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Diffstat (limited to 'library/core/src/num/int_macros.rs')
| -rw-r--r-- | library/core/src/num/int_macros.rs | 2744 |
1 files changed, 2744 insertions, 0 deletions
diff --git a/library/core/src/num/int_macros.rs b/library/core/src/num/int_macros.rs new file mode 100644 index 000000000..a66de19ba --- /dev/null +++ b/library/core/src/num/int_macros.rs @@ -0,0 +1,2744 @@ +macro_rules! int_impl { + ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $BITS_MINUS_ONE:expr, $Min:expr, $Max:expr, + $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr, + $reversed:expr, $le_bytes:expr, $be_bytes:expr, + $to_xe_bytes_doc:expr, $from_xe_bytes_doc:expr, + $bound_condition:expr) => { + /// The smallest value that can be represented by this integer type + #[doc = concat!("(−2<sup>", $BITS_MINUS_ONE, "</sup>", $bound_condition, ")")] + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN, ", stringify!($Min), ");")] + /// ``` + #[stable(feature = "assoc_int_consts", since = "1.43.0")] + pub const MIN: Self = !0 ^ ((!0 as $UnsignedT) >> 1) as Self; + + /// The largest value that can be represented by this integer type + #[doc = concat!("(2<sup>", $BITS_MINUS_ONE, "</sup> − 1", $bound_condition, ")")] + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX, ", stringify!($Max), ");")] + /// ``` + #[stable(feature = "assoc_int_consts", since = "1.43.0")] + pub const MAX: Self = !Self::MIN; + + /// The size of this integer type in bits. + /// + /// # Examples + /// + /// ``` + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::BITS, ", stringify!($BITS), ");")] + /// ``` + #[stable(feature = "int_bits_const", since = "1.53.0")] + pub const BITS: u32 = $BITS; + + /// Converts a string slice in a given base to an integer. + /// + /// The string is expected to be an optional `+` or `-` sign followed by digits. + /// Leading and trailing whitespace represent an error. Digits are a subset of these characters, + /// depending on `radix`: + /// + /// * `0-9` + /// * `a-z` + /// * `A-Z` + /// + /// # Panics + /// + /// This function panics if `radix` is not in the range from 2 to 36. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::from_str_radix(\"A\", 16), Ok(10));")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn from_str_radix(src: &str, radix: u32) -> Result<Self, ParseIntError> { + from_str_radix(src, radix) + } + + /// Returns the number of ones in the binary representation of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = 0b100_0000", stringify!($SelfT), ";")] + /// + /// assert_eq!(n.count_ones(), 1); + /// ``` + /// + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[doc(alias = "popcount")] + #[doc(alias = "popcnt")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn count_ones(self) -> u32 { (self as $UnsignedT).count_ones() } + + /// Returns the number of zeros in the binary representation of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.count_zeros(), 1);")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn count_zeros(self) -> u32 { + (!self).count_ones() + } + + /// Returns the number of leading zeros in the binary representation of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = -1", stringify!($SelfT), ";")] + /// + /// assert_eq!(n.leading_zeros(), 0); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn leading_zeros(self) -> u32 { + (self as $UnsignedT).leading_zeros() + } + + /// Returns the number of trailing zeros in the binary representation of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = -4", stringify!($SelfT), ";")] + /// + /// assert_eq!(n.trailing_zeros(), 2); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn trailing_zeros(self) -> u32 { + (self as $UnsignedT).trailing_zeros() + } + + /// Returns the number of leading ones in the binary representation of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = -1", stringify!($SelfT), ";")] + /// + #[doc = concat!("assert_eq!(n.leading_ones(), ", stringify!($BITS), ");")] + /// ``` + #[stable(feature = "leading_trailing_ones", since = "1.46.0")] + #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn leading_ones(self) -> u32 { + (self as $UnsignedT).leading_ones() + } + + /// Returns the number of trailing ones in the binary representation of `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = 3", stringify!($SelfT), ";")] + /// + /// assert_eq!(n.trailing_ones(), 2); + /// ``` + #[stable(feature = "leading_trailing_ones", since = "1.46.0")] + #[rustc_const_stable(feature = "leading_trailing_ones", since = "1.46.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn trailing_ones(self) -> u32 { + (self as $UnsignedT).trailing_ones() + } + + /// Shifts the bits to the left by a specified amount, `n`, + /// wrapping the truncated bits to the end of the resulting integer. + /// + /// Please note this isn't the same operation as the `<<` shifting operator! + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = ", $rot_op, stringify!($SelfT), ";")] + #[doc = concat!("let m = ", $rot_result, ";")] + /// + #[doc = concat!("assert_eq!(n.rotate_left(", $rot, "), m);")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn rotate_left(self, n: u32) -> Self { + (self as $UnsignedT).rotate_left(n) as Self + } + + /// Shifts the bits to the right by a specified amount, `n`, + /// wrapping the truncated bits to the beginning of the resulting + /// integer. + /// + /// Please note this isn't the same operation as the `>>` shifting operator! + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = ", $rot_result, stringify!($SelfT), ";")] + #[doc = concat!("let m = ", $rot_op, ";")] + /// + #[doc = concat!("assert_eq!(n.rotate_right(", $rot, "), m);")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn rotate_right(self, n: u32) -> Self { + (self as $UnsignedT).rotate_right(n) as Self + } + + /// Reverses the byte order of the integer. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")] + /// + /// let m = n.swap_bytes(); + /// + #[doc = concat!("assert_eq!(m, ", $swapped, ");")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn swap_bytes(self) -> Self { + (self as $UnsignedT).swap_bytes() as Self + } + + /// Reverses the order of bits in the integer. The least significant bit becomes the most significant bit, + /// second least-significant bit becomes second most-significant bit, etc. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = ", $swap_op, stringify!($SelfT), ";")] + /// let m = n.reverse_bits(); + /// + #[doc = concat!("assert_eq!(m, ", $reversed, ");")] + #[doc = concat!("assert_eq!(0, 0", stringify!($SelfT), ".reverse_bits());")] + /// ``` + #[stable(feature = "reverse_bits", since = "1.37.0")] + #[rustc_const_stable(feature = "reverse_bits", since = "1.37.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn reverse_bits(self) -> Self { + (self as $UnsignedT).reverse_bits() as Self + } + + /// Converts an integer from big endian to the target's endianness. + /// + /// On big endian this is a no-op. On little endian the bytes are swapped. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")] + /// + /// if cfg!(target_endian = "big") { + #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n)")] + /// } else { + #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_be(n), n.swap_bytes())")] + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")] + #[must_use] + #[inline] + pub const fn from_be(x: Self) -> Self { + #[cfg(target_endian = "big")] + { + x + } + #[cfg(not(target_endian = "big"))] + { + x.swap_bytes() + } + } + + /// Converts an integer from little endian to the target's endianness. + /// + /// On little endian this is a no-op. On big endian the bytes are swapped. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")] + /// + /// if cfg!(target_endian = "little") { + #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n)")] + /// } else { + #[doc = concat!(" assert_eq!(", stringify!($SelfT), "::from_le(n), n.swap_bytes())")] + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")] + #[must_use] + #[inline] + pub const fn from_le(x: Self) -> Self { + #[cfg(target_endian = "little")] + { + x + } + #[cfg(not(target_endian = "little"))] + { + x.swap_bytes() + } + } + + /// Converts `self` to big endian from the target's endianness. + /// + /// On big endian this is a no-op. On little endian the bytes are swapped. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")] + /// + /// if cfg!(target_endian = "big") { + /// assert_eq!(n.to_be(), n) + /// } else { + /// assert_eq!(n.to_be(), n.swap_bytes()) + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn to_be(self) -> Self { // or not to be? + #[cfg(target_endian = "big")] + { + self + } + #[cfg(not(target_endian = "big"))] + { + self.swap_bytes() + } + } + + /// Converts `self` to little endian from the target's endianness. + /// + /// On little endian this is a no-op. On big endian the bytes are swapped. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let n = 0x1A", stringify!($SelfT), ";")] + /// + /// if cfg!(target_endian = "little") { + /// assert_eq!(n.to_le(), n) + /// } else { + /// assert_eq!(n.to_le(), n.swap_bytes()) + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn to_le(self) -> Self { + #[cfg(target_endian = "little")] + { + self + } + #[cfg(not(target_endian = "little"))] + { + self.swap_bytes() + } + } + + /// Checked integer addition. Computes `self + rhs`, returning `None` + /// if overflow occurred. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(1), Some(", stringify!($SelfT), "::MAX - 1));")] + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add(3), None);")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_add(self, rhs: Self) -> Option<Self> { + let (a, b) = self.overflowing_add(rhs); + if unlikely!(b) {None} else {Some(a)} + } + + /// Unchecked integer addition. Computes `self + rhs`, assuming overflow + /// cannot occur. + /// + /// # Safety + /// + /// This results in undefined behavior when + #[doc = concat!("`self + rhs > ", stringify!($SelfT), "::MAX` or `self + rhs < ", stringify!($SelfT), "::MIN`,")] + /// i.e. when [`checked_add`] would return `None`. + /// + #[doc = concat!("[`checked_add`]: ", stringify!($SelfT), "::checked_add")] + #[unstable( + feature = "unchecked_math", + reason = "niche optimization path", + issue = "85122", + )] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] + #[inline(always)] + #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces + pub const unsafe fn unchecked_add(self, rhs: Self) -> Self { + // SAFETY: the caller must uphold the safety contract for + // `unchecked_add`. + unsafe { intrinsics::unchecked_add(self, rhs) } + } + + /// Checked addition with an unsigned integer. Computes `self + rhs`, + /// returning `None` if overflow occurred. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// # #![feature(mixed_integer_ops)] + #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_add_unsigned(2), Some(3));")] + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).checked_add_unsigned(3), None);")] + /// ``` + #[unstable(feature = "mixed_integer_ops", issue = "87840")] + #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_add_unsigned(self, rhs: $UnsignedT) -> Option<Self> { + let (a, b) = self.overflowing_add_unsigned(rhs); + if unlikely!(b) {None} else {Some(a)} + } + + /// Checked integer subtraction. Computes `self - rhs`, returning `None` if + /// overflow occurred. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub(1), Some(", stringify!($SelfT), "::MIN + 1));")] + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub(3), None);")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_sub(self, rhs: Self) -> Option<Self> { + let (a, b) = self.overflowing_sub(rhs); + if unlikely!(b) {None} else {Some(a)} + } + + /// Unchecked integer subtraction. Computes `self - rhs`, assuming overflow + /// cannot occur. + /// + /// # Safety + /// + /// This results in undefined behavior when + #[doc = concat!("`self - rhs > ", stringify!($SelfT), "::MAX` or `self - rhs < ", stringify!($SelfT), "::MIN`,")] + /// i.e. when [`checked_sub`] would return `None`. + /// + #[doc = concat!("[`checked_sub`]: ", stringify!($SelfT), "::checked_sub")] + #[unstable( + feature = "unchecked_math", + reason = "niche optimization path", + issue = "85122", + )] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] + #[inline(always)] + #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces + pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self { + // SAFETY: the caller must uphold the safety contract for + // `unchecked_sub`. + unsafe { intrinsics::unchecked_sub(self, rhs) } + } + + /// Checked subtraction with an unsigned integer. Computes `self - rhs`, + /// returning `None` if overflow occurred. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// # #![feature(mixed_integer_ops)] + #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".checked_sub_unsigned(2), Some(-1));")] + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).checked_sub_unsigned(3), None);")] + /// ``` + #[unstable(feature = "mixed_integer_ops", issue = "87840")] + #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_sub_unsigned(self, rhs: $UnsignedT) -> Option<Self> { + let (a, b) = self.overflowing_sub_unsigned(rhs); + if unlikely!(b) {None} else {Some(a)} + } + + /// Checked integer multiplication. Computes `self * rhs`, returning `None` if + /// overflow occurred. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(1), Some(", stringify!($SelfT), "::MAX));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_mul(2), None);")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_mul(self, rhs: Self) -> Option<Self> { + let (a, b) = self.overflowing_mul(rhs); + if unlikely!(b) {None} else {Some(a)} + } + + /// Unchecked integer multiplication. Computes `self * rhs`, assuming overflow + /// cannot occur. + /// + /// # Safety + /// + /// This results in undefined behavior when + #[doc = concat!("`self * rhs > ", stringify!($SelfT), "::MAX` or `self * rhs < ", stringify!($SelfT), "::MIN`,")] + /// i.e. when [`checked_mul`] would return `None`. + /// + #[doc = concat!("[`checked_mul`]: ", stringify!($SelfT), "::checked_mul")] + #[unstable( + feature = "unchecked_math", + reason = "niche optimization path", + issue = "85122", + )] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] + #[inline(always)] + #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces + pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self { + // SAFETY: the caller must uphold the safety contract for + // `unchecked_mul`. + unsafe { intrinsics::unchecked_mul(self, rhs) } + } + + /// Checked integer division. Computes `self / rhs`, returning `None` if `rhs == 0` + /// or the division results in overflow. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div(-1), Some(", stringify!($Max), "));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div(-1), None);")] + #[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div(0), None);")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_div(self, rhs: Self) -> Option<Self> { + if unlikely!(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) { + None + } else { + // SAFETY: div by zero and by INT_MIN have been checked above + Some(unsafe { intrinsics::unchecked_div(self, rhs) }) + } + } + + /// Checked Euclidean division. Computes `self.div_euclid(rhs)`, + /// returning `None` if `rhs == 0` or the division results in overflow. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).checked_div_euclid(-1), Some(", stringify!($Max), "));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_div_euclid(-1), None);")] + #[doc = concat!("assert_eq!((1", stringify!($SelfT), ").checked_div_euclid(0), None);")] + /// ``` + #[stable(feature = "euclidean_division", since = "1.38.0")] + #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_div_euclid(self, rhs: Self) -> Option<Self> { + // Using `&` helps LLVM see that it is the same check made in division. + if unlikely!(rhs == 0 || ((self == Self::MIN) & (rhs == -1))) { + None + } else { + Some(self.div_euclid(rhs)) + } + } + + /// Checked integer remainder. Computes `self % rhs`, returning `None` if + /// `rhs == 0` or the division results in overflow. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(2), Some(1));")] + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem(0), None);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem(-1), None);")] + /// ``` + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_checked_int_div", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_rem(self, rhs: Self) -> Option<Self> { + if unlikely!(rhs == 0 || ((self == Self::MIN) && (rhs == -1))) { + None + } else { + // SAFETY: div by zero and by INT_MIN have been checked above + Some(unsafe { intrinsics::unchecked_rem(self, rhs) }) + } + } + + /// Checked Euclidean remainder. Computes `self.rem_euclid(rhs)`, returning `None` + /// if `rhs == 0` or the division results in overflow. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(2), Some(1));")] + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_rem_euclid(0), None);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_rem_euclid(-1), None);")] + /// ``` + #[stable(feature = "euclidean_division", since = "1.38.0")] + #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_rem_euclid(self, rhs: Self) -> Option<Self> { + // Using `&` helps LLVM see that it is the same check made in division. + if unlikely!(rhs == 0 || ((self == Self::MIN) & (rhs == -1))) { + None + } else { + Some(self.rem_euclid(rhs)) + } + } + + /// Checked negation. Computes `-self`, returning `None` if `self == MIN`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_neg(), Some(-5));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_neg(), None);")] + /// ``` + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_neg(self) -> Option<Self> { + let (a, b) = self.overflowing_neg(); + if unlikely!(b) {None} else {Some(a)} + } + + /// Checked shift left. Computes `self << rhs`, returning `None` if `rhs` is larger + /// than or equal to the number of bits in `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(4), Some(0x10));")] + #[doc = concat!("assert_eq!(0x1", stringify!($SelfT), ".checked_shl(129), None);")] + /// ``` + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_shl(self, rhs: u32) -> Option<Self> { + let (a, b) = self.overflowing_shl(rhs); + if unlikely!(b) {None} else {Some(a)} + } + + /// Unchecked shift left. Computes `self << rhs`, assuming that + /// `rhs` is less than the number of bits in `self`. + /// + /// # Safety + /// + /// This results in undefined behavior if `rhs` is larger than + /// or equal to the number of bits in `self`, + /// i.e. when [`checked_shl`] would return `None`. + /// + #[doc = concat!("[`checked_shl`]: ", stringify!($SelfT), "::checked_shl")] + #[unstable( + feature = "unchecked_math", + reason = "niche optimization path", + issue = "85122", + )] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] + #[inline(always)] + #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces + pub const unsafe fn unchecked_shl(self, rhs: Self) -> Self { + // SAFETY: the caller must uphold the safety contract for + // `unchecked_shl`. + unsafe { intrinsics::unchecked_shl(self, rhs) } + } + + /// Checked shift right. Computes `self >> rhs`, returning `None` if `rhs` is + /// larger than or equal to the number of bits in `self`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(4), Some(0x1));")] + #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".checked_shr(128), None);")] + /// ``` + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_shr(self, rhs: u32) -> Option<Self> { + let (a, b) = self.overflowing_shr(rhs); + if unlikely!(b) {None} else {Some(a)} + } + + /// Unchecked shift right. Computes `self >> rhs`, assuming that + /// `rhs` is less than the number of bits in `self`. + /// + /// # Safety + /// + /// This results in undefined behavior if `rhs` is larger than + /// or equal to the number of bits in `self`, + /// i.e. when [`checked_shr`] would return `None`. + /// + #[doc = concat!("[`checked_shr`]: ", stringify!($SelfT), "::checked_shr")] + #[unstable( + feature = "unchecked_math", + reason = "niche optimization path", + issue = "85122", + )] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")] + #[inline(always)] + #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces + pub const unsafe fn unchecked_shr(self, rhs: Self) -> Self { + // SAFETY: the caller must uphold the safety contract for + // `unchecked_shr`. + unsafe { intrinsics::unchecked_shr(self, rhs) } + } + + /// Checked absolute value. Computes `self.abs()`, returning `None` if + /// `self == MIN`. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// + #[doc = concat!("assert_eq!((-5", stringify!($SelfT), ").checked_abs(), Some(5));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.checked_abs(), None);")] + /// ``` + #[stable(feature = "no_panic_abs", since = "1.13.0")] + #[rustc_const_stable(feature = "const_checked_int_methods", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_abs(self) -> Option<Self> { + if self.is_negative() { + self.checked_neg() + } else { + Some(self) + } + } + + /// Checked exponentiation. Computes `self.pow(exp)`, returning `None` if + /// overflow occurred. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(8", stringify!($SelfT), ".checked_pow(2), Some(64));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_pow(2), None);")] + /// ``` + + #[stable(feature = "no_panic_pow", since = "1.34.0")] + #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_pow(self, mut exp: u32) -> Option<Self> { + if exp == 0 { + return Some(1); + } + let mut base = self; + let mut acc: Self = 1; + + while exp > 1 { + if (exp & 1) == 1 { + acc = try_opt!(acc.checked_mul(base)); + } + exp /= 2; + base = try_opt!(base.checked_mul(base)); + } + // since exp!=0, finally the exp must be 1. + // Deal with the final bit of the exponent separately, since + // squaring the base afterwards is not necessary and may cause a + // needless overflow. + Some(try_opt!(acc.checked_mul(base))) + } + + /// Saturating integer addition. Computes `self + rhs`, saturating at the numeric + /// bounds instead of overflowing. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_add(1), 101);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add(100), ", stringify!($SelfT), "::MAX);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_add(-1), ", stringify!($SelfT), "::MIN);")] + /// ``` + + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn saturating_add(self, rhs: Self) -> Self { + intrinsics::saturating_add(self, rhs) + } + + /// Saturating addition with an unsigned integer. Computes `self + rhs`, + /// saturating at the numeric bounds instead of overflowing. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// # #![feature(mixed_integer_ops)] + #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".saturating_add_unsigned(2), 3);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_add_unsigned(100), ", stringify!($SelfT), "::MAX);")] + /// ``` + #[unstable(feature = "mixed_integer_ops", issue = "87840")] + #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn saturating_add_unsigned(self, rhs: $UnsignedT) -> Self { + // Overflow can only happen at the upper bound + // We cannot use `unwrap_or` here because it is not `const` + match self.checked_add_unsigned(rhs) { + Some(x) => x, + None => Self::MAX, + } + } + + /// Saturating integer subtraction. Computes `self - rhs`, saturating at the + /// numeric bounds instead of overflowing. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub(127), -27);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub(100), ", stringify!($SelfT), "::MIN);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_sub(-1), ", stringify!($SelfT), "::MAX);")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn saturating_sub(self, rhs: Self) -> Self { + intrinsics::saturating_sub(self, rhs) + } + + /// Saturating subtraction with an unsigned integer. Computes `self - rhs`, + /// saturating at the numeric bounds instead of overflowing. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// # #![feature(mixed_integer_ops)] + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_sub_unsigned(127), -27);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_sub_unsigned(100), ", stringify!($SelfT), "::MIN);")] + /// ``` + #[unstable(feature = "mixed_integer_ops", issue = "87840")] + #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn saturating_sub_unsigned(self, rhs: $UnsignedT) -> Self { + // Overflow can only happen at the lower bound + // We cannot use `unwrap_or` here because it is not `const` + match self.checked_sub_unsigned(rhs) { + Some(x) => x, + None => Self::MIN, + } + } + + /// Saturating integer negation. Computes `-self`, returning `MAX` if `self == MIN` + /// instead of overflowing. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_neg(), -100);")] + #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").saturating_neg(), 100);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_neg(), ", stringify!($SelfT), "::MAX);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_neg(), ", stringify!($SelfT), "::MIN + 1);")] + /// ``` + + #[stable(feature = "saturating_neg", since = "1.45.0")] + #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn saturating_neg(self) -> Self { + intrinsics::saturating_sub(0, self) + } + + /// Saturating absolute value. Computes `self.abs()`, returning `MAX` if `self == + /// MIN` instead of overflowing. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".saturating_abs(), 100);")] + #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").saturating_abs(), 100);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_abs(), ", stringify!($SelfT), "::MAX);")] + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 1).saturating_abs(), ", stringify!($SelfT), "::MAX);")] + /// ``` + + #[stable(feature = "saturating_neg", since = "1.45.0")] + #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn saturating_abs(self) -> Self { + if self.is_negative() { + self.saturating_neg() + } else { + self + } + } + + /// Saturating integer multiplication. Computes `self * rhs`, saturating at the + /// numeric bounds instead of overflowing. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// + #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".saturating_mul(12), 120);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_mul(10), ", stringify!($SelfT), "::MAX);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_mul(10), ", stringify!($SelfT), "::MIN);")] + /// ``` + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_saturating_int_methods", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn saturating_mul(self, rhs: Self) -> Self { + match self.checked_mul(rhs) { + Some(x) => x, + None => if (self < 0) == (rhs < 0) { + Self::MAX + } else { + Self::MIN + } + } + } + + /// Saturating integer division. Computes `self / rhs`, saturating at the + /// numeric bounds instead of overflowing. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".saturating_div(2), 2);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.saturating_div(-1), ", stringify!($SelfT), "::MIN + 1);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_div(-1), ", stringify!($SelfT), "::MAX);")] + /// + /// ``` + /// + /// ```should_panic + #[doc = concat!("let _ = 1", stringify!($SelfT), ".saturating_div(0);")] + /// + /// ``` + #[stable(feature = "saturating_div", since = "1.58.0")] + #[rustc_const_stable(feature = "saturating_div", since = "1.58.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn saturating_div(self, rhs: Self) -> Self { + match self.overflowing_div(rhs) { + (result, false) => result, + (_result, true) => Self::MAX, // MIN / -1 is the only possible saturating overflow + } + } + + /// Saturating integer exponentiation. Computes `self.pow(exp)`, + /// saturating at the numeric bounds instead of overflowing. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// + #[doc = concat!("assert_eq!((-4", stringify!($SelfT), ").saturating_pow(3), -64);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(2), ", stringify!($SelfT), "::MAX);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.saturating_pow(3), ", stringify!($SelfT), "::MIN);")] + /// ``` + #[stable(feature = "no_panic_pow", since = "1.34.0")] + #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn saturating_pow(self, exp: u32) -> Self { + match self.checked_pow(exp) { + Some(x) => x, + None if self < 0 && exp % 2 == 1 => Self::MIN, + None => Self::MAX, + } + } + + /// Wrapping (modular) addition. Computes `self + rhs`, wrapping around at the + /// boundary of the type. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add(27), 127);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add(2), ", stringify!($SelfT), "::MIN + 1);")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn wrapping_add(self, rhs: Self) -> Self { + intrinsics::wrapping_add(self, rhs) + } + + /// Wrapping (modular) addition with an unsigned integer. Computes + /// `self + rhs`, wrapping around at the boundary of the type. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// # #![feature(mixed_integer_ops)] + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_add_unsigned(27), 127);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.wrapping_add_unsigned(2), ", stringify!($SelfT), "::MIN + 1);")] + /// ``` + #[unstable(feature = "mixed_integer_ops", issue = "87840")] + #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn wrapping_add_unsigned(self, rhs: $UnsignedT) -> Self { + self.wrapping_add(rhs as Self) + } + + /// Wrapping (modular) subtraction. Computes `self - rhs`, wrapping around at the + /// boundary of the type. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub(127), -127);")] + #[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub(", stringify!($SelfT), "::MAX), ", stringify!($SelfT), "::MAX);")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn wrapping_sub(self, rhs: Self) -> Self { + intrinsics::wrapping_sub(self, rhs) + } + + /// Wrapping (modular) subtraction with an unsigned integer. Computes + /// `self - rhs`, wrapping around at the boundary of the type. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// # #![feature(mixed_integer_ops)] + #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".wrapping_sub_unsigned(127), -127);")] + #[doc = concat!("assert_eq!((-2", stringify!($SelfT), ").wrapping_sub_unsigned(", stringify!($UnsignedT), "::MAX), -1);")] + /// ``` + #[unstable(feature = "mixed_integer_ops", issue = "87840")] + #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn wrapping_sub_unsigned(self, rhs: $UnsignedT) -> Self { + self.wrapping_sub(rhs as Self) + } + + /// Wrapping (modular) multiplication. Computes `self * rhs`, wrapping around at + /// the boundary of the type. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".wrapping_mul(12), 120);")] + /// assert_eq!(11i8.wrapping_mul(12), -124); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn wrapping_mul(self, rhs: Self) -> Self { + intrinsics::wrapping_mul(self, rhs) + } + + /// Wrapping (modular) division. Computes `self / rhs`, wrapping around at the + /// boundary of the type. + /// + /// The only case where such wrapping can occur is when one divides `MIN / -1` on a signed type (where + /// `MIN` is the negative minimal value for the type); this is equivalent to `-MIN`, a positive value + /// that is too large to represent in the type. In such a case, this function returns `MIN` itself. + /// + /// # Panics + /// + /// This function will panic if `rhs` is 0. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div(10), 10);")] + /// assert_eq!((-128i8).wrapping_div(-1), -128); + /// ``` + #[stable(feature = "num_wrapping", since = "1.2.0")] + #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn wrapping_div(self, rhs: Self) -> Self { + self.overflowing_div(rhs).0 + } + + /// Wrapping Euclidean division. Computes `self.div_euclid(rhs)`, + /// wrapping around at the boundary of the type. + /// + /// Wrapping will only occur in `MIN / -1` on a signed type (where `MIN` is the negative minimal value + /// for the type). This is equivalent to `-MIN`, a positive value that is too large to represent in the + /// type. In this case, this method returns `MIN` itself. + /// + /// # Panics + /// + /// This function will panic if `rhs` is 0. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_div_euclid(10), 10);")] + /// assert_eq!((-128i8).wrapping_div_euclid(-1), -128); + /// ``` + #[stable(feature = "euclidean_division", since = "1.38.0")] + #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn wrapping_div_euclid(self, rhs: Self) -> Self { + self.overflowing_div_euclid(rhs).0 + } + + /// Wrapping (modular) remainder. Computes `self % rhs`, wrapping around at the + /// boundary of the type. + /// + /// Such wrap-around never actually occurs mathematically; implementation artifacts make `x % y` + /// invalid for `MIN / -1` on a signed type (where `MIN` is the negative minimal value). In such a case, + /// this function returns `0`. + /// + /// # Panics + /// + /// This function will panic if `rhs` is 0. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem(10), 0);")] + /// assert_eq!((-128i8).wrapping_rem(-1), 0); + /// ``` + #[stable(feature = "num_wrapping", since = "1.2.0")] + #[rustc_const_stable(feature = "const_wrapping_int_methods", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn wrapping_rem(self, rhs: Self) -> Self { + self.overflowing_rem(rhs).0 + } + + /// Wrapping Euclidean remainder. Computes `self.rem_euclid(rhs)`, wrapping around + /// at the boundary of the type. + /// + /// Wrapping will only occur in `MIN % -1` on a signed type (where `MIN` is the negative minimal value + /// for the type). In this case, this method returns 0. + /// + /// # Panics + /// + /// This function will panic if `rhs` is 0. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_rem_euclid(10), 0);")] + /// assert_eq!((-128i8).wrapping_rem_euclid(-1), 0); + /// ``` + #[stable(feature = "euclidean_division", since = "1.38.0")] + #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn wrapping_rem_euclid(self, rhs: Self) -> Self { + self.overflowing_rem_euclid(rhs).0 + } + + /// Wrapping (modular) negation. Computes `-self`, wrapping around at the boundary + /// of the type. + /// + /// The only case where such wrapping can occur is when one negates `MIN` on a signed type (where `MIN` + /// is the negative minimal value for the type); this is a positive value that is too large to represent + /// in the type. In such a case, this function returns `MIN` itself. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_neg(), -100);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.wrapping_neg(), ", stringify!($SelfT), "::MIN);")] + /// ``` + #[stable(feature = "num_wrapping", since = "1.2.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn wrapping_neg(self) -> Self { + (0 as $SelfT).wrapping_sub(self) + } + + /// Panic-free bitwise shift-left; yields `self << mask(rhs)`, where `mask` removes + /// any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type. + /// + /// Note that this is *not* the same as a rotate-left; the RHS of a wrapping shift-left is restricted to + /// the range of the type, rather than the bits shifted out of the LHS being returned to the other end. + /// The primitive integer types all implement a [`rotate_left`](Self::rotate_left) function, + /// which may be what you want instead. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!((-1", stringify!($SelfT), ").wrapping_shl(7), -128);")] + #[doc = concat!("assert_eq!((-1", stringify!($SelfT), ").wrapping_shl(128), -1);")] + /// ``` + #[stable(feature = "num_wrapping", since = "1.2.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn wrapping_shl(self, rhs: u32) -> Self { + // SAFETY: the masking by the bitsize of the type ensures that we do not shift + // out of bounds + unsafe { + intrinsics::unchecked_shl(self, (rhs & ($BITS - 1)) as $SelfT) + } + } + + /// Panic-free bitwise shift-right; yields `self >> mask(rhs)`, where `mask` + /// removes any high-order bits of `rhs` that would cause the shift to exceed the bitwidth of the type. + /// + /// Note that this is *not* the same as a rotate-right; the RHS of a wrapping shift-right is restricted + /// to the range of the type, rather than the bits shifted out of the LHS being returned to the other + /// end. The primitive integer types all implement a [`rotate_right`](Self::rotate_right) function, + /// which may be what you want instead. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!((-128", stringify!($SelfT), ").wrapping_shr(7), -1);")] + /// assert_eq!((-128i16).wrapping_shr(64), -128); + /// ``` + #[stable(feature = "num_wrapping", since = "1.2.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn wrapping_shr(self, rhs: u32) -> Self { + // SAFETY: the masking by the bitsize of the type ensures that we do not shift + // out of bounds + unsafe { + intrinsics::unchecked_shr(self, (rhs & ($BITS - 1)) as $SelfT) + } + } + + /// Wrapping (modular) absolute value. Computes `self.abs()`, wrapping around at + /// the boundary of the type. + /// + /// The only case where such wrapping can occur is when one takes the absolute value of the negative + /// minimal value for the type; this is a positive value that is too large to represent in the type. In + /// such a case, this function returns `MIN` itself. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".wrapping_abs(), 100);")] + #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").wrapping_abs(), 100);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.wrapping_abs(), ", stringify!($SelfT), "::MIN);")] + /// assert_eq!((-128i8).wrapping_abs() as u8, 128); + /// ``` + #[stable(feature = "no_panic_abs", since = "1.13.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[allow(unused_attributes)] + #[inline] + pub const fn wrapping_abs(self) -> Self { + if self.is_negative() { + self.wrapping_neg() + } else { + self + } + } + + /// Computes the absolute value of `self` without any wrapping + /// or panicking. + /// + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".unsigned_abs(), 100", stringify!($UnsignedT), ");")] + #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").unsigned_abs(), 100", stringify!($UnsignedT), ");")] + /// assert_eq!((-128i8).unsigned_abs(), 128u8); + /// ``` + #[stable(feature = "unsigned_abs", since = "1.51.0")] + #[rustc_const_stable(feature = "unsigned_abs", since = "1.51.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn unsigned_abs(self) -> $UnsignedT { + self.wrapping_abs() as $UnsignedT + } + + /// Wrapping (modular) exponentiation. Computes `self.pow(exp)`, + /// wrapping around at the boundary of the type. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".wrapping_pow(4), 81);")] + /// assert_eq!(3i8.wrapping_pow(5), -13); + /// assert_eq!(3i8.wrapping_pow(6), -39); + /// ``` + #[stable(feature = "no_panic_pow", since = "1.34.0")] + #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn wrapping_pow(self, mut exp: u32) -> Self { + if exp == 0 { + return 1; + } + let mut base = self; + let mut acc: Self = 1; + + while exp > 1 { + if (exp & 1) == 1 { + acc = acc.wrapping_mul(base); + } + exp /= 2; + base = base.wrapping_mul(base); + } + + // since exp!=0, finally the exp must be 1. + // Deal with the final bit of the exponent separately, since + // squaring the base afterwards is not necessary and may cause a + // needless overflow. + acc.wrapping_mul(base) + } + + /// Calculates `self` + `rhs` + /// + /// Returns a tuple of the addition along with a boolean indicating whether an arithmetic overflow would + /// occur. If an overflow would have occurred then the wrapped value is returned. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (", stringify!($SelfT), "::MIN, true));")] + /// ``` + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn overflowing_add(self, rhs: Self) -> (Self, bool) { + let (a, b) = intrinsics::add_with_overflow(self as $ActualT, rhs as $ActualT); + (a as Self, b) + } + + /// Calculates `self` + `rhs` with an unsigned `rhs` + /// + /// Returns a tuple of the addition along with a boolean indicating + /// whether an arithmetic overflow would occur. If an overflow would + /// have occurred then the wrapped value is returned. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// # #![feature(mixed_integer_ops)] + #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_add_unsigned(2), (3, false));")] + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_add_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MAX, false));")] + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX - 2).overflowing_add_unsigned(3), (", stringify!($SelfT), "::MIN, true));")] + /// ``` + #[unstable(feature = "mixed_integer_ops", issue = "87840")] + #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn overflowing_add_unsigned(self, rhs: $UnsignedT) -> (Self, bool) { + let rhs = rhs as Self; + let (res, overflowed) = self.overflowing_add(rhs); + (res, overflowed ^ (rhs < 0)) + } + + /// Calculates `self` - `rhs` + /// + /// Returns a tuple of the subtraction along with a boolean indicating whether an arithmetic overflow + /// would occur. If an overflow would have occurred then the wrapped value is returned. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_sub(2), (3, false));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_sub(1), (", stringify!($SelfT), "::MAX, true));")] + /// ``` + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn overflowing_sub(self, rhs: Self) -> (Self, bool) { + let (a, b) = intrinsics::sub_with_overflow(self as $ActualT, rhs as $ActualT); + (a as Self, b) + } + + /// Calculates `self` - `rhs` with an unsigned `rhs` + /// + /// Returns a tuple of the subtraction along with a boolean indicating + /// whether an arithmetic overflow would occur. If an overflow would + /// have occurred then the wrapped value is returned. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// # #![feature(mixed_integer_ops)] + #[doc = concat!("assert_eq!(1", stringify!($SelfT), ".overflowing_sub_unsigned(2), (-1, false));")] + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MAX).overflowing_sub_unsigned(", stringify!($UnsignedT), "::MAX), (", stringify!($SelfT), "::MIN, false));")] + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN + 2).overflowing_sub_unsigned(3), (", stringify!($SelfT), "::MAX, true));")] + /// ``` + #[unstable(feature = "mixed_integer_ops", issue = "87840")] + #[rustc_const_unstable(feature = "mixed_integer_ops", issue = "87840")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn overflowing_sub_unsigned(self, rhs: $UnsignedT) -> (Self, bool) { + let rhs = rhs as Self; + let (res, overflowed) = self.overflowing_sub(rhs); + (res, overflowed ^ (rhs < 0)) + } + + /// Calculates the multiplication of `self` and `rhs`. + /// + /// Returns a tuple of the multiplication along with a boolean indicating whether an arithmetic overflow + /// would occur. If an overflow would have occurred then the wrapped value is returned. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_mul(2), (10, false));")] + /// assert_eq!(1_000_000_000i32.overflowing_mul(10), (1410065408, true)); + /// ``` + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn overflowing_mul(self, rhs: Self) -> (Self, bool) { + let (a, b) = intrinsics::mul_with_overflow(self as $ActualT, rhs as $ActualT); + (a as Self, b) + } + + /// Calculates the divisor when `self` is divided by `rhs`. + /// + /// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would + /// occur. If an overflow would occur then self is returned. + /// + /// # Panics + /// + /// This function will panic if `rhs` is 0. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div(2), (2, false));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div(-1), (", stringify!($SelfT), "::MIN, true));")] + /// ``` + #[inline] + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + pub const fn overflowing_div(self, rhs: Self) -> (Self, bool) { + // Using `&` helps LLVM see that it is the same check made in division. + if unlikely!((self == Self::MIN) & (rhs == -1)) { + (self, true) + } else { + (self / rhs, false) + } + } + + /// Calculates the quotient of Euclidean division `self.div_euclid(rhs)`. + /// + /// Returns a tuple of the divisor along with a boolean indicating whether an arithmetic overflow would + /// occur. If an overflow would occur then `self` is returned. + /// + /// # Panics + /// + /// This function will panic if `rhs` is 0. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_div_euclid(2), (2, false));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_div_euclid(-1), (", stringify!($SelfT), "::MIN, true));")] + /// ``` + #[inline] + #[stable(feature = "euclidean_division", since = "1.38.0")] + #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + pub const fn overflowing_div_euclid(self, rhs: Self) -> (Self, bool) { + // Using `&` helps LLVM see that it is the same check made in division. + if unlikely!((self == Self::MIN) & (rhs == -1)) { + (self, true) + } else { + (self.div_euclid(rhs), false) + } + } + + /// Calculates the remainder when `self` is divided by `rhs`. + /// + /// Returns a tuple of the remainder after dividing along with a boolean indicating whether an + /// arithmetic overflow would occur. If an overflow would occur then 0 is returned. + /// + /// # Panics + /// + /// This function will panic if `rhs` is 0. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem(2), (1, false));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem(-1), (0, true));")] + /// ``` + #[inline] + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_overflowing_int_methods", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + pub const fn overflowing_rem(self, rhs: Self) -> (Self, bool) { + if unlikely!(rhs == -1) { + (0, self == Self::MIN) + } else { + (self % rhs, false) + } + } + + + /// Overflowing Euclidean remainder. Calculates `self.rem_euclid(rhs)`. + /// + /// Returns a tuple of the remainder after dividing along with a boolean indicating whether an + /// arithmetic overflow would occur. If an overflow would occur then 0 is returned. + /// + /// # Panics + /// + /// This function will panic if `rhs` is 0. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".overflowing_rem_euclid(2), (1, false));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_rem_euclid(-1), (0, true));")] + /// ``` + #[stable(feature = "euclidean_division", since = "1.38.0")] + #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn overflowing_rem_euclid(self, rhs: Self) -> (Self, bool) { + if unlikely!(rhs == -1) { + (0, self == Self::MIN) + } else { + (self.rem_euclid(rhs), false) + } + } + + + /// Negates self, overflowing if this is equal to the minimum value. + /// + /// Returns a tuple of the negated version of self along with a boolean indicating whether an overflow + /// happened. If `self` is the minimum value (e.g., `i32::MIN` for values of type `i32`), then the + /// minimum value will be returned again and `true` will be returned for an overflow happening. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2, false));")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.overflowing_neg(), (", stringify!($SelfT), "::MIN, true));")] + /// ``` + #[inline] + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[allow(unused_attributes)] + pub const fn overflowing_neg(self) -> (Self, bool) { + if unlikely!(self == Self::MIN) { + (Self::MIN, true) + } else { + (-self, false) + } + } + + /// Shifts self left by `rhs` bits. + /// + /// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift + /// value was larger than or equal to the number of bits. If the shift value is too large, then value is + /// masked (N-1) where N is the number of bits, and this value is then used to perform the shift. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(0x1", stringify!($SelfT),".overflowing_shl(4), (0x10, false));")] + /// assert_eq!(0x1i32.overflowing_shl(36), (0x10, true)); + /// ``` + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn overflowing_shl(self, rhs: u32) -> (Self, bool) { + (self.wrapping_shl(rhs), (rhs > ($BITS - 1))) + } + + /// Shifts self right by `rhs` bits. + /// + /// Returns a tuple of the shifted version of self along with a boolean indicating whether the shift + /// value was larger than or equal to the number of bits. If the shift value is too large, then value is + /// masked (N-1) where N is the number of bits, and this value is then used to perform the shift. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(4), (0x1, false));")] + /// assert_eq!(0x10i32.overflowing_shr(36), (0x1, true)); + /// ``` + #[stable(feature = "wrapping", since = "1.7.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn overflowing_shr(self, rhs: u32) -> (Self, bool) { + (self.wrapping_shr(rhs), (rhs > ($BITS - 1))) + } + + /// Computes the absolute value of `self`. + /// + /// Returns a tuple of the absolute version of self along with a boolean indicating whether an overflow + /// happened. If self is the minimum value + #[doc = concat!("(e.g., ", stringify!($SelfT), "::MIN for values of type ", stringify!($SelfT), "),")] + /// then the minimum value will be returned again and true will be returned + /// for an overflow happening. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".overflowing_abs(), (10, false));")] + #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").overflowing_abs(), (10, false));")] + #[doc = concat!("assert_eq!((", stringify!($SelfT), "::MIN).overflowing_abs(), (", stringify!($SelfT), "::MIN, true));")] + /// ``` + #[stable(feature = "no_panic_abs", since = "1.13.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn overflowing_abs(self) -> (Self, bool) { + (self.wrapping_abs(), self == Self::MIN) + } + + /// Raises self to the power of `exp`, using exponentiation by squaring. + /// + /// Returns a tuple of the exponentiation along with a bool indicating + /// whether an overflow happened. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(3", stringify!($SelfT), ".overflowing_pow(4), (81, false));")] + /// assert_eq!(3i8.overflowing_pow(5), (-13, true)); + /// ``` + #[stable(feature = "no_panic_pow", since = "1.34.0")] + #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) { + if exp == 0 { + return (1,false); + } + let mut base = self; + let mut acc: Self = 1; + let mut overflown = false; + // Scratch space for storing results of overflowing_mul. + let mut r; + + while exp > 1 { + if (exp & 1) == 1 { + r = acc.overflowing_mul(base); + acc = r.0; + overflown |= r.1; + } + exp /= 2; + r = base.overflowing_mul(base); + base = r.0; + overflown |= r.1; + } + + // since exp!=0, finally the exp must be 1. + // Deal with the final bit of the exponent separately, since + // squaring the base afterwards is not necessary and may cause a + // needless overflow. + r = acc.overflowing_mul(base); + r.1 |= overflown; + r + } + + /// Raises self to the power of `exp`, using exponentiation by squaring. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let x: ", stringify!($SelfT), " = 2; // or any other integer type")] + /// + /// assert_eq!(x.pow(5), 32); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + #[rustc_inherit_overflow_checks] + pub const fn pow(self, mut exp: u32) -> Self { + if exp == 0 { + return 1; + } + let mut base = self; + let mut acc = 1; + + while exp > 1 { + if (exp & 1) == 1 { + acc = acc * base; + } + exp /= 2; + base = base * base; + } + + // since exp!=0, finally the exp must be 1. + // Deal with the final bit of the exponent separately, since + // squaring the base afterwards is not necessary and may cause a + // needless overflow. + acc * base + } + + /// Calculates the quotient of Euclidean division of `self` by `rhs`. + /// + /// This computes the integer `q` such that `self = q * rhs + r`, with + /// `r = self.rem_euclid(rhs)` and `0 <= r < abs(rhs)`. + /// + /// In other words, the result is `self / rhs` rounded to the integer `q` + /// such that `self >= q * rhs`. + /// If `self > 0`, this is equal to round towards zero (the default in Rust); + /// if `self < 0`, this is equal to round towards +/- infinity. + /// + /// # Panics + /// + /// This function will panic if `rhs` is 0 or the division results in overflow. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")] + /// let b = 4; + /// + /// assert_eq!(a.div_euclid(b), 1); // 7 >= 4 * 1 + /// assert_eq!(a.div_euclid(-b), -1); // 7 >= -4 * -1 + /// assert_eq!((-a).div_euclid(b), -2); // -7 >= 4 * -2 + /// assert_eq!((-a).div_euclid(-b), 2); // -7 >= -4 * 2 + /// ``` + #[stable(feature = "euclidean_division", since = "1.38.0")] + #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + #[rustc_inherit_overflow_checks] + pub const fn div_euclid(self, rhs: Self) -> Self { + let q = self / rhs; + if self % rhs < 0 { + return if rhs > 0 { q - 1 } else { q + 1 } + } + q + } + + + /// Calculates the least nonnegative remainder of `self (mod rhs)`. + /// + /// This is done as if by the Euclidean division algorithm -- given + /// `r = self.rem_euclid(rhs)`, `self = rhs * self.div_euclid(rhs) + r`, and + /// `0 <= r < abs(rhs)`. + /// + /// # Panics + /// + /// This function will panic if `rhs` is 0 or the division results in overflow. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("let a: ", stringify!($SelfT), " = 7; // or any other integer type")] + /// let b = 4; + /// + /// assert_eq!(a.rem_euclid(b), 3); + /// assert_eq!((-a).rem_euclid(b), 1); + /// assert_eq!(a.rem_euclid(-b), 3); + /// assert_eq!((-a).rem_euclid(-b), 1); + /// ``` + #[stable(feature = "euclidean_division", since = "1.38.0")] + #[rustc_const_stable(feature = "const_euclidean_int_methods", since = "1.52.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + #[rustc_inherit_overflow_checks] + pub const fn rem_euclid(self, rhs: Self) -> Self { + let r = self % rhs; + if r < 0 { + if rhs < 0 { + r - rhs + } else { + r + rhs + } + } else { + r + } + } + + /// Calculates the quotient of `self` and `rhs`, rounding the result towards negative infinity. + /// + /// # Panics + /// + /// This function will panic if `rhs` is zero. + /// + /// ## Overflow behavior + /// + /// On overflow, this function will panic if overflow checks are enabled (default in debug + /// mode) and wrap if overflow checks are disabled (default in release mode). + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(int_roundings)] + #[doc = concat!("let a: ", stringify!($SelfT)," = 8;")] + /// let b = 3; + /// + /// assert_eq!(a.div_floor(b), 2); + /// assert_eq!(a.div_floor(-b), -3); + /// assert_eq!((-a).div_floor(b), -3); + /// assert_eq!((-a).div_floor(-b), 2); + /// ``` + #[unstable(feature = "int_roundings", issue = "88581")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + #[rustc_inherit_overflow_checks] + pub const fn div_floor(self, rhs: Self) -> Self { + let d = self / rhs; + let r = self % rhs; + if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) { + d - 1 + } else { + d + } + } + + /// Calculates the quotient of `self` and `rhs`, rounding the result towards positive infinity. + /// + /// # Panics + /// + /// This function will panic if `rhs` is zero. + /// + /// ## Overflow behavior + /// + /// On overflow, this function will panic if overflow checks are enabled (default in debug + /// mode) and wrap if overflow checks are disabled (default in release mode). + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(int_roundings)] + #[doc = concat!("let a: ", stringify!($SelfT)," = 8;")] + /// let b = 3; + /// + /// assert_eq!(a.div_ceil(b), 3); + /// assert_eq!(a.div_ceil(-b), -2); + /// assert_eq!((-a).div_ceil(b), -2); + /// assert_eq!((-a).div_ceil(-b), 3); + /// ``` + #[unstable(feature = "int_roundings", issue = "88581")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + #[rustc_inherit_overflow_checks] + pub const fn div_ceil(self, rhs: Self) -> Self { + let d = self / rhs; + let r = self % rhs; + if (r > 0 && rhs > 0) || (r < 0 && rhs < 0) { + d + 1 + } else { + d + } + } + + /// If `rhs` is positive, calculates the smallest value greater than or + /// equal to `self` that is a multiple of `rhs`. If `rhs` is negative, + /// calculates the largest value less than or equal to `self` that is a + /// multiple of `rhs`. + /// + /// # Panics + /// + /// This function will panic if `rhs` is zero. + /// + /// ## Overflow behavior + /// + /// On overflow, this function will panic if overflow checks are enabled (default in debug + /// mode) and wrap if overflow checks are disabled (default in release mode). + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(int_roundings)] + #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(8), 16);")] + #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(8), 24);")] + #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".next_multiple_of(-8), 16);")] + #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".next_multiple_of(-8), 16);")] + #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(8), -16);")] + #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(8), -16);")] + #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").next_multiple_of(-8), -16);")] + #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").next_multiple_of(-8), -24);")] + /// ``` + #[unstable(feature = "int_roundings", issue = "88581")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + #[rustc_inherit_overflow_checks] + pub const fn next_multiple_of(self, rhs: Self) -> Self { + // This would otherwise fail when calculating `r` when self == T::MIN. + if rhs == -1 { + return self; + } + + let r = self % rhs; + let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) { + r + rhs + } else { + r + }; + + if m == 0 { + self + } else { + self + (rhs - m) + } + } + + /// If `rhs` is positive, calculates the smallest value greater than or + /// equal to `self` that is a multiple of `rhs`. If `rhs` is negative, + /// calculates the largest value less than or equal to `self` that is a + /// multiple of `rhs`. Returns `None` if `rhs` is zero or the operation + /// would result in overflow. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + /// #![feature(int_roundings)] + #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(16));")] + #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(8), Some(24));")] + #[doc = concat!("assert_eq!(16_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")] + #[doc = concat!("assert_eq!(23_", stringify!($SelfT), ".checked_next_multiple_of(-8), Some(16));")] + #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")] + #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(8), Some(-16));")] + #[doc = concat!("assert_eq!((-16_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-16));")] + #[doc = concat!("assert_eq!((-23_", stringify!($SelfT), ").checked_next_multiple_of(-8), Some(-24));")] + #[doc = concat!("assert_eq!(1_", stringify!($SelfT), ".checked_next_multiple_of(0), None);")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.checked_next_multiple_of(2), None);")] + /// ``` + #[unstable(feature = "int_roundings", issue = "88581")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_next_multiple_of(self, rhs: Self) -> Option<Self> { + // This would otherwise fail when calculating `r` when self == T::MIN. + if rhs == -1 { + return Some(self); + } + + let r = try_opt!(self.checked_rem(rhs)); + let m = if (r > 0 && rhs < 0) || (r < 0 && rhs > 0) { + // r + rhs cannot overflow because they have opposite signs + r + rhs + } else { + r + }; + + if m == 0 { + Some(self) + } else { + // rhs - m cannot overflow because m has the same sign as rhs + self.checked_add(rhs - m) + } + } + + /// Returns the logarithm of the number with respect to an arbitrary base, + /// rounded down. + /// + /// This method might not be optimized owing to implementation details; + /// `log2` can produce results more efficiently for base 2, and `log10` + /// can produce results more efficiently for base 10. + /// + /// # Panics + /// + /// When the number is negative, zero, or if the base is not at least 2; it + /// panics in debug mode and the return value is 0 in release + /// mode. + /// + /// # Examples + /// + /// ``` + /// #![feature(int_log)] + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".log(5), 1);")] + /// ``` + #[unstable(feature = "int_log", issue = "70887")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + #[track_caller] + #[rustc_inherit_overflow_checks] + #[allow(arithmetic_overflow)] + pub const fn log(self, base: Self) -> u32 { + match self.checked_log(base) { + Some(n) => n, + None => { + // In debug builds, trigger a panic on None. + // This should optimize completely out in release builds. + let _ = Self::MAX + 1; + + 0 + }, + } + } + + /// Returns the base 2 logarithm of the number, rounded down. + /// + /// # Panics + /// + /// When the number is negative or zero it panics in debug mode and the return value + /// is 0 in release mode. + /// + /// # Examples + /// + /// ``` + /// #![feature(int_log)] + #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".log2(), 1);")] + /// ``` + #[unstable(feature = "int_log", issue = "70887")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + #[track_caller] + #[rustc_inherit_overflow_checks] + #[allow(arithmetic_overflow)] + pub const fn log2(self) -> u32 { + match self.checked_log2() { + Some(n) => n, + None => { + // In debug builds, trigger a panic on None. + // This should optimize completely out in release builds. + let _ = Self::MAX + 1; + + 0 + }, + } + } + + /// Returns the base 10 logarithm of the number, rounded down. + /// + /// # Panics + /// + /// When the number is negative or zero it panics in debug mode and the return value + /// is 0 in release mode. + /// + /// # Example + /// + /// ``` + /// #![feature(int_log)] + #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".log10(), 1);")] + /// ``` + #[unstable(feature = "int_log", issue = "70887")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + #[track_caller] + #[rustc_inherit_overflow_checks] + #[allow(arithmetic_overflow)] + pub const fn log10(self) -> u32 { + match self.checked_log10() { + Some(n) => n, + None => { + // In debug builds, trigger a panic on None. + // This should optimize completely out in release builds. + let _ = Self::MAX + 1; + + 0 + }, + } + } + + /// Returns the logarithm of the number with respect to an arbitrary base, + /// rounded down. + /// + /// Returns `None` if the number is negative or zero, or if the base is not at least 2. + /// + /// This method might not be optimized owing to implementation details; + /// `checked_log2` can produce results more efficiently for base 2, and + /// `checked_log10` can produce results more efficiently for base 10. + /// + /// # Examples + /// + /// ``` + /// #![feature(int_log)] + #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_log(5), Some(1));")] + /// ``` + #[unstable(feature = "int_log", issue = "70887")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_log(self, base: Self) -> Option<u32> { + if self <= 0 || base <= 1 { + None + } else { + let mut n = 0; + let mut r = self; + + // Optimization for 128 bit wide integers. + if Self::BITS == 128 { + let b = Self::log2(self) / (Self::log2(base) + 1); + n += b; + r /= base.pow(b as u32); + } + + while r >= base { + r /= base; + n += 1; + } + Some(n) + } + } + + /// Returns the base 2 logarithm of the number, rounded down. + /// + /// Returns `None` if the number is negative or zero. + /// + /// # Examples + /// + /// ``` + /// #![feature(int_log)] + #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_log2(), Some(1));")] + /// ``` + #[unstable(feature = "int_log", issue = "70887")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_log2(self) -> Option<u32> { + if self <= 0 { + None + } else { + // SAFETY: We just checked that this number is positive + let log = (Self::BITS - 1) - unsafe { intrinsics::ctlz_nonzero(self) as u32 }; + Some(log) + } + } + + /// Returns the base 10 logarithm of the number, rounded down. + /// + /// Returns `None` if the number is negative or zero. + /// + /// # Example + /// + /// ``` + /// #![feature(int_log)] + #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_log10(), Some(1));")] + /// ``` + #[unstable(feature = "int_log", issue = "70887")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn checked_log10(self) -> Option<u32> { + if self > 0 { + Some(int_log10::$ActualT(self as $ActualT)) + } else { + None + } + } + + /// Computes the absolute value of `self`. + /// + /// # Overflow behavior + /// + /// The absolute value of + #[doc = concat!("`", stringify!($SelfT), "::MIN`")] + /// cannot be represented as an + #[doc = concat!("`", stringify!($SelfT), "`,")] + /// and attempting to calculate it will cause an overflow. This means + /// that code in debug mode will trigger a panic on this case and + /// optimized code will return + #[doc = concat!("`", stringify!($SelfT), "::MIN`")] + /// without a panic. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".abs(), 10);")] + #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").abs(), 10);")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[allow(unused_attributes)] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + #[rustc_inherit_overflow_checks] + pub const fn abs(self) -> Self { + // Note that the #[rustc_inherit_overflow_checks] and #[inline] + // above mean that the overflow semantics of the subtraction + // depend on the crate we're being called from. + if self.is_negative() { + -self + } else { + self + } + } + + /// Computes the absolute difference between `self` and `other`. + /// + /// This function always returns the correct answer without overflow or + /// panics by returning an unsigned integer. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(80), 20", stringify!($UnsignedT), ");")] + #[doc = concat!("assert_eq!(100", stringify!($SelfT), ".abs_diff(110), 10", stringify!($UnsignedT), ");")] + #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(80), 180", stringify!($UnsignedT), ");")] + #[doc = concat!("assert_eq!((-100", stringify!($SelfT), ").abs_diff(-120), 20", stringify!($UnsignedT), ");")] + #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.abs_diff(", stringify!($SelfT), "::MAX), ", stringify!($UnsignedT), "::MAX);")] + /// ``` + #[stable(feature = "int_abs_diff", since = "1.60.0")] + #[rustc_const_stable(feature = "int_abs_diff", since = "1.60.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn abs_diff(self, other: Self) -> $UnsignedT { + if self < other { + // Converting a non-negative x from signed to unsigned by using + // `x as U` is left unchanged, but a negative x is converted + // to value x + 2^N. Thus if `s` and `o` are binary variables + // respectively indicating whether `self` and `other` are + // negative, we are computing the mathematical value: + // + // (other + o*2^N) - (self + s*2^N) mod 2^N + // other - self + (o-s)*2^N mod 2^N + // other - self mod 2^N + // + // Finally, taking the mod 2^N of the mathematical value of + // `other - self` does not change it as it already is + // in the range [0, 2^N). + (other as $UnsignedT).wrapping_sub(self as $UnsignedT) + } else { + (self as $UnsignedT).wrapping_sub(other as $UnsignedT) + } + } + + /// Returns a number representing sign of `self`. + /// + /// - `0` if the number is zero + /// - `1` if the number is positive + /// - `-1` if the number is negative + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".signum(), 1);")] + #[doc = concat!("assert_eq!(0", stringify!($SelfT), ".signum(), 0);")] + #[doc = concat!("assert_eq!((-10", stringify!($SelfT), ").signum(), -1);")] + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_sign", since = "1.47.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline(always)] + pub const fn signum(self) -> Self { + match self { + n if n > 0 => 1, + 0 => 0, + _ => -1, + } + } + + /// Returns `true` if `self` is positive and `false` if the number is zero or + /// negative. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert!(10", stringify!($SelfT), ".is_positive());")] + #[doc = concat!("assert!(!(-10", stringify!($SelfT), ").is_positive());")] + /// ``` + #[must_use] + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[inline(always)] + pub const fn is_positive(self) -> bool { self > 0 } + + /// Returns `true` if `self` is negative and `false` if the number is zero or + /// positive. + /// + /// # Examples + /// + /// Basic usage: + /// + /// ``` + #[doc = concat!("assert!((-10", stringify!($SelfT), ").is_negative());")] + #[doc = concat!("assert!(!10", stringify!($SelfT), ".is_negative());")] + /// ``` + #[must_use] + #[stable(feature = "rust1", since = "1.0.0")] + #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")] + #[inline(always)] + pub const fn is_negative(self) -> bool { self < 0 } + + /// Return the memory representation of this integer as a byte array in + /// big-endian (network) byte order. + /// + #[doc = $to_xe_bytes_doc] + /// + /// # Examples + /// + /// ``` + #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_be_bytes();")] + #[doc = concat!("assert_eq!(bytes, ", $be_bytes, ");")] + /// ``` + #[stable(feature = "int_to_from_bytes", since = "1.32.0")] + #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn to_be_bytes(self) -> [u8; mem::size_of::<Self>()] { + self.to_be().to_ne_bytes() + } + + /// Return the memory representation of this integer as a byte array in + /// little-endian byte order. + /// + #[doc = $to_xe_bytes_doc] + /// + /// # Examples + /// + /// ``` + #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_le_bytes();")] + #[doc = concat!("assert_eq!(bytes, ", $le_bytes, ");")] + /// ``` + #[stable(feature = "int_to_from_bytes", since = "1.32.0")] + #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn to_le_bytes(self) -> [u8; mem::size_of::<Self>()] { + self.to_le().to_ne_bytes() + } + + /// Return the memory representation of this integer as a byte array in + /// native byte order. + /// + /// As the target platform's native endianness is used, portable code + /// should use [`to_be_bytes`] or [`to_le_bytes`], as appropriate, + /// instead. + /// + #[doc = $to_xe_bytes_doc] + /// + /// [`to_be_bytes`]: Self::to_be_bytes + /// [`to_le_bytes`]: Self::to_le_bytes + /// + /// # Examples + /// + /// ``` + #[doc = concat!("let bytes = ", $swap_op, stringify!($SelfT), ".to_ne_bytes();")] + /// assert_eq!( + /// bytes, + /// if cfg!(target_endian = "big") { + #[doc = concat!(" ", $be_bytes)] + /// } else { + #[doc = concat!(" ", $le_bytes)] + /// } + /// ); + /// ``` + #[stable(feature = "int_to_from_bytes", since = "1.32.0")] + #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] + // SAFETY: const sound because integers are plain old datatypes so we can always + // transmute them to arrays of bytes + #[must_use = "this returns the result of the operation, \ + without modifying the original"] + #[inline] + pub const fn to_ne_bytes(self) -> [u8; mem::size_of::<Self>()] { + // SAFETY: integers are plain old datatypes so we can always transmute them to + // arrays of bytes + unsafe { mem::transmute(self) } + } + + /// Create an integer value from its representation as a byte array in + /// big endian. + /// + #[doc = $from_xe_bytes_doc] + /// + /// # Examples + /// + /// ``` + #[doc = concat!("let value = ", stringify!($SelfT), "::from_be_bytes(", $be_bytes, ");")] + #[doc = concat!("assert_eq!(value, ", $swap_op, ");")] + /// ``` + /// + /// When starting from a slice rather than an array, fallible conversion APIs can be used: + /// + /// ``` + #[doc = concat!("fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")] + #[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")] + /// *input = rest; + #[doc = concat!(" ", stringify!($SelfT), "::from_be_bytes(int_bytes.try_into().unwrap())")] + /// } + /// ``` + #[stable(feature = "int_to_from_bytes", since = "1.32.0")] + #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] + #[must_use] + #[inline] + pub const fn from_be_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self { + Self::from_be(Self::from_ne_bytes(bytes)) + } + + /// Create an integer value from its representation as a byte array in + /// little endian. + /// + #[doc = $from_xe_bytes_doc] + /// + /// # Examples + /// + /// ``` + #[doc = concat!("let value = ", stringify!($SelfT), "::from_le_bytes(", $le_bytes, ");")] + #[doc = concat!("assert_eq!(value, ", $swap_op, ");")] + /// ``` + /// + /// When starting from a slice rather than an array, fallible conversion APIs can be used: + /// + /// ``` + #[doc = concat!("fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")] + #[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")] + /// *input = rest; + #[doc = concat!(" ", stringify!($SelfT), "::from_le_bytes(int_bytes.try_into().unwrap())")] + /// } + /// ``` + #[stable(feature = "int_to_from_bytes", since = "1.32.0")] + #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] + #[must_use] + #[inline] + pub const fn from_le_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self { + Self::from_le(Self::from_ne_bytes(bytes)) + } + + /// Create an integer value from its memory representation as a byte + /// array in native endianness. + /// + /// As the target platform's native endianness is used, portable code + /// likely wants to use [`from_be_bytes`] or [`from_le_bytes`], as + /// appropriate instead. + /// + /// [`from_be_bytes`]: Self::from_be_bytes + /// [`from_le_bytes`]: Self::from_le_bytes + /// + #[doc = $from_xe_bytes_doc] + /// + /// # Examples + /// + /// ``` + #[doc = concat!("let value = ", stringify!($SelfT), "::from_ne_bytes(if cfg!(target_endian = \"big\") {")] + #[doc = concat!(" ", $be_bytes)] + /// } else { + #[doc = concat!(" ", $le_bytes)] + /// }); + #[doc = concat!("assert_eq!(value, ", $swap_op, ");")] + /// ``` + /// + /// When starting from a slice rather than an array, fallible conversion APIs can be used: + /// + /// ``` + #[doc = concat!("fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT), " {")] + #[doc = concat!(" let (int_bytes, rest) = input.split_at(std::mem::size_of::<", stringify!($SelfT), ">());")] + /// *input = rest; + #[doc = concat!(" ", stringify!($SelfT), "::from_ne_bytes(int_bytes.try_into().unwrap())")] + /// } + /// ``` + #[stable(feature = "int_to_from_bytes", since = "1.32.0")] + #[rustc_const_stable(feature = "const_int_conversion", since = "1.44.0")] + #[must_use] + // SAFETY: const sound because integers are plain old datatypes so we can always + // transmute to them + #[inline] + pub const fn from_ne_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self { + // SAFETY: integers are plain old datatypes so we can always transmute to them + unsafe { mem::transmute(bytes) } + } + + /// New code should prefer to use + #[doc = concat!("[`", stringify!($SelfT), "::MIN", "`] instead.")] + /// + /// Returns the smallest value that can be represented by this integer type. + #[stable(feature = "rust1", since = "1.0.0")] + #[inline(always)] + #[rustc_promotable] + #[rustc_const_stable(feature = "const_min_value", since = "1.32.0")] + #[deprecated(since = "TBD", note = "replaced by the `MIN` associated constant on this type")] + pub const fn min_value() -> Self { + Self::MIN + } + + /// New code should prefer to use + #[doc = concat!("[`", stringify!($SelfT), "::MAX", "`] instead.")] + /// + /// Returns the largest value that can be represented by this integer type. + #[stable(feature = "rust1", since = "1.0.0")] + #[inline(always)] + #[rustc_promotable] + #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")] + #[deprecated(since = "TBD", note = "replaced by the `MAX` associated constant on this type")] + pub const fn max_value() -> Self { + Self::MAX + } + } +} |