Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1124 insertions, 0 deletions

diff --git a/library/core/src/num/mod.rs b/library/core/src/num/mod.rs
new file mode 100644
index 000000000..f481399fd
--- /dev/null
+++ b/library/core/src/num/mod.rs
@@ -0,0 +1,1124 @@
+//! Numeric traits and functions for the built-in numeric types.
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+use crate::ascii;
+use crate::intrinsics;
+use crate::mem;
+use crate::ops::{Add, Mul, Sub};
+use crate::str::FromStr;
+
+// Used because the `?` operator is not allowed in a const context.
+macro_rules! try_opt {
+    ($e:expr) => {
+        match $e {
+            Some(x) => x,
+            None => return None,
+        }
+    };
+}
+
+#[allow_internal_unstable(const_likely)]
+macro_rules! unlikely {
+    ($e: expr) => {
+        intrinsics::unlikely($e)
+    };
+}
+
+// All these modules are technically private and only exposed for coretests:
+#[cfg(not(no_fp_fmt_parse))]
+pub mod bignum;
+#[cfg(not(no_fp_fmt_parse))]
+pub mod dec2flt;
+#[cfg(not(no_fp_fmt_parse))]
+pub mod diy_float;
+#[cfg(not(no_fp_fmt_parse))]
+pub mod flt2dec;
+pub mod fmt;
+
+#[macro_use]
+mod int_macros; // import int_impl!
+#[macro_use]
+mod uint_macros; // import uint_impl!
+
+mod error;
+mod int_log10;
+mod nonzero;
+#[unstable(feature = "saturating_int_impl", issue = "87920")]
+mod saturating;
+mod wrapping;
+
+#[unstable(feature = "saturating_int_impl", issue = "87920")]
+pub use saturating::Saturating;
+#[stable(feature = "rust1", since = "1.0.0")]
+pub use wrapping::Wrapping;
+
+#[stable(feature = "rust1", since = "1.0.0")]
+#[cfg(not(no_fp_fmt_parse))]
+pub use dec2flt::ParseFloatError;
+
+#[stable(feature = "rust1", since = "1.0.0")]
+pub use error::ParseIntError;
+
+#[stable(feature = "nonzero", since = "1.28.0")]
+pub use nonzero::{NonZeroU128, NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU8, NonZeroUsize};
+
+#[stable(feature = "signed_nonzero", since = "1.34.0")]
+pub use nonzero::{NonZeroI128, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI8, NonZeroIsize};
+
+#[stable(feature = "try_from", since = "1.34.0")]
+pub use error::TryFromIntError;
+
+#[stable(feature = "int_error_matching", since = "1.55.0")]
+pub use error::IntErrorKind;
+
+macro_rules! usize_isize_to_xe_bytes_doc {
+    () => {
+        "
+
+**Note**: This function returns an array of length 2, 4 or 8 bytes
+depending on the target pointer size.
+
+"
+    };
+}
+
+macro_rules! usize_isize_from_xe_bytes_doc {
+    () => {
+        "
+
+**Note**: This function takes an array of length 2, 4 or 8 bytes
+depending on the target pointer size.
+
+"
+    };
+}
+
+macro_rules! widening_impl {
+    ($SelfT:ty, $WideT:ty, $BITS:literal, unsigned) => {
+        /// Calculates the complete product `self * rhs` without the possibility to overflow.
+        ///
+        /// This returns the low-order (wrapping) bits and the high-order (overflow) bits
+        /// of the result as two separate values, in that order.
+        ///
+        /// # Examples
+        ///
+        /// Basic usage:
+        ///
+        /// Please note that this example is shared between integer types.
+        /// Which explains why `u32` is used here.
+        ///
+        /// ```
+        /// #![feature(bigint_helper_methods)]
+        /// assert_eq!(5u32.widening_mul(2), (10, 0));
+        /// assert_eq!(1_000_000_000u32.widening_mul(10), (1410065408, 2));
+        /// ```
+        #[unstable(feature = "bigint_helper_methods", issue = "85532")]
+        #[rustc_const_unstable(feature = "const_bigint_helper_methods", issue = "85532")]
+        #[must_use = "this returns the result of the operation, \
+                      without modifying the original"]
+        #[inline]
+        pub const fn widening_mul(self, rhs: Self) -> (Self, Self) {
+            // note: longer-term this should be done via an intrinsic,
+            //   but for now we can deal without an impl for u128/i128
+            // SAFETY: overflow will be contained within the wider types
+            let wide = unsafe { (self as $WideT).unchecked_mul(rhs as $WideT) };
+            (wide as $SelfT, (wide >> $BITS) as $SelfT)
+        }
+
+        /// Calculates the "full multiplication" `self * rhs + carry`
+        /// without the possibility to overflow.
+        ///
+        /// This returns the low-order (wrapping) bits and the high-order (overflow) bits
+        /// of the result as two separate values, in that order.
+        ///
+        /// Performs "long multiplication" which takes in an extra amount to add, and may return an
+        /// additional amount of overflow. This allows for chaining together multiple
+        /// multiplications to create "big integers" which represent larger values.
+        ///
+        /// # Examples
+        ///
+        /// Basic usage:
+        ///
+        /// Please note that this example is shared between integer types.
+        /// Which explains why `u32` is used here.
+        ///
+        /// ```
+        /// #![feature(bigint_helper_methods)]
+        /// assert_eq!(5u32.carrying_mul(2, 0), (10, 0));
+        /// assert_eq!(5u32.carrying_mul(2, 10), (20, 0));
+        /// assert_eq!(1_000_000_000u32.carrying_mul(10, 0), (1410065408, 2));
+        /// assert_eq!(1_000_000_000u32.carrying_mul(10, 10), (1410065418, 2));
+        #[doc = concat!("assert_eq!(",
+            stringify!($SelfT), "::MAX.carrying_mul(", stringify!($SelfT), "::MAX, ", stringify!($SelfT), "::MAX), ",
+            "(0, ", stringify!($SelfT), "::MAX));"
+        )]
+        /// ```
+        ///
+        /// If `carry` is zero, this is similar to [`overflowing_mul`](Self::overflowing_mul),
+        /// except that it gives the value of the overflow instead of just whether one happened:
+        ///
+        /// ```
+        /// #![feature(bigint_helper_methods)]
+        /// let r = u8::carrying_mul(7, 13, 0);
+        /// assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(7, 13));
+        /// let r = u8::carrying_mul(13, 42, 0);
+        /// assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(13, 42));
+        /// ```
+        ///
+        /// The value of the first field in the returned tuple matches what you'd get
+        /// by combining the [`wrapping_mul`](Self::wrapping_mul) and
+        /// [`wrapping_add`](Self::wrapping_add) methods:
+        ///
+        /// ```
+        /// #![feature(bigint_helper_methods)]
+        /// assert_eq!(
+        ///     789_u16.carrying_mul(456, 123).0,
+        ///     789_u16.wrapping_mul(456).wrapping_add(123),
+        /// );
+        /// ```
+        #[unstable(feature = "bigint_helper_methods", issue = "85532")]
+        #[rustc_const_unstable(feature = "bigint_helper_methods", issue = "85532")]
+        #[must_use = "this returns the result of the operation, \
+                      without modifying the original"]
+        #[inline]
+        pub const fn carrying_mul(self, rhs: Self, carry: Self) -> (Self, Self) {
+            // note: longer-term this should be done via an intrinsic,
+            //   but for now we can deal without an impl for u128/i128
+            // SAFETY: overflow will be contained within the wider types
+            let wide = unsafe {
+                (self as $WideT).unchecked_mul(rhs as $WideT).unchecked_add(carry as $WideT)
+            };
+            (wide as $SelfT, (wide >> $BITS) as $SelfT)
+        }
+    };
+}
+
+impl i8 {
+    int_impl! { i8, i8, u8, 8, 7, -128, 127, 2, "-0x7e", "0xa", "0x12", "0x12", "0x48",
+    "[0x12]", "[0x12]", "", "", "" }
+}
+
+impl i16 {
+    int_impl! { i16, i16, u16, 16, 15, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234", "0x3412",
+    "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]", "", "", "" }
+}
+
+impl i32 {
+    int_impl! { i32, i32, u32, 32, 31, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
+    "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
+    "[0x12, 0x34, 0x56, 0x78]", "", "", "" }
+}
+
+impl i64 {
+    int_impl! { i64, i64, u64, 64, 63, -9223372036854775808, 9223372036854775807, 12,
+    "0xaa00000000006e1", "0x6e10aa", "0x1234567890123456", "0x5634129078563412",
+    "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
+    "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]", "", "", "" }
+}
+
+impl i128 {
+    int_impl! { i128, i128, u128, 128, 127, -170141183460469231731687303715884105728,
+    170141183460469231731687303715884105727, 16,
+    "0x13f40000000000000000000000004f76", "0x4f7613f4", "0x12345678901234567890123456789012",
+    "0x12907856341290785634129078563412", "0x48091e6a2c48091e6a2c48091e6a2c48",
+    "[0x12, 0x90, 0x78, 0x56, 0x34, 0x12, 0x90, 0x78, \
+      0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
+    "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, \
+      0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]", "", "", "" }
+}
+
+#[cfg(target_pointer_width = "16")]
+impl isize {
+    int_impl! { isize, i16, usize, 16, 15, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234",
+    "0x3412", "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]",
+    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
+    " on 16-bit targets" }
+}
+
+#[cfg(target_pointer_width = "32")]
+impl isize {
+    int_impl! { isize, i32, usize, 32, 31, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
+    "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
+    "[0x12, 0x34, 0x56, 0x78]",
+    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
+    " on 32-bit targets" }
+}
+
+#[cfg(target_pointer_width = "64")]
+impl isize {
+    int_impl! { isize, i64, usize, 64, 63, -9223372036854775808, 9223372036854775807,
+    12, "0xaa00000000006e1", "0x6e10aa",  "0x1234567890123456", "0x5634129078563412",
+    "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
+    "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
+    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
+    " on 64-bit targets" }
+}
+
+/// If 6th bit set ascii is upper case.
+const ASCII_CASE_MASK: u8 = 0b0010_0000;
+
+impl u8 {
+    uint_impl! { u8, u8, i8, NonZeroU8, 8, 255, 2, "0x82", "0xa", "0x12", "0x12", "0x48", "[0x12]",
+    "[0x12]", "", "", "" }
+    widening_impl! { u8, u16, 8, unsigned }
+
+    /// Checks if the value is within the ASCII range.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let ascii = 97u8;
+    /// let non_ascii = 150u8;
+    ///
+    /// assert!(ascii.is_ascii());
+    /// assert!(!non_ascii.is_ascii());
+    /// ```
+    #[must_use]
+    #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
+    #[rustc_const_stable(feature = "const_u8_is_ascii", since = "1.43.0")]
+    #[inline]
+    pub const fn is_ascii(&self) -> bool {
+        *self & 128 == 0
+    }
+
+    /// Makes a copy of the value in its ASCII upper case equivalent.
+    ///
+    /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z',
+    /// but non-ASCII letters are unchanged.
+    ///
+    /// To uppercase the value in-place, use [`make_ascii_uppercase`].
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let lowercase_a = 97u8;
+    ///
+    /// assert_eq!(65, lowercase_a.to_ascii_uppercase());
+    /// ```
+    ///
+    /// [`make_ascii_uppercase`]: Self::make_ascii_uppercase
+    #[must_use = "to uppercase the value in-place, use `make_ascii_uppercase()`"]
+    #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
+    #[rustc_const_stable(feature = "const_ascii_methods_on_intrinsics", since = "1.52.0")]
+    #[inline]
+    pub const fn to_ascii_uppercase(&self) -> u8 {
+        // Toggle the fifth bit if this is a lowercase letter
+        *self ^ ((self.is_ascii_lowercase() as u8) * ASCII_CASE_MASK)
+    }
+
+    /// Makes a copy of the value in its ASCII lower case equivalent.
+    ///
+    /// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z',
+    /// but non-ASCII letters are unchanged.
+    ///
+    /// To lowercase the value in-place, use [`make_ascii_lowercase`].
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let uppercase_a = 65u8;
+    ///
+    /// assert_eq!(97, uppercase_a.to_ascii_lowercase());
+    /// ```
+    ///
+    /// [`make_ascii_lowercase`]: Self::make_ascii_lowercase
+    #[must_use = "to lowercase the value in-place, use `make_ascii_lowercase()`"]
+    #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
+    #[rustc_const_stable(feature = "const_ascii_methods_on_intrinsics", since = "1.52.0")]
+    #[inline]
+    pub const fn to_ascii_lowercase(&self) -> u8 {
+        // Set the fifth bit if this is an uppercase letter
+        *self | (self.is_ascii_uppercase() as u8 * ASCII_CASE_MASK)
+    }
+
+    /// Assumes self is ascii
+    #[inline]
+    pub(crate) const fn ascii_change_case_unchecked(&self) -> u8 {
+        *self ^ ASCII_CASE_MASK
+    }
+
+    /// Checks that two values are an ASCII case-insensitive match.
+    ///
+    /// This is equivalent to `to_ascii_lowercase(a) == to_ascii_lowercase(b)`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let lowercase_a = 97u8;
+    /// let uppercase_a = 65u8;
+    ///
+    /// assert!(lowercase_a.eq_ignore_ascii_case(&uppercase_a));
+    /// ```
+    #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
+    #[rustc_const_stable(feature = "const_ascii_methods_on_intrinsics", since = "1.52.0")]
+    #[inline]
+    pub const fn eq_ignore_ascii_case(&self, other: &u8) -> bool {
+        self.to_ascii_lowercase() == other.to_ascii_lowercase()
+    }
+
+    /// Converts this value to its ASCII upper case equivalent in-place.
+    ///
+    /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z',
+    /// but non-ASCII letters are unchanged.
+    ///
+    /// To return a new uppercased value without modifying the existing one, use
+    /// [`to_ascii_uppercase`].
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let mut byte = b'a';
+    ///
+    /// byte.make_ascii_uppercase();
+    ///
+    /// assert_eq!(b'A', byte);
+    /// ```
+    ///
+    /// [`to_ascii_uppercase`]: Self::to_ascii_uppercase
+    #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
+    #[inline]
+    pub fn make_ascii_uppercase(&mut self) {
+        *self = self.to_ascii_uppercase();
+    }
+
+    /// Converts this value to its ASCII lower case equivalent in-place.
+    ///
+    /// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z',
+    /// but non-ASCII letters are unchanged.
+    ///
+    /// To return a new lowercased value without modifying the existing one, use
+    /// [`to_ascii_lowercase`].
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let mut byte = b'A';
+    ///
+    /// byte.make_ascii_lowercase();
+    ///
+    /// assert_eq!(b'a', byte);
+    /// ```
+    ///
+    /// [`to_ascii_lowercase`]: Self::to_ascii_lowercase
+    #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
+    #[inline]
+    pub fn make_ascii_lowercase(&mut self) {
+        *self = self.to_ascii_lowercase();
+    }
+
+    /// Checks if the value is an ASCII alphabetic character:
+    ///
+    /// - U+0041 'A' ..= U+005A 'Z', or
+    /// - U+0061 'a' ..= U+007A 'z'.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let uppercase_a = b'A';
+    /// let uppercase_g = b'G';
+    /// let a = b'a';
+    /// let g = b'g';
+    /// let zero = b'0';
+    /// let percent = b'%';
+    /// let space = b' ';
+    /// let lf = b'\n';
+    /// let esc = b'\x1b';
+    ///
+    /// assert!(uppercase_a.is_ascii_alphabetic());
+    /// assert!(uppercase_g.is_ascii_alphabetic());
+    /// assert!(a.is_ascii_alphabetic());
+    /// assert!(g.is_ascii_alphabetic());
+    /// assert!(!zero.is_ascii_alphabetic());
+    /// assert!(!percent.is_ascii_alphabetic());
+    /// assert!(!space.is_ascii_alphabetic());
+    /// assert!(!lf.is_ascii_alphabetic());
+    /// assert!(!esc.is_ascii_alphabetic());
+    /// ```
+    #[must_use]
+    #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
+    #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")]
+    #[inline]
+    pub const fn is_ascii_alphabetic(&self) -> bool {
+        matches!(*self, b'A'..=b'Z' | b'a'..=b'z')
+    }
+
+    /// Checks if the value is an ASCII uppercase character:
+    /// U+0041 'A' ..= U+005A 'Z'.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let uppercase_a = b'A';
+    /// let uppercase_g = b'G';
+    /// let a = b'a';
+    /// let g = b'g';
+    /// let zero = b'0';
+    /// let percent = b'%';
+    /// let space = b' ';
+    /// let lf = b'\n';
+    /// let esc = b'\x1b';
+    ///
+    /// assert!(uppercase_a.is_ascii_uppercase());
+    /// assert!(uppercase_g.is_ascii_uppercase());
+    /// assert!(!a.is_ascii_uppercase());
+    /// assert!(!g.is_ascii_uppercase());
+    /// assert!(!zero.is_ascii_uppercase());
+    /// assert!(!percent.is_ascii_uppercase());
+    /// assert!(!space.is_ascii_uppercase());
+    /// assert!(!lf.is_ascii_uppercase());
+    /// assert!(!esc.is_ascii_uppercase());
+    /// ```
+    #[must_use]
+    #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
+    #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")]
+    #[inline]
+    pub const fn is_ascii_uppercase(&self) -> bool {
+        matches!(*self, b'A'..=b'Z')
+    }
+
+    /// Checks if the value is an ASCII lowercase character:
+    /// U+0061 'a' ..= U+007A 'z'.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let uppercase_a = b'A';
+    /// let uppercase_g = b'G';
+    /// let a = b'a';
+    /// let g = b'g';
+    /// let zero = b'0';
+    /// let percent = b'%';
+    /// let space = b' ';
+    /// let lf = b'\n';
+    /// let esc = b'\x1b';
+    ///
+    /// assert!(!uppercase_a.is_ascii_lowercase());
+    /// assert!(!uppercase_g.is_ascii_lowercase());
+    /// assert!(a.is_ascii_lowercase());
+    /// assert!(g.is_ascii_lowercase());
+    /// assert!(!zero.is_ascii_lowercase());
+    /// assert!(!percent.is_ascii_lowercase());
+    /// assert!(!space.is_ascii_lowercase());
+    /// assert!(!lf.is_ascii_lowercase());
+    /// assert!(!esc.is_ascii_lowercase());
+    /// ```
+    #[must_use]
+    #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
+    #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")]
+    #[inline]
+    pub const fn is_ascii_lowercase(&self) -> bool {
+        matches!(*self, b'a'..=b'z')
+    }
+
+    /// Checks if the value is an ASCII alphanumeric character:
+    ///
+    /// - U+0041 'A' ..= U+005A 'Z', or
+    /// - U+0061 'a' ..= U+007A 'z', or
+    /// - U+0030 '0' ..= U+0039 '9'.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let uppercase_a = b'A';
+    /// let uppercase_g = b'G';
+    /// let a = b'a';
+    /// let g = b'g';
+    /// let zero = b'0';
+    /// let percent = b'%';
+    /// let space = b' ';
+    /// let lf = b'\n';
+    /// let esc = b'\x1b';
+    ///
+    /// assert!(uppercase_a.is_ascii_alphanumeric());
+    /// assert!(uppercase_g.is_ascii_alphanumeric());
+    /// assert!(a.is_ascii_alphanumeric());
+    /// assert!(g.is_ascii_alphanumeric());
+    /// assert!(zero.is_ascii_alphanumeric());
+    /// assert!(!percent.is_ascii_alphanumeric());
+    /// assert!(!space.is_ascii_alphanumeric());
+    /// assert!(!lf.is_ascii_alphanumeric());
+    /// assert!(!esc.is_ascii_alphanumeric());
+    /// ```
+    #[must_use]
+    #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
+    #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")]
+    #[inline]
+    pub const fn is_ascii_alphanumeric(&self) -> bool {
+        matches!(*self, b'0'..=b'9' | b'A'..=b'Z' | b'a'..=b'z')
+    }
+
+    /// Checks if the value is an ASCII decimal digit:
+    /// U+0030 '0' ..= U+0039 '9'.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let uppercase_a = b'A';
+    /// let uppercase_g = b'G';
+    /// let a = b'a';
+    /// let g = b'g';
+    /// let zero = b'0';
+    /// let percent = b'%';
+    /// let space = b' ';
+    /// let lf = b'\n';
+    /// let esc = b'\x1b';
+    ///
+    /// assert!(!uppercase_a.is_ascii_digit());
+    /// assert!(!uppercase_g.is_ascii_digit());
+    /// assert!(!a.is_ascii_digit());
+    /// assert!(!g.is_ascii_digit());
+    /// assert!(zero.is_ascii_digit());
+    /// assert!(!percent.is_ascii_digit());
+    /// assert!(!space.is_ascii_digit());
+    /// assert!(!lf.is_ascii_digit());
+    /// assert!(!esc.is_ascii_digit());
+    /// ```
+    #[must_use]
+    #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
+    #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")]
+    #[inline]
+    pub const fn is_ascii_digit(&self) -> bool {
+        matches!(*self, b'0'..=b'9')
+    }
+
+    /// Checks if the value is an ASCII hexadecimal digit:
+    ///
+    /// - U+0030 '0' ..= U+0039 '9', or
+    /// - U+0041 'A' ..= U+0046 'F', or
+    /// - U+0061 'a' ..= U+0066 'f'.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let uppercase_a = b'A';
+    /// let uppercase_g = b'G';
+    /// let a = b'a';
+    /// let g = b'g';
+    /// let zero = b'0';
+    /// let percent = b'%';
+    /// let space = b' ';
+    /// let lf = b'\n';
+    /// let esc = b'\x1b';
+    ///
+    /// assert!(uppercase_a.is_ascii_hexdigit());
+    /// assert!(!uppercase_g.is_ascii_hexdigit());
+    /// assert!(a.is_ascii_hexdigit());
+    /// assert!(!g.is_ascii_hexdigit());
+    /// assert!(zero.is_ascii_hexdigit());
+    /// assert!(!percent.is_ascii_hexdigit());
+    /// assert!(!space.is_ascii_hexdigit());
+    /// assert!(!lf.is_ascii_hexdigit());
+    /// assert!(!esc.is_ascii_hexdigit());
+    /// ```
+    #[must_use]
+    #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
+    #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")]
+    #[inline]
+    pub const fn is_ascii_hexdigit(&self) -> bool {
+        matches!(*self, b'0'..=b'9' | b'A'..=b'F' | b'a'..=b'f')
+    }
+
+    /// Checks if the value is an ASCII punctuation character:
+    ///
+    /// - U+0021 ..= U+002F `! " # $ % & ' ( ) * + , - . /`, or
+    /// - U+003A ..= U+0040 `: ; < = > ? @`, or
+    /// - U+005B ..= U+0060 ``[ \ ] ^ _ ` ``, or
+    /// - U+007B ..= U+007E `{ | } ~`
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let uppercase_a = b'A';
+    /// let uppercase_g = b'G';
+    /// let a = b'a';
+    /// let g = b'g';
+    /// let zero = b'0';
+    /// let percent = b'%';
+    /// let space = b' ';
+    /// let lf = b'\n';
+    /// let esc = b'\x1b';
+    ///
+    /// assert!(!uppercase_a.is_ascii_punctuation());
+    /// assert!(!uppercase_g.is_ascii_punctuation());
+    /// assert!(!a.is_ascii_punctuation());
+    /// assert!(!g.is_ascii_punctuation());
+    /// assert!(!zero.is_ascii_punctuation());
+    /// assert!(percent.is_ascii_punctuation());
+    /// assert!(!space.is_ascii_punctuation());
+    /// assert!(!lf.is_ascii_punctuation());
+    /// assert!(!esc.is_ascii_punctuation());
+    /// ```
+    #[must_use]
+    #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
+    #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")]
+    #[inline]
+    pub const fn is_ascii_punctuation(&self) -> bool {
+        matches!(*self, b'!'..=b'/' | b':'..=b'@' | b'['..=b'`' | b'{'..=b'~')
+    }
+
+    /// Checks if the value is an ASCII graphic character:
+    /// U+0021 '!' ..= U+007E '~'.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let uppercase_a = b'A';
+    /// let uppercase_g = b'G';
+    /// let a = b'a';
+    /// let g = b'g';
+    /// let zero = b'0';
+    /// let percent = b'%';
+    /// let space = b' ';
+    /// let lf = b'\n';
+    /// let esc = b'\x1b';
+    ///
+    /// assert!(uppercase_a.is_ascii_graphic());
+    /// assert!(uppercase_g.is_ascii_graphic());
+    /// assert!(a.is_ascii_graphic());
+    /// assert!(g.is_ascii_graphic());
+    /// assert!(zero.is_ascii_graphic());
+    /// assert!(percent.is_ascii_graphic());
+    /// assert!(!space.is_ascii_graphic());
+    /// assert!(!lf.is_ascii_graphic());
+    /// assert!(!esc.is_ascii_graphic());
+    /// ```
+    #[must_use]
+    #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
+    #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")]
+    #[inline]
+    pub const fn is_ascii_graphic(&self) -> bool {
+        matches!(*self, b'!'..=b'~')
+    }
+
+    /// Checks if the value is an ASCII whitespace character:
+    /// U+0020 SPACE, U+0009 HORIZONTAL TAB, U+000A LINE FEED,
+    /// U+000C FORM FEED, or U+000D CARRIAGE RETURN.
+    ///
+    /// Rust uses the WhatWG Infra Standard's [definition of ASCII
+    /// whitespace][infra-aw]. There are several other definitions in
+    /// wide use. For instance, [the POSIX locale][pct] includes
+    /// U+000B VERTICAL TAB as well as all the above characters,
+    /// but—from the very same specification—[the default rule for
+    /// "field splitting" in the Bourne shell][bfs] considers *only*
+    /// SPACE, HORIZONTAL TAB, and LINE FEED as whitespace.
+    ///
+    /// If you are writing a program that will process an existing
+    /// file format, check what that format's definition of whitespace is
+    /// before using this function.
+    ///
+    /// [infra-aw]: https://infra.spec.whatwg.org/#ascii-whitespace
+    /// [pct]: https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap07.html#tag_07_03_01
+    /// [bfs]: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_05
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let uppercase_a = b'A';
+    /// let uppercase_g = b'G';
+    /// let a = b'a';
+    /// let g = b'g';
+    /// let zero = b'0';
+    /// let percent = b'%';
+    /// let space = b' ';
+    /// let lf = b'\n';
+    /// let esc = b'\x1b';
+    ///
+    /// assert!(!uppercase_a.is_ascii_whitespace());
+    /// assert!(!uppercase_g.is_ascii_whitespace());
+    /// assert!(!a.is_ascii_whitespace());
+    /// assert!(!g.is_ascii_whitespace());
+    /// assert!(!zero.is_ascii_whitespace());
+    /// assert!(!percent.is_ascii_whitespace());
+    /// assert!(space.is_ascii_whitespace());
+    /// assert!(lf.is_ascii_whitespace());
+    /// assert!(!esc.is_ascii_whitespace());
+    /// ```
+    #[must_use]
+    #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
+    #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")]
+    #[inline]
+    pub const fn is_ascii_whitespace(&self) -> bool {
+        matches!(*self, b'\t' | b'\n' | b'\x0C' | b'\r' | b' ')
+    }
+
+    /// Checks if the value is an ASCII control character:
+    /// U+0000 NUL ..= U+001F UNIT SEPARATOR, or U+007F DELETE.
+    /// Note that most ASCII whitespace characters are control
+    /// characters, but SPACE is not.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let uppercase_a = b'A';
+    /// let uppercase_g = b'G';
+    /// let a = b'a';
+    /// let g = b'g';
+    /// let zero = b'0';
+    /// let percent = b'%';
+    /// let space = b' ';
+    /// let lf = b'\n';
+    /// let esc = b'\x1b';
+    ///
+    /// assert!(!uppercase_a.is_ascii_control());
+    /// assert!(!uppercase_g.is_ascii_control());
+    /// assert!(!a.is_ascii_control());
+    /// assert!(!g.is_ascii_control());
+    /// assert!(!zero.is_ascii_control());
+    /// assert!(!percent.is_ascii_control());
+    /// assert!(!space.is_ascii_control());
+    /// assert!(lf.is_ascii_control());
+    /// assert!(esc.is_ascii_control());
+    /// ```
+    #[must_use]
+    #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")]
+    #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")]
+    #[inline]
+    pub const fn is_ascii_control(&self) -> bool {
+        matches!(*self, b'\0'..=b'\x1F' | b'\x7F')
+    }
+
+    /// Returns an iterator that produces an escaped version of a `u8`,
+    /// treating it as an ASCII character.
+    ///
+    /// The behavior is identical to [`ascii::escape_default`].
+    ///
+    /// # Examples
+    ///
+    /// ```
+    ///
+    /// assert_eq!("0", b'0'.escape_ascii().to_string());
+    /// assert_eq!("\\t", b'\t'.escape_ascii().to_string());
+    /// assert_eq!("\\r", b'\r'.escape_ascii().to_string());
+    /// assert_eq!("\\n", b'\n'.escape_ascii().to_string());
+    /// assert_eq!("\\'", b'\''.escape_ascii().to_string());
+    /// assert_eq!("\\\"", b'"'.escape_ascii().to_string());
+    /// assert_eq!("\\\\", b'\\'.escape_ascii().to_string());
+    /// assert_eq!("\\x9d", b'\x9d'.escape_ascii().to_string());
+    /// ```
+    #[must_use = "this returns the escaped byte as an iterator, \
+                  without modifying the original"]
+    #[stable(feature = "inherent_ascii_escape", since = "1.60.0")]
+    #[inline]
+    pub fn escape_ascii(self) -> ascii::EscapeDefault {
+        ascii::escape_default(self)
+    }
+
+    #[inline]
+    pub(crate) const fn is_utf8_char_boundary(self) -> bool {
+        // This is bit magic equivalent to: b < 128 || b >= 192
+        (self as i8) >= -0x40
+    }
+}
+
+impl u16 {
+    uint_impl! { u16, u16, i16, NonZeroU16, 16, 65535, 4, "0xa003", "0x3a", "0x1234", "0x3412", "0x2c48",
+    "[0x34, 0x12]", "[0x12, 0x34]", "", "", "" }
+    widening_impl! { u16, u32, 16, unsigned }
+
+    /// Checks if the value is a Unicode surrogate code point, which are disallowed values for [`char`].
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(utf16_extra)]
+    ///
+    /// let low_non_surrogate = 0xA000u16;
+    /// let low_surrogate = 0xD800u16;
+    /// let high_surrogate = 0xDC00u16;
+    /// let high_non_surrogate = 0xE000u16;
+    ///
+    /// assert!(!low_non_surrogate.is_utf16_surrogate());
+    /// assert!(low_surrogate.is_utf16_surrogate());
+    /// assert!(high_surrogate.is_utf16_surrogate());
+    /// assert!(!high_non_surrogate.is_utf16_surrogate());
+    /// ```
+    #[must_use]
+    #[unstable(feature = "utf16_extra", issue = "94919")]
+    #[rustc_const_unstable(feature = "utf16_extra_const", issue = "94919")]
+    #[inline]
+    pub const fn is_utf16_surrogate(self) -> bool {
+        matches!(self, 0xD800..=0xDFFF)
+    }
+}
+
+impl u32 {
+    uint_impl! { u32, u32, i32, NonZeroU32, 32, 4294967295, 8, "0x10000b3", "0xb301", "0x12345678",
+    "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]", "[0x12, 0x34, 0x56, 0x78]", "", "", "" }
+    widening_impl! { u32, u64, 32, unsigned }
+}
+
+impl u64 {
+    uint_impl! { u64, u64, i64, NonZeroU64, 64, 18446744073709551615, 12, "0xaa00000000006e1", "0x6e10aa",
+    "0x1234567890123456", "0x5634129078563412", "0x6a2c48091e6a2c48",
+    "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
+    "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
+    "", "", ""}
+    widening_impl! { u64, u128, 64, unsigned }
+}
+
+impl u128 {
+    uint_impl! { u128, u128, i128, NonZeroU128, 128, 340282366920938463463374607431768211455, 16,
+    "0x13f40000000000000000000000004f76", "0x4f7613f4", "0x12345678901234567890123456789012",
+    "0x12907856341290785634129078563412", "0x48091e6a2c48091e6a2c48091e6a2c48",
+    "[0x12, 0x90, 0x78, 0x56, 0x34, 0x12, 0x90, 0x78, \
+      0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
+    "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56, \
+      0x78, 0x90, 0x12, 0x34, 0x56, 0x78, 0x90, 0x12]",
+     "", "", ""}
+}
+
+#[cfg(target_pointer_width = "16")]
+impl usize {
+    uint_impl! { usize, u16, isize, NonZeroUsize, 16, 65535, 4, "0xa003", "0x3a", "0x1234", "0x3412", "0x2c48",
+    "[0x34, 0x12]", "[0x12, 0x34]",
+    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
+    " on 16-bit targets" }
+    widening_impl! { usize, u32, 16, unsigned }
+}
+#[cfg(target_pointer_width = "32")]
+impl usize {
+    uint_impl! { usize, u32, isize, NonZeroUsize, 32, 4294967295, 8, "0x10000b3", "0xb301", "0x12345678",
+    "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]", "[0x12, 0x34, 0x56, 0x78]",
+    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
+    " on 32-bit targets" }
+    widening_impl! { usize, u64, 32, unsigned }
+}
+
+#[cfg(target_pointer_width = "64")]
+impl usize {
+    uint_impl! { usize, u64, isize, NonZeroUsize, 64, 18446744073709551615, 12, "0xaa00000000006e1", "0x6e10aa",
+    "0x1234567890123456", "0x5634129078563412", "0x6a2c48091e6a2c48",
+    "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
+    "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",
+    usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!(),
+    " on 64-bit targets" }
+    widening_impl! { usize, u128, 64, unsigned }
+}
+
+impl usize {
+    /// Returns an `usize` where every byte is equal to `x`.
+    #[inline]
+    pub(crate) const fn repeat_u8(x: u8) -> usize {
+        usize::from_ne_bytes([x; mem::size_of::<usize>()])
+    }
+
+    /// Returns an `usize` where every byte pair is equal to `x`.
+    #[inline]
+    pub(crate) const fn repeat_u16(x: u16) -> usize {
+        let mut r = 0usize;
+        let mut i = 0;
+        while i < mem::size_of::<usize>() {
+            // Use `wrapping_shl` to make it work on targets with 16-bit `usize`
+            r = r.wrapping_shl(16) | (x as usize);
+            i += 2;
+        }
+        r
+    }
+}
+
+/// A classification of floating point numbers.
+///
+/// This `enum` is used as the return type for [`f32::classify`] and [`f64::classify`]. See
+/// their documentation for more.
+///
+/// # Examples
+///
+/// ```
+/// use std::num::FpCategory;
+///
+/// let num = 12.4_f32;
+/// let inf = f32::INFINITY;
+/// let zero = 0f32;
+/// let sub: f32 = 1.1754942e-38;
+/// let nan = f32::NAN;
+///
+/// assert_eq!(num.classify(), FpCategory::Normal);
+/// assert_eq!(inf.classify(), FpCategory::Infinite);
+/// assert_eq!(zero.classify(), FpCategory::Zero);
+/// assert_eq!(nan.classify(), FpCategory::Nan);
+/// assert_eq!(sub.classify(), FpCategory::Subnormal);
+/// ```
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+#[stable(feature = "rust1", since = "1.0.0")]
+pub enum FpCategory {
+    /// NaN (not a number): this value results from calculations like `(-1.0).sqrt()`.
+    ///
+    /// See [the documentation for `f32`](f32) for more information on the unusual properties
+    /// of NaN.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    Nan,
+
+    /// Positive or negative infinity, which often results from dividing a nonzero number
+    /// by zero.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    Infinite,
+
+    /// Positive or negative zero.
+    ///
+    /// See [the documentation for `f32`](f32) for more information on the signedness of zeroes.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    Zero,
+
+    /// “Subnormal” or “denormal” floating point representation (less precise, relative to
+    /// their magnitude, than [`Normal`]).
+    ///
+    /// Subnormal numbers are larger in magnitude than [`Zero`] but smaller in magnitude than all
+    /// [`Normal`] numbers.
+    ///
+    /// [`Normal`]: Self::Normal
+    /// [`Zero`]: Self::Zero
+    #[stable(feature = "rust1", since = "1.0.0")]
+    Subnormal,
+
+    /// A regular floating point number, not any of the exceptional categories.
+    ///
+    /// The smallest positive normal numbers are [`f32::MIN_POSITIVE`] and [`f64::MIN_POSITIVE`],
+    /// and the largest positive normal numbers are [`f32::MAX`] and [`f64::MAX`]. (Unlike signed
+    /// integers, floating point numbers are symmetric in their range, so negating any of these
+    /// constants will produce their negative counterpart.)
+    #[stable(feature = "rust1", since = "1.0.0")]
+    Normal,
+}
+
+#[doc(hidden)]
+trait FromStrRadixHelper:
+    PartialOrd + Copy + Add<Output = Self> + Sub<Output = Self> + Mul<Output = Self>
+{
+    const MIN: Self;
+    fn from_u32(u: u32) -> Self;
+    fn checked_mul(&self, other: u32) -> Option<Self>;
+    fn checked_sub(&self, other: u32) -> Option<Self>;
+    fn checked_add(&self, other: u32) -> Option<Self>;
+}
+
+macro_rules! from_str_radix_int_impl {
+    ($($t:ty)*) => {$(
+        #[stable(feature = "rust1", since = "1.0.0")]
+        impl FromStr for $t {
+            type Err = ParseIntError;
+            fn from_str(src: &str) -> Result<Self, ParseIntError> {
+                from_str_radix(src, 10)
+            }
+        }
+    )*}
+}
+from_str_radix_int_impl! { isize i8 i16 i32 i64 i128 usize u8 u16 u32 u64 u128 }
+
+macro_rules! impl_helper_for {
+    ($($t:ty)*) => ($(impl FromStrRadixHelper for $t {
+        const MIN: Self = Self::MIN;
+        #[inline]
+        fn from_u32(u: u32) -> Self { u as Self }
+        #[inline]
+        fn checked_mul(&self, other: u32) -> Option<Self> {
+            Self::checked_mul(*self, other as Self)
+        }
+        #[inline]
+        fn checked_sub(&self, other: u32) -> Option<Self> {
+            Self::checked_sub(*self, other as Self)
+        }
+        #[inline]
+        fn checked_add(&self, other: u32) -> Option<Self> {
+            Self::checked_add(*self, other as Self)
+        }
+    })*)
+}
+impl_helper_for! { i8 i16 i32 i64 i128 isize u8 u16 u32 u64 u128 usize }
+
+/// Determines if a string of text of that length of that radix could be guaranteed to be
+/// stored in the given type T.
+/// Note that if the radix is known to the compiler, it is just the check of digits.len that
+/// is done at runtime.
+#[doc(hidden)]
+#[inline(always)]
+#[unstable(issue = "none", feature = "std_internals")]
+pub fn can_not_overflow<T>(radix: u32, is_signed_ty: bool, digits: &[u8]) -> bool {
+    radix <= 16 && digits.len() <= mem::size_of::<T>() * 2 - is_signed_ty as usize
+}
+
+fn from_str_radix<T: FromStrRadixHelper>(src: &str, radix: u32) -> Result<T, ParseIntError> {
+    use self::IntErrorKind::*;
+    use self::ParseIntError as PIE;
+
+    assert!(
+        (2..=36).contains(&radix),
+        "from_str_radix_int: must lie in the range `[2, 36]` - found {}",
+        radix
+    );
+
+    if src.is_empty() {
+        return Err(PIE { kind: Empty });
+    }
+
+    let is_signed_ty = T::from_u32(0) > T::MIN;
+
+    // all valid digits are ascii, so we will just iterate over the utf8 bytes
+    // and cast them to chars. .to_digit() will safely return None for anything
+    // other than a valid ascii digit for the given radix, including the first-byte
+    // of multi-byte sequences
+    let src = src.as_bytes();
+
+    let (is_positive, digits) = match src[0] {
+        b'+' | b'-' if src[1..].is_empty() => {
+            return Err(PIE { kind: InvalidDigit });
+        }
+        b'+' => (true, &src[1..]),
+        b'-' if is_signed_ty => (false, &src[1..]),
+        _ => (true, src),
+    };
+
+    let mut result = T::from_u32(0);
+
+    if can_not_overflow::<T>(radix, is_signed_ty, digits) {
+        // If the len of the str is short compared to the range of the type
+        // we are parsing into, then we can be certain that an overflow will not occur.
+        // This bound is when `radix.pow(digits.len()) - 1 <= T::MAX` but the condition
+        // above is a faster (conservative) approximation of this.
+        //
+        // Consider radix 16 as it has the highest information density per digit and will thus overflow the earliest:
+        // `u8::MAX` is `ff` - any str of len 2 is guaranteed to not overflow.
+        // `i8::MAX` is `7f` - only a str of len 1 is guaranteed to not overflow.
+        macro_rules! run_unchecked_loop {
+            ($unchecked_additive_op:expr) => {
+                for &c in digits {
+                    result = result * T::from_u32(radix);
+                    let x = (c as char).to_digit(radix).ok_or(PIE { kind: InvalidDigit })?;
+                    result = $unchecked_additive_op(result, T::from_u32(x));
+                }
+            };
+        }
+        if is_positive {
+            run_unchecked_loop!(<T as core::ops::Add>::add)
+        } else {
+            run_unchecked_loop!(<T as core::ops::Sub>::sub)
+        };
+    } else {
+        macro_rules! run_checked_loop {
+            ($checked_additive_op:ident, $overflow_err:expr) => {
+                for &c in digits {
+                    // When `radix` is passed in as a literal, rather than doing a slow `imul`
+                    // the compiler can use shifts if `radix` can be expressed as a
+                    // sum of powers of 2 (x*10 can be written as x*8 + x*2).
+                    // When the compiler can't use these optimisations,
+                    // the latency of the multiplication can be hidden by issuing it
+                    // before the result is needed to improve performance on
+                    // modern out-of-order CPU as multiplication here is slower
+                    // than the other instructions, we can get the end result faster
+                    // doing multiplication first and let the CPU spends other cycles
+                    // doing other computation and get multiplication result later.
+                    let mul = result.checked_mul(radix);
+                    let x = (c as char).to_digit(radix).ok_or(PIE { kind: InvalidDigit })?;
+                    result = mul.ok_or_else($overflow_err)?;
+                    result = T::$checked_additive_op(&result, x).ok_or_else($overflow_err)?;
+                }
+            };
+        }
+        if is_positive {
+            run_checked_loop!(checked_add, || PIE { kind: PosOverflow })
+        } else {
+            run_checked_loop!(checked_sub, || PIE { kind: NegOverflow })
+        };
+    }
+    Ok(result)
+}