iterator_range.h revision 341825
1274955Ssvnmir//===- iterator_range.h - A range adaptor for iterators ---------*- C++ -*-===// 2274955Ssvnmir// 3274955Ssvnmir// The LLVM Compiler Infrastructure 4274955Ssvnmir// 5274955Ssvnmir// This file is distributed under the University of Illinois Open Source 6274955Ssvnmir// License. See LICENSE.TXT for details. 7274955Ssvnmir// 8274955Ssvnmir//===----------------------------------------------------------------------===// 9274955Ssvnmir/// \file 10274955Ssvnmir/// This provides a very simple, boring adaptor for a begin and end iterator 11274955Ssvnmir/// into a range type. This should be used to build range views that work well 12274955Ssvnmir/// with range based for loops and range based constructors. 13274955Ssvnmir/// 14274955Ssvnmir/// Note that code here follows more standards-based coding conventions as it 15274955Ssvnmir/// is mirroring proposed interfaces for standardization. 16274955Ssvnmir/// 17274955Ssvnmir//===----------------------------------------------------------------------===// 18274955Ssvnmir 19274955Ssvnmir#ifndef LLVM_ADT_ITERATOR_RANGE_H 20274955Ssvnmir#define LLVM_ADT_ITERATOR_RANGE_H 21274955Ssvnmir 22321369Sdim#include <iterator> 23274955Ssvnmir#include <utility> 24274955Ssvnmir 25274955Ssvnmirnamespace llvm { 26274955Ssvnmir 27341825Sdim/// A range adaptor for a pair of iterators. 28274955Ssvnmir/// 29274955Ssvnmir/// This just wraps two iterators into a range-compatible interface. Nothing 30274955Ssvnmir/// fancy at all. 31274955Ssvnmirtemplate <typename IteratorT> 32274955Ssvnmirclass iterator_range { 33274955Ssvnmir IteratorT begin_iterator, end_iterator; 34274955Ssvnmir 35274955Ssvnmirpublic: 36296417Sdim //TODO: Add SFINAE to test that the Container's iterators match the range's 37296417Sdim // iterators. 38296417Sdim template <typename Container> 39296417Sdim iterator_range(Container &&c) 40296417Sdim //TODO: Consider ADL/non-member begin/end calls. 41296417Sdim : begin_iterator(c.begin()), end_iterator(c.end()) {} 42274955Ssvnmir iterator_range(IteratorT begin_iterator, IteratorT end_iterator) 43274955Ssvnmir : begin_iterator(std::move(begin_iterator)), 44274955Ssvnmir end_iterator(std::move(end_iterator)) {} 45274955Ssvnmir 46274955Ssvnmir IteratorT begin() const { return begin_iterator; } 47274955Ssvnmir IteratorT end() const { return end_iterator; } 48274955Ssvnmir}; 49274955Ssvnmir 50341825Sdim/// Convenience function for iterating over sub-ranges. 51274955Ssvnmir/// 52274955Ssvnmir/// This provides a bit of syntactic sugar to make using sub-ranges 53274955Ssvnmir/// in for loops a bit easier. Analogous to std::make_pair(). 54274955Ssvnmirtemplate <class T> iterator_range<T> make_range(T x, T y) { 55274955Ssvnmir return iterator_range<T>(std::move(x), std::move(y)); 56274955Ssvnmir} 57280031Sdim 58280031Sdimtemplate <typename T> iterator_range<T> make_range(std::pair<T, T> p) { 59280031Sdim return iterator_range<T>(std::move(p.first), std::move(p.second)); 60274955Ssvnmir} 61296417Sdim 62341825Sdimtemplate <typename T> 63341825Sdimiterator_range<decltype(adl_begin(std::declval<T>()))> drop_begin(T &&t, 64341825Sdim int n) { 65341825Sdim return make_range(std::next(adl_begin(t), n), adl_end(t)); 66280031Sdim} 67296417Sdim} 68274955Ssvnmir 69274955Ssvnmir#endif 70