/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* vim: set ts=8 sts=2 et sw=2 tw=80: */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ /* Iterator over ranges of integers */ #ifndef mozilla_IntegerRange_h #define mozilla_IntegerRange_h #include "mozilla/Assertions.h" #include "mozilla/ReverseIterator.h" #include "mozilla/TypeTraits.h" namespace mozilla { namespace detail { template<typename IntTypeT> class IntegerIterator { public: template<typename IntType> explicit IntegerIterator(IntType aCurrent) : mCurrent(aCurrent) { } template<typename IntType> explicit IntegerIterator(const IntegerIterator<IntType>& aOther) : mCurrent(aOther.mCurrent) { } IntTypeT operator*() const { return mCurrent; } /* Increment and decrement operators */ IntegerIterator& operator++() { ++mCurrent; return *this; } IntegerIterator& operator--() { --mCurrent; return *this; } IntegerIterator operator++(int) { auto ret = *this; ++mCurrent; return ret; } IntegerIterator operator--(int) { auto ret = *this; --mCurrent; return ret; } /* Comparison operators */ template<typename IntType1, typename IntType2> friend bool operator==(const IntegerIterator<IntType1>& aIter1, const IntegerIterator<IntType2>& aIter2); template<typename IntType1, typename IntType2> friend bool operator!=(const IntegerIterator<IntType1>& aIter1, const IntegerIterator<IntType2>& aIter2); template<typename IntType1, typename IntType2> friend bool operator<(const IntegerIterator<IntType1>& aIter1, const IntegerIterator<IntType2>& aIter2); template<typename IntType1, typename IntType2> friend bool operator<=(const IntegerIterator<IntType1>& aIter1, const IntegerIterator<IntType2>& aIter2); template<typename IntType1, typename IntType2> friend bool operator>(const IntegerIterator<IntType1>& aIter1, const IntegerIterator<IntType2>& aIter2); template<typename IntType1, typename IntType2> friend bool operator>=(const IntegerIterator<IntType1>& aIter1, const IntegerIterator<IntType2>& aIter2); private: IntTypeT mCurrent; }; template<typename IntType1, typename IntType2> bool operator==(const IntegerIterator<IntType1>& aIter1, const IntegerIterator<IntType2>& aIter2) { return aIter1.mCurrent == aIter2.mCurrent; } template<typename IntType1, typename IntType2> bool operator!=(const IntegerIterator<IntType1>& aIter1, const IntegerIterator<IntType2>& aIter2) { return aIter1.mCurrent != aIter2.mCurrent; } template<typename IntType1, typename IntType2> bool operator<(const IntegerIterator<IntType1>& aIter1, const IntegerIterator<IntType2>& aIter2) { return aIter1.mCurrent < aIter2.mCurrent; } template<typename IntType1, typename IntType2> bool operator<=(const IntegerIterator<IntType1>& aIter1, const IntegerIterator<IntType2>& aIter2) { return aIter1.mCurrent <= aIter2.mCurrent; } template<typename IntType1, typename IntType2> bool operator>(const IntegerIterator<IntType1>& aIter1, const IntegerIterator<IntType2>& aIter2) { return aIter1.mCurrent > aIter2.mCurrent; } template<typename IntType1, typename IntType2> bool operator>=(const IntegerIterator<IntType1>& aIter1, const IntegerIterator<IntType2>& aIter2) { return aIter1.mCurrent >= aIter2.mCurrent; } template<typename IntTypeT> class IntegerRange { public: typedef IntegerIterator<IntTypeT> iterator; typedef IntegerIterator<IntTypeT> const_iterator; typedef ReverseIterator<IntegerIterator<IntTypeT>> reverse_iterator; typedef ReverseIterator<IntegerIterator<IntTypeT>> const_reverse_iterator; template<typename IntType> explicit IntegerRange(IntType aEnd) : mBegin(0), mEnd(aEnd) { } template<typename IntType1, typename IntType2> IntegerRange(IntType1 aBegin, IntType2 aEnd) : mBegin(aBegin), mEnd(aEnd) { } iterator begin() const { return iterator(mBegin); } const_iterator cbegin() const { return begin(); } iterator end() const { return iterator(mEnd); } const_iterator cend() const { return end(); } reverse_iterator rbegin() const { return reverse_iterator(mEnd); } const_reverse_iterator crbegin() const { return rbegin(); } reverse_iterator rend() const { return reverse_iterator(mBegin); } const_reverse_iterator crend() const { return rend(); } private: IntTypeT mBegin; IntTypeT mEnd; }; template<typename T, bool = IsUnsigned<T>::value> struct GeqZero { static bool check(T t) { return t >= 0; } }; template<typename T> struct GeqZero<T, true> { static bool check(T t) { return true; } }; } // namespace detail template<typename IntType> detail::IntegerRange<IntType> MakeRange(IntType aEnd) { static_assert(IsIntegral<IntType>::value, "value must be integral"); MOZ_ASSERT(detail::GeqZero<IntType>::check(aEnd), "Should never have negative value here"); return detail::IntegerRange<IntType>(aEnd); } template<typename IntType1, typename IntType2> detail::IntegerRange<IntType2> MakeRange(IntType1 aBegin, IntType2 aEnd) { static_assert(IsIntegral<IntType1>::value && IsIntegral<IntType2>::value, "values must both be integral"); static_assert(IsSigned<IntType1>::value == IsSigned<IntType2>::value, "signed/unsigned mismatch"); MOZ_ASSERT(aEnd >= aBegin, "End value should be larger than begin value"); return detail::IntegerRange<IntType2>(aBegin, aEnd); } } // namespace mozilla #endif // mozilla_IntegerRange_h