1//===- iterator_range.h - A range adaptor for iterators ---------*- C++ -*-===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8/// \file 9/// This provides a very simple, boring adaptor for a begin and end iterator 10/// into a range type. This should be used to build range views that work well 11/// with range based for loops and range based constructors. 12/// 13/// Note that code here follows more standards-based coding conventions as it 14/// is mirroring proposed interfaces for standardization. 15/// 16//===----------------------------------------------------------------------===// 17 18#ifndef LLVM_ADT_ITERATOR_RANGE_H 19#define LLVM_ADT_ITERATOR_RANGE_H 20 21#include <iterator> 22#include <utility> 23 24namespace llvm { 25 26/// A range adaptor for a pair of iterators. 27/// 28/// This just wraps two iterators into a range-compatible interface. Nothing 29/// fancy at all. 30template <typename IteratorT> 31class iterator_range { 32 IteratorT begin_iterator, end_iterator; 33 34public: 35 //TODO: Add SFINAE to test that the Container's iterators match the range's 36 // iterators. 37 template <typename Container> 38 iterator_range(Container &&c) 39 //TODO: Consider ADL/non-member begin/end calls. 40 : begin_iterator(c.begin()), end_iterator(c.end()) {} 41 iterator_range(IteratorT begin_iterator, IteratorT end_iterator) 42 : begin_iterator(std::move(begin_iterator)), 43 end_iterator(std::move(end_iterator)) {} 44 45 IteratorT begin() const { return begin_iterator; } 46 IteratorT end() const { return end_iterator; } 47 bool empty() const { return begin_iterator == end_iterator; } 48}; 49 50/// Convenience function for iterating over sub-ranges. 51/// 52/// This provides a bit of syntactic sugar to make using sub-ranges 53/// in for loops a bit easier. Analogous to std::make_pair(). 54template <class T> iterator_range<T> make_range(T x, T y) { 55 return iterator_range<T>(std::move(x), std::move(y)); 56} 57 58template <typename T> iterator_range<T> make_range(std::pair<T, T> p) { 59 return iterator_range<T>(std::move(p.first), std::move(p.second)); 60} 61 62} 63 64#endif 65