1 //===- iterator_range.h - A range adaptor for iterators ---------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
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.
13 /// Note that code here follows more standards-based coding conventions as it
14 /// is mirroring proposed interfaces for standardization.
16 //===----------------------------------------------------------------------===//
18 #ifndef LLVM_ADT_ITERATOR_RANGE_H
19 #define LLVM_ADT_ITERATOR_RANGE_H
26 /// A range adaptor for a pair of iterators.
28 /// This just wraps two iterators into a range-compatible interface. Nothing
30 template <typename IteratorT>
31 class iterator_range {
32 IteratorT begin_iterator, end_iterator;
35 //TODO: Add SFINAE to test that the Container's iterators match the range's
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)) {}
45 IteratorT begin() const { return begin_iterator; }
46 IteratorT end() const { return end_iterator; }
47 bool empty() const { return begin_iterator == end_iterator; }
50 /// Convenience function for iterating over sub-ranges.
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().
54 template <class T> iterator_range<T> make_range(T x, T y) {
55 return iterator_range<T>(std::move(x), std::move(y));
58 template <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));