| // Copyright 2019 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_BASE_ENUM_SET_H_ |
| #define V8_BASE_ENUM_SET_H_ |
| |
| #include <type_traits> |
| |
| #include "src/base/logging.h" |
| |
| namespace v8 { |
| namespace base { |
| |
| // A poor man's version of STL's bitset: A bit set of enums E (without explicit |
| // values), fitting into an integral type T. |
| template <class E, class T = int> |
| class EnumSet { |
| static_assert(std::is_enum<E>::value, "EnumSet can only be used with enums"); |
| |
| public: |
| constexpr EnumSet() = default; |
| |
| EnumSet(std::initializer_list<E> init) { |
| for (E e : init) Add(e); |
| } |
| |
| bool empty() const { return bits_ == 0; } |
| bool contains(E element) const { return (bits_ & Mask(element)) != 0; } |
| bool contains_any(const EnumSet& set) const { |
| return (bits_ & set.bits_) != 0; |
| } |
| void Add(E element) { bits_ |= Mask(element); } |
| void Add(const EnumSet& set) { bits_ |= set.bits_; } |
| void Remove(E element) { bits_ &= ~Mask(element); } |
| void Remove(const EnumSet& set) { bits_ &= ~set.bits_; } |
| void RemoveAll() { bits_ = 0; } |
| void Intersect(const EnumSet& set) { bits_ &= set.bits_; } |
| T ToIntegral() const { return bits_; } |
| bool operator==(const EnumSet& set) const { return bits_ == set.bits_; } |
| bool operator!=(const EnumSet& set) const { return bits_ != set.bits_; } |
| EnumSet operator|(const EnumSet& set) const { |
| return EnumSet(bits_ | set.bits_); |
| } |
| EnumSet operator&(const EnumSet& set) const { |
| return EnumSet(bits_ & set.bits_); |
| } |
| |
| static constexpr EnumSet FromIntegral(T bits) { return EnumSet{bits}; } |
| |
| private: |
| explicit constexpr EnumSet(T bits) : bits_(bits) {} |
| |
| static T Mask(E element) { |
| DCHECK_GT(sizeof(T) * 8, static_cast<int>(element)); |
| return T{1} << static_cast<typename std::underlying_type<E>::type>(element); |
| } |
| |
| T bits_ = 0; |
| }; |
| |
| } // namespace base |
| } // namespace v8 |
| |
| #endif // V8_BASE_ENUM_SET_H_ |