1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/mfbt/EnumSet.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,177 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim: set ts=8 sts=2 et sw=2 tw=80: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +/* A set abstraction for enumeration values. */
1.11 +
1.12 +#ifndef mozilla_EnumSet_h
1.13 +#define mozilla_EnumSet_h
1.14 +
1.15 +#include "mozilla/Assertions.h"
1.16 +
1.17 +#include <stdint.h>
1.18 +
1.19 +namespace mozilla {
1.20 +
1.21 +/**
1.22 + * EnumSet<T> is a set of values defined by an enumeration. It is implemented
1.23 + * using a 32 bit mask for each value so it will only work for enums with an int
1.24 + * representation less than 32. It works both for enum and enum class types.
1.25 + */
1.26 +template<typename T>
1.27 +class EnumSet
1.28 +{
1.29 + public:
1.30 + EnumSet()
1.31 + : mBitField(0)
1.32 + { }
1.33 +
1.34 + EnumSet(T aEnum)
1.35 + : mBitField(aEnum)
1.36 + { }
1.37 +
1.38 + EnumSet(T aEnum1, T aEnum2)
1.39 + : mBitField(bitFor(aEnum1) |
1.40 + bitFor(aEnum2))
1.41 + { }
1.42 +
1.43 + EnumSet(T aEnum1, T aEnum2, T aEnum3)
1.44 + : mBitField(bitFor(aEnum1) |
1.45 + bitFor(aEnum2) |
1.46 + bitFor(aEnum3))
1.47 + { }
1.48 +
1.49 + EnumSet(T aEnum1, T aEnum2, T aEnum3, T aEnum4)
1.50 + : mBitField(bitFor(aEnum1) |
1.51 + bitFor(aEnum2) |
1.52 + bitFor(aEnum3) |
1.53 + bitFor(aEnum4))
1.54 + { }
1.55 +
1.56 + EnumSet(const EnumSet& aEnumSet)
1.57 + : mBitField(aEnumSet.mBitField)
1.58 + { }
1.59 +
1.60 + /**
1.61 + * Add an element
1.62 + */
1.63 + void operator+=(T aEnum) {
1.64 + mBitField |= bitFor(aEnum);
1.65 + }
1.66 +
1.67 + /**
1.68 + * Add an element
1.69 + */
1.70 + EnumSet<T> operator+(T aEnum) const {
1.71 + EnumSet<T> result(*this);
1.72 + result += aEnum;
1.73 + return result;
1.74 + }
1.75 +
1.76 + /**
1.77 + * Union
1.78 + */
1.79 + void operator+=(const EnumSet<T> aEnumSet) {
1.80 + mBitField |= aEnumSet.mBitField;
1.81 + }
1.82 +
1.83 + /**
1.84 + * Union
1.85 + */
1.86 + EnumSet<T> operator+(const EnumSet<T> aEnumSet) const {
1.87 + EnumSet<T> result(*this);
1.88 + result += aEnumSet;
1.89 + return result;
1.90 + }
1.91 +
1.92 + /**
1.93 + * Remove an element
1.94 + */
1.95 + void operator-=(T aEnum) {
1.96 + mBitField &= ~(bitFor(aEnum));
1.97 + }
1.98 +
1.99 + /**
1.100 + * Remove an element
1.101 + */
1.102 + EnumSet<T> operator-(T aEnum) const {
1.103 + EnumSet<T> result(*this);
1.104 + result -= aEnum;
1.105 + return result;
1.106 + }
1.107 +
1.108 + /**
1.109 + * Remove a set of elements
1.110 + */
1.111 + void operator-=(const EnumSet<T> aEnumSet) {
1.112 + mBitField &= ~(aEnumSet.mBitField);
1.113 + }
1.114 +
1.115 + /**
1.116 + * Remove a set of elements
1.117 + */
1.118 + EnumSet<T> operator-(const EnumSet<T> aEnumSet) const {
1.119 + EnumSet<T> result(*this);
1.120 + result -= aEnumSet;
1.121 + return result;
1.122 + }
1.123 +
1.124 + /**
1.125 + * Intersection
1.126 + */
1.127 + void operator&=(const EnumSet<T> aEnumSet) {
1.128 + mBitField &= aEnumSet.mBitField;
1.129 + }
1.130 +
1.131 + /**
1.132 + * Intersection
1.133 + */
1.134 + EnumSet<T> operator&(const EnumSet<T> aEnumSet) const {
1.135 + EnumSet<T> result(*this);
1.136 + result &= aEnumSet;
1.137 + return result;
1.138 + }
1.139 +
1.140 + /**
1.141 + * Equality
1.142 + */
1.143 +
1.144 + bool operator==(const EnumSet<T> aEnumSet) const {
1.145 + return mBitField == aEnumSet.mBitField;
1.146 + }
1.147 +
1.148 + /**
1.149 + * Test is an element is contained in the set
1.150 + */
1.151 + bool contains(T aEnum) const {
1.152 + return mBitField & bitFor(aEnum);
1.153 + }
1.154 +
1.155 + /**
1.156 + * Return the number of elements in the set
1.157 + */
1.158 +
1.159 + uint8_t size() {
1.160 + uint8_t count = 0;
1.161 + for (uint32_t bitField = mBitField; bitField; bitField >>= 1) {
1.162 + if (bitField & 1)
1.163 + count++;
1.164 + }
1.165 + return count;
1.166 + }
1.167 +
1.168 + private:
1.169 + static uint32_t bitFor(T aEnum) {
1.170 + uint32_t bitNumber(aEnum);
1.171 + MOZ_ASSERT(bitNumber < 32);
1.172 + return 1U << bitNumber;
1.173 + }
1.174 +
1.175 + uint32_t mBitField;
1.176 +};
1.177 +
1.178 +} // namespace mozilla
1.179 +
1.180 +#endif /* mozilla_EnumSet_h_*/
