1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
12 #![crate_name = "rustc_bitflags"]
13 #![feature(associated_consts)]
14 #![feature(staged_api)]
15 #![crate_type = "rlib"]
17 #![unstable(feature = "rustc_private", issue = "27812")]
20 //! A typesafe bitmask flag generator.
26 /// The `bitflags!` macro generates a `struct` that holds a set of C-style
27 /// bitmask flags. It is useful for creating typesafe wrappers for C APIs.
29 /// The flags should only be defined for integer types, otherwise unexpected
30 /// type errors may occur at compile time.
35 /// #![feature(rustc_private)]
36 /// #![feature(associated_consts)]
37 /// #[macro_use] extern crate rustc_bitflags;
40 /// flags Flags: u32 {
41 /// const FLAG_A = 0b00000001,
42 /// const FLAG_B = 0b00000010,
43 /// const FLAG_C = 0b00000100,
44 /// const FLAG_ABC = Flags::FLAG_A.bits
45 /// | Flags::FLAG_B.bits
46 /// | Flags::FLAG_C.bits,
51 /// let e1 = Flags::FLAG_A | Flags::FLAG_C;
52 /// let e2 = Flags::FLAG_B | Flags::FLAG_C;
53 /// assert!((e1 | e2) == Flags::FLAG_ABC); // union
54 /// assert!((e1 & e2) == Flags::FLAG_C); // intersection
55 /// assert!((e1 - e2) == Flags::FLAG_A); // set difference
56 /// assert!(!e2 == Flags::FLAG_A); // set complement
60 /// The generated `struct`s can also be extended with type and trait implementations:
63 /// #![feature(rustc_private)]
64 /// #[macro_use] extern crate rustc_bitflags;
69 /// flags Flags: u32 {
70 /// const FLAG_A = 0b00000001,
71 /// const FLAG_B = 0b00000010,
76 /// pub fn clear(&mut self) {
77 /// self.bits = 0; // The `bits` field can be accessed from within the
78 /// // same module where the `bitflags!` macro was invoked.
82 /// impl fmt::Debug for Flags {
83 /// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
89 /// let mut flags = Flags::FLAG_A | Flags::FLAG_B;
91 /// assert!(flags.is_empty());
92 /// assert_eq!(format!("{:?}", flags), "hi!");
98 /// Attributes can be attached to the generated `struct` by placing them
99 /// before the `flags` keyword.
103 /// The `PartialEq` and `Clone` traits are automatically derived for the `struct` using
104 /// the `deriving` attribute. Additional traits can be derived by providing an
105 /// explicit `deriving` attribute on `flags`.
109 /// The following operator traits are implemented for the generated `struct`:
112 /// - `BitAnd`: intersection
113 /// - `BitXor`: toggle
114 /// - `Sub`: set difference
115 /// - `Not`: set complement
119 /// The following methods are defined for the generated `struct`:
121 /// - `empty`: an empty set of flags
122 /// - `all`: the set of all flags
123 /// - `bits`: the raw value of the flags currently stored
124 /// - `from_bits`: convert from underlying bit representation, unless that
125 /// representation contains bits that do not correspond to a flag
126 /// - `from_bits_truncate`: convert from underlying bit representation, dropping
127 /// any bits that do not correspond to flags
128 /// - `is_empty`: `true` if no flags are currently stored
129 /// - `is_all`: `true` if all flags are currently set
130 /// - `intersects`: `true` if there are flags common to both `self` and `other`
131 /// - `contains`: `true` all of the flags in `other` are contained within `self`
132 /// - `insert`: inserts the specified flags in-place
133 /// - `remove`: removes the specified flags in-place
134 /// - `toggle`: the specified flags will be inserted if not present, and removed
137 macro_rules! bitflags {
138 ($(#[$attr:meta])* flags $BitFlags:ident: $T:ty {
139 $($(#[$Flag_attr:meta])* const $Flag:ident = $value:expr),+
141 #[derive(Copy, PartialEq, Eq, Clone, PartialOrd, Ord, Hash)]
143 pub struct $BitFlags {
148 $($(#[$Flag_attr])* pub const $Flag: $BitFlags = $BitFlags { bits: $value };)+
150 /// Returns an empty set of flags.
152 pub fn empty() -> $BitFlags {
153 $BitFlags { bits: 0 }
156 /// Returns the set containing all flags.
158 pub fn all() -> $BitFlags {
159 $BitFlags { bits: $($value)|+ }
162 /// Returns the raw value of the flags currently stored.
164 pub fn bits(&self) -> $T {
168 /// Convert from underlying bit representation, unless that
169 /// representation contains bits that do not correspond to a flag.
171 pub fn from_bits(bits: $T) -> ::std::option::Option<$BitFlags> {
172 if (bits & !$BitFlags::all().bits()) != 0 {
173 ::std::option::Option::None
175 ::std::option::Option::Some($BitFlags { bits: bits })
179 /// Convert from underlying bit representation, dropping any bits
180 /// that do not correspond to flags.
182 pub fn from_bits_truncate(bits: $T) -> $BitFlags {
183 $BitFlags { bits: bits } & $BitFlags::all()
186 /// Returns `true` if no flags are currently stored.
188 pub fn is_empty(&self) -> bool {
189 *self == $BitFlags::empty()
192 /// Returns `true` if all flags are currently set.
194 pub fn is_all(&self) -> bool {
195 *self == $BitFlags::all()
198 /// Returns `true` if there are flags common to both `self` and `other`.
200 pub fn intersects(&self, other: $BitFlags) -> bool {
201 !(*self & other).is_empty()
204 /// Returns `true` if all of the flags in `other` are contained within `self`.
206 pub fn contains(&self, other: $BitFlags) -> bool {
207 (*self & other) == other
210 /// Inserts the specified flags in-place.
212 pub fn insert(&mut self, other: $BitFlags) {
213 self.bits |= other.bits;
216 /// Removes the specified flags in-place.
218 pub fn remove(&mut self, other: $BitFlags) {
219 self.bits &= !other.bits;
222 /// Toggles the specified flags in-place.
224 pub fn toggle(&mut self, other: $BitFlags) {
225 self.bits ^= other.bits;
229 impl ::std::ops::BitOr for $BitFlags {
230 type Output = $BitFlags;
232 /// Returns the union of the two sets of flags.
234 fn bitor(self, other: $BitFlags) -> $BitFlags {
235 $BitFlags { bits: self.bits | other.bits }
239 impl ::std::ops::BitXor for $BitFlags {
240 type Output = $BitFlags;
242 /// Returns the left flags, but with all the right flags toggled.
244 fn bitxor(self, other: $BitFlags) -> $BitFlags {
245 $BitFlags { bits: self.bits ^ other.bits }
249 impl ::std::ops::BitAnd for $BitFlags {
250 type Output = $BitFlags;
252 /// Returns the intersection between the two sets of flags.
254 fn bitand(self, other: $BitFlags) -> $BitFlags {
255 $BitFlags { bits: self.bits & other.bits }
259 impl ::std::ops::Sub for $BitFlags {
260 type Output = $BitFlags;
262 /// Returns the set difference of the two sets of flags.
264 fn sub(self, other: $BitFlags) -> $BitFlags {
265 $BitFlags { bits: self.bits & !other.bits }
269 impl ::std::ops::Not for $BitFlags {
270 type Output = $BitFlags;
272 /// Returns the complement of this set of flags.
274 fn not(self) -> $BitFlags {
275 $BitFlags { bits: !self.bits } & $BitFlags::all()
279 ($(#[$attr:meta])* flags $BitFlags:ident: $T:ty {
280 $($(#[$Flag_attr:meta])* const $Flag:ident = $value:expr),+,
284 flags $BitFlags: $T {
285 $($(#[$Flag_attr])* const $Flag = $value),+
292 #[allow(non_upper_case_globals)]
294 use std::hash::{Hash, Hasher};
295 use std::collections::hash_map::DefaultHasher;
296 use std::option::Option::{None, Some};
299 #[doc = "> The first principle is that you must not fool yourself — and"]
300 #[doc = "> you are the easiest person to fool."]
302 #[doc = "> - Richard Feynman"]
304 const FlagA = 0b00000001,
305 #[doc = "<pcwalton> macros are way better at generating code than trans is"]
306 const FlagB = 0b00000010,
307 const FlagC = 0b00000100,
309 #[doc = "* strcat table"]
310 #[doc = "<strcat> wait what?"]
311 const FlagABC = Flags::FlagA.bits
318 flags AnotherSetOfFlags: i8 {
319 const AnotherFlag = -1,
325 assert_eq!(Flags::empty().bits(), 0b00000000);
326 assert_eq!(Flags::FlagA.bits(), 0b00000001);
327 assert_eq!(Flags::FlagABC.bits(), 0b00000111);
329 assert_eq!(AnotherSetOfFlags::empty().bits(), 0b00);
330 assert_eq!(AnotherSetOfFlags::AnotherFlag.bits(), !0);
334 fn test_from_bits() {
335 assert!(Flags::from_bits(0) == Some(Flags::empty()));
336 assert!(Flags::from_bits(0b1) == Some(Flags::FlagA));
337 assert!(Flags::from_bits(0b10) == Some(Flags::FlagB));
338 assert!(Flags::from_bits(0b11) == Some(Flags::FlagA | Flags::FlagB));
339 assert!(Flags::from_bits(0b1000) == None);
341 assert!(AnotherSetOfFlags::from_bits(!0) == Some(AnotherSetOfFlags::AnotherFlag));
345 fn test_from_bits_truncate() {
346 assert!(Flags::from_bits_truncate(0) == Flags::empty());
347 assert!(Flags::from_bits_truncate(0b1) == Flags::FlagA);
348 assert!(Flags::from_bits_truncate(0b10) == Flags::FlagB);
349 assert!(Flags::from_bits_truncate(0b11) == (Flags::FlagA | Flags::FlagB));
350 assert!(Flags::from_bits_truncate(0b1000) == Flags::empty());
351 assert!(Flags::from_bits_truncate(0b1001) == Flags::FlagA);
353 assert!(AnotherSetOfFlags::from_bits_truncate(0) == AnotherSetOfFlags::empty());
358 assert!(Flags::empty().is_empty());
359 assert!(!Flags::FlagA.is_empty());
360 assert!(!Flags::FlagABC.is_empty());
362 assert!(!AnotherSetOfFlags::AnotherFlag.is_empty());
367 assert!(Flags::all().is_all());
368 assert!(!Flags::FlagA.is_all());
369 assert!(Flags::FlagABC.is_all());
371 assert!(AnotherSetOfFlags::AnotherFlag.is_all());
375 fn test_two_empties_do_not_intersect() {
376 let e1 = Flags::empty();
377 let e2 = Flags::empty();
378 assert!(!e1.intersects(e2));
380 assert!(AnotherSetOfFlags::AnotherFlag.intersects(AnotherSetOfFlags::AnotherFlag));
384 fn test_empty_does_not_intersect_with_full() {
385 let e1 = Flags::empty();
386 let e2 = Flags::FlagABC;
387 assert!(!e1.intersects(e2));
391 fn test_disjoint_intersects() {
392 let e1 = Flags::FlagA;
393 let e2 = Flags::FlagB;
394 assert!(!e1.intersects(e2));
398 fn test_overlapping_intersects() {
399 let e1 = Flags::FlagA;
400 let e2 = Flags::FlagA | Flags::FlagB;
401 assert!(e1.intersects(e2));
406 let e1 = Flags::FlagA;
407 let e2 = Flags::FlagA | Flags::FlagB;
408 assert!(!e1.contains(e2));
409 assert!(e2.contains(e1));
410 assert!(Flags::FlagABC.contains(e2));
412 assert!(AnotherSetOfFlags::AnotherFlag.contains(AnotherSetOfFlags::AnotherFlag));
417 let mut e1 = Flags::FlagA;
418 let e2 = Flags::FlagA | Flags::FlagB;
422 let mut e3 = AnotherSetOfFlags::empty();
423 e3.insert(AnotherSetOfFlags::AnotherFlag);
424 assert!(e3 == AnotherSetOfFlags::AnotherFlag);
429 let mut e1 = Flags::FlagA | Flags::FlagB;
430 let e2 = Flags::FlagA | Flags::FlagC;
432 assert!(e1 == Flags::FlagB);
434 let mut e3 = AnotherSetOfFlags::AnotherFlag;
435 e3.remove(AnotherSetOfFlags::AnotherFlag);
436 assert!(e3 == AnotherSetOfFlags::empty());
440 fn test_operators() {
441 let e1 = Flags::FlagA | Flags::FlagC;
442 let e2 = Flags::FlagB | Flags::FlagC;
443 assert!((e1 | e2) == Flags::FlagABC); // union
444 assert!((e1 & e2) == Flags::FlagC); // intersection
445 assert!((e1 - e2) == Flags::FlagA); // set difference
446 assert!(!e2 == Flags::FlagA); // set complement
447 assert!(e1 ^ e2 == Flags::FlagA | Flags::FlagB); // toggle
450 assert!(e3 == Flags::FlagA | Flags::FlagB);
452 let mut m4 = AnotherSetOfFlags::empty();
453 m4.toggle(AnotherSetOfFlags::empty());
454 assert!(m4 == AnotherSetOfFlags::empty());
459 let mut a = Flags::empty();
460 let mut b = Flags::empty();
462 assert!(!(a < b) && !(b < a));
466 assert!(!(a < b) && b < a);
467 b = Flags::FlagC | Flags::FlagB;
473 let mut a = Flags::empty();
474 let mut b = Flags::empty();
476 assert!(a <= b && a >= b);
478 assert!(a > b && a >= b);
479 assert!(b < a && b <= a);
481 assert!(b > a && b >= a);
482 assert!(a < b && a <= b);
487 let mut x = Flags::empty();
488 let mut y = Flags::empty();
489 assert!(hash(&x) == hash(&y));
492 assert!(hash(&x) == hash(&y));
495 fn hash<T: Hash>(t: &T) -> u64 {
496 let mut s = DefaultHasher::new();