/rust/registry/src/index.crates.io-6f17d22bba15001f/itoa-1.0.14/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/1.0.14")]
#![no_std]
#![allow(
    clippy::cast_lossless,
    clippy::cast_possible_truncation,
    clippy::cast_possible_wrap,
    clippy::cast_sign_loss,
    clippy::expl_impl_clone_on_copy,
    clippy::must_use_candidate,
    clippy::needless_doctest_main,
    clippy::unreadable_literal
)]

mod udiv128;

use core::hint;
use core::mem::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_STR_LEN],
}

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

impl Copy for Buffer {}

impl Clone for Buffer {
    #[inline]
    #[allow(clippy::non_canonical_clone_impl)] // 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_STR_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 {
        let string = i.write(unsafe {
            &mut *(&mut self.bytes as *mut [MaybeUninit<u8>; i128::MAX_STR_LEN]
                as *mut <I as private::Sealed>::Buffer)
        });
        if string.len() > I::MAX_STR_LEN {
            unsafe { hint::unreachable_unchecked() };
        }
        string
    }
}

/// 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 {
    /// The maximum length of string that formatting an integer of this type can
    /// produce on the current target platform.
    const MAX_STR_LEN: usize;
}

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

const DEC_DIGITS_LUT: [u8; 200] = *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 {
    ($t:ty[len = $max_len:expr] as $large_unsigned:ty) => {
        impl Integer for $t {
            const MAX_STR_LEN: usize = $max_len;
        }

        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 $large_unsigned
                } else {
                    // Convert negative number to positive by summing 1 to its two's complement.
                    (!(self as $large_unsigned)).wrapping_add(1)
                };
                let mut curr = buf.len();
                let buf_ptr = buf.as_mut_ptr() as *mut u8;
                let lut_ptr = DEC_DIGITS_LUT.as_ptr();

                // Render 4 digits at a time.
                while n >= 10000 {
                    let rem = n % 10000;
                    n /= 10000;

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

                // Render 2 more digits, if >2 digits.
                if n >= 100 {
                    let d1 = ((n % 100) << 1) as usize;
                    n /= 100;
                    curr -= 2;
                    unsafe {
                        ptr::copy_nonoverlapping(lut_ptr.add(d1), buf_ptr.add(curr), 2);
                    }
                }

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

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

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

impl_Integer!(i8[len = 4] as u32);
impl_Integer!(u8[len = 3] as u32);
impl_Integer!(i16[len = 6] as u32);
impl_Integer!(u16[len = 5] as u32);
impl_Integer!(i32[len = 11] as u32);
impl_Integer!(u32[len = 10] as u32);
impl_Integer!(i64[len = 20] as u64);
impl_Integer!(u64[len = 20] as u64);

macro_rules! impl_Integer_size {
    ($t:ty as $primitive:ident #[cfg(target_pointer_width = $width:literal)]) => {
        #[cfg(target_pointer_width = $width)]
        impl Integer for $t {
            const MAX_STR_LEN: usize = <$primitive as Integer>::MAX_STR_LEN;
        }

        #[cfg(target_pointer_width = $width)]
        impl private::Sealed for $t {
            type Buffer = <$primitive as private::Sealed>::Buffer;

            #[inline]
            #[cfg_attr(feature = "no-panic", no_panic)]
            fn write(self, buf: &mut Self::Buffer) -> &str {
                (self as $primitive).write(buf)
            }
        }
    };
}

impl_Integer_size!(isize as i16 #[cfg(target_pointer_width = "16")]);
impl_Integer_size!(usize as u16 #[cfg(target_pointer_width = "16")]);
impl_Integer_size!(isize as i32 #[cfg(target_pointer_width = "32")]);
impl_Integer_size!(usize as u32 #[cfg(target_pointer_width = "32")]);
impl_Integer_size!(isize as i64 #[cfg(target_pointer_width = "64")]);
impl_Integer_size!(usize as u64 #[cfg(target_pointer_width = "64")]);

macro_rules! impl_Integer128 {
    ($t:ty[len = $max_len:expr]) => {
        impl Integer for $t {
            const MAX_STR_LEN: usize = $max_len;
        }

        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 negative number to positive by summing 1 to its two's complement.
                    (!(self as u128)).wrapping_add(1)
                };
                let mut curr = buf.len();
                let buf_ptr = buf.as_mut_ptr() as *mut u8;

                // Divide by 10^19 which is the highest power less than 2^64.
                let (n, rem) = udiv128::udivmod_1e19(n);
                let buf1 = unsafe {
                    buf_ptr.add(curr - u64::MAX_STR_LEN) as *mut [MaybeUninit<u8>; u64::MAX_STR_LEN]
                };
                curr -= rem.write(unsafe { &mut *buf1 }).len();

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

                    // Divide by 10^19 again.
                    let (n, rem) = udiv128::udivmod_1e19(n);
                    let buf2 = unsafe {
                        buf_ptr.add(curr - u64::MAX_STR_LEN)
                            as *mut [MaybeUninit<u8>; u64::MAX_STR_LEN]
                    };
                    curr -= rem.write(unsafe { &mut *buf2 }).len();

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

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

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

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

impl_Integer128!(i128[len = 40]);
impl_Integer128!(u128[len = 39]);

Coverage Report

Created: 2025-07-11 06:39

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/1.0.14")]
34		#![no_std]
35		#![allow(
36		clippy::cast_lossless,
37		clippy::cast_possible_truncation,
38		clippy::cast_possible_wrap,
39		clippy::cast_sign_loss,
40		clippy::expl_impl_clone_on_copy,
41		clippy::must_use_candidate,
42		clippy::needless_doctest_main,
43		clippy::unreadable_literal
44		)]
45
46		mod udiv128;
47
48		use core::hint;
49		use core::mem::MaybeUninit;
50		use core::{ptr, slice, str};
51		#[cfg(feature = "no-panic")]
52		use no_panic::no_panic;
53
54		/// A correctly sized stack allocation for the formatted integer to be written
55		/// into.
56		///
57		/// # Example
58		///
59		/// ```
60		/// let mut buffer = itoa::Buffer::new();
61		/// let printed = buffer.format(1234);
62		/// assert_eq!(printed, "1234");
63		/// ```
64		pub struct Buffer {
65		bytes: [MaybeUninit<u8>; i128::MAX_STR_LEN],
66		}
67
68		impl Default for Buffer {
69		#[inline]
70		fn default() -> Buffer {
71		Buffer::new()
72		}
73		}
74
75		impl Copy for Buffer {}
76
77		impl Clone for Buffer {
78		#[inline]
79		#[allow(clippy::non_canonical_clone_impl)] // false positive https://github.com/rust-lang/rust-clippy/issues/11072
80		fn clone(&self) -> Self {
81		Buffer::new()
82		}
83		}
84
85		impl Buffer {
86		/// This is a cheap operation; you don't need to worry about reusing buffers
87		/// for efficiency.
88		#[inline]
89		#[cfg_attr(feature = "no-panic", no_panic)]
90	0	pub fn new() -> Buffer {
91	0	let bytes = [MaybeUninit::<u8>::uninit(); i128::MAX_STR_LEN];
92	0	Buffer { bytes }
93	0	}
94
95		/// Print an integer into this buffer and return a reference to its string
96		/// representation within the buffer.
97		#[cfg_attr(feature = "no-panic", no_panic)]
98	0	pub fn format<I: Integer>(&mut self, i: I) -> &str {
99	0	let string = i.write(unsafe {
100	0	&mut (&mut self.bytes as mut [MaybeUninit<u8>; i128::MAX_STR_LEN]
101	0	as *mut <I as private::Sealed>::Buffer)
102	0	});
103	0	if string.len() > I::MAX_STR_LEN {
104	0	unsafe { hint::unreachable_unchecked() };
105	0	}
106	0	string
107	0	} Unexecuted instantiation: <itoa::Buffer>::format::<u8> Unexecuted instantiation: <itoa::Buffer>::format::<u32> Unexecuted instantiation: <itoa::Buffer>::format::<u128> Unexecuted instantiation: <itoa::Buffer>::format::<u16> Unexecuted instantiation: <itoa::Buffer>::format::<u64>
108		}
109
110		/// An integer that can be written into an [`itoa::Buffer`][Buffer].
111		///
112		/// This trait is sealed and cannot be implemented for types outside of itoa.
113		pub trait Integer: private::Sealed {
114		/// The maximum length of string that formatting an integer of this type can
115		/// produce on the current target platform.
116		const MAX_STR_LEN: usize;
117		}
118
119		// Seal to prevent downstream implementations of the Integer trait.
120		mod private {
121		#[doc(hidden)]
122		pub trait Sealed: Copy {
123		#[doc(hidden)]
124		type Buffer: 'static;
125		fn write(self, buf: &mut Self::Buffer) -> &str;
126		}
127		}
128
129		const DEC_DIGITS_LUT: [u8; 200] = *b"\
130		0001020304050607080910111213141516171819\
131		2021222324252627282930313233343536373839\
132		4041424344454647484950515253545556575859\
133		6061626364656667686970717273747576777879\
134		8081828384858687888990919293949596979899";
135
136		// Adaptation of the original implementation at
137		// https://github.com/rust-lang/rust/blob/b8214dc6c6fc20d0a660fb5700dca9ebf51ebe89/src/libcore/fmt/num.rs#L188-L266
138		macro_rules! impl_Integer {
139		($t:ty[len = $max_len:expr] as $large_unsigned:ty) => {
140		impl Integer for $t {
141		const MAX_STR_LEN: usize = $max_len;
142		}
143
144		impl private::Sealed for $t {
145		type Buffer = [MaybeUninit<u8>; $max_len];
146
147		#[allow(unused_comparisons)]
148		#[inline]
149		#[cfg_attr(feature = "no-panic", no_panic)]
150	0	fn write(self, buf: &mut [MaybeUninit<u8>; $max_len]) -> &str {
151	0	let is_nonnegative = self >= 0;
152	0	let mut n = if is_nonnegative {
153	0	self as $large_unsigned
154		} else {
155		// Convert negative number to positive by summing 1 to its two's complement.
156	0	(!(self as $large_unsigned)).wrapping_add(1)
157		};
158	0	let mut curr = buf.len();
159	0	let buf_ptr = buf.as_mut_ptr() as *mut u8;
160	0	let lut_ptr = DEC_DIGITS_LUT.as_ptr();
161
162		// Render 4 digits at a time.
163	0	while n >= 10000 {
164	0	let rem = n % 10000;
165	0	n /= 10000;
166	0
167	0	let d1 = ((rem / 100) << 1) as usize;
168	0	let d2 = ((rem % 100) << 1) as usize;
169	0	curr -= 4;
170	0	unsafe {
171	0	ptr::copy_nonoverlapping(lut_ptr.add(d1), buf_ptr.add(curr), 2);
172	0	ptr::copy_nonoverlapping(lut_ptr.add(d2), buf_ptr.add(curr + 2), 2);
173	0	}
174		}
175
176		// Render 2 more digits, if >2 digits.
177	0	if n >= 100 {
178	0	let d1 = ((n % 100) << 1) as usize;
179	0	n /= 100;
180	0	curr -= 2;
181	0	unsafe {
182	0	ptr::copy_nonoverlapping(lut_ptr.add(d1), buf_ptr.add(curr), 2);
183	0	}
184	0	}
185
186		// Render last 1 or 2 digits.
187	0	if n < 10 {
188	0	curr -= 1;
189	0	unsafe {
190	0	*buf_ptr.add(curr) = (n as u8) + b'0';
191	0	}
192		} else {
193	0	let d1 = (n << 1) as usize;
194	0	curr -= 2;
195	0	unsafe {
196	0	ptr::copy_nonoverlapping(lut_ptr.add(d1), buf_ptr.add(curr), 2);
197	0	}
198		}
199
200	0	if !is_nonnegative {
201	0	curr -= 1;
202	0	unsafe {
203	0	*buf_ptr.add(curr) = b'-';
204	0	}
205	0	}
206
207	0	let len = buf.len() - curr;
208	0	let bytes = unsafe { slice::from_raw_parts(buf_ptr.add(curr), len) };
209	0	unsafe { str::from_utf8_unchecked(bytes) }
210	0	} Unexecuted instantiation: <u8 as itoa::private::Sealed>::write Unexecuted instantiation: <u16 as itoa::private::Sealed>::write Unexecuted instantiation: <u32 as itoa::private::Sealed>::write Unexecuted instantiation: <u64 as itoa::private::Sealed>::write
211		}
212		};
213		}
214
215		impl_Integer!(i8[len = 4] as u32);
216		impl_Integer!(u8[len = 3] as u32);
217		impl_Integer!(i16[len = 6] as u32);
218		impl_Integer!(u16[len = 5] as u32);
219		impl_Integer!(i32[len = 11] as u32);
220		impl_Integer!(u32[len = 10] as u32);
221		impl_Integer!(i64[len = 20] as u64);
222		impl_Integer!(u64[len = 20] as u64);
223
224		macro_rules! impl_Integer_size {
225		($t:ty as $primitive:ident #[cfg(target_pointer_width = $width:literal)]) => {
226		#[cfg(target_pointer_width = $width)]
227		impl Integer for $t {
228		const MAX_STR_LEN: usize = <$primitive as Integer>::MAX_STR_LEN;
229		}
230
231		#[cfg(target_pointer_width = $width)]
232		impl private::Sealed for $t {
233		type Buffer = <$primitive as private::Sealed>::Buffer;
234
235		#[inline]
236		#[cfg_attr(feature = "no-panic", no_panic)]
237		fn write(self, buf: &mut Self::Buffer) -> &str {
238		(self as $primitive).write(buf)
239		}
240		}
241		};
242		}
243
244		impl_Integer_size!(isize as i16 #[cfg(target_pointer_width = "16")]);
245		impl_Integer_size!(usize as u16 #[cfg(target_pointer_width = "16")]);
246		impl_Integer_size!(isize as i32 #[cfg(target_pointer_width = "32")]);
247		impl_Integer_size!(usize as u32 #[cfg(target_pointer_width = "32")]);
248		impl_Integer_size!(isize as i64 #[cfg(target_pointer_width = "64")]);
249		impl_Integer_size!(usize as u64 #[cfg(target_pointer_width = "64")]);
250
251		macro_rules! impl_Integer128 {
252		($t:ty[len = $max_len:expr]) => {
253		impl Integer for $t {
254		const MAX_STR_LEN: usize = $max_len;
255		}
256
257		impl private::Sealed for $t {
258		type Buffer = [MaybeUninit<u8>; $max_len];
259
260		#[allow(unused_comparisons)]
261		#[inline]
262		#[cfg_attr(feature = "no-panic", no_panic)]
263	0	fn write(self, buf: &mut [MaybeUninit<u8>; $max_len]) -> &str {
264	0	let is_nonnegative = self >= 0;
265	0	let n = if is_nonnegative {
266	0	self as u128
267		} else {
268		// Convert negative number to positive by summing 1 to its two's complement.
269	0	(!(self as u128)).wrapping_add(1)
270		};
271	0	let mut curr = buf.len();
272	0	let buf_ptr = buf.as_mut_ptr() as *mut u8;
273	0
274	0	// Divide by 10^19 which is the highest power less than 2^64.
275	0	let (n, rem) = udiv128::udivmod_1e19(n);
276	0	let buf1 = unsafe {
277	0	buf_ptr.add(curr - u64::MAX_STR_LEN) as *mut [MaybeUninit<u8>; u64::MAX_STR_LEN]
278	0	};
279	0	curr -= rem.write(unsafe { &mut *buf1 }).len();
280	0
281	0	if n != 0 {
282		// Memset the base10 leading zeros of rem.
283	0	let target = buf.len() - 19;
284	0	unsafe {
285	0	ptr::write_bytes(buf_ptr.add(target), b'0', curr - target);
286	0	}
287	0	curr = target;
288	0
289	0	// Divide by 10^19 again.
290	0	let (n, rem) = udiv128::udivmod_1e19(n);
291	0	let buf2 = unsafe {
292	0	buf_ptr.add(curr - u64::MAX_STR_LEN)
293	0	as *mut [MaybeUninit<u8>; u64::MAX_STR_LEN]
294	0	};
295	0	curr -= rem.write(unsafe { &mut *buf2 }).len();
296	0
297	0	if n != 0 {
298		// Memset the leading zeros.
299	0	let target = buf.len() - 38;
300	0	unsafe {
301	0	ptr::write_bytes(buf_ptr.add(target), b'0', curr - target);
302	0	}
303	0	curr = target;
304	0
305	0	// There is at most one digit left
306	0	// because u128::MAX / 10^19 / 10^19 is 3.
307	0	curr -= 1;
308	0	unsafe {
309	0	*buf_ptr.add(curr) = (n as u8) + b'0';
310	0	}
311	0	}
312	0	}
313
314	0	if !is_nonnegative {
315	0	curr -= 1;
316	0	unsafe {
317	0	*buf_ptr.add(curr) = b'-';
318	0	}
319	0	}
320
321	0	let len = buf.len() - curr;
322	0	let bytes = unsafe { slice::from_raw_parts(buf_ptr.add(curr), len) };
323	0	unsafe { str::from_utf8_unchecked(bytes) }
324	0	}
325		}
326		};
327		}
328
329		impl_Integer128!(i128[len = 40]);
330		impl_Integer128!(u128[len = 39]);