(3));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_sub_signed(-4), None);")] /// ``` #[unstable(feature = "mixed_integer_ops_unsigned_sub", issue = "126043")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_sub_signed(self, rhs: $SignedT) -> Option { let (res, overflow) = self.overflowing_sub_signed(rhs); if !overflow { Some(res) } else { None } } #[doc = concat!( "Checked integer subtraction. Computes `self - rhs` and checks if the result fits into an [`", stringify!($SignedT), "`], returning `None` if overflow occurred." )] /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(unsigned_signed_diff)] #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_signed_diff(2), Some(8));")] #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_signed_diff(10), Some(-8));")] #[doc = concat!( "assert_eq!(", stringify!($SelfT), "::MAX.checked_signed_diff(", stringify!($SignedT), "::MAX as ", stringify!($SelfT), "), None);" )] #[doc = concat!( "assert_eq!((", stringify!($SignedT), "::MAX as ", stringify!($SelfT), ").checked_signed_diff(", stringify!($SelfT), "::MAX), Some(", stringify!($SignedT), "::MIN));" )] #[doc = concat!( "assert_eq!((", stringify!($SignedT), "::MAX as ", stringify!($SelfT), " + 1).checked_signed_diff(0), None);" )] #[doc = concat!( "assert_eq!(", stringify!($SelfT), "::MAX.checked_signed_diff(", stringify!($SelfT), "::MAX), Some(0));" )] /// ``` #[unstable(feature = "unsigned_signed_diff", issue = "126041")] #[inline] pub const fn checked_signed_diff(self, rhs: Self) -> Option<$SignedT> { let res = self.wrapping_sub(rhs) as $SignedT; let overflow = (self >= rhs) == (res < 0); if !overflow { Some(res) } else { None } } /// Checked integer multiplication. Computes `self * rhs`, returning /// `None` if overflow occurred. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_mul(1), Some(5));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(2), None);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_mul(self, rhs: Self) -> Option { let (a, b) = self.overflowing_mul(rhs); if intrinsics::unlikely(b) { None } else { Some(a) } } /// Strict integer multiplication. Computes `self * rhs`, panicking if /// overflow occurred. /// /// # Panics /// /// ## Overflow behavior /// /// This function will always panic on overflow, regardless of whether overflow checks are enabled. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(strict_overflow_ops)] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".strict_mul(1), 5);")] /// ``` /// /// The following panics because of overflow: /// /// ``` should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_mul(2);")] /// ``` #[unstable(feature = "strict_overflow_ops", issue = "118260")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn strict_mul(self, rhs: Self) -> Self { let (a, b) = self.overflowing_mul(rhs); if b { overflow_panic::mul() } else { a } } /// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow /// cannot occur. /// /// Calling `x.unchecked_mul(y)` is semantically equivalent to calling /// `x.`[`checked_mul`]`(y).`[`unwrap_unchecked`]`()`. /// /// If you're just trying to avoid the panic in debug mode, then **do not** /// use this. Instead, you're looking for [`wrapping_mul`]. /// /// # Safety /// /// This results in undefined behavior when #[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX` or `self * rhs < ", stringify!($SelfT), "::MIN`,")] /// i.e. when [`checked_mul`] would return `None`. /// /// [`unwrap_unchecked`]: option/enum.Option.html#method.unwrap_unchecked #[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")] #[doc = concat!("[`wrapping_mul`]: ", stringify!($SelfT), "::wrapping_mul")] #[stable(feature = "unchecked_math", since = "1.79.0")] #[rustc_const_stable(feature = "unchecked_math", since = "1.79.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self { assert_unsafe_precondition!( check_language_ub, concat!(stringify!($SelfT), "::unchecked_mul cannot overflow"), ( lhs: $SelfT = self, rhs: $SelfT = rhs, ) => !lhs.overflowing_mul(rhs).1, ); // SAFETY: this is guaranteed to be safe by the caller. unsafe { intrinsics::unchecked_mul(self, rhs) } } /// Checked integer division. Computes `self / rhs`, returning `None` /// if `rhs == 0`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".checked_div(2), Some(64));")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_div(0), None);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_div(self, rhs: Self) -> Option { if intrinsics::unlikely(rhs == 0) { None } else { // SAFETY: div by zero has been checked above and unsigned types have no other // failure modes for division Some(unsafe { intrinsics::unchecked_div(self, rhs) }) } } /// Strict integer division. Computes `self / rhs`. /// /// Strict division on unsigned types is just normal division. There's no /// way overflow could ever happen. This function exists so that all /// operations are accounted for in the strict operations. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(strict_overflow_ops)] #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_div(10), 10);")] /// ``` /// /// The following panics because of division by zero: /// /// ```should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div(0);")] /// ``` #[unstable(feature = "strict_overflow_ops", issue = "118260")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[track_caller] pub const fn strict_div(self, rhs: Self) -> Self { self / rhs } /// Checked Euclidean division. Computes `self.div_euclid(rhs)`, returning `None` /// if `rhs == 0`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".checked_div_euclid(2), Some(64));")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_div_euclid(0), None);")] /// ``` #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_div_euclid(self, rhs: Self) -> Option { if intrinsics::unlikely(rhs == 0) { None } else { Some(self.div_euclid(rhs)) } } /// Strict Euclidean division. Computes `self.div_euclid(rhs)`. /// /// Strict division on unsigned types is just normal division. There's no /// way overflow could ever happen. This function exists so that all /// operations are accounted for in the strict operations. Since, for the /// positive integers, all common definitions of division are equal, this /// is exactly equal to `self.strict_div(rhs)`. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(strict_overflow_ops)] #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_div_euclid(10), 10);")] /// ``` /// The following panics because of division by zero: /// /// ```should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = (1", stringify!($SelfT), ").strict_div_euclid(0);")] /// ``` #[unstable(feature = "strict_overflow_ops", issue = "118260")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[track_caller] pub const fn strict_div_euclid(self, rhs: Self) -> Self { self / rhs } /// Checked integer remainder. Computes `self % rhs`, returning `None` /// if `rhs == 0`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(2), Some(1));")] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(0), None);")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_rem(self, rhs: Self) -> Option { if intrinsics::unlikely(rhs == 0) { None } else { // SAFETY: div by zero has been checked above and unsigned types have no other // failure modes for division Some(unsafe { intrinsics::unchecked_rem(self, rhs) }) } } /// Strict integer remainder. Computes `self % rhs`. /// /// Strict remainder calculation on unsigned types is just the regular /// remainder calculation. There's no way overflow could ever happen. /// This function exists so that all operations are accounted for in the /// strict operations. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(strict_overflow_ops)] #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_rem(10), 0);")] /// ``` /// /// The following panics because of division by zero: /// /// ```should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem(0);")] /// ``` #[unstable(feature = "strict_overflow_ops", issue = "118260")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[track_caller] pub const fn strict_rem(self, rhs: Self) -> Self { self % rhs } /// Checked Euclidean modulo. Computes `self.rem_euclid(rhs)`, returning `None` /// if `rhs == 0`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(2), Some(1));")] #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(0), None);")] /// ``` #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_rem_euclid(self, rhs: Self) -> Option { if intrinsics::unlikely(rhs == 0) { None } else { Some(self.rem_euclid(rhs)) } } /// Strict Euclidean modulo. Computes `self.rem_euclid(rhs)`. /// /// Strict modulo calculation on unsigned types is just the regular /// remainder calculation. There's no way overflow could ever happen. /// This function exists so that all operations are accounted for in the /// strict operations. Since, for the positive integers, all common /// definitions of division are equal, this is exactly equal to /// `self.strict_rem(rhs)`. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(strict_overflow_ops)] #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".strict_rem_euclid(10), 0);")] /// ``` /// /// The following panics because of division by zero: /// /// ```should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = 5", stringify!($SelfT), ".strict_rem_euclid(0);")] /// ``` #[unstable(feature = "strict_overflow_ops", issue = "118260")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[track_caller] pub const fn strict_rem_euclid(self, rhs: Self) -> Self { self % rhs } /// Same value as `self | other`, but UB if any bit position is set in both inputs. /// /// This is a situational micro-optimization for places where you'd rather /// use addition on some platforms and bitwise or on other platforms, based /// on exactly which instructions combine better with whatever else you're /// doing. Note that there's no reason to bother using this for places /// where it's clear from the operations involved that they can't overlap. /// For example, if you're combining `u16`s into a `u32` with /// `((a as u32) << 16) | (b as u32)`, that's fine, as the backend will /// know those sides of the `|` are disjoint without needing help. /// /// # Examples /// /// ``` /// #![feature(disjoint_bitor)] /// /// // SAFETY: `1` and `4` have no bits in common. /// unsafe { #[doc = concat!(" assert_eq!(1_", stringify!($SelfT), ".unchecked_disjoint_bitor(4), 5);")] /// } /// ``` /// /// # Safety /// /// Requires that `(self & other) == 0`, otherwise it's immediate UB. /// /// Equivalently, requires that `(self | other) == (self + other)`. #[unstable(feature = "disjoint_bitor", issue = "135758")] #[rustc_const_unstable(feature = "disjoint_bitor", issue = "135758")] #[inline] pub const unsafe fn unchecked_disjoint_bitor(self, other: Self) -> Self { assert_unsafe_precondition!( check_language_ub, concat!(stringify!($SelfT), "::unchecked_disjoint_bitor cannot have overlapping bits"), ( lhs: $SelfT = self, rhs: $SelfT = other, ) => (lhs & rhs) == 0, ); // SAFETY: Same precondition unsafe { intrinsics::disjoint_bitor(self, other) } } /// Returns the logarithm of the number with respect to an arbitrary base, /// rounded down. /// /// This method might not be optimized owing to implementation details; /// `ilog2` can produce results more efficiently for base 2, and `ilog10` /// can produce results more efficiently for base 10. /// /// # Panics /// /// This function will panic if `self` is zero, or if `base` is less than 2. /// /// # Examples /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".ilog(5), 1);")] /// ``` #[stable(feature = "int_log", since = "1.67.0")] #[rustc_const_stable(feature = "int_log", since = "1.67.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn ilog(self, base: Self) -> u32 { assert!(base >= 2, "base of integer logarithm must be at least 2"); if let Some(log) = self.checked_ilog(base) { log } else { int_log10::panic_for_nonpositive_argument() } } /// Returns the base 2 logarithm of the number, rounded down. /// /// # Panics /// /// This function will panic if `self` is zero. /// /// # Examples /// /// ``` #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".ilog2(), 1);")] /// ``` #[stable(feature = "int_log", since = "1.67.0")] #[rustc_const_stable(feature = "int_log", since = "1.67.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn ilog2(self) -> u32 { if let Some(log) = self.checked_ilog2() { log } else { int_log10::panic_for_nonpositive_argument() } } /// Returns the base 10 logarithm of the number, rounded down. /// /// # Panics /// /// This function will panic if `self` is zero. /// /// # Example /// /// ``` #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".ilog10(), 1);")] /// ``` #[stable(feature = "int_log", since = "1.67.0")] #[rustc_const_stable(feature = "int_log", since = "1.67.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn ilog10(self) -> u32 { if let Some(log) = self.checked_ilog10() { log } else { int_log10::panic_for_nonpositive_argument() } } /// Returns the logarithm of the number with respect to an arbitrary base, /// rounded down. /// /// Returns `None` if the number is 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 /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_ilog(5), Some(1));")] /// ``` #[stable(feature = "int_log", since = "1.67.0")] #[rustc_const_stable(feature = "int_log", since = "1.67.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_ilog(self, base: Self) -> Option { if self <= 0 || base <= 1 { None } else if self < base { Some(0) } else { // Since base >= self, n >= 1 let mut n = 1; let mut r = base; // Optimization for 128 bit wide integers. if Self::BITS == 128 { // The following is a correct lower bound for ⌊log(base,self)⌋ because // // log(base,self) = log(2,self) / log(2,base) // ≥ ⌊log(2,self)⌋ / (⌊log(2,base)⌋ + 1) // // hence // // ⌊log(base,self)⌋ ≥ ⌊ ⌊log(2,self)⌋ / (⌊log(2,base)⌋ + 1) ⌋ . n = self.ilog2() / (base.ilog2() + 1); r = base.pow(n); } while r <= self / base { n += 1; r *= base; } Some(n) } } /// Returns the base 2 logarithm of the number, rounded down. /// /// Returns `None` if the number is zero. /// /// # Examples /// /// ``` #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_ilog2(), Some(1));")] /// ``` #[stable(feature = "int_log", since = "1.67.0")] #[rustc_const_stable(feature = "int_log", since = "1.67.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_ilog2(self) -> Option { match NonZero::new(self) { Some(x) => Some(x.ilog2()), None => None, } } /// Returns the base 10 logarithm of the number, rounded down. /// /// Returns `None` if the number is zero. /// /// # Examples /// /// ``` #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_ilog10(), Some(1));")] /// ``` #[stable(feature = "int_log", since = "1.67.0")] #[rustc_const_stable(feature = "int_log", since = "1.67.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_ilog10(self) -> Option { match NonZero::new(self) { Some(x) => Some(x.ilog10()), None => None, } } /// Checked negation. Computes `-self`, returning `None` unless `self == /// 0`. /// /// Note that negating any positive integer will overflow. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".checked_neg(), Some(0));")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_neg(), None);")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_neg(self) -> Option { let (a, b) = self.overflowing_neg(); if intrinsics::unlikely(b) { None } else { Some(a) } } /// Strict negation. Computes `-self`, panicking unless `self == /// 0`. /// /// Note that negating any positive integer will overflow. /// /// # Panics /// /// ## Overflow behavior /// /// This function will always panic on overflow, regardless of whether overflow checks are enabled. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(strict_overflow_ops)] #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".strict_neg(), 0);")] /// ``` /// /// The following panics because of overflow: /// /// ```should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = 1", stringify!($SelfT), ".strict_neg();")] /// #[unstable(feature = "strict_overflow_ops", issue = "118260")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn strict_neg(self) -> Self { let (a, b) = self.overflowing_neg(); if b { overflow_panic::neg() } else { a } } /// Checked shift left. Computes `self << rhs`, returning `None` /// if `rhs` is larger than or equal to the number of bits in `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(4), Some(0x10));")] #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shl(129), None);")] #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shl(", stringify!($BITS_MINUS_ONE), "), Some(0));")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_shl(self, rhs: u32) -> Option { // Not using overflowing_shl as that's a wrapping shift if rhs < Self::BITS { // SAFETY: just checked the RHS is in-range Some(unsafe { self.unchecked_shl(rhs) }) } else { None } } /// Strict shift left. Computes `self << rhs`, panicking if `rhs` is larger /// than or equal to the number of bits in `self`. /// /// # Panics /// /// ## Overflow behavior /// /// This function will always panic on overflow, regardless of whether overflow checks are enabled. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(strict_overflow_ops)] #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".strict_shl(4), 0x10);")] /// ``` /// /// The following panics because of overflow: /// /// ```should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = 0x10", stringify!($SelfT), ".strict_shl(129);")] /// ``` #[unstable(feature = "strict_overflow_ops", issue = "118260")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn strict_shl(self, rhs: u32) -> Self { let (a, b) = self.overflowing_shl(rhs); if b { overflow_panic::shl() } else { a } } /// Unchecked shift left. Computes `self << rhs`, assuming that /// `rhs` is less than the number of bits in `self`. /// /// # Safety /// /// This results in undefined behavior if `rhs` is larger than /// or equal to the number of bits in `self`, /// i.e. when [`checked_shl`] would return `None`. /// #[doc = concat!("[`checked_shl`]: ", stringify!($SelfT), "::checked_shl")] #[unstable( feature = "unchecked_shifts", reason = "niche optimization path", issue = "85122", )] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_shl(self, rhs: u32) -> Self { assert_unsafe_precondition!( check_language_ub, concat!(stringify!($SelfT), "::unchecked_shl cannot overflow"), ( rhs: u32 = rhs, ) => rhs < <$ActualT>::BITS, ); // SAFETY: this is guaranteed to be safe by the caller. unsafe { intrinsics::unchecked_shl(self, rhs) } } /// Unbounded shift left. Computes `self << rhs`, without bounding the value of `rhs`. /// /// If `rhs` is larger or equal to the number of bits in `self`, /// the entire value is shifted out, and `0` is returned. /// /// # Examples /// /// Basic usage: /// ``` #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".unbounded_shl(4), 0x10);")] #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".unbounded_shl(129), 0);")] /// ``` #[stable(feature = "unbounded_shifts", since = "1.87.0")] #[rustc_const_stable(feature = "unbounded_shifts", since = "1.87.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn unbounded_shl(self, rhs: u32) -> $SelfT{ if rhs < Self::BITS { // SAFETY: // rhs is just checked to be in-range above unsafe { self.unchecked_shl(rhs) } } else { 0 } } /// Checked shift right. Computes `self >> rhs`, returning `None` /// if `rhs` is larger than or equal to the number of bits in `self`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(4), Some(0x1));")] #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(129), None);")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_shr(self, rhs: u32) -> Option { // Not using overflowing_shr as that's a wrapping shift if rhs < Self::BITS { // SAFETY: just checked the RHS is in-range Some(unsafe { self.unchecked_shr(rhs) }) } else { None } } /// Strict shift right. Computes `self >> rhs`, panicking `rhs` is /// larger than or equal to the number of bits in `self`. /// /// # Panics /// /// ## Overflow behavior /// /// This function will always panic on overflow, regardless of whether overflow checks are enabled. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(strict_overflow_ops)] #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".strict_shr(4), 0x1);")] /// ``` /// /// The following panics because of overflow: /// /// ```should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = 0x10", stringify!($SelfT), ".strict_shr(129);")] /// ``` #[unstable(feature = "strict_overflow_ops", issue = "118260")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn strict_shr(self, rhs: u32) -> Self { let (a, b) = self.overflowing_shr(rhs); if b { overflow_panic::shr() } else { a } } /// Unchecked shift right. Computes `self >> rhs`, assuming that /// `rhs` is less than the number of bits in `self`. /// /// # Safety /// /// This results in undefined behavior if `rhs` is larger than /// or equal to the number of bits in `self`, /// i.e. when [`checked_shr`] would return `None`. /// #[doc = concat!("[`checked_shr`]: ", stringify!($SelfT), "::checked_shr")] #[unstable( feature = "unchecked_shifts", reason = "niche optimization path", issue = "85122", )] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces pub const unsafe fn unchecked_shr(self, rhs: u32) -> Self { assert_unsafe_precondition!( check_language_ub, concat!(stringify!($SelfT), "::unchecked_shr cannot overflow"), ( rhs: u32 = rhs, ) => rhs < <$ActualT>::BITS, ); // SAFETY: this is guaranteed to be safe by the caller. unsafe { intrinsics::unchecked_shr(self, rhs) } } /// Unbounded shift right. Computes `self >> rhs`, without bounding the value of `rhs`. /// /// If `rhs` is larger or equal to the number of bits in `self`, /// the entire value is shifted out, and `0` is returned. /// /// # Examples /// /// Basic usage: /// ``` #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".unbounded_shr(4), 0x1);")] #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".unbounded_shr(129), 0);")] /// ``` #[stable(feature = "unbounded_shifts", since = "1.87.0")] #[rustc_const_stable(feature = "unbounded_shifts", since = "1.87.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn unbounded_shr(self, rhs: u32) -> $SelfT{ if rhs < Self::BITS { // SAFETY: // rhs is just checked to be in-range above unsafe { self.unchecked_shr(rhs) } } else { 0 } } /// Checked exponentiation. Computes `self.pow(exp)`, returning `None` if /// overflow occurred. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_pow(5), Some(32));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_pow(2), None);")] /// ``` #[stable(feature = "no_panic_pow", since = "1.34.0")] #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_pow(self, mut exp: u32) -> Option { if exp == 0 { return Some(1); } let mut base = self; let mut acc: Self = 1; loop { if (exp & 1) == 1 { acc = try_opt!(acc.checked_mul(base)); // since exp!=0, finally the exp must be 1. if exp == 1 { return Some(acc); } } exp /= 2; base = try_opt!(base.checked_mul(base)); } } /// Strict exponentiation. Computes `self.pow(exp)`, panicking if /// overflow occurred. /// /// # Panics /// /// ## Overflow behavior /// /// This function will always panic on overflow, regardless of whether overflow checks are enabled. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(strict_overflow_ops)] #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".strict_pow(5), 32);")] /// ``` /// /// The following panics because of overflow: /// /// ```should_panic /// #![feature(strict_overflow_ops)] #[doc = concat!("let _ = ", stringify!($SelfT), "::MAX.strict_pow(2);")] /// ``` #[unstable(feature = "strict_overflow_ops", issue = "118260")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn strict_pow(self, mut exp: u32) -> Self { if exp == 0 { return 1; } let mut base = self; let mut acc: Self = 1; loop { if (exp & 1) == 1 { acc = acc.strict_mul(base); // since exp!=0, finally the exp must be 1. if exp == 1 { return acc; } } exp /= 2; base = base.strict_mul(base); } } /// Saturating integer addition. Computes `self + rhs`, saturating at /// the numeric bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_add(1), 101);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add(127), ", stringify!($SelfT), "::MAX);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")] #[inline(always)] pub const fn saturating_add(self, rhs: Self) -> Self { intrinsics::saturating_add(self, rhs) } /// Saturating addition with a signed integer. Computes `self + rhs`, /// saturating at the numeric bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_signed(2), 3);")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_signed(-2), 0);")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).saturating_add_signed(4), ", stringify!($SelfT), "::MAX);")] /// ``` #[stable(feature = "mixed_integer_ops", since = "1.66.0")] #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn saturating_add_signed(self, rhs: $SignedT) -> Self { let (res, overflow) = self.overflowing_add(rhs as Self); if overflow == (rhs < 0) { res } else if overflow { Self::MAX } else { 0 } } /// Saturating integer subtraction. Computes `self - rhs`, saturating /// at the numeric bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub(27), 73);")] #[doc = concat!("assert_eq!(13", stringify!($SelfT), ".saturating_sub(127), 0);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")] #[inline(always)] pub const fn saturating_sub(self, rhs: Self) -> Self { intrinsics::saturating_sub(self, rhs) } /// Saturating integer subtraction. Computes `self` - `rhs`, saturating at /// the numeric bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(mixed_integer_ops_unsigned_sub)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_sub_signed(2), 0);")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_sub_signed(-2), 3);")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).saturating_sub_signed(-4), ", stringify!($SelfT), "::MAX);")] /// ``` #[unstable(feature = "mixed_integer_ops_unsigned_sub", issue = "126043")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn saturating_sub_signed(self, rhs: $SignedT) -> Self { let (res, overflow) = self.overflowing_sub_signed(rhs); if !overflow { res } else if rhs < 0 { Self::MAX } else { 0 } } /// Saturating integer multiplication. Computes `self * rhs`, /// saturating at the numeric bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".saturating_mul(10), 20);")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX).saturating_mul(10), ", stringify!($SelfT),"::MAX);")] /// ``` #[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 => Self::MAX, } } /// Saturating integer division. Computes `self / rhs`, saturating at the /// numeric bounds instead of overflowing. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".saturating_div(2), 2);")] /// /// ``` #[stable(feature = "saturating_div", since = "1.58.0")] #[rustc_const_stable(feature = "saturating_div", since = "1.58.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn saturating_div(self, rhs: Self) -> Self { // on unsigned types, there is no overflow in integer division self.wrapping_div(rhs) } /// Saturating integer exponentiation. Computes `self.pow(exp)`, /// saturating at the numeric bounds instead of overflowing. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(4", stringify!($SelfT), ".saturating_pow(3), 64);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_pow(2), ", stringify!($SelfT), "::MAX);")] /// ``` #[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 => Self::MAX, } } /// Wrapping (modular) addition. Computes `self + rhs`, /// wrapping around at the boundary of the type. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(200", stringify!($SelfT), ".wrapping_add(55), 255);")] #[doc = concat!("assert_eq!(200", stringify!($SelfT), ".wrapping_add(", stringify!($SelfT), "::MAX), 199);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn wrapping_add(self, rhs: Self) -> Self { intrinsics::wrapping_add(self, rhs) } /// Wrapping (modular) addition with a signed integer. Computes /// `self + rhs`, wrapping around at the boundary of the type. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_add_signed(2), 3);")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_add_signed(-2), ", stringify!($SelfT), "::MAX);")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).wrapping_add_signed(4), 1);")] /// ``` #[stable(feature = "mixed_integer_ops", since = "1.66.0")] #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn wrapping_add_signed(self, rhs: $SignedT) -> Self { self.wrapping_add(rhs as Self) } /// Wrapping (modular) subtraction. Computes `self - rhs`, /// wrapping around at the boundary of the type. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_sub(100), 0);")] #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_sub(", stringify!($SelfT), "::MAX), 101);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_wrapping_math", 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 a signed integer. Computes /// `self - rhs`, wrapping around at the boundary of the type. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(mixed_integer_ops_unsigned_sub)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_sub_signed(2), ", stringify!($SelfT), "::MAX);")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".wrapping_sub_signed(-2), 3);")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).wrapping_sub_signed(-4), 1);")] /// ``` #[unstable(feature = "mixed_integer_ops_unsigned_sub", issue = "126043")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn wrapping_sub_signed(self, rhs: $SignedT) -> Self { self.wrapping_sub(rhs as Self) } /// Wrapping (modular) multiplication. Computes `self * /// rhs`, wrapping around at the boundary of the type. /// /// # Examples /// /// Basic usage: /// /// Please note that this example is shared between integer types. /// Which explains why `u8` is used here. /// /// ``` /// assert_eq!(10u8.wrapping_mul(12), 120); /// assert_eq!(25u8.wrapping_mul(12), 44); /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn wrapping_mul(self, rhs: Self) -> Self { intrinsics::wrapping_mul(self, rhs) } /// Wrapping (modular) division. Computes `self / rhs`. /// /// Wrapped division on unsigned types is just normal division. There's /// no way wrapping could ever happen. This function exists so that all /// operations are accounted for in the wrapping operations. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div(10), 10);")] /// ``` #[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(always)] #[track_caller] pub const fn wrapping_div(self, rhs: Self) -> Self { self / rhs } /// Wrapping Euclidean division. Computes `self.div_euclid(rhs)`. /// /// Wrapped division on unsigned types is just normal division. There's /// no way wrapping could ever happen. This function exists so that all /// operations are accounted for in the wrapping operations. Since, for /// the positive integers, all common definitions of division are equal, /// this is exactly equal to `self.wrapping_div(rhs)`. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div_euclid(10), 10);")] /// ``` #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[track_caller] pub const fn wrapping_div_euclid(self, rhs: Self) -> Self { self / rhs } /// Wrapping (modular) remainder. Computes `self % rhs`. /// /// Wrapped remainder calculation on unsigned types is just the regular /// remainder calculation. There's no way wrapping could ever happen. /// This function exists so that all operations are accounted for in the /// wrapping operations. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem(10), 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(always)] #[track_caller] pub const fn wrapping_rem(self, rhs: Self) -> Self { self % rhs } /// Wrapping Euclidean modulo. Computes `self.rem_euclid(rhs)`. /// /// Wrapped modulo calculation on unsigned types is just the regular /// remainder calculation. There's no way wrapping could ever happen. /// This function exists so that all operations are accounted for in the /// wrapping operations. Since, for the positive integers, all common /// definitions of division are equal, this is exactly equal to /// `self.wrapping_rem(rhs)`. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem_euclid(10), 0);")] /// ``` #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[track_caller] pub const fn wrapping_rem_euclid(self, rhs: Self) -> Self { self % rhs } /// Wrapping (modular) negation. Computes `-self`, /// wrapping around at the boundary of the type. /// /// Since unsigned types do not have negative equivalents /// all applications of this function will wrap (except for `-0`). /// For values smaller than the corresponding signed type's maximum /// the result is the same as casting the corresponding signed value. /// Any larger values are equivalent to `MAX + 1 - (val - MAX - 1)` where /// `MAX` is the corresponding signed type's maximum. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(0_", stringify!($SelfT), ".wrapping_neg(), 0);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_neg(), 1);")] #[doc = concat!("assert_eq!(13_", stringify!($SelfT), ".wrapping_neg(), (!13) + 1);")] #[doc = concat!("assert_eq!(42_", stringify!($SelfT), ".wrapping_neg(), !(42 - 1));")] /// ``` #[stable(feature = "num_wrapping", since = "1.2.0")] #[rustc_const_stable(feature = "const_wrapping_math", 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!($SelfT), ".wrapping_shl(128), 1);")] /// ``` #[stable(feature = "num_wrapping", since = "1.2.0")] #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn wrapping_shl(self, rhs: u32) -> Self { // SAFETY: the masking by the bitsize of the type ensures that we do not shift // out of bounds unsafe { self.unchecked_shl(rhs & (Self::BITS - 1)) } } /// Panic-free bitwise shift-right; yields `self >> mask(rhs)`, /// where `mask` removes any high-order bits of `rhs` that /// would cause the shift to exceed the bitwidth of the type. /// /// Note that this is *not* the same as a rotate-right; the /// RHS of a wrapping shift-right is restricted to the range /// of the type, rather than the bits shifted out of the LHS /// being returned to the other end. The primitive integer /// types all implement a [`rotate_right`](Self::rotate_right) function, /// which may be what you want instead. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".wrapping_shr(7), 1);")] #[doc = concat!("assert_eq!(128", stringify!($SelfT), ".wrapping_shr(128), 128);")] /// ``` #[stable(feature = "num_wrapping", since = "1.2.0")] #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn wrapping_shr(self, rhs: u32) -> Self { // SAFETY: the masking by the bitsize of the type ensures that we do not shift // out of bounds unsafe { self.unchecked_shr(rhs & (Self::BITS - 1)) } } /// Wrapping (modular) exponentiation. Computes `self.pow(exp)`, /// wrapping around at the boundary of the type. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_pow(5), 243);")] /// assert_eq!(3u8.wrapping_pow(6), 217); /// ``` #[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; if intrinsics::is_val_statically_known(exp) { 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. acc.wrapping_mul(base) } else { // This is faster than the above when the exponent is not known // at compile time. We can't use the same code for the constant // exponent case because LLVM is currently unable to unroll // this loop. loop { if (exp & 1) == 1 { acc = acc.wrapping_mul(base); // since exp!=0, finally the exp must be 1. if exp == 1 { return acc; } } exp /= 2; base = base.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), (0, true));")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_wrapping_math", 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 $ActualT); (a as Self, b) } /// Calculates `self` + `rhs` + `carry` and returns a tuple containing /// the sum and the output carry. /// /// Performs "ternary addition" of two integer operands and a carry-in /// bit, and returns an output integer and a carry-out bit. This allows /// chaining together multiple additions to create a wider addition, and /// can be useful for bignum addition. /// #[doc = concat!("This can be thought of as a ", stringify!($BITS), "-bit \"full adder\", in the electronics sense.")] /// /// If the input carry is false, this method is equivalent to /// [`overflowing_add`](Self::overflowing_add), and the output carry is /// equal to the overflow flag. Note that although carry and overflow /// flags are similar for unsigned integers, they are different for /// signed integers. /// /// # Examples /// /// ``` /// #![feature(bigint_helper_methods)] /// #[doc = concat!("// 3 MAX (a = 3 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")] #[doc = concat!("// + 5 7 (b = 5 × 2^", stringify!($BITS), " + 7)")] /// // --------- #[doc = concat!("// 9 6 (sum = 9 × 2^", stringify!($BITS), " + 6)")] /// #[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (3, ", stringify!($SelfT), "::MAX);")] #[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (5, 7);")] /// let carry0 = false; /// /// let (sum0, carry1) = a0.carrying_add(b0, carry0); /// assert_eq!(carry1, true); /// let (sum1, carry2) = a1.carrying_add(b1, carry1); /// assert_eq!(carry2, false); /// /// assert_eq!((sum1, sum0), (9, 6)); /// ``` #[unstable(feature = "bigint_helper_methods", issue = "85532")] #[rustc_const_unstable(feature = "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, but this has been shown // to generate optimal code for now, and LLVM doesn't have an equivalent intrinsic let (a, c1) = self.overflowing_add(rhs); let (b, c2) = a.overflowing_add(carry as $SelfT); // Ideally LLVM would know this is disjoint without us telling them, // but it doesn't // SAFETY: Only one of `c1` and `c2` can be set. // For c1 to be set we need to have overflowed, but if we did then // `a` is at most `MAX-1`, which means that `c2` cannot possibly // overflow because it's adding at most `1` (since it came from `bool`) (b, unsafe { intrinsics::disjoint_bitor(c1, c2) }) } /// Calculates `self` + `rhs` with a signed `rhs`. /// /// Returns a tuple of the addition along with a boolean indicating /// whether an arithmetic overflow would occur. If an overflow would /// have occurred then the wrapped value is returned. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_signed(2), (3, false));")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_signed(-2), (", stringify!($SelfT), "::MAX, true));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_add_signed(4), (1, true));")] /// ``` #[stable(feature = "mixed_integer_ops", since = "1.66.0")] #[rustc_const_stable(feature = "mixed_integer_ops", since = "1.66.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn overflowing_add_signed(self, rhs: $SignedT) -> (Self, bool) { let (res, overflowed) = self.overflowing_add(rhs as Self); (res, overflowed ^ (rhs < 0)) } /// Calculates `self` - `rhs`. /// /// Returns a tuple of the subtraction along with a boolean indicating /// whether an arithmetic overflow would occur. If an overflow would /// have occurred then the wrapped value is returned. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")] #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".overflowing_sub(1), (", stringify!($SelfT), "::MAX, true));")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_wrapping_math", 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 $ActualT); (a as Self, b) } /// Calculates `self` − `rhs` − `borrow` and returns a tuple /// containing the difference and the output borrow. /// /// Performs "ternary subtraction" by subtracting both an integer /// operand and a borrow-in bit from `self`, and returns an output /// integer and a borrow-out bit. This allows chaining together multiple /// subtractions to create a wider subtraction, and can be useful for /// bignum subtraction. /// /// # Examples /// /// ``` /// #![feature(bigint_helper_methods)] /// #[doc = concat!("// 9 6 (a = 9 × 2^", stringify!($BITS), " + 6)")] #[doc = concat!("// - 5 7 (b = 5 × 2^", stringify!($BITS), " + 7)")] /// // --------- #[doc = concat!("// 3 MAX (diff = 3 × 2^", stringify!($BITS), " + 2^", stringify!($BITS), " - 1)")] /// #[doc = concat!("let (a1, a0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (9, 6);")] #[doc = concat!("let (b1, b0): (", stringify!($SelfT), ", ", stringify!($SelfT), ") = (5, 7);")] /// let borrow0 = false; /// /// let (diff0, borrow1) = a0.borrowing_sub(b0, borrow0); /// assert_eq!(borrow1, true); /// let (diff1, borrow2) = a1.borrowing_sub(b1, borrow1); /// assert_eq!(borrow2, false); /// #[doc = concat!("assert_eq!((diff1, diff0), (3, ", stringify!($SelfT), "::MAX));")] /// ``` #[unstable(feature = "bigint_helper_methods", issue = "85532")] #[rustc_const_unstable(feature = "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, but this has been shown // to generate optimal code for now, and LLVM doesn't have an equivalent intrinsic let (a, c1) = self.overflowing_sub(rhs); let (b, c2) = a.overflowing_sub(borrow as $SelfT); // SAFETY: Only one of `c1` and `c2` can be set. // For c1 to be set we need to have underflowed, but if we did then // `a` is nonzero, which means that `c2` cannot possibly // underflow because it's subtracting at most `1` (since it came from `bool`) (b, unsafe { intrinsics::disjoint_bitor(c1, c2) }) } /// Calculates `self` - `rhs` with a signed `rhs` /// /// Returns a tuple of the subtraction along with a boolean indicating /// whether an arithmetic overflow would occur. If an overflow would /// have occurred then the wrapped value is returned. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(mixed_integer_ops_unsigned_sub)] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_signed(2), (", stringify!($SelfT), "::MAX, true));")] #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_signed(-2), (3, false));")] #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_sub_signed(-4), (1, true));")] /// ``` #[unstable(feature = "mixed_integer_ops_unsigned_sub", issue = "126043")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn overflowing_sub_signed(self, rhs: $SignedT) -> (Self, bool) { let (res, overflow) = self.overflowing_sub(rhs as Self); (res, overflow ^ (rhs < 0)) } /// Computes the absolute difference between `self` and `other`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(80), 20", stringify!($SelfT), ");")] #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(110), 10", stringify!($SelfT), ");")] /// ``` #[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) -> Self { if size_of::() == 1 { // Trick LLVM into generating the psadbw instruction when SSE2 // is available and this function is autovectorized for u8's. (self as i32).wrapping_sub(other as i32).abs() as Self } else { if self < other { other - self } else { self - other } } } /// 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: /// /// Please note that this example is shared between integer types. /// Which explains why `u32` is used here. /// /// ``` /// assert_eq!(5u32.overflowing_mul(2), (10, false)); /// assert_eq!(1_000_000_000u32.overflowing_mul(10), (1410065408, true)); /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_wrapping_math", 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 complete product `self * rhs` without the possibility to overflow. /// /// This returns the low-order (wrapping) bits and the high-order (overflow) bits /// of the result as two separate values, in that order. /// /// If you also need to add a carry to the wide result, then you want /// [`Self::carrying_mul`] instead. /// /// # Examples /// /// Basic usage: /// /// Please note that this example is shared between integer types. /// Which explains why `u32` is used here. /// /// ``` /// #![feature(bigint_helper_methods)] /// assert_eq!(5u32.widening_mul(2), (10, 0)); /// assert_eq!(1_000_000_000u32.widening_mul(10), (1410065408, 2)); /// ``` #[unstable(feature = "bigint_helper_methods", issue = "85532")] #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn widening_mul(self, rhs: Self) -> (Self, Self) { Self::carrying_mul_add(self, rhs, 0, 0) } /// Calculates the "full multiplication" `self * rhs + carry` /// without the possibility to overflow. /// /// This returns the low-order (wrapping) bits and the high-order (overflow) bits /// of the result as two separate values, in that order. /// /// Performs "long multiplication" which takes in an extra amount to add, and may return an /// additional amount of overflow. This allows for chaining together multiple /// multiplications to create "big integers" which represent larger values. /// /// If you don't need the `carry`, then you can use [`Self::widening_mul`] instead. /// /// # Examples /// /// Basic usage: /// /// Please note that this example is shared between integer types. /// Which explains why `u32` is used here. /// /// ``` /// #![feature(bigint_helper_methods)] /// assert_eq!(5u32.carrying_mul(2, 0), (10, 0)); /// assert_eq!(5u32.carrying_mul(2, 10), (20, 0)); /// assert_eq!(1_000_000_000u32.carrying_mul(10, 0), (1410065408, 2)); /// assert_eq!(1_000_000_000u32.carrying_mul(10, 10), (1410065418, 2)); #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_mul(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ", "(0, ", stringify!($SelfT), "::MAX));" )] /// ``` /// /// This is the core operation needed for scalar multiplication when /// implementing it for wider-than-native types. /// /// ``` /// #![feature(bigint_helper_methods)] /// fn scalar_mul_eq(little_endian_digits: &mut Vec, multiplicand: u16) { /// let mut carry = 0; /// for d in little_endian_digits.iter_mut() { /// (*d, carry) = d.carrying_mul(multiplicand, carry); /// } /// if carry != 0 { /// little_endian_digits.push(carry); /// } /// } /// /// let mut v = vec![10, 20]; /// scalar_mul_eq(&mut v, 3); /// assert_eq!(v, [30, 60]); /// /// assert_eq!(0x87654321_u64 * 0xFEED, 0x86D3D159E38D); /// let mut v = vec![0x4321, 0x8765]; /// scalar_mul_eq(&mut v, 0xFEED); /// assert_eq!(v, [0xE38D, 0xD159, 0x86D3]); /// ``` /// /// If `carry` is zero, this is similar to [`overflowing_mul`](Self::overflowing_mul), /// except that it gives the value of the overflow instead of just whether one happened: /// /// ``` /// #![feature(bigint_helper_methods)] /// let r = u8::carrying_mul(7, 13, 0); /// assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(7, 13)); /// let r = u8::carrying_mul(13, 42, 0); /// assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(13, 42)); /// ``` /// /// The value of the first field in the returned tuple matches what you'd get /// by combining the [`wrapping_mul`](Self::wrapping_mul) and /// [`wrapping_add`](Self::wrapping_add) methods: /// /// ``` /// #![feature(bigint_helper_methods)] /// assert_eq!( /// 789_u16.carrying_mul(456, 123).0, /// 789_u16.wrapping_mul(456).wrapping_add(123), /// ); /// ``` #[unstable(feature = "bigint_helper_methods", issue = "85532")] #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn carrying_mul(self, rhs: Self, carry: Self) -> (Self, Self) { Self::carrying_mul_add(self, rhs, carry, 0) } /// Calculates the "full multiplication" `self * rhs + carry1 + carry2` /// without the possibility to overflow. /// /// This returns the low-order (wrapping) bits and the high-order (overflow) bits /// of the result as two separate values, in that order. /// /// Performs "long multiplication" which takes in an extra amount to add, and may return an /// additional amount of overflow. This allows for chaining together multiple /// multiplications to create "big integers" which represent larger values. /// /// If you don't need either `carry`, then you can use [`Self::widening_mul`] instead, /// and if you only need one `carry`, then you can use [`Self::carrying_mul`] instead. /// /// # Examples /// /// Basic usage: /// /// Please note that this example is shared between integer types, /// which explains why `u32` is used here. /// /// ``` /// #![feature(bigint_helper_methods)] /// assert_eq!(5u32.carrying_mul_add(2, 0, 0), (10, 0)); /// assert_eq!(5u32.carrying_mul_add(2, 10, 10), (30, 0)); /// assert_eq!(1_000_000_000u32.carrying_mul_add(10, 0, 0), (1410065408, 2)); /// assert_eq!(1_000_000_000u32.carrying_mul_add(10, 10, 10), (1410065428, 2)); #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_mul_add(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ", "(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX));" )] /// ``` /// /// This is the core per-digit operation for "grade school" O(n²) multiplication. /// /// Please note that this example is shared between integer types, /// using `u8` for simplicity of the demonstration. /// /// ``` /// #![feature(bigint_helper_methods)] /// /// fn quadratic_mul(a: [u8; N], b: [u8; N]) -> [u8; N] { /// let mut out = [0; N]; /// for j in 0..N { /// let mut carry = 0; /// for i in 0..(N - j) { /// (out[j + i], carry) = u8::carrying_mul_add(a[i], b[j], out[j + i], carry); /// } /// } /// out /// } /// /// // -1 * -1 == 1 /// assert_eq!(quadratic_mul([0xFF; 3], [0xFF; 3]), [1, 0, 0]); /// /// assert_eq!(u32::wrapping_mul(0x9e3779b9, 0x7f4a7c15), 0xCFFC982D); /// assert_eq!( /// quadratic_mul(u32::to_le_bytes(0x9e3779b9), u32::to_le_bytes(0x7f4a7c15)), /// u32::to_le_bytes(0xCFFC982D) /// ); /// ``` #[unstable(feature = "bigint_helper_methods", issue = "85532")] #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn carrying_mul_add(self, rhs: Self, carry: Self, add: Self) -> (Self, Self) { intrinsics::carrying_mul_add(self, rhs, carry, add) } /// Calculates the divisor when `self` is divided by `rhs`. /// /// Returns a tuple of the divisor along with a boolean indicating /// whether an arithmetic overflow would occur. Note that for unsigned /// integers overflow never occurs, so the second value is always /// `false`. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")] /// ``` #[inline(always)] #[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"] #[track_caller] pub const fn overflowing_div(self, rhs: Self) -> (Self, bool) { (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. Note that for unsigned /// integers overflow never occurs, so the second value is always /// `false`. /// Since, for the positive integers, all common /// definitions of division are equal, this /// is exactly equal to `self.overflowing_div(rhs)`. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div_euclid(2), (2, false));")] /// ``` #[inline(always)] #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[track_caller] pub const fn overflowing_div_euclid(self, rhs: Self) -> (Self, bool) { (self / rhs, false) } /// Calculates the remainder when `self` is divided by `rhs`. /// /// Returns a tuple of the remainder after dividing along with a boolean /// indicating whether an arithmetic overflow would occur. Note that for /// unsigned integers overflow never occurs, so the second value is /// always `false`. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem(2), (1, false));")] /// ``` #[inline(always)] #[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"] #[track_caller] pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) { (self % rhs, false) } /// Calculates the remainder `self.rem_euclid(rhs)` as if by Euclidean division. /// /// Returns a tuple of the modulo after dividing along with a boolean /// indicating whether an arithmetic overflow would occur. Note that for /// unsigned integers overflow never occurs, so the second value is /// always `false`. /// Since, for the positive integers, all common /// definitions of division are equal, this operation /// is exactly equal to `self.overflowing_rem(rhs)`. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem_euclid(2), (1, false));")] /// ``` #[inline(always)] #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[track_caller] pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) { (self % rhs, false) } /// Negates self in an overflowing fashion. /// /// Returns `!self + 1` using wrapping operations to return the value /// that represents the negation of this unsigned value. Note that for /// positive unsigned values overflow always occurs, but negating 0 does /// not overflow. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".overflowing_neg(), (0, false));")] #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2i32 as ", stringify!($SelfT), ", true));")] /// ``` #[inline(always)] #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] pub const fn overflowing_neg(self) -> (Self, bool) { ((!self).wrapping_add(1), self != 0) } /// 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!($SelfT), ".overflowing_shl(4), (0x10, false));")] #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".overflowing_shl(132), (0x10, true));")] #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shl(", stringify!($BITS_MINUS_ONE), "), (0, false));")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn overflowing_shl(self, rhs: u32) -> (Self, bool) { (self.wrapping_shl(rhs), rhs >= Self::BITS) } /// 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!($SelfT), ".overflowing_shr(4), (0x1, false));")] #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(132), (0x1, true));")] /// ``` #[stable(feature = "wrapping", since = "1.7.0")] #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) { (self.wrapping_shr(rhs), rhs >= Self::BITS) } /// 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!($SelfT), ".overflowing_pow(5), (243, false));")] /// assert_eq!(3u8.overflowing_pow(6), (217, true)); /// ``` #[stable(feature = "no_panic_pow", since = "1.34.0")] #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) { if exp == 0{ return (1,false); } let mut base = self; let mut acc: Self = 1; let mut overflown = false; // Scratch space for storing results of overflowing_mul. let mut r; loop { if (exp & 1) == 1 { r = acc.overflowing_mul(base); // since exp!=0, finally the exp must be 1. if exp == 1 { r.1 |= overflown; return r; } acc = r.0; overflown |= r.1; } exp /= 2; r = base.overflowing_mul(base); base = r.0; overflown |= r.1; } } /// Raises self to the power of `exp`, using exponentiation by squaring. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".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; if intrinsics::is_val_statically_known(exp) { 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 } else { // This is faster than the above when the exponent is not known // at compile time. We can't use the same code for the constant // exponent case because LLVM is currently unable to unroll // this loop. loop { if (exp & 1) == 1 { acc = acc * base; // since exp!=0, finally the exp must be 1. if exp == 1 { return acc; } } exp /= 2; base = base * base; } } } /// Returns the square root of the number, rounded down. /// /// # Examples /// /// Basic usage: /// ``` #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".isqrt(), 3);")] /// ``` #[stable(feature = "isqrt", since = "1.84.0")] #[rustc_const_stable(feature = "isqrt", since = "1.84.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn isqrt(self) -> Self { let result = crate::num::int_sqrt::$ActualT(self as $ActualT) as $SelfT; // Inform the optimizer what the range of outputs is. If testing // `core` crashes with no panic message and a `num::int_sqrt::u*` // test failed, it's because your edits caused these assertions or // the assertions in `fn isqrt` of `nonzero.rs` to become false. // // SAFETY: Integer square root is a monotonically nondecreasing // function, which means that increasing the input will never // cause the output to decrease. Thus, since the input for unsigned // integers is bounded by `[0, <$ActualT>::MAX]`, sqrt(n) will be // bounded by `[sqrt(0), sqrt(<$ActualT>::MAX)]`. unsafe { const MAX_RESULT: $SelfT = crate::num::int_sqrt::$ActualT(<$ActualT>::MAX) as $SelfT; crate::hint::assert_unchecked(result <= MAX_RESULT); } result } /// Performs Euclidean division. /// /// Since, for the positive integers, all common /// definitions of division are equal, this /// is exactly equal to `self / rhs`. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(7", stringify!($SelfT), ".div_euclid(4), 1); // or any other integer type")] /// ``` #[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(always)] #[track_caller] pub const fn div_euclid(self, rhs: Self) -> Self { self / rhs } /// Calculates the least remainder of `self (mod rhs)`. /// /// Since, for the positive integers, all common /// definitions of division are equal, this /// is exactly equal to `self % rhs`. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(7", stringify!($SelfT), ".rem_euclid(4), 3); // or any other integer type")] /// ``` #[doc(alias = "modulo", alias = "mod")] #[stable(feature = "euclidean_division", since = "1.38.0")] #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[track_caller] pub const fn rem_euclid(self, rhs: Self) -> Self { self % rhs } /// Calculates the quotient of `self` and `rhs`, rounding the result towards negative infinity. /// /// This is the same as performing `self / rhs` for all unsigned integers. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(int_roundings)] #[doc = concat!("assert_eq!(7_", stringify!($SelfT), ".div_floor(4), 1);")] /// ``` #[unstable(feature = "int_roundings", issue = "88581")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline(always)] #[track_caller] pub const fn div_floor(self, rhs: Self) -> Self { self / rhs } /// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(7_", stringify!($SelfT), ".div_ceil(4), 2);")] /// ``` #[stable(feature = "int_roundings1", since = "1.73.0")] #[rustc_const_stable(feature = "int_roundings1", since = "1.73.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[track_caller] pub const fn div_ceil(self, rhs: Self) -> Self { let d = self / rhs; let r = self % rhs; if r > 0 { d + 1 } else { d } } /// Calculates the smallest value greater than or equal to `self` that /// is a multiple of `rhs`. /// /// # Panics /// /// This function will panic if `rhs` is zero. /// /// ## Overflow behavior /// /// On overflow, this function will panic if overflow checks are enabled (default in debug /// mode) and wrap if overflow checks are disabled (default in release mode). /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(8), 16);")] #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(8), 24);")] /// ``` #[stable(feature = "int_roundings1", since = "1.73.0")] #[rustc_const_stable(feature = "int_roundings1", since = "1.73.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[rustc_inherit_overflow_checks] pub const fn next_multiple_of(self, rhs: Self) -> Self { match self % rhs { 0 => self, r => self + (rhs - r) } } /// Calculates the smallest value greater than or equal to `self` that /// is a multiple of `rhs`. Returns `None` if `rhs` is zero or the /// operation would result in overflow. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(16_", stringify!($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!($SelfT), "::MAX.checked_next_multiple_of(2), None);")] /// ``` #[stable(feature = "int_roundings1", since = "1.73.0")] #[rustc_const_stable(feature = "int_roundings1", since = "1.73.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] pub const fn checked_next_multiple_of(self, rhs: Self) -> Option { match try_opt!(self.checked_rem(rhs)) { 0 => Some(self), // rhs - r cannot overflow because r is smaller than rhs r => self.checked_add(rhs - r) } } /// Returns `true` if `self` is an integer multiple of `rhs`, and false otherwise. /// /// This function is equivalent to `self % rhs == 0`, except that it will not panic /// for `rhs == 0`. Instead, `0.is_multiple_of(0) == true`, and for any non-zero `n`, /// `n.is_multiple_of(0) == false`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert!(6_", stringify!($SelfT), ".is_multiple_of(2));")] #[doc = concat!("assert!(!5_", stringify!($SelfT), ".is_multiple_of(2));")] /// #[doc = concat!("assert!(0_", stringify!($SelfT), ".is_multiple_of(0));")] #[doc = concat!("assert!(!6_", stringify!($SelfT), ".is_multiple_of(0));")] /// ``` #[stable(feature = "unsigned_is_multiple_of", since = "1.87.0")] #[rustc_const_stable(feature = "unsigned_is_multiple_of", since = "1.87.0")] #[must_use] #[inline] #[rustc_inherit_overflow_checks] pub const fn is_multiple_of(self, rhs: Self) -> bool { match rhs { 0 => self == 0, _ => self % rhs == 0, } } /// Returns `true` if and only if `self == 2^k` for some unsigned integer `k`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert!(16", stringify!($SelfT), ".is_power_of_two());")] #[doc = concat!("assert!(!10", stringify!($SelfT), ".is_power_of_two());")] /// ``` #[must_use] #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_is_power_of_two", since = "1.32.0")] #[inline(always)] pub const fn is_power_of_two(self) -> bool { self.count_ones() == 1 } // Returns one less than next power of two. // (For 8u8 next power of two is 8u8 and for 6u8 it is 8u8) // // 8u8.one_less_than_next_power_of_two() == 7 // 6u8.one_less_than_next_power_of_two() == 7 // // This method cannot overflow, as in the `next_power_of_two` // overflow cases it instead ends up returning the maximum value // of the type, and can return 0 for 0. #[inline] const fn one_less_than_next_power_of_two(self) -> Self { if self <= 1 { return 0; } let p = self - 1; // SAFETY: Because `p > 0`, it cannot consist entirely of leading zeros. // That means the shift is always in-bounds, and some processors // (such as intel pre-haswell) have more efficient ctlz // intrinsics when the argument is non-zero. let z = unsafe { intrinsics::ctlz_nonzero(p) }; <$SelfT>::MAX >> z } /// Returns the smallest power of two greater than or equal to `self`. /// /// When return value overflows (i.e., `self > (1 << (N-1))` for type /// `uN`), it panics in debug mode and the return value is wrapped to 0 in /// release mode (the only situation in which this method can return 0). /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".next_power_of_two(), 2);")] #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".next_power_of_two(), 4);")] #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".next_power_of_two(), 1);")] /// ``` #[stable(feature = "rust1", since = "1.0.0")] #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[inline] #[rustc_inherit_overflow_checks] pub const fn next_power_of_two(self) -> Self { self.one_less_than_next_power_of_two() + 1 } /// Returns the smallest power of two greater than or equal to `self`. If /// the next power of two is greater than the type's maximum value, /// `None` is returned, otherwise the power of two is wrapped in `Some`. /// /// # Examples /// /// Basic usage: /// /// ``` #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_next_power_of_two(), Some(2));")] #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".checked_next_power_of_two(), Some(4));")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_power_of_two(), None);")] /// ``` #[inline] #[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"] pub const fn checked_next_power_of_two(self) -> Option { self.one_less_than_next_power_of_two().checked_add(1) } /// Returns the smallest power of two greater than or equal to `n`. If /// the next power of two is greater than the type's maximum value, /// the return value is wrapped to `0`. /// /// # Examples /// /// Basic usage: /// /// ``` /// #![feature(wrapping_next_power_of_two)] /// #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".wrapping_next_power_of_two(), 2);")] #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_next_power_of_two(), 4);")] #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_next_power_of_two(), 0);")] /// ``` #[inline] #[unstable(feature = "wrapping_next_power_of_two", issue = "32463", reason = "needs decision on wrapping behavior")] #[must_use = "this returns the result of the operation, \ without modifying the original"] pub const fn wrapping_next_power_of_two(self) -> Self { self.one_less_than_next_power_of_two().wrapping_add(1) } /// Returns 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; size_of::()] { self.to_be().to_ne_bytes() } /// Returns 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; size_of::()] { self.to_le().to_ne_bytes() } /// Returns 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")] #[must_use = "this returns the result of the operation, \ without modifying the original"] #[cfg_attr(not(bootstrap), allow(unnecessary_transmutes))] // SAFETY: const sound because integers are plain old datatypes so we can always // transmute them to arrays of bytes #[inline] pub const fn to_ne_bytes(self) -> [u8; size_of::()] { // SAFETY: integers are plain old datatypes so we can always transmute them to // arrays of bytes unsafe { mem::transmute(self) } } /// Creates a native endian 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!($SelfT), " {")] #[doc = concat!(" let (int_bytes, rest) = input.split_at(size_of::<", stringify!($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; size_of::()]) -> Self { Self::from_be(Self::from_ne_bytes(bytes)) } /// Creates a native endian 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!($SelfT), " {")] #[doc = concat!(" let (int_bytes, rest) = input.split_at(size_of::<", stringify!($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; size_of::()]) -> Self { Self::from_le(Self::from_ne_bytes(bytes)) } /// Creates a native endian 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!($SelfT), " {")] #[doc = concat!(" let (int_bytes, rest) = input.split_at(size_of::<", stringify!($SelfT), ">());")] /// *input = rest; #[doc = concat!(" ", stringify!($SelfT), "::from_ne_bytes(int_bytes.try_into().unwrap())")] /// } /// ``` #[stable(feature = "int_to_from_bytes", since = "1.32.0")] #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] #[cfg_attr(not(bootstrap), allow(unnecessary_transmutes))] #[must_use] // SAFETY: const sound because integers are plain old datatypes so we can always // transmute to them #[inline] pub const fn from_ne_bytes(bytes: [u8; size_of::()]) -> Self { // SAFETY: integers are plain old datatypes so we can always transmute to them unsafe { mem::transmute(bytes) } } /// New code should prefer to use #[doc = concat!("[`", stringify!($SelfT), "::MIN", "`] instead.")] /// /// Returns the smallest value that can be represented by this integer type. #[stable(feature = "rust1", since = "1.0.0")] #[rustc_promotable] #[inline(always)] #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")] #[deprecated(since = "TBD", note = "replaced by the `MIN` associated constant on this type")] #[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_min_value")] pub const fn min_value() -> Self { Self::MIN } /// New code should prefer to use #[doc = concat!("[`", stringify!($SelfT), "::MAX", "`] instead.")] /// /// Returns the largest value that can be represented by this integer type. #[stable(feature = "rust1", since = "1.0.0")] #[rustc_promotable] #[inline(always)] #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")] #[deprecated(since = "TBD", note = "replaced by the `MAX` associated constant on this type")] #[rustc_diagnostic_item = concat!(stringify!($SelfT), "_legacy_fn_max_value")] pub const fn max_value() -> Self { Self::MAX } } }