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iterator_range.h
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1 //===- iterator_range.h - A range adaptor for iterators ---------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 /// \file
10 /// This provides a very simple, boring adaptor for a begin and end iterator
11 /// into a range type. This should be used to build range views that work well
12 /// with range based for loops and range based constructors.
13 ///
14 /// Note that code here follows more standards-based coding conventions as it
15 /// is mirroring proposed interfaces for standardization.
16 ///
17 //===----------------------------------------------------------------------===//
18 
19 #ifndef LLVM_ADT_ITERATOR_RANGE_H
20 #define LLVM_ADT_ITERATOR_RANGE_H
21 
22 #include <iterator>
23 #include <utility>
24 
25 namespace llvm {
26 
27 /// \brief A range adaptor for a pair of iterators.
28 ///
29 /// This just wraps two iterators into a range-compatible interface. Nothing
30 /// fancy at all.
31 template <typename IteratorT>
33  IteratorT begin_iterator, end_iterator;
34 
35 public:
36  //TODO: Add SFINAE to test that the Container's iterators match the range's
37  // iterators.
38  template <typename Container>
39  iterator_range(Container &&c)
40  //TODO: Consider ADL/non-member begin/end calls.
41  : begin_iterator(c.begin()), end_iterator(c.end()) {}
42  iterator_range(IteratorT begin_iterator, IteratorT end_iterator)
43  : begin_iterator(std::move(begin_iterator)),
44  end_iterator(std::move(end_iterator)) {}
45 
46  IteratorT begin() const { return begin_iterator; }
47  IteratorT end() const { return end_iterator; }
48 };
49 
50 /// \brief 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().
54 template <class T> iterator_range<T> make_range(T x, T y) {
55  return iterator_range<T>(std::move(x), std::move(y));
56 }
57 
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));
60 }
61 
62 template<typename T>
64  return make_range(std::next(begin(t), n), end(t));
65 }
66 }
67 
68 #endif
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
Definition: BitVector.h:920
iterator_range< T > make_range(T x, T y)
Convenience function for iterating over sub-ranges.
iterator_range(Container &&c)
A range adaptor for a pair of iterators.
iterator_range(IteratorT begin_iterator, IteratorT end_iterator)
IteratorT begin() const
iterator_range< decltype(begin(std::declval< T >)))> drop_begin(T &&t, int n)
IteratorT end() const