1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291
//! Definitions of integer that is known not to equal zero.
use crate::fmt;
use crate::ops::{BitOr, BitOrAssign, Div, Rem};
use crate::str::FromStr;
use super::from_str_radix;
use super::{IntErrorKind, ParseIntError};
use crate::intrinsics;
macro_rules! impl_nonzero_fmt {
( #[$stability: meta] ( $( $Trait: ident ),+ ) for $Ty: ident ) => {
$(
#[$stability]
impl fmt::$Trait for $Ty {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.get().fmt(f)
}
}
)+
}
}
macro_rules! nonzero_integers {
( $( #[$stability: meta] #[$const_new_unchecked_stability: meta] $Ty: ident($Int: ty); )+ ) => {
$(
/// An integer that is known not to equal zero.
///
/// This enables some memory layout optimization.
#[doc = concat!("For example, `Option<", stringify!($Ty), ">` is the same size as `", stringify!($Int), "`:")]
///
/// ```rust
/// use std::mem::size_of;
#[doc = concat!("assert_eq!(size_of::<Option<core::num::", stringify!($Ty), ">>(), size_of::<", stringify!($Int), ">());")]
/// ```
#[$stability]
#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
#[repr(transparent)]
#[rustc_layout_scalar_valid_range_start(1)]
#[rustc_nonnull_optimization_guaranteed]
#[rustc_diagnostic_item = stringify!($Ty)]
pub struct $Ty($Int);
impl $Ty {
/// Creates a non-zero without checking whether the value is non-zero.
/// This results in undefined behaviour if the value is zero.
///
/// # Safety
///
/// The value must not be zero.
#[$stability]
#[$const_new_unchecked_stability]
#[must_use]
#[inline]
pub const unsafe fn new_unchecked(n: $Int) -> Self {
// SAFETY: this is guaranteed to be safe by the caller.
unsafe {
core::intrinsics::assert_unsafe_precondition!(
concat!(stringify!($Ty), "::new_unchecked requires a non-zero argument"),
(n: $Int) => n != 0
);
Self(n)
}
}
/// Creates a non-zero if the given value is not zero.
#[$stability]
#[rustc_const_stable(feature = "const_nonzero_int_methods", since = "1.47.0")]
#[must_use]
#[inline]
pub const fn new(n: $Int) -> Option<Self> {
if n != 0 {
// SAFETY: we just checked that there's no `0`
Some(unsafe { Self(n) })
} else {
None
}
}
/// Returns the value as a primitive type.
#[$stability]
#[inline]
#[rustc_const_stable(feature = "const_nonzero_get", since = "1.34.0")]
pub const fn get(self) -> $Int {
self.0
}
}
#[stable(feature = "from_nonzero", since = "1.31.0")]
#[rustc_const_unstable(feature = "const_num_from_num", issue = "87852")]
impl const From<$Ty> for $Int {
#[doc = concat!("Converts a `", stringify!($Ty), "` into an `", stringify!($Int), "`")]
#[inline]
fn from(nonzero: $Ty) -> Self {
nonzero.0
}
}
#[stable(feature = "nonzero_bitor", since = "1.45.0")]
#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
impl const BitOr for $Ty {
type Output = Self;
#[inline]
fn bitor(self, rhs: Self) -> Self::Output {
// SAFETY: since `self` and `rhs` are both nonzero, the
// result of the bitwise-or will be nonzero.
unsafe { $Ty::new_unchecked(self.get() | rhs.get()) }
}
}
#[stable(feature = "nonzero_bitor", since = "1.45.0")]
#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
impl const BitOr<$Int> for $Ty {
type Output = Self;
#[inline]
fn bitor(self, rhs: $Int) -> Self::Output {
// SAFETY: since `self` is nonzero, the result of the
// bitwise-or will be nonzero regardless of the value of
// `rhs`.
unsafe { $Ty::new_unchecked(self.get() | rhs) }
}
}
#[stable(feature = "nonzero_bitor", since = "1.45.0")]
#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
impl const BitOr<$Ty> for $Int {
type Output = $Ty;
#[inline]
fn bitor(self, rhs: $Ty) -> Self::Output {
// SAFETY: since `rhs` is nonzero, the result of the
// bitwise-or will be nonzero regardless of the value of
// `self`.
unsafe { $Ty::new_unchecked(self | rhs.get()) }
}
}
#[stable(feature = "nonzero_bitor", since = "1.45.0")]
#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
impl const BitOrAssign for $Ty {
#[inline]
fn bitor_assign(&mut self, rhs: Self) {
*self = *self | rhs;
}
}
#[stable(feature = "nonzero_bitor", since = "1.45.0")]
#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
impl const BitOrAssign<$Int> for $Ty {
#[inline]
fn bitor_assign(&mut self, rhs: $Int) {
*self = *self | rhs;
}
}
impl_nonzero_fmt! {
#[$stability] (Debug, Display, Binary, Octal, LowerHex, UpperHex) for $Ty
}
)+
}
}
nonzero_integers! {
#[stable(feature = "nonzero", since = "1.28.0")] #[rustc_const_stable(feature = "nonzero", since = "1.28.0")] NonZeroU8(u8);
#[stable(feature = "nonzero", since = "1.28.0")] #[rustc_const_stable(feature = "nonzero", since = "1.28.0")] NonZeroU16(u16);
#[stable(feature = "nonzero", since = "1.28.0")] #[rustc_const_stable(feature = "nonzero", since = "1.28.0")] NonZeroU32(u32);
#[stable(feature = "nonzero", since = "1.28.0")] #[rustc_const_stable(feature = "nonzero", since = "1.28.0")] NonZeroU64(u64);
#[stable(feature = "nonzero", since = "1.28.0")] #[rustc_const_stable(feature = "nonzero", since = "1.28.0")] NonZeroU128(u128);
#[stable(feature = "nonzero", since = "1.28.0")] #[rustc_const_stable(feature = "nonzero", since = "1.28.0")] NonZeroUsize(usize);
#[stable(feature = "signed_nonzero", since = "1.34.0")] #[rustc_const_stable(feature = "signed_nonzero", since = "1.34.0")] NonZeroI8(i8);
#[stable(feature = "signed_nonzero", since = "1.34.0")] #[rustc_const_stable(feature = "signed_nonzero", since = "1.34.0")] NonZeroI16(i16);
#[stable(feature = "signed_nonzero", since = "1.34.0")] #[rustc_const_stable(feature = "signed_nonzero", since = "1.34.0")] NonZeroI32(i32);
#[stable(feature = "signed_nonzero", since = "1.34.0")] #[rustc_const_stable(feature = "signed_nonzero", since = "1.34.0")] NonZeroI64(i64);
#[stable(feature = "signed_nonzero", since = "1.34.0")] #[rustc_const_stable(feature = "signed_nonzero", since = "1.34.0")] NonZeroI128(i128);
#[stable(feature = "signed_nonzero", since = "1.34.0")] #[rustc_const_stable(feature = "signed_nonzero", since = "1.34.0")] NonZeroIsize(isize);
}
macro_rules! from_str_radix_nzint_impl {
($($t:ty)*) => {$(
#[stable(feature = "nonzero_parse", since = "1.35.0")]
impl FromStr for $t {
type Err = ParseIntError;
fn from_str(src: &str) -> Result<Self, Self::Err> {
Self::new(from_str_radix(src, 10)?)
.ok_or(ParseIntError {
kind: IntErrorKind::Zero
})
}
}
)*}
}
from_str_radix_nzint_impl! { NonZeroU8 NonZeroU16 NonZeroU32 NonZeroU64 NonZeroU128 NonZeroUsize
NonZeroI8 NonZeroI16 NonZeroI32 NonZeroI64 NonZeroI128 NonZeroIsize }
macro_rules! nonzero_leading_trailing_zeros {
( $( $Ty: ident($Uint: ty) , $LeadingTestExpr:expr ;)+ ) => {
$(
impl $Ty {
/// Returns the number of leading zeros in the binary representation of `self`.
///
/// On many architectures, this function can perform better than `leading_zeros()` on the underlying integer type, as special handling of zero can be avoided.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = std::num::", stringify!($Ty), "::new(", stringify!($LeadingTestExpr), ").unwrap();")]
///
/// assert_eq!(n.leading_zeros(), 0);
/// ```
#[stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
#[rustc_const_stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn leading_zeros(self) -> u32 {
// SAFETY: since `self` cannot be zero, it is safe to call `ctlz_nonzero`.
unsafe { intrinsics::ctlz_nonzero(self.0 as $Uint) as u32 }
}
/// Returns the number of trailing zeros in the binary representation
/// of `self`.
///
/// On many architectures, this function can perform better than `trailing_zeros()` on the underlying integer type, as special handling of zero can be avoided.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let n = std::num::", stringify!($Ty), "::new(0b0101000).unwrap();")]
///
/// assert_eq!(n.trailing_zeros(), 3);
/// ```
#[stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
#[rustc_const_stable(feature = "nonzero_leading_trailing_zeros", since = "1.53.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn trailing_zeros(self) -> u32 {
// SAFETY: since `self` cannot be zero, it is safe to call `cttz_nonzero`.
unsafe { intrinsics::cttz_nonzero(self.0 as $Uint) as u32 }
}
}
)+
}
}
nonzero_leading_trailing_zeros! {
NonZeroU8(u8), u8::MAX;
NonZeroU16(u16), u16::MAX;
NonZeroU32(u32), u32::MAX;
NonZeroU64(u64), u64::MAX;
NonZeroU128(u128), u128::MAX;
NonZeroUsize(usize), usize::MAX;
NonZeroI8(u8), -1i8;
NonZeroI16(u16), -1i16;
NonZeroI32(u32), -1i32;
NonZeroI64(u64), -1i64;
NonZeroI128(u128), -1i128;
NonZeroIsize(usize), -1isize;
}
macro_rules! nonzero_integers_div {
( $( $Ty: ident($Int: ty); )+ ) => {
$(
#[stable(feature = "nonzero_div", since = "1.51.0")]
#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
impl const Div<$Ty> for $Int {
type Output = $Int;
/// This operation rounds towards zero,
/// truncating any fractional part of the exact result, and cannot panic.
#[inline]
fn div(self, other: $Ty) -> $Int {
// SAFETY: div by zero is checked because `other` is a nonzero,
// and MIN/-1 is checked because `self` is an unsigned int.
unsafe { crate::intrinsics::unchecked_div(self, other.get()) }
}
}
#[stable(feature = "nonzero_div", since = "1.51.0")]
#[rustc_const_unstable(feature = "const_ops", issue = "90080")]
impl const Rem<$Ty> for $Int {
type Output = $Int;
/// This operation satisfies `n % d == n - (n / d) * d`, and cannot panic.
#[inline]
fn rem(self, other: $Ty) -> $Int {
// SAFETY: rem by zero is checked because `other` is a nonzero,
// and MIN/-1 is checked because `self` is an unsigned int.
unsafe { crate::intrinsics::unchecked_rem(self, other.get()) }
}
}
)+
}
}
nonzero_integers_div! {
NonZeroU8(u8);
NonZeroU16(u16);
NonZeroU32(u32);
NonZeroU64(u64);
NonZeroU128(u128);
NonZeroUsize(usize);
}
// A bunch of methods for unsigned nonzero types only.
macro_rules! nonzero_unsigned_operations {
( $( $Ty: ident($Int: ident); )+ ) => {
$(
impl $Ty {
/// Adds an unsigned integer to a non-zero value.
/// Checks for overflow and returns [`None`] on overflow.
/// As a consequence, the result cannot wrap to zero.
///
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let one = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(Some(two), one.checked_add(1));
/// assert_eq!(None, max.checked_add(1));
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_add(self, other: $Int) -> Option<$Ty> {
if let Some(result) = self.get().checked_add(other) {
// SAFETY: $Int::checked_add returns None on overflow
// so the result cannot be zero.
Some(unsafe { $Ty::new_unchecked(result) })
} else {
None
}
}
/// Adds an unsigned integer to a non-zero value.
#[doc = concat!("Return [`", stringify!($Int), "::MAX`] on overflow.")]
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let one = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(two, one.saturating_add(1));
/// assert_eq!(max, max.saturating_add(1));
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn saturating_add(self, other: $Int) -> $Ty {
// SAFETY: $Int::saturating_add returns $Int::MAX on overflow
// so the result cannot be zero.
unsafe { $Ty::new_unchecked(self.get().saturating_add(other)) }
}
/// Adds an unsigned integer to a non-zero value,
/// assuming overflow cannot occur.
/// Overflow is unchecked, and it is undefined behaviour to overflow
/// *even if the result would wrap to a non-zero value*.
/// The behaviour is undefined as soon as
#[doc = concat!("`self + rhs > ", stringify!($Int), "::MAX`.")]
///
/// # Examples
///
/// ```
/// #![feature(nonzero_ops)]
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let one = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
///
/// assert_eq!(two, unsafe { one.unchecked_add(1) });
/// # Some(())
/// # }
/// ```
#[unstable(feature = "nonzero_ops", issue = "84186")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const unsafe fn unchecked_add(self, other: $Int) -> $Ty {
// SAFETY: The caller ensures there is no overflow.
unsafe { $Ty::new_unchecked(self.get().unchecked_add(other)) }
}
/// Returns the smallest power of two greater than or equal to n.
/// Checks for overflow and returns [`None`]
/// if the next power of two is greater than the type’s maximum value.
/// As a consequence, the result cannot wrap to zero.
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let three = ", stringify!($Ty), "::new(3)?;")]
#[doc = concat!("let four = ", stringify!($Ty), "::new(4)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(Some(two), two.checked_next_power_of_two() );
/// assert_eq!(Some(four), three.checked_next_power_of_two() );
/// assert_eq!(None, max.checked_next_power_of_two() );
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_next_power_of_two(self) -> Option<$Ty> {
if let Some(nz) = self.get().checked_next_power_of_two() {
// SAFETY: The next power of two is positive
// and overflow is checked.
Some(unsafe { $Ty::new_unchecked(nz) })
} else {
None
}
}
/// Returns the base 2 logarithm of the number, rounded down.
///
/// This is the same operation as
#[doc = concat!("[`", stringify!($Int), "::ilog2`],")]
/// except that it has no failure cases to worry about
/// since this value can never be zero.
///
/// # Examples
///
/// ```
/// #![feature(int_log)]
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
#[doc = concat!("assert_eq!(", stringify!($Ty), "::new(7).unwrap().ilog2(), 2);")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::new(8).unwrap().ilog2(), 3);")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::new(9).unwrap().ilog2(), 3);")]
/// ```
#[unstable(feature = "int_log", issue = "70887")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn ilog2(self) -> u32 {
Self::BITS - 1 - self.leading_zeros()
}
/// Returns the base 10 logarithm of the number, rounded down.
///
/// This is the same operation as
#[doc = concat!("[`", stringify!($Int), "::ilog10`],")]
/// except that it has no failure cases to worry about
/// since this value can never be zero.
///
/// # Examples
///
/// ```
/// #![feature(int_log)]
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
#[doc = concat!("assert_eq!(", stringify!($Ty), "::new(99).unwrap().ilog10(), 1);")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::new(100).unwrap().ilog10(), 2);")]
#[doc = concat!("assert_eq!(", stringify!($Ty), "::new(101).unwrap().ilog10(), 2);")]
/// ```
#[unstable(feature = "int_log", issue = "70887")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn ilog10(self) -> u32 {
super::int_log10::$Int(self.0)
}
}
)+
}
}
nonzero_unsigned_operations! {
NonZeroU8(u8);
NonZeroU16(u16);
NonZeroU32(u32);
NonZeroU64(u64);
NonZeroU128(u128);
NonZeroUsize(usize);
}
// A bunch of methods for signed nonzero types only.
macro_rules! nonzero_signed_operations {
( $( $Ty: ident($Int: ty) -> $Uty: ident($Uint: ty); )+ ) => {
$(
impl $Ty {
/// Computes the absolute value of self.
#[doc = concat!("See [`", stringify!($Int), "::abs`]")]
/// for documentation on overflow behaviour.
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let neg = ", stringify!($Ty), "::new(-1)?;")]
///
/// assert_eq!(pos, pos.abs());
/// assert_eq!(pos, neg.abs());
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn abs(self) -> $Ty {
// SAFETY: This cannot overflow to zero.
unsafe { $Ty::new_unchecked(self.get().abs()) }
}
/// Checked absolute value.
/// Checks for overflow and returns [`None`] if
#[doc = concat!("`self == ", stringify!($Int), "::MIN`.")]
/// The result cannot be zero.
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let neg = ", stringify!($Ty), "::new(-1)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
///
/// assert_eq!(Some(pos), neg.checked_abs());
/// assert_eq!(None, min.checked_abs());
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_abs(self) -> Option<$Ty> {
if let Some(nz) = self.get().checked_abs() {
// SAFETY: absolute value of nonzero cannot yield zero values.
Some(unsafe { $Ty::new_unchecked(nz) })
} else {
None
}
}
/// Computes the absolute value of self,
/// with overflow information, see
#[doc = concat!("[`", stringify!($Int), "::overflowing_abs`].")]
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let neg = ", stringify!($Ty), "::new(-1)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
///
/// assert_eq!((pos, false), pos.overflowing_abs());
/// assert_eq!((pos, false), neg.overflowing_abs());
/// assert_eq!((min, true), min.overflowing_abs());
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn overflowing_abs(self) -> ($Ty, bool) {
let (nz, flag) = self.get().overflowing_abs();
(
// SAFETY: absolute value of nonzero cannot yield zero values.
unsafe { $Ty::new_unchecked(nz) },
flag,
)
}
/// Saturating absolute value, see
#[doc = concat!("[`", stringify!($Int), "::saturating_abs`].")]
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let neg = ", stringify!($Ty), "::new(-1)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
#[doc = concat!("let min_plus = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN + 1)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(pos, pos.saturating_abs());
/// assert_eq!(pos, neg.saturating_abs());
/// assert_eq!(max, min.saturating_abs());
/// assert_eq!(max, min_plus.saturating_abs());
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn saturating_abs(self) -> $Ty {
// SAFETY: absolute value of nonzero cannot yield zero values.
unsafe { $Ty::new_unchecked(self.get().saturating_abs()) }
}
/// Wrapping absolute value, see
#[doc = concat!("[`", stringify!($Int), "::wrapping_abs`].")]
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let neg = ", stringify!($Ty), "::new(-1)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(pos, pos.wrapping_abs());
/// assert_eq!(pos, neg.wrapping_abs());
/// assert_eq!(min, min.wrapping_abs());
/// # // FIXME: add once Neg is implemented?
/// # // assert_eq!(max, (-max).wrapping_abs());
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn wrapping_abs(self) -> $Ty {
// SAFETY: absolute value of nonzero cannot yield zero values.
unsafe { $Ty::new_unchecked(self.get().wrapping_abs()) }
}
/// Computes the absolute value of self
/// without any wrapping or panicking.
///
/// # Example
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
#[doc = concat!("# use std::num::", stringify!($Uty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let u_pos = ", stringify!($Uty), "::new(1)?;")]
#[doc = concat!("let i_pos = ", stringify!($Ty), "::new(1)?;")]
#[doc = concat!("let i_neg = ", stringify!($Ty), "::new(-1)?;")]
#[doc = concat!("let i_min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
#[doc = concat!("let u_max = ", stringify!($Uty), "::new(",
stringify!($Uint), "::MAX / 2 + 1)?;")]
///
/// assert_eq!(u_pos, i_pos.unsigned_abs());
/// assert_eq!(u_pos, i_neg.unsigned_abs());
/// assert_eq!(u_max, i_min.unsigned_abs());
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn unsigned_abs(self) -> $Uty {
// SAFETY: absolute value of nonzero cannot yield zero values.
unsafe { $Uty::new_unchecked(self.get().unsigned_abs()) }
}
/// Returns `true` if `self` is negative and `false` if the
/// number is positive.
///
/// # Example
///
/// ```
/// #![feature(nonzero_negation_ops)]
///
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")]
#[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")]
///
/// assert!(neg_five.is_negative());
/// assert!(!pos_five.is_negative());
/// # Some(())
/// # }
/// ```
#[must_use]
#[inline]
#[unstable(feature = "nonzero_negation_ops", issue = "102443")]
pub const fn is_negative(self) -> bool {
self.get().is_negative()
}
/// Checked negation. Computes `-self`, returning `None` if `self == i32::MIN`.
///
/// # Example
///
/// ```
/// #![feature(nonzero_negation_ops)]
///
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")]
#[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
///
/// assert_eq!(pos_five.checked_neg(), Some(neg_five));
/// assert_eq!(min.checked_neg(), None);
/// # Some(())
/// # }
/// ```
#[inline]
#[unstable(feature = "nonzero_negation_ops", issue = "102443")]
pub const fn checked_neg(self) -> Option<$Ty> {
if let Some(result) = self.get().checked_neg() {
// SAFETY: negation of nonzero cannot yield zero values.
return Some(unsafe { $Ty::new_unchecked(result) });
}
None
}
/// Negates self, overflowing if this is equal to the minimum value.
///
#[doc = concat!("See [`", stringify!($Int), "::overflowing_neg`]")]
/// for documentation on overflow behaviour.
///
/// # Example
///
/// ```
/// #![feature(nonzero_negation_ops)]
///
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")]
#[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
///
/// assert_eq!(pos_five.overflowing_neg(), (neg_five, false));
/// assert_eq!(min.overflowing_neg(), (min, true));
/// # Some(())
/// # }
/// ```
#[inline]
#[unstable(feature = "nonzero_negation_ops", issue = "102443")]
pub const fn overflowing_neg(self) -> ($Ty, bool) {
let (result, overflow) = self.get().overflowing_neg();
// SAFETY: negation of nonzero cannot yield zero values.
((unsafe { $Ty::new_unchecked(result) }), overflow)
}
/// Saturating negation. Computes `-self`, returning `MAX` if
/// `self == i32::MIN` instead of overflowing.
///
/// # Example
///
/// ```
/// #![feature(nonzero_negation_ops)]
///
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")]
#[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
#[doc = concat!("let min_plus_one = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN + 1)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(pos_five.saturating_neg(), neg_five);
/// assert_eq!(min.saturating_neg(), max);
/// assert_eq!(max.saturating_neg(), min_plus_one);
/// # Some(())
/// # }
/// ```
#[inline]
#[unstable(feature = "nonzero_negation_ops", issue = "102443")]
pub const fn saturating_neg(self) -> $Ty {
if let Some(result) = self.checked_neg() {
return result;
}
$Ty::MAX
}
/// Wrapping (modular) negation. Computes `-self`, wrapping around at the boundary
/// of the type.
///
#[doc = concat!("See [`", stringify!($Int), "::wrapping_neg`]")]
/// for documentation on overflow behaviour.
///
/// # Example
///
/// ```
/// #![feature(nonzero_negation_ops)]
///
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let pos_five = ", stringify!($Ty), "::new(5)?;")]
#[doc = concat!("let neg_five = ", stringify!($Ty), "::new(-5)?;")]
#[doc = concat!("let min = ", stringify!($Ty), "::new(",
stringify!($Int), "::MIN)?;")]
///
/// assert_eq!(pos_five.wrapping_neg(), neg_five);
/// assert_eq!(min.wrapping_neg(), min);
/// # Some(())
/// # }
/// ```
#[inline]
#[unstable(feature = "nonzero_negation_ops", issue = "102443")]
pub const fn wrapping_neg(self) -> $Ty {
let result = self.get().wrapping_neg();
// SAFETY: negation of nonzero cannot yield zero values.
unsafe { $Ty::new_unchecked(result) }
}
}
)+
}
}
nonzero_signed_operations! {
NonZeroI8(i8) -> NonZeroU8(u8);
NonZeroI16(i16) -> NonZeroU16(u16);
NonZeroI32(i32) -> NonZeroU32(u32);
NonZeroI64(i64) -> NonZeroU64(u64);
NonZeroI128(i128) -> NonZeroU128(u128);
NonZeroIsize(isize) -> NonZeroUsize(usize);
}
// A bunch of methods for both signed and unsigned nonzero types.
macro_rules! nonzero_unsigned_signed_operations {
( $( $signedness:ident $Ty: ident($Int: ty); )+ ) => {
$(
impl $Ty {
/// Multiplies two non-zero integers together.
/// Checks for overflow and returns [`None`] on overflow.
/// As a consequence, the result cannot wrap to zero.
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let four = ", stringify!($Ty), "::new(4)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(Some(four), two.checked_mul(two));
/// assert_eq!(None, max.checked_mul(two));
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_mul(self, other: $Ty) -> Option<$Ty> {
if let Some(result) = self.get().checked_mul(other.get()) {
// SAFETY: checked_mul returns None on overflow
// and `other` is also non-null
// so the result cannot be zero.
Some(unsafe { $Ty::new_unchecked(result) })
} else {
None
}
}
/// Multiplies two non-zero integers together.
#[doc = concat!("Return [`", stringify!($Int), "::MAX`] on overflow.")]
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let four = ", stringify!($Ty), "::new(4)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(four, two.saturating_mul(two));
/// assert_eq!(max, four.saturating_mul(max));
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn saturating_mul(self, other: $Ty) -> $Ty {
// SAFETY: saturating_mul returns u*::MAX on overflow
// and `other` is also non-null
// so the result cannot be zero.
unsafe { $Ty::new_unchecked(self.get().saturating_mul(other.get())) }
}
/// Multiplies two non-zero integers together,
/// assuming overflow cannot occur.
/// Overflow is unchecked, and it is undefined behaviour to overflow
/// *even if the result would wrap to a non-zero value*.
/// The behaviour is undefined as soon as
#[doc = sign_dependent_expr!{
$signedness ?
if signed {
concat!("`self * rhs > ", stringify!($Int), "::MAX`, ",
"or `self * rhs < ", stringify!($Int), "::MIN`.")
}
if unsigned {
concat!("`self * rhs > ", stringify!($Int), "::MAX`.")
}
}]
///
/// # Examples
///
/// ```
/// #![feature(nonzero_ops)]
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let two = ", stringify!($Ty), "::new(2)?;")]
#[doc = concat!("let four = ", stringify!($Ty), "::new(4)?;")]
///
/// assert_eq!(four, unsafe { two.unchecked_mul(two) });
/// # Some(())
/// # }
/// ```
#[unstable(feature = "nonzero_ops", issue = "84186")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const unsafe fn unchecked_mul(self, other: $Ty) -> $Ty {
// SAFETY: The caller ensures there is no overflow.
unsafe { $Ty::new_unchecked(self.get().unchecked_mul(other.get())) }
}
/// Raises non-zero value to an integer power.
/// Checks for overflow and returns [`None`] on overflow.
/// As a consequence, the result cannot wrap to zero.
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let three = ", stringify!($Ty), "::new(3)?;")]
#[doc = concat!("let twenty_seven = ", stringify!($Ty), "::new(27)?;")]
#[doc = concat!("let half_max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX / 2)?;")]
///
/// assert_eq!(Some(twenty_seven), three.checked_pow(3));
/// assert_eq!(None, half_max.checked_pow(3));
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn checked_pow(self, other: u32) -> Option<$Ty> {
if let Some(result) = self.get().checked_pow(other) {
// SAFETY: checked_pow returns None on overflow
// so the result cannot be zero.
Some(unsafe { $Ty::new_unchecked(result) })
} else {
None
}
}
/// Raise non-zero value to an integer power.
#[doc = sign_dependent_expr!{
$signedness ?
if signed {
concat!("Return [`", stringify!($Int), "::MIN`] ",
"or [`", stringify!($Int), "::MAX`] on overflow.")
}
if unsigned {
concat!("Return [`", stringify!($Int), "::MAX`] on overflow.")
}
}]
///
/// # Examples
///
/// ```
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
/// # fn main() { test().unwrap(); }
/// # fn test() -> Option<()> {
#[doc = concat!("let three = ", stringify!($Ty), "::new(3)?;")]
#[doc = concat!("let twenty_seven = ", stringify!($Ty), "::new(27)?;")]
#[doc = concat!("let max = ", stringify!($Ty), "::new(",
stringify!($Int), "::MAX)?;")]
///
/// assert_eq!(twenty_seven, three.saturating_pow(3));
/// assert_eq!(max, max.saturating_pow(3));
/// # Some(())
/// # }
/// ```
#[stable(feature = "nonzero_checked_ops", since = "1.64.0")]
#[rustc_const_stable(feature = "const_nonzero_checked_ops", since = "1.64.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[inline]
pub const fn saturating_pow(self, other: u32) -> $Ty {
// SAFETY: saturating_pow returns u*::MAX on overflow
// so the result cannot be zero.
unsafe { $Ty::new_unchecked(self.get().saturating_pow(other)) }
}
}
)+
}
}
// Use this when the generated code should differ between signed and unsigned types.
macro_rules! sign_dependent_expr {
(signed ? if signed { $signed_case:expr } if unsigned { $unsigned_case:expr } ) => {
$signed_case
};
(unsigned ? if signed { $signed_case:expr } if unsigned { $unsigned_case:expr } ) => {
$unsigned_case
};
}
nonzero_unsigned_signed_operations! {
unsigned NonZeroU8(u8);
unsigned NonZeroU16(u16);
unsigned NonZeroU32(u32);
unsigned NonZeroU64(u64);
unsigned NonZeroU128(u128);
unsigned NonZeroUsize(usize);
signed NonZeroI8(i8);
signed NonZeroI16(i16);
signed NonZeroI32(i32);
signed NonZeroI64(i64);
signed NonZeroI128(i128);
signed NonZeroIsize(isize);
}
macro_rules! nonzero_unsigned_is_power_of_two {
( $( $Ty: ident )+ ) => {
$(
impl $Ty {
/// Returns `true` if and only if `self == (1 << k)` for some `k`.
///
/// On many architectures, this function can perform better than `is_power_of_two()`
/// on the underlying integer type, as special handling of zero can be avoided.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("let eight = std::num::", stringify!($Ty), "::new(8).unwrap();")]
/// assert!(eight.is_power_of_two());
#[doc = concat!("let ten = std::num::", stringify!($Ty), "::new(10).unwrap();")]
/// assert!(!ten.is_power_of_two());
/// ```
#[must_use]
#[stable(feature = "nonzero_is_power_of_two", since = "1.59.0")]
#[rustc_const_stable(feature = "nonzero_is_power_of_two", since = "1.59.0")]
#[inline]
pub const fn is_power_of_two(self) -> bool {
// LLVM 11 normalizes `unchecked_sub(x, 1) & x == 0` to the implementation seen here.
// On the basic x86-64 target, this saves 3 instructions for the zero check.
// On x86_64 with BMI1, being nonzero lets it codegen to `BLSR`, which saves an instruction
// compared to the `POPCNT` implementation on the underlying integer type.
intrinsics::ctpop(self.get()) < 2
}
}
)+
}
}
nonzero_unsigned_is_power_of_two! { NonZeroU8 NonZeroU16 NonZeroU32 NonZeroU64 NonZeroU128 NonZeroUsize }
macro_rules! nonzero_min_max_unsigned {
( $( $Ty: ident($Int: ident); )+ ) => {
$(
impl $Ty {
/// The smallest value that can be represented by this non-zero
/// integer type, 1.
///
/// # Examples
///
/// ```
/// #![feature(nonzero_min_max)]
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
#[doc = concat!("assert_eq!(", stringify!($Ty), "::MIN.get(), 1", stringify!($Int), ");")]
/// ```
#[unstable(feature = "nonzero_min_max", issue = "89065")]
pub const MIN: Self = Self::new(1).unwrap();
/// The largest value that can be represented by this non-zero
/// integer type,
#[doc = concat!("equal to [`", stringify!($Int), "::MAX`].")]
///
/// # Examples
///
/// ```
/// #![feature(nonzero_min_max)]
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
#[doc = concat!("assert_eq!(", stringify!($Ty), "::MAX.get(), ", stringify!($Int), "::MAX);")]
/// ```
#[unstable(feature = "nonzero_min_max", issue = "89065")]
pub const MAX: Self = Self::new(<$Int>::MAX).unwrap();
}
)+
}
}
macro_rules! nonzero_min_max_signed {
( $( $Ty: ident($Int: ident); )+ ) => {
$(
impl $Ty {
/// The smallest value that can be represented by this non-zero
/// integer type,
#[doc = concat!("equal to [`", stringify!($Int), "::MIN`].")]
///
/// Note: While most integer types are defined for every whole
/// number between `MIN` and `MAX`, signed non-zero integers are
/// a special case. They have a "gap" at 0.
///
/// # Examples
///
/// ```
/// #![feature(nonzero_min_max)]
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
#[doc = concat!("assert_eq!(", stringify!($Ty), "::MIN.get(), ", stringify!($Int), "::MIN);")]
/// ```
#[unstable(feature = "nonzero_min_max", issue = "89065")]
pub const MIN: Self = Self::new(<$Int>::MIN).unwrap();
/// The largest value that can be represented by this non-zero
/// integer type,
#[doc = concat!("equal to [`", stringify!($Int), "::MAX`].")]
///
/// Note: While most integer types are defined for every whole
/// number between `MIN` and `MAX`, signed non-zero integers are
/// a special case. They have a "gap" at 0.
///
/// # Examples
///
/// ```
/// #![feature(nonzero_min_max)]
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
#[doc = concat!("assert_eq!(", stringify!($Ty), "::MAX.get(), ", stringify!($Int), "::MAX);")]
/// ```
#[unstable(feature = "nonzero_min_max", issue = "89065")]
pub const MAX: Self = Self::new(<$Int>::MAX).unwrap();
}
)+
}
}
nonzero_min_max_unsigned! {
NonZeroU8(u8);
NonZeroU16(u16);
NonZeroU32(u32);
NonZeroU64(u64);
NonZeroU128(u128);
NonZeroUsize(usize);
}
nonzero_min_max_signed! {
NonZeroI8(i8);
NonZeroI16(i16);
NonZeroI32(i32);
NonZeroI64(i64);
NonZeroI128(i128);
NonZeroIsize(isize);
}
macro_rules! nonzero_bits {
( $( $Ty: ident($Int: ty); )+ ) => {
$(
impl $Ty {
/// The size of this non-zero integer type in bits.
///
#[doc = concat!("This value is equal to [`", stringify!($Int), "::BITS`].")]
///
/// # Examples
///
/// ```
/// #![feature(nonzero_bits)]
#[doc = concat!("# use std::num::", stringify!($Ty), ";")]
///
#[doc = concat!("assert_eq!(", stringify!($Ty), "::BITS, ", stringify!($Int), "::BITS);")]
/// ```
#[unstable(feature = "nonzero_bits", issue = "94881")]
pub const BITS: u32 = <$Int>::BITS;
}
)+
}
}
nonzero_bits! {
NonZeroU8(u8);
NonZeroI8(i8);
NonZeroU16(u16);
NonZeroI16(i16);
NonZeroU32(u32);
NonZeroI32(i32);
NonZeroU64(u64);
NonZeroI64(i64);
NonZeroU128(u128);
NonZeroI128(i128);
NonZeroUsize(usize);
NonZeroIsize(isize);
}