core/convert/
num.rs1use crate::num::TryFromIntError;
2
3mod private {
4 /// This trait being unreachable from outside the crate
5 /// prevents other implementations of the `FloatToInt` trait,
6 /// which allows potentially adding more trait methods after the trait is `#[stable]`.
7 #[unstable(feature = "convert_float_to_int", issue = "67057")]
8 pub trait Sealed {}
9}
10
11/// Supporting trait for inherent methods of `f32` and `f64` such as `to_int_unchecked`.
12/// Typically doesn’t need to be used directly.
13#[unstable(feature = "convert_float_to_int", issue = "67057")]
14pub trait FloatToInt<Int>: private::Sealed + Sized {
15 #[unstable(feature = "convert_float_to_int", issue = "67057")]
16 #[doc(hidden)]
17 unsafe fn to_int_unchecked(self) -> Int;
18}
19
20macro_rules! impl_float_to_int {
21 ($Float:ty => $($Int:ty),+) => {
22 #[unstable(feature = "convert_float_to_int", issue = "67057")]
23 impl private::Sealed for $Float {}
24 $(
25 #[unstable(feature = "convert_float_to_int", issue = "67057")]
26 impl FloatToInt<$Int> for $Float {
27 #[inline]
28 unsafe fn to_int_unchecked(self) -> $Int {
29 // SAFETY: the safety contract must be upheld by the caller.
30 unsafe { crate::intrinsics::float_to_int_unchecked(self) }
31 }
32 }
33 )+
34 }
35}
36
37impl_float_to_int!(f16 => u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize);
38impl_float_to_int!(f32 => u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize);
39impl_float_to_int!(f64 => u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize);
40impl_float_to_int!(f128 => u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize);
41
42// Conversion traits for primitive integer and float types
43// Conversions T -> T are covered by a blanket impl and therefore excluded
44// Some conversions from and to usize/isize are not implemented due to portability concerns
45macro_rules! impl_from {
46 (bool => $Int:ty $(,)?) => {
47 impl_from!(
48 bool => $Int,
49 #[stable(feature = "from_bool", since = "1.28.0")],
50 concat!(
51 "Converts a [`bool`] to [`", stringify!($Int), "`] losslessly.\n",
52 "The resulting value is `0` for `false` and `1` for `true` values.\n",
53 "\n",
54 "# Examples\n",
55 "\n",
56 "```\n",
57 "assert_eq!(", stringify!($Int), "::from(true), 1);\n",
58 "assert_eq!(", stringify!($Int), "::from(false), 0);\n",
59 "```\n",
60 ),
61 );
62 };
63 ($Small:ty => $Large:ty, #[$attr:meta] $(,)?) => {
64 impl_from!(
65 $Small => $Large,
66 #[$attr],
67 concat!("Converts [`", stringify!($Small), "`] to [`", stringify!($Large), "`] losslessly."),
68 );
69 };
70 ($Small:ty => $Large:ty, #[$attr:meta], $doc:expr $(,)?) => {
71 #[$attr]
72 #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
73 impl const From<$Small> for $Large {
74 // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
75 // Rustdocs on functions do not.
76 #[doc = $doc]
77 #[inline(always)]
78 fn from(small: $Small) -> Self {
79 small as Self
80 }
81 }
82 };
83}
84
85// boolean -> integer
86impl_from!(bool => u8);
87impl_from!(bool => u16);
88impl_from!(bool => u32);
89impl_from!(bool => u64);
90impl_from!(bool => u128);
91impl_from!(bool => usize);
92impl_from!(bool => i8);
93impl_from!(bool => i16);
94impl_from!(bool => i32);
95impl_from!(bool => i64);
96impl_from!(bool => i128);
97impl_from!(bool => isize);
98
99// unsigned integer -> unsigned integer
100impl_from!(u8 => u16, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
101impl_from!(u8 => u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
102impl_from!(u8 => u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
103impl_from!(u8 => u128, #[stable(feature = "i128", since = "1.26.0")]);
104impl_from!(u8 => usize, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
105impl_from!(u16 => u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
106impl_from!(u16 => u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
107impl_from!(u16 => u128, #[stable(feature = "i128", since = "1.26.0")]);
108impl_from!(u32 => u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
109impl_from!(u32 => u128, #[stable(feature = "i128", since = "1.26.0")]);
110impl_from!(u64 => u128, #[stable(feature = "i128", since = "1.26.0")]);
111
112// signed integer -> signed integer
113impl_from!(i8 => i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
114impl_from!(i8 => i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
115impl_from!(i8 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
116impl_from!(i8 => i128, #[stable(feature = "i128", since = "1.26.0")]);
117impl_from!(i8 => isize, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
118impl_from!(i16 => i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
119impl_from!(i16 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
120impl_from!(i16 => i128, #[stable(feature = "i128", since = "1.26.0")]);
121impl_from!(i32 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
122impl_from!(i32 => i128, #[stable(feature = "i128", since = "1.26.0")]);
123impl_from!(i64 => i128, #[stable(feature = "i128", since = "1.26.0")]);
124
125// unsigned integer -> signed integer
126impl_from!(u8 => i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
127impl_from!(u8 => i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
128impl_from!(u8 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
129impl_from!(u8 => i128, #[stable(feature = "i128", since = "1.26.0")]);
130impl_from!(u16 => i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
131impl_from!(u16 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
132impl_from!(u16 => i128, #[stable(feature = "i128", since = "1.26.0")]);
133impl_from!(u32 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
134impl_from!(u32 => i128, #[stable(feature = "i128", since = "1.26.0")]);
135impl_from!(u64 => i128, #[stable(feature = "i128", since = "1.26.0")]);
136
137// The C99 standard defines bounds on INTPTR_MIN, INTPTR_MAX, and UINTPTR_MAX
138// which imply that pointer-sized integers must be at least 16 bits:
139// https://port70.net/~nsz/c/c99/n1256.html#7.18.2.4
140impl_from!(u16 => usize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")]);
141impl_from!(u8 => isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")]);
142impl_from!(i16 => isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")]);
143
144// RISC-V defines the possibility of a 128-bit address space (RV128).
145
146// CHERI proposes 128-bit “capabilities”. Unclear if this would be relevant to usize/isize.
147// https://www.cl.cam.ac.uk/research/security/ctsrd/pdfs/20171017a-cheri-poster.pdf
148// https://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-951.pdf
149
150// Note: integers can only be represented with full precision in a float if
151// they fit in the significand, which is:
152// * 11 bits in f16
153// * 24 bits in f32
154// * 53 bits in f64
155// * 113 bits in f128
156// Lossy float conversions are not implemented at this time.
157// FIXME(f16_f128): The `f16`/`f128` impls `#[stable]` attributes should be changed to reference
158// `f16`/`f128` when they are stabilised (trait impls have to have a `#[stable]` attribute, but none
159// of the `f16`/`f128` impls can be used on stable as the `f16` and `f128` types are unstable).
160
161// signed integer -> float
162impl_from!(i8 => f16, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
163impl_from!(i8 => f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
164impl_from!(i8 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
165impl_from!(i8 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
166impl_from!(i16 => f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
167impl_from!(i16 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
168impl_from!(i16 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
169impl_from!(i32 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
170impl_from!(i32 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
171// FIXME(f16_f128): This impl would allow using `f128` on stable before it is stabilised.
172// impl_from!(i64 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
173
174// unsigned integer -> float
175impl_from!(u8 => f16, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
176impl_from!(u8 => f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
177impl_from!(u8 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
178impl_from!(u8 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
179impl_from!(u16 => f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
180impl_from!(u16 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
181impl_from!(u16 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
182impl_from!(u32 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
183impl_from!(u32 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
184// FIXME(f16_f128): This impl would allow using `f128` on stable before it is stabilised.
185// impl_from!(u64 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
186
187// float -> float
188// FIXME(f16_f128): adding additional `From<{float}>` impls to `f32` breaks inference. See
189// <https://github.com/rust-lang/rust/issues/123831>
190impl_from!(f16 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
191impl_from!(f16 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
192impl_from!(f32 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
193impl_from!(f32 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
194impl_from!(f64 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
195
196macro_rules! impl_float_from_bool {
197 (
198 $float:ty $(;
199 doctest_prefix: $(#[doc = $doctest_prefix:literal])*
200 doctest_suffix: $(#[doc = $doctest_suffix:literal])*
201 )?
202 ) => {
203 #[stable(feature = "float_from_bool", since = "1.68.0")]
204 #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
205 impl const From<bool> for $float {
206 #[doc = concat!("Converts a [`bool`] to [`", stringify!($float),"`] losslessly.")]
207 /// The resulting value is positive `0.0` for `false` and `1.0` for `true` values.
208 ///
209 /// # Examples
210 /// ```
211 $($(#[doc = $doctest_prefix])*)?
212 #[doc = concat!("let x: ", stringify!($float)," = false.into();")]
213 /// assert_eq!(x, 0.0);
214 /// assert!(x.is_sign_positive());
215 ///
216 #[doc = concat!("let y: ", stringify!($float)," = true.into();")]
217 /// assert_eq!(y, 1.0);
218 $($(#[doc = $doctest_suffix])*)?
219 /// ```
220 #[inline]
221 fn from(small: bool) -> Self {
222 small as u8 as Self
223 }
224 }
225 };
226}
227
228// boolean -> float
229impl_float_from_bool!(
230 f16;
231 doctest_prefix:
232 // rustdoc doesn't remove the conventional space after the `///`
233 ///#![feature(f16)]
234 ///# #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
235 ///
236 doctest_suffix:
237 ///# }
238);
239impl_float_from_bool!(f32);
240impl_float_from_bool!(f64);
241impl_float_from_bool!(
242 f128;
243 doctest_prefix:
244 ///#![feature(f128)]
245 ///# #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
246 ///
247 doctest_suffix:
248 ///# }
249);
250
251// no possible bounds violation
252macro_rules! impl_try_from_unbounded {
253 ($source:ty => $($target:ty),+) => {$(
254 #[stable(feature = "try_from", since = "1.34.0")]
255 #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
256 impl const TryFrom<$source> for $target {
257 type Error = TryFromIntError;
258
259 /// Tries to create the target number type from a source
260 /// number type. This returns an error if the source value
261 /// is outside of the range of the target type.
262 #[inline]
263 fn try_from(value: $source) -> Result<Self, Self::Error> {
264 Ok(value as Self)
265 }
266 }
267 )*}
268}
269
270// only negative bounds
271macro_rules! impl_try_from_lower_bounded {
272 ($source:ty => $($target:ty),+) => {$(
273 #[stable(feature = "try_from", since = "1.34.0")]
274 #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
275 impl const TryFrom<$source> for $target {
276 type Error = TryFromIntError;
277
278 /// Tries to create the target number type from a source
279 /// number type. This returns an error if the source value
280 /// is outside of the range of the target type.
281 #[inline]
282 fn try_from(u: $source) -> Result<Self, Self::Error> {
283 if u >= 0 {
284 Ok(u as Self)
285 } else {
286 Err(TryFromIntError(()))
287 }
288 }
289 }
290 )*}
291}
292
293// unsigned to signed (only positive bound)
294macro_rules! impl_try_from_upper_bounded {
295 ($source:ty => $($target:ty),+) => {$(
296 #[stable(feature = "try_from", since = "1.34.0")]
297 #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
298 impl const TryFrom<$source> for $target {
299 type Error = TryFromIntError;
300
301 /// Tries to create the target number type from a source
302 /// number type. This returns an error if the source value
303 /// is outside of the range of the target type.
304 #[inline]
305 fn try_from(u: $source) -> Result<Self, Self::Error> {
306 if u > (Self::MAX as $source) {
307 Err(TryFromIntError(()))
308 } else {
309 Ok(u as Self)
310 }
311 }
312 }
313 )*}
314}
315
316// all other cases
317macro_rules! impl_try_from_both_bounded {
318 ($source:ty => $($target:ty),+) => {$(
319 #[stable(feature = "try_from", since = "1.34.0")]
320 #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
321 impl const TryFrom<$source> for $target {
322 type Error = TryFromIntError;
323
324 /// Tries to create the target number type from a source
325 /// number type. This returns an error if the source value
326 /// is outside of the range of the target type.
327 #[inline]
328 fn try_from(u: $source) -> Result<Self, Self::Error> {
329 let min = Self::MIN as $source;
330 let max = Self::MAX as $source;
331 if u < min || u > max {
332 Err(TryFromIntError(()))
333 } else {
334 Ok(u as Self)
335 }
336 }
337 }
338 )*}
339}
340
341macro_rules! rev {
342 ($mac:ident, $source:ty => $($target:ty),+) => {$(
343 $mac!($target => $source);
344 )*}
345}
346
347// unsigned integer -> unsigned integer
348impl_try_from_upper_bounded!(u16 => u8);
349impl_try_from_upper_bounded!(u32 => u8, u16);
350impl_try_from_upper_bounded!(u64 => u8, u16, u32);
351impl_try_from_upper_bounded!(u128 => u8, u16, u32, u64);
352
353// signed integer -> signed integer
354impl_try_from_both_bounded!(i16 => i8);
355impl_try_from_both_bounded!(i32 => i8, i16);
356impl_try_from_both_bounded!(i64 => i8, i16, i32);
357impl_try_from_both_bounded!(i128 => i8, i16, i32, i64);
358
359// unsigned integer -> signed integer
360impl_try_from_upper_bounded!(u8 => i8);
361impl_try_from_upper_bounded!(u16 => i8, i16);
362impl_try_from_upper_bounded!(u32 => i8, i16, i32);
363impl_try_from_upper_bounded!(u64 => i8, i16, i32, i64);
364impl_try_from_upper_bounded!(u128 => i8, i16, i32, i64, i128);
365
366// signed integer -> unsigned integer
367impl_try_from_lower_bounded!(i8 => u8, u16, u32, u64, u128);
368impl_try_from_both_bounded!(i16 => u8);
369impl_try_from_lower_bounded!(i16 => u16, u32, u64, u128);
370impl_try_from_both_bounded!(i32 => u8, u16);
371impl_try_from_lower_bounded!(i32 => u32, u64, u128);
372impl_try_from_both_bounded!(i64 => u8, u16, u32);
373impl_try_from_lower_bounded!(i64 => u64, u128);
374impl_try_from_both_bounded!(i128 => u8, u16, u32, u64);
375impl_try_from_lower_bounded!(i128 => u128);
376
377// usize/isize
378impl_try_from_upper_bounded!(usize => isize);
379impl_try_from_lower_bounded!(isize => usize);
380
381#[cfg(target_pointer_width = "16")]
382mod ptr_try_from_impls {
383 use super::TryFromIntError;
384
385 impl_try_from_upper_bounded!(usize => u8);
386 impl_try_from_unbounded!(usize => u16, u32, u64, u128);
387 impl_try_from_upper_bounded!(usize => i8, i16);
388 impl_try_from_unbounded!(usize => i32, i64, i128);
389
390 impl_try_from_both_bounded!(isize => u8);
391 impl_try_from_lower_bounded!(isize => u16, u32, u64, u128);
392 impl_try_from_both_bounded!(isize => i8);
393 impl_try_from_unbounded!(isize => i16, i32, i64, i128);
394
395 rev!(impl_try_from_upper_bounded, usize => u32, u64, u128);
396 rev!(impl_try_from_lower_bounded, usize => i8, i16);
397 rev!(impl_try_from_both_bounded, usize => i32, i64, i128);
398
399 rev!(impl_try_from_upper_bounded, isize => u16, u32, u64, u128);
400 rev!(impl_try_from_both_bounded, isize => i32, i64, i128);
401}
402
403#[cfg(target_pointer_width = "32")]
404mod ptr_try_from_impls {
405 use super::TryFromIntError;
406
407 impl_try_from_upper_bounded!(usize => u8, u16);
408 impl_try_from_unbounded!(usize => u32, u64, u128);
409 impl_try_from_upper_bounded!(usize => i8, i16, i32);
410 impl_try_from_unbounded!(usize => i64, i128);
411
412 impl_try_from_both_bounded!(isize => u8, u16);
413 impl_try_from_lower_bounded!(isize => u32, u64, u128);
414 impl_try_from_both_bounded!(isize => i8, i16);
415 impl_try_from_unbounded!(isize => i32, i64, i128);
416
417 rev!(impl_try_from_unbounded, usize => u32);
418 rev!(impl_try_from_upper_bounded, usize => u64, u128);
419 rev!(impl_try_from_lower_bounded, usize => i8, i16, i32);
420 rev!(impl_try_from_both_bounded, usize => i64, i128);
421
422 rev!(impl_try_from_unbounded, isize => u16);
423 rev!(impl_try_from_upper_bounded, isize => u32, u64, u128);
424 rev!(impl_try_from_unbounded, isize => i32);
425 rev!(impl_try_from_both_bounded, isize => i64, i128);
426}
427
428#[cfg(target_pointer_width = "64")]
429mod ptr_try_from_impls {
430 use super::TryFromIntError;
431
432 impl_try_from_upper_bounded!(usize => u8, u16, u32);
433 impl_try_from_unbounded!(usize => u64, u128);
434 impl_try_from_upper_bounded!(usize => i8, i16, i32, i64);
435 impl_try_from_unbounded!(usize => i128);
436
437 impl_try_from_both_bounded!(isize => u8, u16, u32);
438 impl_try_from_lower_bounded!(isize => u64, u128);
439 impl_try_from_both_bounded!(isize => i8, i16, i32);
440 impl_try_from_unbounded!(isize => i64, i128);
441
442 rev!(impl_try_from_unbounded, usize => u32, u64);
443 rev!(impl_try_from_upper_bounded, usize => u128);
444 rev!(impl_try_from_lower_bounded, usize => i8, i16, i32, i64);
445 rev!(impl_try_from_both_bounded, usize => i128);
446
447 rev!(impl_try_from_unbounded, isize => u16, u32);
448 rev!(impl_try_from_upper_bounded, isize => u64, u128);
449 rev!(impl_try_from_unbounded, isize => i32, i64);
450 rev!(impl_try_from_both_bounded, isize => i128);
451}
452
453// Conversion traits for non-zero integer types
454use crate::num::NonZero;
455
456macro_rules! impl_nonzero_int_from_nonzero_int {
457 ($Small:ty => $Large:ty) => {
458 #[stable(feature = "nz_int_conv", since = "1.41.0")]
459 #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
460 impl const From<NonZero<$Small>> for NonZero<$Large> {
461 // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
462 // Rustdocs on functions do not.
463 #[doc = concat!("Converts <code>[NonZero]\\<[", stringify!($Small), "]></code> ")]
464 #[doc = concat!("to <code>[NonZero]\\<[", stringify!($Large), "]></code> losslessly.")]
465 #[inline]
466 fn from(small: NonZero<$Small>) -> Self {
467 // SAFETY: input type guarantees the value is non-zero
468 unsafe { Self::new_unchecked(From::from(small.get())) }
469 }
470 }
471 };
472}
473
474// non-zero unsigned integer -> non-zero unsigned integer
475impl_nonzero_int_from_nonzero_int!(u8 => u16);
476impl_nonzero_int_from_nonzero_int!(u8 => u32);
477impl_nonzero_int_from_nonzero_int!(u8 => u64);
478impl_nonzero_int_from_nonzero_int!(u8 => u128);
479impl_nonzero_int_from_nonzero_int!(u8 => usize);
480impl_nonzero_int_from_nonzero_int!(u16 => u32);
481impl_nonzero_int_from_nonzero_int!(u16 => u64);
482impl_nonzero_int_from_nonzero_int!(u16 => u128);
483impl_nonzero_int_from_nonzero_int!(u16 => usize);
484impl_nonzero_int_from_nonzero_int!(u32 => u64);
485impl_nonzero_int_from_nonzero_int!(u32 => u128);
486impl_nonzero_int_from_nonzero_int!(u64 => u128);
487
488// non-zero signed integer -> non-zero signed integer
489impl_nonzero_int_from_nonzero_int!(i8 => i16);
490impl_nonzero_int_from_nonzero_int!(i8 => i32);
491impl_nonzero_int_from_nonzero_int!(i8 => i64);
492impl_nonzero_int_from_nonzero_int!(i8 => i128);
493impl_nonzero_int_from_nonzero_int!(i8 => isize);
494impl_nonzero_int_from_nonzero_int!(i16 => i32);
495impl_nonzero_int_from_nonzero_int!(i16 => i64);
496impl_nonzero_int_from_nonzero_int!(i16 => i128);
497impl_nonzero_int_from_nonzero_int!(i16 => isize);
498impl_nonzero_int_from_nonzero_int!(i32 => i64);
499impl_nonzero_int_from_nonzero_int!(i32 => i128);
500impl_nonzero_int_from_nonzero_int!(i64 => i128);
501
502// non-zero unsigned -> non-zero signed integer
503impl_nonzero_int_from_nonzero_int!(u8 => i16);
504impl_nonzero_int_from_nonzero_int!(u8 => i32);
505impl_nonzero_int_from_nonzero_int!(u8 => i64);
506impl_nonzero_int_from_nonzero_int!(u8 => i128);
507impl_nonzero_int_from_nonzero_int!(u8 => isize);
508impl_nonzero_int_from_nonzero_int!(u16 => i32);
509impl_nonzero_int_from_nonzero_int!(u16 => i64);
510impl_nonzero_int_from_nonzero_int!(u16 => i128);
511impl_nonzero_int_from_nonzero_int!(u32 => i64);
512impl_nonzero_int_from_nonzero_int!(u32 => i128);
513impl_nonzero_int_from_nonzero_int!(u64 => i128);
514
515macro_rules! impl_nonzero_int_try_from_int {
516 ($Int:ty) => {
517 #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")]
518 #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
519 impl const TryFrom<$Int> for NonZero<$Int> {
520 type Error = TryFromIntError;
521
522 // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
523 // Rustdocs on functions do not.
524 #[doc = concat!("Attempts to convert [`", stringify!($Int), "`] ")]
525 #[doc = concat!("to <code>[NonZero]\\<[", stringify!($Int), "]></code>.")]
526 #[inline]
527 fn try_from(value: $Int) -> Result<Self, Self::Error> {
528 Self::new(value).ok_or(TryFromIntError(()))
529 }
530 }
531 };
532}
533
534// integer -> non-zero integer
535impl_nonzero_int_try_from_int!(u8);
536impl_nonzero_int_try_from_int!(u16);
537impl_nonzero_int_try_from_int!(u32);
538impl_nonzero_int_try_from_int!(u64);
539impl_nonzero_int_try_from_int!(u128);
540impl_nonzero_int_try_from_int!(usize);
541impl_nonzero_int_try_from_int!(i8);
542impl_nonzero_int_try_from_int!(i16);
543impl_nonzero_int_try_from_int!(i32);
544impl_nonzero_int_try_from_int!(i64);
545impl_nonzero_int_try_from_int!(i128);
546impl_nonzero_int_try_from_int!(isize);
547
548macro_rules! impl_nonzero_int_try_from_nonzero_int {
549 ($source:ty => $($target:ty),+) => {$(
550 #[stable(feature = "nzint_try_from_nzint_conv", since = "1.49.0")]
551 #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
552 impl const TryFrom<NonZero<$source>> for NonZero<$target> {
553 type Error = TryFromIntError;
554
555 // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
556 // Rustdocs on functions do not.
557 #[doc = concat!("Attempts to convert <code>[NonZero]\\<[", stringify!($source), "]></code> ")]
558 #[doc = concat!("to <code>[NonZero]\\<[", stringify!($target), "]></code>.")]
559 #[inline]
560 fn try_from(value: NonZero<$source>) -> Result<Self, Self::Error> {
561 // SAFETY: Input is guaranteed to be non-zero.
562 Ok(unsafe { Self::new_unchecked(<$target>::try_from(value.get())?) })
563 }
564 }
565 )*};
566}
567
568// unsigned non-zero integer -> unsigned non-zero integer
569impl_nonzero_int_try_from_nonzero_int!(u16 => u8);
570impl_nonzero_int_try_from_nonzero_int!(u32 => u8, u16, usize);
571impl_nonzero_int_try_from_nonzero_int!(u64 => u8, u16, u32, usize);
572impl_nonzero_int_try_from_nonzero_int!(u128 => u8, u16, u32, u64, usize);
573impl_nonzero_int_try_from_nonzero_int!(usize => u8, u16, u32, u64, u128);
574
575// signed non-zero integer -> signed non-zero integer
576impl_nonzero_int_try_from_nonzero_int!(i16 => i8);
577impl_nonzero_int_try_from_nonzero_int!(i32 => i8, i16, isize);
578impl_nonzero_int_try_from_nonzero_int!(i64 => i8, i16, i32, isize);
579impl_nonzero_int_try_from_nonzero_int!(i128 => i8, i16, i32, i64, isize);
580impl_nonzero_int_try_from_nonzero_int!(isize => i8, i16, i32, i64, i128);
581
582// unsigned non-zero integer -> signed non-zero integer
583impl_nonzero_int_try_from_nonzero_int!(u8 => i8);
584impl_nonzero_int_try_from_nonzero_int!(u16 => i8, i16, isize);
585impl_nonzero_int_try_from_nonzero_int!(u32 => i8, i16, i32, isize);
586impl_nonzero_int_try_from_nonzero_int!(u64 => i8, i16, i32, i64, isize);
587impl_nonzero_int_try_from_nonzero_int!(u128 => i8, i16, i32, i64, i128, isize);
588impl_nonzero_int_try_from_nonzero_int!(usize => i8, i16, i32, i64, i128, isize);
589
590// signed non-zero integer -> unsigned non-zero integer
591impl_nonzero_int_try_from_nonzero_int!(i8 => u8, u16, u32, u64, u128, usize);
592impl_nonzero_int_try_from_nonzero_int!(i16 => u8, u16, u32, u64, u128, usize);
593impl_nonzero_int_try_from_nonzero_int!(i32 => u8, u16, u32, u64, u128, usize);
594impl_nonzero_int_try_from_nonzero_int!(i64 => u8, u16, u32, u64, u128, usize);
595impl_nonzero_int_try_from_nonzero_int!(i128 => u8, u16, u32, u64, u128, usize);
596impl_nonzero_int_try_from_nonzero_int!(isize => u8, u16, u32, u64, u128, usize);