core/convert/
num.rs

1use crate::num::TryFromIntError;
2
3#[cfg(not(feature = "ferrocene_subset"))]
4mod private {
5    /// This trait being unreachable from outside the crate
6    /// prevents other implementations of the `FloatToInt` trait,
7    /// which allows potentially adding more trait methods after the trait is `#[stable]`.
8    #[unstable(feature = "convert_float_to_int", issue = "67057")]
9    pub trait Sealed {}
10}
11
12/// Supporting trait for inherent methods of `f32` and `f64` such as `to_int_unchecked`.
13/// Typically doesn’t need to be used directly.
14#[cfg(not(feature = "ferrocene_subset"))]
15#[unstable(feature = "convert_float_to_int", issue = "67057")]
16pub trait FloatToInt<Int>: private::Sealed + Sized {
17    #[unstable(feature = "convert_float_to_int", issue = "67057")]
18    #[doc(hidden)]
19    unsafe fn to_int_unchecked(self) -> Int;
20}
21
22#[cfg(not(feature = "ferrocene_subset"))]
23macro_rules! impl_float_to_int {
24    ($Float:ty => $($Int:ty),+) => {
25        #[unstable(feature = "convert_float_to_int", issue = "67057")]
26        impl private::Sealed for $Float {}
27        $(
28            #[unstable(feature = "convert_float_to_int", issue = "67057")]
29            impl FloatToInt<$Int> for $Float {
30                #[inline]
31                unsafe fn to_int_unchecked(self) -> $Int {
32                    // SAFETY: the safety contract must be upheld by the caller.
33                    unsafe { crate::intrinsics::float_to_int_unchecked(self) }
34                }
35            }
36        )+
37    }
38}
39
40#[cfg(not(feature = "ferrocene_subset"))]
41impl_float_to_int!(f16 => u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize);
42#[cfg(not(feature = "ferrocene_subset"))]
43impl_float_to_int!(f32 => u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize);
44#[cfg(not(feature = "ferrocene_subset"))]
45impl_float_to_int!(f64 => u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize);
46#[cfg(not(feature = "ferrocene_subset"))]
47impl_float_to_int!(f128 => u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize);
48
49// Conversion traits for primitive integer and float types
50// Conversions T -> T are covered by a blanket impl and therefore excluded
51// Some conversions from and to usize/isize are not implemented due to portability concerns
52macro_rules! impl_from {
53    (bool => $Int:ty $(,)?) => {
54        impl_from!(
55            bool => $Int,
56            #[stable(feature = "from_bool", since = "1.28.0")],
57            concat!(
58                "Converts a [`bool`] to [`", stringify!($Int), "`] losslessly.\n",
59                "The resulting value is `0` for `false` and `1` for `true` values.\n",
60                "\n",
61                "# Examples\n",
62                "\n",
63                "```\n",
64                "assert_eq!(", stringify!($Int), "::from(true), 1);\n",
65                "assert_eq!(", stringify!($Int), "::from(false), 0);\n",
66                "```\n",
67            ),
68        );
69    };
70    ($Small:ty => $Large:ty, #[$attr:meta] $(,)?) => {
71        impl_from!(
72            $Small => $Large,
73            #[$attr],
74            concat!("Converts [`", stringify!($Small), "`] to [`", stringify!($Large), "`] losslessly."),
75        );
76    };
77    ($Small:ty => $Large:ty, #[$attr:meta], $doc:expr $(,)?) => {
78        #[$attr]
79        #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
80        impl const From<$Small> for $Large {
81            // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
82            // Rustdocs on functions do not.
83            #[doc = $doc]
84            #[inline(always)]
85            fn from(small: $Small) -> Self {
86                small as Self
87            }
88        }
89    };
90}
91
92// boolean -> integer
93impl_from!(bool => u8);
94impl_from!(bool => u16);
95impl_from!(bool => u32);
96impl_from!(bool => u64);
97impl_from!(bool => u128);
98impl_from!(bool => usize);
99impl_from!(bool => i8);
100impl_from!(bool => i16);
101impl_from!(bool => i32);
102impl_from!(bool => i64);
103impl_from!(bool => i128);
104impl_from!(bool => isize);
105
106// unsigned integer -> unsigned integer
107impl_from!(u8 => u16, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
108impl_from!(u8 => u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
109impl_from!(u8 => u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
110impl_from!(u8 => u128, #[stable(feature = "i128", since = "1.26.0")]);
111impl_from!(u8 => usize, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
112impl_from!(u16 => u32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
113impl_from!(u16 => u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
114impl_from!(u16 => u128, #[stable(feature = "i128", since = "1.26.0")]);
115impl_from!(u32 => u64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
116impl_from!(u32 => u128, #[stable(feature = "i128", since = "1.26.0")]);
117impl_from!(u64 => u128, #[stable(feature = "i128", since = "1.26.0")]);
118
119// signed integer -> signed integer
120impl_from!(i8 => i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
121impl_from!(i8 => i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
122impl_from!(i8 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
123impl_from!(i8 => i128, #[stable(feature = "i128", since = "1.26.0")]);
124impl_from!(i8 => isize, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
125impl_from!(i16 => i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
126impl_from!(i16 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
127impl_from!(i16 => i128, #[stable(feature = "i128", since = "1.26.0")]);
128impl_from!(i32 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
129impl_from!(i32 => i128, #[stable(feature = "i128", since = "1.26.0")]);
130impl_from!(i64 => i128, #[stable(feature = "i128", since = "1.26.0")]);
131
132// unsigned integer -> signed integer
133#[cfg(not(feature = "ferrocene_subset"))]
134impl_from!(u8 => i16, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
135#[cfg(not(feature = "ferrocene_subset"))]
136impl_from!(u8 => i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
137#[cfg(not(feature = "ferrocene_subset"))]
138impl_from!(u8 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
139#[cfg(not(feature = "ferrocene_subset"))]
140impl_from!(u8 => i128, #[stable(feature = "i128", since = "1.26.0")]);
141#[cfg(not(feature = "ferrocene_subset"))]
142impl_from!(u16 => i32, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
143#[cfg(not(feature = "ferrocene_subset"))]
144impl_from!(u16 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
145#[cfg(not(feature = "ferrocene_subset"))]
146impl_from!(u16 => i128, #[stable(feature = "i128", since = "1.26.0")]);
147#[cfg(not(feature = "ferrocene_subset"))]
148impl_from!(u32 => i64, #[stable(feature = "lossless_int_conv", since = "1.5.0")]);
149#[cfg(not(feature = "ferrocene_subset"))]
150impl_from!(u32 => i128, #[stable(feature = "i128", since = "1.26.0")]);
151#[cfg(not(feature = "ferrocene_subset"))]
152impl_from!(u64 => i128, #[stable(feature = "i128", since = "1.26.0")]);
153
154// The C99 standard defines bounds on INTPTR_MIN, INTPTR_MAX, and UINTPTR_MAX
155// which imply that pointer-sized integers must be at least 16 bits:
156// https://port70.net/~nsz/c/c99/n1256.html#7.18.2.4
157impl_from!(u16 => usize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")]);
158impl_from!(u8 => isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")]);
159impl_from!(i16 => isize, #[stable(feature = "lossless_iusize_conv", since = "1.26.0")]);
160
161// RISC-V defines the possibility of a 128-bit address space (RV128).
162
163// CHERI proposes 128-bit “capabilities”. Unclear if this would be relevant to usize/isize.
164// https://www.cl.cam.ac.uk/research/security/ctsrd/pdfs/20171017a-cheri-poster.pdf
165// https://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-951.pdf
166
167// Note: integers can only be represented with full precision in a float if
168// they fit in the significand, which is:
169// * 11 bits in f16
170// * 24 bits in f32
171// * 53 bits in f64
172// * 113 bits in f128
173// Lossy float conversions are not implemented at this time.
174// FIXME(f16,f128): The `f16`/`f128` impls `#[stable]` attributes should be changed to reference
175// `f16`/`f128` when they are stabilised (trait impls have to have a `#[stable]` attribute, but none
176// of the `f16`/`f128` impls can be used on stable as the `f16` and `f128` types are unstable).
177
178// signed integer -> float
179#[cfg(not(feature = "ferrocene_subset"))]
180impl_from!(i8 => f16, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
181#[cfg(not(feature = "ferrocene_subset"))]
182impl_from!(i8 => f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
183#[cfg(not(feature = "ferrocene_subset"))]
184impl_from!(i8 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
185#[cfg(not(feature = "ferrocene_subset"))]
186impl_from!(i8 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
187#[cfg(not(feature = "ferrocene_subset"))]
188impl_from!(i16 => f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
189#[cfg(not(feature = "ferrocene_subset"))]
190impl_from!(i16 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
191#[cfg(not(feature = "ferrocene_subset"))]
192impl_from!(i16 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
193#[cfg(not(feature = "ferrocene_subset"))]
194impl_from!(i32 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
195#[cfg(not(feature = "ferrocene_subset"))]
196impl_from!(i32 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
197// FIXME(f128): This impl would allow using `f128` on stable before it is stabilised.
198// impl_from!(i64 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
199
200// unsigned integer -> float
201#[cfg(not(feature = "ferrocene_subset"))]
202impl_from!(u8 => f16, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
203#[cfg(not(feature = "ferrocene_subset"))]
204impl_from!(u8 => f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
205#[cfg(not(feature = "ferrocene_subset"))]
206impl_from!(u8 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
207#[cfg(not(feature = "ferrocene_subset"))]
208impl_from!(u8 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
209#[cfg(not(feature = "ferrocene_subset"))]
210impl_from!(u16 => f32, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
211#[cfg(not(feature = "ferrocene_subset"))]
212impl_from!(u16 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
213#[cfg(not(feature = "ferrocene_subset"))]
214impl_from!(u16 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
215#[cfg(not(feature = "ferrocene_subset"))]
216impl_from!(u32 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
217#[cfg(not(feature = "ferrocene_subset"))]
218impl_from!(u32 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
219// FIXME(f128): This impl would allow using `f128` on stable before it is stabilised.
220// impl_from!(u64 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
221
222// float -> float
223// FIXME(f16,f128): adding additional `From<{float}>` impls to `f32` breaks inference. See
224// <https://github.com/rust-lang/rust/issues/123831>
225#[cfg(not(feature = "ferrocene_subset"))]
226impl_from!(f16 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
227#[cfg(not(feature = "ferrocene_subset"))]
228impl_from!(f16 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
229#[cfg(not(feature = "ferrocene_subset"))]
230impl_from!(f32 => f64, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
231#[cfg(not(feature = "ferrocene_subset"))]
232impl_from!(f32 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
233#[cfg(not(feature = "ferrocene_subset"))]
234impl_from!(f64 => f128, #[stable(feature = "lossless_float_conv", since = "1.6.0")]);
235
236#[cfg(not(feature = "ferrocene_subset"))]
237macro_rules! impl_float_from_bool {
238    (
239        $float:ty $(;
240            doctest_prefix: $(#[doc = $doctest_prefix:literal])*
241            doctest_suffix: $(#[doc = $doctest_suffix:literal])*
242        )?
243    ) => {
244        #[stable(feature = "float_from_bool", since = "1.68.0")]
245        #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
246            impl const From<bool> for $float {
247            #[doc = concat!("Converts a [`bool`] to [`", stringify!($float),"`] losslessly.")]
248            /// The resulting value is positive `0.0` for `false` and `1.0` for `true` values.
249            ///
250            /// # Examples
251            /// ```
252            $($(#[doc = $doctest_prefix])*)?
253            #[doc = concat!("let x: ", stringify!($float)," = false.into();")]
254            /// assert_eq!(x, 0.0);
255            /// assert!(x.is_sign_positive());
256            ///
257            #[doc = concat!("let y: ", stringify!($float)," = true.into();")]
258            /// assert_eq!(y, 1.0);
259            $($(#[doc = $doctest_suffix])*)?
260            /// ```
261            #[inline]
262            fn from(small: bool) -> Self {
263                small as u8 as Self
264            }
265        }
266    };
267}
268
269// boolean -> float
270#[cfg(not(feature = "ferrocene_subset"))]
271impl_float_from_bool!(
272    f16;
273    doctest_prefix:
274    // rustdoc doesn't remove the conventional space after the `///`
275    ///#![feature(f16)]
276    ///# #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
277    ///
278    doctest_suffix:
279    ///# }
280);
281#[cfg(not(feature = "ferrocene_subset"))]
282impl_float_from_bool!(f32);
283#[cfg(not(feature = "ferrocene_subset"))]
284impl_float_from_bool!(f64);
285#[cfg(not(feature = "ferrocene_subset"))]
286impl_float_from_bool!(
287    f128;
288    doctest_prefix:
289    ///#![feature(f128)]
290    ///# #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
291    ///
292    doctest_suffix:
293    ///# }
294);
295
296// no possible bounds violation
297macro_rules! impl_try_from_unbounded {
298    ($source:ty => $($target:ty),+) => {$(
299        #[stable(feature = "try_from", since = "1.34.0")]
300        #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
301        impl const TryFrom<$source> for $target {
302            type Error = TryFromIntError;
303
304            /// Tries to create the target number type from a source
305            /// number type. This returns an error if the source value
306            /// is outside of the range of the target type.
307            #[inline]
308            fn try_from(value: $source) -> Result<Self, Self::Error> {
309                Ok(value as Self)
310            }
311        }
312    )*}
313}
314
315// only negative bounds
316macro_rules! impl_try_from_lower_bounded {
317    ($source:ty => $($target:ty),+) => {$(
318        #[stable(feature = "try_from", since = "1.34.0")]
319        #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
320        impl const TryFrom<$source> for $target {
321            type Error = TryFromIntError;
322
323            /// Tries to create the target number type from a source
324            /// number type. This returns an error if the source value
325            /// is outside of the range of the target type.
326            #[inline]
327            fn try_from(u: $source) -> Result<Self, Self::Error> {
328                if u >= 0 {
329                    Ok(u as Self)
330                } else {
331                    Err(TryFromIntError(()))
332                }
333            }
334        }
335    )*}
336}
337
338// unsigned to signed (only positive bound)
339macro_rules! impl_try_from_upper_bounded {
340    ($source:ty => $($target:ty),+) => {$(
341        #[stable(feature = "try_from", since = "1.34.0")]
342        #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
343        impl const TryFrom<$source> for $target {
344            type Error = TryFromIntError;
345
346            /// Tries to create the target number type from a source
347            /// number type. This returns an error if the source value
348            /// is outside of the range of the target type.
349            #[inline]
350            fn try_from(u: $source) -> Result<Self, Self::Error> {
351                if u > (Self::MAX as $source) {
352                    Err(TryFromIntError(()))
353                } else {
354                    Ok(u as Self)
355                }
356            }
357        }
358    )*}
359}
360
361// all other cases
362macro_rules! impl_try_from_both_bounded {
363    ($source:ty => $($target:ty),+) => {$(
364        #[stable(feature = "try_from", since = "1.34.0")]
365        #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
366        impl const TryFrom<$source> for $target {
367            type Error = TryFromIntError;
368
369            /// Tries to create the target number type from a source
370            /// number type. This returns an error if the source value
371            /// is outside of the range of the target type.
372            #[inline]
373            fn try_from(u: $source) -> Result<Self, Self::Error> {
374                let min = Self::MIN as $source;
375                let max = Self::MAX as $source;
376                if u < min || u > max {
377                    Err(TryFromIntError(()))
378                } else {
379                    Ok(u as Self)
380                }
381            }
382        }
383    )*}
384}
385
386macro_rules! rev {
387    ($mac:ident, $source:ty => $($target:ty),+) => {$(
388        $mac!($target => $source);
389    )*}
390}
391
392// unsigned integer -> unsigned integer
393impl_try_from_upper_bounded!(u16 => u8);
394impl_try_from_upper_bounded!(u32 => u8, u16);
395impl_try_from_upper_bounded!(u64 => u8, u16, u32);
396impl_try_from_upper_bounded!(u128 => u8, u16, u32, u64);
397
398// signed integer -> signed integer
399#[cfg(not(feature = "ferrocene_subset"))]
400impl_try_from_both_bounded!(i16 => i8);
401#[cfg(not(feature = "ferrocene_subset"))]
402impl_try_from_both_bounded!(i32 => i8, i16);
403#[cfg(not(feature = "ferrocene_subset"))]
404impl_try_from_both_bounded!(i64 => i8, i16, i32);
405#[cfg(not(feature = "ferrocene_subset"))]
406impl_try_from_both_bounded!(i128 => i8, i16, i32, i64);
407
408// unsigned integer -> signed integer
409#[cfg(not(feature = "ferrocene_subset"))]
410impl_try_from_upper_bounded!(u8 => i8);
411#[cfg(not(feature = "ferrocene_subset"))]
412impl_try_from_upper_bounded!(u16 => i8, i16);
413#[cfg(not(feature = "ferrocene_subset"))]
414impl_try_from_upper_bounded!(u32 => i8, i16, i32);
415#[cfg(not(feature = "ferrocene_subset"))]
416impl_try_from_upper_bounded!(u64 => i8, i16, i32, i64);
417#[cfg(not(feature = "ferrocene_subset"))]
418impl_try_from_upper_bounded!(u128 => i8, i16, i32, i64, i128);
419
420// signed integer -> unsigned integer
421#[cfg(not(feature = "ferrocene_subset"))]
422impl_try_from_lower_bounded!(i8 => u8, u16, u32, u64, u128);
423#[cfg(not(feature = "ferrocene_subset"))]
424impl_try_from_both_bounded!(i16 => u8);
425#[cfg(not(feature = "ferrocene_subset"))]
426impl_try_from_lower_bounded!(i16 => u16, u32, u64, u128);
427impl_try_from_both_bounded!(i32 => u8, u16);
428impl_try_from_lower_bounded!(i32 => u32, u64, u128);
429#[cfg(not(feature = "ferrocene_subset"))]
430impl_try_from_both_bounded!(i64 => u8, u16, u32);
431#[cfg(not(feature = "ferrocene_subset"))]
432impl_try_from_lower_bounded!(i64 => u64, u128);
433#[cfg(not(feature = "ferrocene_subset"))]
434impl_try_from_both_bounded!(i128 => u8, u16, u32, u64);
435#[cfg(not(feature = "ferrocene_subset"))]
436impl_try_from_lower_bounded!(i128 => u128);
437
438// usize/isize
439#[cfg(not(feature = "ferrocene_subset"))]
440impl_try_from_upper_bounded!(usize => isize);
441#[cfg(not(feature = "ferrocene_subset"))]
442impl_try_from_lower_bounded!(isize => usize);
443
444#[cfg(target_pointer_width = "16")]
445mod ptr_try_from_impls {
446    use super::TryFromIntError;
447
448    impl_try_from_upper_bounded!(usize => u8);
449    impl_try_from_unbounded!(usize => u16, u32, u64, u128);
450    #[cfg(not(feature = "ferrocene_subset"))]
451    impl_try_from_upper_bounded!(usize => i8, i16);
452    #[cfg(not(feature = "ferrocene_subset"))]
453    impl_try_from_unbounded!(usize => i32, i64, i128);
454
455    #[cfg(not(feature = "ferrocene_subset"))]
456    impl_try_from_both_bounded!(isize => u8);
457    #[cfg(not(feature = "ferrocene_subset"))]
458    impl_try_from_lower_bounded!(isize => u16, u32, u64, u128);
459    #[cfg(not(feature = "ferrocene_subset"))]
460    impl_try_from_both_bounded!(isize => i8);
461    #[cfg(not(feature = "ferrocene_subset"))]
462    impl_try_from_unbounded!(isize => i16, i32, i64, i128);
463
464    rev!(impl_try_from_upper_bounded, usize => u32, u64, u128);
465    rev!(impl_try_from_lower_bounded, usize => i8, i16);
466    rev!(impl_try_from_both_bounded, usize => i32, i64, i128);
467
468    #[cfg(not(feature = "ferrocene_subset"))]
469    rev!(impl_try_from_upper_bounded, isize => u16, u32, u64, u128);
470    #[cfg(not(feature = "ferrocene_subset"))]
471    rev!(impl_try_from_both_bounded, isize => i32, i64, i128);
472}
473
474#[cfg(target_pointer_width = "32")]
475mod ptr_try_from_impls {
476    use super::TryFromIntError;
477
478    impl_try_from_upper_bounded!(usize => u8, u16);
479    impl_try_from_unbounded!(usize => u32, u64, u128);
480    #[cfg(not(feature = "ferrocene_subset"))]
481    impl_try_from_upper_bounded!(usize => i8, i16, i32);
482    #[cfg(not(feature = "ferrocene_subset"))]
483    impl_try_from_unbounded!(usize => i64, i128);
484
485    #[cfg(not(feature = "ferrocene_subset"))]
486    impl_try_from_both_bounded!(isize => u8, u16);
487    #[cfg(not(feature = "ferrocene_subset"))]
488    impl_try_from_lower_bounded!(isize => u32, u64, u128);
489    #[cfg(not(feature = "ferrocene_subset"))]
490    impl_try_from_both_bounded!(isize => i8, i16);
491    #[cfg(not(feature = "ferrocene_subset"))]
492    impl_try_from_unbounded!(isize => i32, i64, i128);
493
494    rev!(impl_try_from_unbounded, usize => u32);
495    rev!(impl_try_from_upper_bounded, usize => u64, u128);
496    rev!(impl_try_from_lower_bounded, usize => i8, i16, i32);
497    rev!(impl_try_from_both_bounded, usize => i64, i128);
498
499    #[cfg(not(feature = "ferrocene_subset"))]
500    rev!(impl_try_from_unbounded, isize => u16);
501    #[cfg(not(feature = "ferrocene_subset"))]
502    rev!(impl_try_from_upper_bounded, isize => u32, u64, u128);
503    #[cfg(not(feature = "ferrocene_subset"))]
504    rev!(impl_try_from_unbounded, isize => i32);
505    #[cfg(not(feature = "ferrocene_subset"))]
506    rev!(impl_try_from_both_bounded, isize => i64, i128);
507}
508
509#[cfg(target_pointer_width = "64")]
510mod ptr_try_from_impls {
511    use super::TryFromIntError;
512
513    impl_try_from_upper_bounded!(usize => u8, u16, u32);
514    impl_try_from_unbounded!(usize => u64, u128);
515    #[cfg(not(feature = "ferrocene_subset"))]
516    impl_try_from_upper_bounded!(usize => i8, i16, i32, i64);
517    #[cfg(not(feature = "ferrocene_subset"))]
518    impl_try_from_unbounded!(usize => i128);
519
520    #[cfg(not(feature = "ferrocene_subset"))]
521    impl_try_from_both_bounded!(isize => u8, u16, u32);
522    #[cfg(not(feature = "ferrocene_subset"))]
523    impl_try_from_lower_bounded!(isize => u64, u128);
524    #[cfg(not(feature = "ferrocene_subset"))]
525    impl_try_from_both_bounded!(isize => i8, i16, i32);
526    #[cfg(not(feature = "ferrocene_subset"))]
527    impl_try_from_unbounded!(isize => i64, i128);
528
529    rev!(impl_try_from_unbounded, usize => u32, u64);
530    rev!(impl_try_from_upper_bounded, usize => u128);
531    rev!(impl_try_from_lower_bounded, usize => i8, i16, i32, i64);
532    rev!(impl_try_from_both_bounded, usize => i128);
533
534    #[cfg(not(feature = "ferrocene_subset"))]
535    rev!(impl_try_from_unbounded, isize => u16, u32);
536    #[cfg(not(feature = "ferrocene_subset"))]
537    rev!(impl_try_from_upper_bounded, isize => u64, u128);
538    #[cfg(not(feature = "ferrocene_subset"))]
539    rev!(impl_try_from_unbounded, isize => i32, i64);
540    #[cfg(not(feature = "ferrocene_subset"))]
541    rev!(impl_try_from_both_bounded, isize => i128);
542}
543
544// Conversion traits for non-zero integer types
545#[cfg(not(feature = "ferrocene_subset"))]
546use crate::num::NonZero;
547
548#[cfg(not(feature = "ferrocene_subset"))]
549macro_rules! impl_nonzero_int_from_nonzero_int {
550    ($Small:ty => $Large:ty) => {
551        #[stable(feature = "nz_int_conv", since = "1.41.0")]
552        #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
553        impl const From<NonZero<$Small>> for NonZero<$Large> {
554            // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
555            // Rustdocs on functions do not.
556            #[doc = concat!("Converts <code>[NonZero]\\<[", stringify!($Small), "]></code> ")]
557            #[doc = concat!("to <code>[NonZero]\\<[", stringify!($Large), "]></code> losslessly.")]
558            #[inline]
559            fn from(small: NonZero<$Small>) -> Self {
560                // SAFETY: input type guarantees the value is non-zero
561                unsafe { Self::new_unchecked(From::from(small.get())) }
562            }
563        }
564    };
565}
566
567// non-zero unsigned integer -> non-zero unsigned integer
568#[cfg(not(feature = "ferrocene_subset"))]
569impl_nonzero_int_from_nonzero_int!(u8 => u16);
570#[cfg(not(feature = "ferrocene_subset"))]
571impl_nonzero_int_from_nonzero_int!(u8 => u32);
572#[cfg(not(feature = "ferrocene_subset"))]
573impl_nonzero_int_from_nonzero_int!(u8 => u64);
574#[cfg(not(feature = "ferrocene_subset"))]
575impl_nonzero_int_from_nonzero_int!(u8 => u128);
576#[cfg(not(feature = "ferrocene_subset"))]
577impl_nonzero_int_from_nonzero_int!(u8 => usize);
578#[cfg(not(feature = "ferrocene_subset"))]
579impl_nonzero_int_from_nonzero_int!(u16 => u32);
580#[cfg(not(feature = "ferrocene_subset"))]
581impl_nonzero_int_from_nonzero_int!(u16 => u64);
582#[cfg(not(feature = "ferrocene_subset"))]
583impl_nonzero_int_from_nonzero_int!(u16 => u128);
584#[cfg(not(feature = "ferrocene_subset"))]
585impl_nonzero_int_from_nonzero_int!(u16 => usize);
586#[cfg(not(feature = "ferrocene_subset"))]
587impl_nonzero_int_from_nonzero_int!(u32 => u64);
588#[cfg(not(feature = "ferrocene_subset"))]
589impl_nonzero_int_from_nonzero_int!(u32 => u128);
590#[cfg(not(feature = "ferrocene_subset"))]
591impl_nonzero_int_from_nonzero_int!(u64 => u128);
592
593// non-zero signed integer -> non-zero signed integer
594#[cfg(not(feature = "ferrocene_subset"))]
595impl_nonzero_int_from_nonzero_int!(i8 => i16);
596#[cfg(not(feature = "ferrocene_subset"))]
597impl_nonzero_int_from_nonzero_int!(i8 => i32);
598#[cfg(not(feature = "ferrocene_subset"))]
599impl_nonzero_int_from_nonzero_int!(i8 => i64);
600#[cfg(not(feature = "ferrocene_subset"))]
601impl_nonzero_int_from_nonzero_int!(i8 => i128);
602#[cfg(not(feature = "ferrocene_subset"))]
603impl_nonzero_int_from_nonzero_int!(i8 => isize);
604#[cfg(not(feature = "ferrocene_subset"))]
605impl_nonzero_int_from_nonzero_int!(i16 => i32);
606#[cfg(not(feature = "ferrocene_subset"))]
607impl_nonzero_int_from_nonzero_int!(i16 => i64);
608#[cfg(not(feature = "ferrocene_subset"))]
609impl_nonzero_int_from_nonzero_int!(i16 => i128);
610#[cfg(not(feature = "ferrocene_subset"))]
611impl_nonzero_int_from_nonzero_int!(i16 => isize);
612#[cfg(not(feature = "ferrocene_subset"))]
613impl_nonzero_int_from_nonzero_int!(i32 => i64);
614#[cfg(not(feature = "ferrocene_subset"))]
615impl_nonzero_int_from_nonzero_int!(i32 => i128);
616#[cfg(not(feature = "ferrocene_subset"))]
617impl_nonzero_int_from_nonzero_int!(i64 => i128);
618
619// non-zero unsigned -> non-zero signed integer
620#[cfg(not(feature = "ferrocene_subset"))]
621impl_nonzero_int_from_nonzero_int!(u8 => i16);
622#[cfg(not(feature = "ferrocene_subset"))]
623impl_nonzero_int_from_nonzero_int!(u8 => i32);
624#[cfg(not(feature = "ferrocene_subset"))]
625impl_nonzero_int_from_nonzero_int!(u8 => i64);
626#[cfg(not(feature = "ferrocene_subset"))]
627impl_nonzero_int_from_nonzero_int!(u8 => i128);
628#[cfg(not(feature = "ferrocene_subset"))]
629impl_nonzero_int_from_nonzero_int!(u8 => isize);
630#[cfg(not(feature = "ferrocene_subset"))]
631impl_nonzero_int_from_nonzero_int!(u16 => i32);
632#[cfg(not(feature = "ferrocene_subset"))]
633impl_nonzero_int_from_nonzero_int!(u16 => i64);
634#[cfg(not(feature = "ferrocene_subset"))]
635impl_nonzero_int_from_nonzero_int!(u16 => i128);
636#[cfg(not(feature = "ferrocene_subset"))]
637impl_nonzero_int_from_nonzero_int!(u32 => i64);
638#[cfg(not(feature = "ferrocene_subset"))]
639impl_nonzero_int_from_nonzero_int!(u32 => i128);
640#[cfg(not(feature = "ferrocene_subset"))]
641impl_nonzero_int_from_nonzero_int!(u64 => i128);
642
643#[cfg(not(feature = "ferrocene_subset"))]
644macro_rules! impl_nonzero_int_try_from_int {
645    ($Int:ty) => {
646        #[stable(feature = "nzint_try_from_int_conv", since = "1.46.0")]
647        #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
648        impl const TryFrom<$Int> for NonZero<$Int> {
649            type Error = TryFromIntError;
650
651            // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
652            // Rustdocs on functions do not.
653            #[doc = concat!("Attempts to convert [`", stringify!($Int), "`] ")]
654            #[doc = concat!("to <code>[NonZero]\\<[", stringify!($Int), "]></code>.")]
655            #[inline]
656            fn try_from(value: $Int) -> Result<Self, Self::Error> {
657                Self::new(value).ok_or(TryFromIntError(()))
658            }
659        }
660    };
661}
662
663// integer -> non-zero integer
664#[cfg(not(feature = "ferrocene_subset"))]
665impl_nonzero_int_try_from_int!(u8);
666#[cfg(not(feature = "ferrocene_subset"))]
667impl_nonzero_int_try_from_int!(u16);
668#[cfg(not(feature = "ferrocene_subset"))]
669impl_nonzero_int_try_from_int!(u32);
670#[cfg(not(feature = "ferrocene_subset"))]
671impl_nonzero_int_try_from_int!(u64);
672#[cfg(not(feature = "ferrocene_subset"))]
673impl_nonzero_int_try_from_int!(u128);
674#[cfg(not(feature = "ferrocene_subset"))]
675impl_nonzero_int_try_from_int!(usize);
676#[cfg(not(feature = "ferrocene_subset"))]
677impl_nonzero_int_try_from_int!(i8);
678#[cfg(not(feature = "ferrocene_subset"))]
679impl_nonzero_int_try_from_int!(i16);
680#[cfg(not(feature = "ferrocene_subset"))]
681impl_nonzero_int_try_from_int!(i32);
682#[cfg(not(feature = "ferrocene_subset"))]
683impl_nonzero_int_try_from_int!(i64);
684#[cfg(not(feature = "ferrocene_subset"))]
685impl_nonzero_int_try_from_int!(i128);
686#[cfg(not(feature = "ferrocene_subset"))]
687impl_nonzero_int_try_from_int!(isize);
688
689#[cfg(not(feature = "ferrocene_subset"))]
690macro_rules! impl_nonzero_int_try_from_nonzero_int {
691    ($source:ty => $($target:ty),+) => {$(
692        #[stable(feature = "nzint_try_from_nzint_conv", since = "1.49.0")]
693        #[rustc_const_unstable(feature = "const_convert", issue = "143773")]
694        impl const TryFrom<NonZero<$source>> for NonZero<$target> {
695            type Error = TryFromIntError;
696
697            // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
698            // Rustdocs on functions do not.
699            #[doc = concat!("Attempts to convert <code>[NonZero]\\<[", stringify!($source), "]></code> ")]
700            #[doc = concat!("to <code>[NonZero]\\<[", stringify!($target), "]></code>.")]
701            #[inline]
702            fn try_from(value: NonZero<$source>) -> Result<Self, Self::Error> {
703                // SAFETY: Input is guaranteed to be non-zero.
704                Ok(unsafe { Self::new_unchecked(<$target>::try_from(value.get())?) })
705            }
706        }
707    )*};
708}
709
710// unsigned non-zero integer -> unsigned non-zero integer
711#[cfg(not(feature = "ferrocene_subset"))]
712impl_nonzero_int_try_from_nonzero_int!(u16 => u8);
713#[cfg(not(feature = "ferrocene_subset"))]
714impl_nonzero_int_try_from_nonzero_int!(u32 => u8, u16, usize);
715#[cfg(not(feature = "ferrocene_subset"))]
716impl_nonzero_int_try_from_nonzero_int!(u64 => u8, u16, u32, usize);
717#[cfg(not(feature = "ferrocene_subset"))]
718impl_nonzero_int_try_from_nonzero_int!(u128 => u8, u16, u32, u64, usize);
719#[cfg(not(feature = "ferrocene_subset"))]
720impl_nonzero_int_try_from_nonzero_int!(usize => u8, u16, u32, u64, u128);
721
722// signed non-zero integer -> signed non-zero integer
723#[cfg(not(feature = "ferrocene_subset"))]
724impl_nonzero_int_try_from_nonzero_int!(i16 => i8);
725#[cfg(not(feature = "ferrocene_subset"))]
726impl_nonzero_int_try_from_nonzero_int!(i32 => i8, i16, isize);
727#[cfg(not(feature = "ferrocene_subset"))]
728impl_nonzero_int_try_from_nonzero_int!(i64 => i8, i16, i32, isize);
729#[cfg(not(feature = "ferrocene_subset"))]
730impl_nonzero_int_try_from_nonzero_int!(i128 => i8, i16, i32, i64, isize);
731#[cfg(not(feature = "ferrocene_subset"))]
732impl_nonzero_int_try_from_nonzero_int!(isize => i8, i16, i32, i64, i128);
733
734// unsigned non-zero integer -> signed non-zero integer
735#[cfg(not(feature = "ferrocene_subset"))]
736impl_nonzero_int_try_from_nonzero_int!(u8 => i8);
737#[cfg(not(feature = "ferrocene_subset"))]
738impl_nonzero_int_try_from_nonzero_int!(u16 => i8, i16, isize);
739#[cfg(not(feature = "ferrocene_subset"))]
740impl_nonzero_int_try_from_nonzero_int!(u32 => i8, i16, i32, isize);
741#[cfg(not(feature = "ferrocene_subset"))]
742impl_nonzero_int_try_from_nonzero_int!(u64 => i8, i16, i32, i64, isize);
743#[cfg(not(feature = "ferrocene_subset"))]
744impl_nonzero_int_try_from_nonzero_int!(u128 => i8, i16, i32, i64, i128, isize);
745#[cfg(not(feature = "ferrocene_subset"))]
746impl_nonzero_int_try_from_nonzero_int!(usize => i8, i16, i32, i64, i128, isize);
747
748// signed non-zero integer -> unsigned non-zero integer
749#[cfg(not(feature = "ferrocene_subset"))]
750impl_nonzero_int_try_from_nonzero_int!(i8 => u8, u16, u32, u64, u128, usize);
751#[cfg(not(feature = "ferrocene_subset"))]
752impl_nonzero_int_try_from_nonzero_int!(i16 => u8, u16, u32, u64, u128, usize);
753#[cfg(not(feature = "ferrocene_subset"))]
754impl_nonzero_int_try_from_nonzero_int!(i32 => u8, u16, u32, u64, u128, usize);
755#[cfg(not(feature = "ferrocene_subset"))]
756impl_nonzero_int_try_from_nonzero_int!(i64 => u8, u16, u32, u64, u128, usize);
757#[cfg(not(feature = "ferrocene_subset"))]
758impl_nonzero_int_try_from_nonzero_int!(i128 => u8, u16, u32, u64, u128, usize);
759#[cfg(not(feature = "ferrocene_subset"))]
760impl_nonzero_int_try_from_nonzero_int!(isize => u8, u16, u32, u64, u128, usize);
core/convert/num.rs

core/convert/
num.rs
