1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ART_RUNTIME_STRIDE_ITERATOR_H_ 18 #define ART_RUNTIME_STRIDE_ITERATOR_H_ 19 20 #include <iterator> 21 22 #include "base/logging.h" 23 24 namespace art { 25 26 template<typename T> 27 class StrideIterator : public std::iterator<std::forward_iterator_tag, T> { 28 public: 29 StrideIterator(const StrideIterator&) = default; 30 StrideIterator(StrideIterator&&) = default; 31 StrideIterator& operator=(const StrideIterator&) = default; 32 StrideIterator& operator=(StrideIterator&&) = default; 33 34 StrideIterator(T* ptr, size_t stride) 35 : ptr_(reinterpret_cast<uintptr_t>(ptr)), 36 stride_(stride) {} 37 38 bool operator==(const StrideIterator& other) const { 39 DCHECK_EQ(stride_, other.stride_); 40 return ptr_ == other.ptr_; 41 } 42 43 bool operator!=(const StrideIterator& other) const { 44 return !(*this == other); 45 } 46 47 StrideIterator operator++() { // Value after modification. 48 ptr_ += stride_; 49 return *this; 50 } 51 52 StrideIterator operator++(int) { 53 StrideIterator<T> temp = *this; 54 ptr_ += stride_; 55 return temp; 56 } 57 58 StrideIterator operator+(ssize_t delta) const { 59 StrideIterator<T> temp = *this; 60 temp += delta; 61 return temp; 62 } 63 64 StrideIterator& operator+=(ssize_t delta) { 65 ptr_ += static_cast<ssize_t>(stride_) * delta; 66 return *this; 67 } 68 69 T& operator*() const { 70 return *reinterpret_cast<T*>(ptr_); 71 } 72 73 T* operator->() const { 74 return &**this; 75 } 76 77 private: 78 uintptr_t ptr_; 79 // Not const for operator=. 80 size_t stride_; 81 }; 82 83 } // namespace art 84 85 #endif // ART_RUNTIME_STRIDE_ITERATOR_H_ 86
