/rust/registry/src/index.crates.io-6f17d22bba15001f/itoa-1.0.9/src/lib.rs

Source (jump to first uncovered line)
//! [![github]](https://github.com/dtolnay/itoa)&ensp;[![crates-io]](https://crates.io/crates/itoa)&ensp;[![docs-rs]](https://docs.rs/itoa)
//!
//! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github
//! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust
//! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs
//!
//! <br>
//!
//! This crate provides a fast conversion of integer primitives to decimal
//! strings. The implementation comes straight from [libcore] but avoids the
//! performance penalty of going through [`core::fmt::Formatter`].
//!
//! See also [`ryu`] for printing floating point primitives.
//!
//! [libcore]: https://github.com/rust-lang/rust/blob/b8214dc6c6fc20d0a660fb5700dca9ebf51ebe89/src/libcore/fmt/num.rs#L201-L254
//! [`core::fmt::Formatter`]: https://doc.rust-lang.org/std/fmt/struct.Formatter.html
//! [`ryu`]: https://github.com/dtolnay/ryu
//!
//! # Example
//!
//! ```
//! fn main() {
//!     let mut buffer = itoa::Buffer::new();
//!     let printed = buffer.format(128u64);
//!     assert_eq!(printed, "128");
//! }
//! ```
//!
//! # Performance (lower is better)
//!
//! ![performance](https://raw.githubusercontent.com/dtolnay/itoa/master/performance.png)

#![doc(html_root_url = "https://docs.rs/itoa/1.0.9")]
#![no_std]
#![allow(
    clippy::cast_lossless,
    clippy::cast_possible_truncation,
    clippy::expl_impl_clone_on_copy,
    clippy::must_use_candidate,
    clippy::unreadable_literal
)]

mod udiv128;

use core::mem::{self, MaybeUninit};
use core::{ptr, slice, str};
#[cfg(feature = "no-panic")]
use no_panic::no_panic;

/// A correctly sized stack allocation for the formatted integer to be written
/// into.
///
/// # Example
///
/// ```
/// let mut buffer = itoa::Buffer::new();
/// let printed = buffer.format(1234);
/// assert_eq!(printed, "1234");
/// ```
pub struct Buffer {
    bytes: [MaybeUninit<u8>; I128_MAX_LEN],
}

impl Default for Buffer {
    #[inline]
    fn default() -> Buffer {
        Buffer::new()
    }
}

impl Copy for Buffer {}

impl Clone for Buffer {
    #[inline]
    #[allow(clippy::incorrect_clone_impl_on_copy_type)] // false positive https://github.com/rust-lang/rust-clippy/issues/11072
    fn clone(&self) -> Self {
        Buffer::new()
    }
}

impl Buffer {
    /// This is a cheap operation; you don't need to worry about reusing buffers
    /// for efficiency.
    #[inline]
    #[cfg_attr(feature = "no-panic", no_panic)]
    pub fn new() -> Buffer {
        let bytes = [MaybeUninit::<u8>::uninit(); I128_MAX_LEN];
        Buffer { bytes }
    }

    /// Print an integer into this buffer and return a reference to its string
    /// representation within the buffer.
    #[cfg_attr(feature = "no-panic", no_panic)]
    pub fn format<I: Integer>(&mut self, i: I) -> &str {
        i.write(unsafe {
            &mut *(&mut self.bytes as *mut [MaybeUninit<u8>; I128_MAX_LEN]
                as *mut <I as private::Sealed>::Buffer)
        })
    }
}

/// An integer that can be written into an [`itoa::Buffer`][Buffer].
///
/// This trait is sealed and cannot be implemented for types outside of itoa.
pub trait Integer: private::Sealed {}

// Seal to prevent downstream implementations of the Integer trait.
mod private {
    pub trait Sealed: Copy {
        type Buffer: 'static;
        fn write(self, buf: &mut Self::Buffer) -> &str;
    }
}

const DEC_DIGITS_LUT: &[u8] = b"\
      0001020304050607080910111213141516171819\
      2021222324252627282930313233343536373839\
      4041424344454647484950515253545556575859\
      6061626364656667686970717273747576777879\
      8081828384858687888990919293949596979899";

// Adaptation of the original implementation at
// https://github.com/rust-lang/rust/blob/b8214dc6c6fc20d0a660fb5700dca9ebf51ebe89/src/libcore/fmt/num.rs#L188-L266
macro_rules! impl_Integer {
    ($($max_len:expr => $t:ident),* as $conv_fn:ident) => {$(
        impl Integer for $t {}

        impl private::Sealed for $t {
            type Buffer = [MaybeUninit<u8>; $max_len];

            #[allow(unused_comparisons)]
            #[inline]
            #[cfg_attr(feature = "no-panic", no_panic)]
            fn write(self, buf: &mut [MaybeUninit<u8>; $max_len]) -> &str {
                let is_nonnegative = self >= 0;
                let mut n = if is_nonnegative {
                    self as $conv_fn
                } else {
                    // convert the negative num to positive by summing 1 to it's 2 complement
                    (!(self as $conv_fn)).wrapping_add(1)
                };
                let mut curr = buf.len() as isize;
                let buf_ptr = buf.as_mut_ptr() as *mut u8;
                let lut_ptr = DEC_DIGITS_LUT.as_ptr();

                unsafe {
                    // need at least 16 bits for the 4-characters-at-a-time to work.
                    if mem::size_of::<$t>() >= 2 {
                        // eagerly decode 4 characters at a time
                        while n >= 10000 {
                            let rem = (n % 10000) as isize;
                            n /= 10000;

                            let d1 = (rem / 100) << 1;
                            let d2 = (rem % 100) << 1;
                            curr -= 4;
                            ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
                            ptr::copy_nonoverlapping(lut_ptr.offset(d2), buf_ptr.offset(curr + 2), 2);
                        }
                    }

                    // if we reach here numbers are <= 9999, so at most 4 chars long
                    let mut n = n as isize; // possibly reduce 64bit math

                    // decode 2 more chars, if > 2 chars
                    if n >= 100 {
                        let d1 = (n % 100) << 1;
                        n /= 100;
                        curr -= 2;
                        ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
                    }

                    // decode last 1 or 2 chars
                    if n < 10 {
                        curr -= 1;
                        *buf_ptr.offset(curr) = (n as u8) + b'0';
                    } else {
                        let d1 = n << 1;
                        curr -= 2;
                        ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
                    }

                    if !is_nonnegative {
                        curr -= 1;
                        *buf_ptr.offset(curr) = b'-';
                    }
                }

                let len = buf.len() - curr as usize;
                let bytes = unsafe { slice::from_raw_parts(buf_ptr.offset(curr), len) };
                unsafe { str::from_utf8_unchecked(bytes) }
            }
        }
    )*};
}

const I8_MAX_LEN: usize = 4;
const U8_MAX_LEN: usize = 3;
const I16_MAX_LEN: usize = 6;
const U16_MAX_LEN: usize = 5;
const I32_MAX_LEN: usize = 11;
const U32_MAX_LEN: usize = 10;
const I64_MAX_LEN: usize = 20;
const U64_MAX_LEN: usize = 20;

impl_Integer!(
    I8_MAX_LEN => i8,
    U8_MAX_LEN => u8,
    I16_MAX_LEN => i16,
    U16_MAX_LEN => u16,
    I32_MAX_LEN => i32,
    U32_MAX_LEN => u32
    as u32);

impl_Integer!(I64_MAX_LEN => i64, U64_MAX_LEN => u64 as u64);

#[cfg(target_pointer_width = "16")]
impl_Integer!(I16_MAX_LEN => isize, U16_MAX_LEN => usize as u16);

#[cfg(target_pointer_width = "32")]
impl_Integer!(I32_MAX_LEN => isize, U32_MAX_LEN => usize as u32);

#[cfg(target_pointer_width = "64")]
impl_Integer!(I64_MAX_LEN => isize, U64_MAX_LEN => usize as u64);

macro_rules! impl_Integer128 {
    ($($max_len:expr => $t:ident),*) => {$(
        impl Integer for $t {}

        impl private::Sealed for $t {
            type Buffer = [MaybeUninit<u8>; $max_len];

            #[allow(unused_comparisons)]
            #[inline]
            #[cfg_attr(feature = "no-panic", no_panic)]
            fn write(self, buf: &mut [MaybeUninit<u8>; $max_len]) -> &str {
                let is_nonnegative = self >= 0;
                let n = if is_nonnegative {
                    self as u128
                } else {
                    // convert the negative num to positive by summing 1 to it's 2 complement
                    (!(self as u128)).wrapping_add(1)
                };
                let mut curr = buf.len() as isize;
                let buf_ptr = buf.as_mut_ptr() as *mut u8;

                unsafe {
                    // Divide by 10^19 which is the highest power less than 2^64.
                    let (n, rem) = udiv128::udivmod_1e19(n);
                    let buf1 = buf_ptr.offset(curr - U64_MAX_LEN as isize) as *mut [MaybeUninit<u8>; U64_MAX_LEN];
                    curr -= rem.write(&mut *buf1).len() as isize;

                    if n != 0 {
                        // Memset the base10 leading zeros of rem.
                        let target = buf.len() as isize - 19;
                        ptr::write_bytes(buf_ptr.offset(target), b'0', (curr - target) as usize);
                        curr = target;

                        // Divide by 10^19 again.
                        let (n, rem) = udiv128::udivmod_1e19(n);
                        let buf2 = buf_ptr.offset(curr - U64_MAX_LEN as isize) as *mut [MaybeUninit<u8>; U64_MAX_LEN];
                        curr -= rem.write(&mut *buf2).len() as isize;

                        if n != 0 {
                            // Memset the leading zeros.
                            let target = buf.len() as isize - 38;
                            ptr::write_bytes(buf_ptr.offset(target), b'0', (curr - target) as usize);
                            curr = target;

                            // There is at most one digit left
                            // because u128::max / 10^19 / 10^19 is 3.
                            curr -= 1;
                            *buf_ptr.offset(curr) = (n as u8) + b'0';
                        }
                    }

                    if !is_nonnegative {
                        curr -= 1;
                        *buf_ptr.offset(curr) = b'-';
                    }

                    let len = buf.len() - curr as usize;
                    let bytes = slice::from_raw_parts(buf_ptr.offset(curr), len);
                    str::from_utf8_unchecked(bytes)
                }
            }
        }
    )*};
}

const U128_MAX_LEN: usize = 39;
const I128_MAX_LEN: usize = 40;

impl_Integer128!(I128_MAX_LEN => i128, U128_MAX_LEN => u128);

Coverage Report

Created: 2025-06-24 06:17

Line	Count	Source (jump to first uncovered line)
1		//! [![github]](https://github.com/dtolnay/itoa)&ensp;[![crates-io]](https://crates.io/crates/itoa)&ensp;[![docs-rs]](https://docs.rs/itoa)
2		//!
3		//! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github
4		//! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust
5		//! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs
6		//!
7		//! <br>
8		//!
9		//! This crate provides a fast conversion of integer primitives to decimal
10		//! strings. The implementation comes straight from [libcore] but avoids the
11		//! performance penalty of going through [`core::fmt::Formatter`].
12		//!
13		//! See also [`ryu`] for printing floating point primitives.
14		//!
15		//! [libcore]: https://github.com/rust-lang/rust/blob/b8214dc6c6fc20d0a660fb5700dca9ebf51ebe89/src/libcore/fmt/num.rs#L201-L254
16		//! [`core::fmt::Formatter`]: https://doc.rust-lang.org/std/fmt/struct.Formatter.html
17		//! [`ryu`]: https://github.com/dtolnay/ryu
18		//!
19		//! # Example
20		//!
21		//! ```
22		//! fn main() {
23		//! let mut buffer = itoa::Buffer::new();
24		//! let printed = buffer.format(128u64);
25		//! assert_eq!(printed, "128");
26		//! }
27		//! ```
28		//!
29		//! # Performance (lower is better)
30		//!
31		//! ![performance](https://raw.githubusercontent.com/dtolnay/itoa/master/performance.png)
32
33		#![doc(html_root_url = "https://docs.rs/itoa/1.0.9")]
34		#![no_std]
35		#![allow(
36		clippy::cast_lossless,
37		clippy::cast_possible_truncation,
38		clippy::expl_impl_clone_on_copy,
39		clippy::must_use_candidate,
40		clippy::unreadable_literal
41		)]
42
43		mod udiv128;
44
45		use core::mem::{self, MaybeUninit};
46		use core::{ptr, slice, str};
47		#[cfg(feature = "no-panic")]
48		use no_panic::no_panic;
49
50		/// A correctly sized stack allocation for the formatted integer to be written
51		/// into.
52		///
53		/// # Example
54		///
55		/// ```
56		/// let mut buffer = itoa::Buffer::new();
57		/// let printed = buffer.format(1234);
58		/// assert_eq!(printed, "1234");
59		/// ```
60		pub struct Buffer {
61		bytes: [MaybeUninit<u8>; I128_MAX_LEN],
62		}
63
64		impl Default for Buffer {
65		#[inline]
66	0	fn default() -> Buffer {
67	0	Buffer::new()
68	0	}
69		}
70
71		impl Copy for Buffer {}
72
73		impl Clone for Buffer {
74		#[inline]
75		#[allow(clippy::incorrect_clone_impl_on_copy_type)] // false positive https://github.com/rust-lang/rust-clippy/issues/11072
76	0	fn clone(&self) -> Self {
77	0	Buffer::new()
78	0	}
79		}
80
81		impl Buffer {
82		/// This is a cheap operation; you don't need to worry about reusing buffers
83		/// for efficiency.
84		#[inline]
85		#[cfg_attr(feature = "no-panic", no_panic)]
86	0	pub fn new() -> Buffer {
87	0	let bytes = [MaybeUninit::<u8>::uninit(); I128_MAX_LEN];
88	0	Buffer { bytes }
89	0	}
90
91		/// Print an integer into this buffer and return a reference to its string
92		/// representation within the buffer.
93		#[cfg_attr(feature = "no-panic", no_panic)]
94	0	pub fn format<I: Integer>(&mut self, i: I) -> &str {
95	0	i.write(unsafe {
96	0	&mut (&mut self.bytes as mut [MaybeUninit<u8>; I128_MAX_LEN]
97	0	as *mut <I as private::Sealed>::Buffer)
98	0	})
99	0	} Unexecuted instantiation: <itoa::Buffer>::format::<u64> Unexecuted instantiation: <itoa::Buffer>::format::<u8> Unexecuted instantiation: <itoa::Buffer>::format::<u32> Unexecuted instantiation: <itoa::Buffer>::format::<u16> Unexecuted instantiation: <itoa::Buffer>::format::<u32> Unexecuted instantiation: <itoa::Buffer>::format::<_> Unexecuted instantiation: <itoa::Buffer>::format::<u64> Unexecuted instantiation: <itoa::Buffer>::format::<i64> Unexecuted instantiation: <itoa::Buffer>::format::<u8> Unexecuted instantiation: <itoa::Buffer>::format::<u32> Unexecuted instantiation: <itoa::Buffer>::format::<u16>
100		}
101
102		/// An integer that can be written into an [`itoa::Buffer`][Buffer].
103		///
104		/// This trait is sealed and cannot be implemented for types outside of itoa.
105		pub trait Integer: private::Sealed {}
106
107		// Seal to prevent downstream implementations of the Integer trait.
108		mod private {
109		pub trait Sealed: Copy {
110		type Buffer: 'static;
111		fn write(self, buf: &mut Self::Buffer) -> &str;
112		}
113		}
114
115		const DEC_DIGITS_LUT: &[u8] = b"\
116		0001020304050607080910111213141516171819\
117		2021222324252627282930313233343536373839\
118		4041424344454647484950515253545556575859\
119		6061626364656667686970717273747576777879\
120		8081828384858687888990919293949596979899";
121
122		// Adaptation of the original implementation at
123		// https://github.com/rust-lang/rust/blob/b8214dc6c6fc20d0a660fb5700dca9ebf51ebe89/src/libcore/fmt/num.rs#L188-L266
124		macro_rules! impl_Integer {
125		($($max_len:expr => $t:ident),* as $conv_fn:ident) => {$(
126		impl Integer for $t {}
127
128		impl private::Sealed for $t {
129		type Buffer = [MaybeUninit<u8>; $max_len];
130
131		#[allow(unused_comparisons)]
132		#[inline]
133		#[cfg_attr(feature = "no-panic", no_panic)]
134	0	fn write(self, buf: &mut [MaybeUninit<u8>; $max_len]) -> &str {
135	0	let is_nonnegative = self >= 0;
136	0	let mut n = if is_nonnegative {
137	0	self as $conv_fn
138		} else {
139		// convert the negative num to positive by summing 1 to it's 2 complement
140	0	(!(self as $conv_fn)).wrapping_add(1)
141		};
142	0	let mut curr = buf.len() as isize;
143	0	let buf_ptr = buf.as_mut_ptr() as *mut u8;
144	0	let lut_ptr = DEC_DIGITS_LUT.as_ptr();
145	0
146	0	unsafe {
147	0	// need at least 16 bits for the 4-characters-at-a-time to work.
148	0	if mem::size_of::<$t>() >= 2 {
149		// eagerly decode 4 characters at a time
150	0	while n >= 10000 {
151	0	let rem = (n % 10000) as isize;
152	0	n /= 10000;
153	0
154	0	let d1 = (rem / 100) << 1;
155	0	let d2 = (rem % 100) << 1;
156	0	curr -= 4;
157	0	ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
158	0	ptr::copy_nonoverlapping(lut_ptr.offset(d2), buf_ptr.offset(curr + 2), 2);
159	0	}
160	0	}
161
162		// if we reach here numbers are <= 9999, so at most 4 chars long
163	0	let mut n = n as isize; // possibly reduce 64bit math
164	0
165	0	// decode 2 more chars, if > 2 chars
166	0	if n >= 100 {
167	0	let d1 = (n % 100) << 1;
168	0	n /= 100;
169	0	curr -= 2;
170	0	ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
171	0	}
172
173		// decode last 1 or 2 chars
174	0	if n < 10 {
175	0	curr -= 1;
176	0	*buf_ptr.offset(curr) = (n as u8) + b'0';
177	0	} else {
178	0	let d1 = n << 1;
179	0	curr -= 2;
180	0	ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
181	0	}
182
183	0	if !is_nonnegative {
184	0	curr -= 1;
185	0	*buf_ptr.offset(curr) = b'-';
186	0	}
187		}
188
189	0	let len = buf.len() - curr as usize;
190	0	let bytes = unsafe { slice::from_raw_parts(buf_ptr.offset(curr), len) };
191	0	unsafe { str::from_utf8_unchecked(bytes) }
192	0	} Unexecuted instantiation: <i8 as itoa::private::Sealed>::write Unexecuted instantiation: <u8 as itoa::private::Sealed>::write Unexecuted instantiation: <i16 as itoa::private::Sealed>::write Unexecuted instantiation: <u16 as itoa::private::Sealed>::write Unexecuted instantiation: <i32 as itoa::private::Sealed>::write Unexecuted instantiation: <u32 as itoa::private::Sealed>::write Unexecuted instantiation: <i64 as itoa::private::Sealed>::write Unexecuted instantiation: <u64 as itoa::private::Sealed>::write Unexecuted instantiation: <isize as itoa::private::Sealed>::write Unexecuted instantiation: <usize as itoa::private::Sealed>::write
193		}
194		)*};
195		}
196
197		const I8_MAX_LEN: usize = 4;
198		const U8_MAX_LEN: usize = 3;
199		const I16_MAX_LEN: usize = 6;
200		const U16_MAX_LEN: usize = 5;
201		const I32_MAX_LEN: usize = 11;
202		const U32_MAX_LEN: usize = 10;
203		const I64_MAX_LEN: usize = 20;
204		const U64_MAX_LEN: usize = 20;
205
206		impl_Integer!(
207		I8_MAX_LEN => i8,
208		U8_MAX_LEN => u8,
209		I16_MAX_LEN => i16,
210		U16_MAX_LEN => u16,
211		I32_MAX_LEN => i32,
212		U32_MAX_LEN => u32
213		as u32);
214
215		impl_Integer!(I64_MAX_LEN => i64, U64_MAX_LEN => u64 as u64);
216
217		#[cfg(target_pointer_width = "16")]
218		impl_Integer!(I16_MAX_LEN => isize, U16_MAX_LEN => usize as u16);
219
220		#[cfg(target_pointer_width = "32")]
221		impl_Integer!(I32_MAX_LEN => isize, U32_MAX_LEN => usize as u32);
222
223		#[cfg(target_pointer_width = "64")]
224		impl_Integer!(I64_MAX_LEN => isize, U64_MAX_LEN => usize as u64);
225
226		macro_rules! impl_Integer128 {
227		($($max_len:expr => $t:ident),*) => {$(
228		impl Integer for $t {}
229
230		impl private::Sealed for $t {
231		type Buffer = [MaybeUninit<u8>; $max_len];
232
233		#[allow(unused_comparisons)]
234		#[inline]
235		#[cfg_attr(feature = "no-panic", no_panic)]
236	0	fn write(self, buf: &mut [MaybeUninit<u8>; $max_len]) -> &str {
237	0	let is_nonnegative = self >= 0;
238	0	let n = if is_nonnegative {
239	0	self as u128
240		} else {
241		// convert the negative num to positive by summing 1 to it's 2 complement
242	0	(!(self as u128)).wrapping_add(1)
243		};
244	0	let mut curr = buf.len() as isize;
245	0	let buf_ptr = buf.as_mut_ptr() as *mut u8;
246	0
247	0	unsafe {
248	0	// Divide by 10^19 which is the highest power less than 2^64.
249	0	let (n, rem) = udiv128::udivmod_1e19(n);
250	0	let buf1 = buf_ptr.offset(curr - U64_MAX_LEN as isize) as *mut [MaybeUninit<u8>; U64_MAX_LEN];
251	0	curr -= rem.write(&mut *buf1).len() as isize;
252	0
253	0	if n != 0 {
254		// Memset the base10 leading zeros of rem.
255	0	let target = buf.len() as isize - 19;
256	0	ptr::write_bytes(buf_ptr.offset(target), b'0', (curr - target) as usize);
257	0	curr = target;
258	0
259	0	// Divide by 10^19 again.
260	0	let (n, rem) = udiv128::udivmod_1e19(n);
261	0	let buf2 = buf_ptr.offset(curr - U64_MAX_LEN as isize) as *mut [MaybeUninit<u8>; U64_MAX_LEN];
262	0	curr -= rem.write(&mut *buf2).len() as isize;
263	0
264	0	if n != 0 {
265	0	// Memset the leading zeros.
266	0	let target = buf.len() as isize - 38;
267	0	ptr::write_bytes(buf_ptr.offset(target), b'0', (curr - target) as usize);
268	0	curr = target;
269	0
270	0	// There is at most one digit left
271	0	// because u128::max / 10^19 / 10^19 is 3.
272	0	curr -= 1;
273	0	*buf_ptr.offset(curr) = (n as u8) + b'0';
274	0	}
275	0	}
276
277	0	if !is_nonnegative {
278	0	curr -= 1;
279	0	*buf_ptr.offset(curr) = b'-';
280	0	}
281
282	0	let len = buf.len() - curr as usize;
283	0	let bytes = slice::from_raw_parts(buf_ptr.offset(curr), len);
284	0	str::from_utf8_unchecked(bytes)
285	0	}
286	0	} Unexecuted instantiation: <i128 as itoa::private::Sealed>::write Unexecuted instantiation: <u128 as itoa::private::Sealed>::write
287		}
288		)*};
289		}
290
291		const U128_MAX_LEN: usize = 39;
292		const I128_MAX_LEN: usize = 40;
293
294		impl_Integer128!(I128_MAX_LEN => i128, U128_MAX_LEN => u128);