SetVector.h revision 0bdc620c16963908d74db498f79676e558f09e82 
1//===- llvm/ADT/SetVector.h - Set with insert order iteration ---*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by Reid Spencer and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements a set that has insertion order iteration
11// characteristics. This is useful for keeping a set of things that need to be
12// visited later but in a deterministic order (insertion order). The interface
13// is purposefully minimal.
14//
15//===----------------------------------------------------------------------===//
16
17#ifndef LLVM_ADT_SETVECTOR_H
18#define LLVM_ADT_SETVECTOR_H
19
20#include <set>
21#include <vector>
22#include <cassert>
23#include <algorithm>
24
25namespace llvm {
26
27/// This class provides a way to keep a set of things that also has the
28/// property of a deterministic iteration order. The order of iteration is the
29/// order of insertion.
30/// @brief A vector that has set insertion semantics.
31template <typename T>
32class SetVector {
33public:
34  typedef T value_type;
35  typedef T key_type;
36  typedef T& reference;
37  typedef const T& const_reference;
38  typedef std::set<value_type> set_type;
39  typedef std::vector<value_type> vector_type;
40  typedef typename vector_type::iterator iterator;
41  typedef typename vector_type::const_iterator const_iterator;
42  typedef typename vector_type::size_type size_type;
43
44  /// @brief Construct an empty SetVector
45  SetVector() {}
46
47  /// @brief Initialize a SetVector with a range of elements
48  template<typename It>
49  SetVector(It Start, It End) {
50    insert(Start, End);
51  }
52
53  /// @brief Determine if the SetVector is empty or not.
54  bool empty() const {
55    return vector_.empty();
56  }
57
58  /// @brief Determine the number of elements in the SetVector.
59  size_type size() const {
60    return vector_.size();
61  }
62
63  /// @brief Get an iterator to the beginning of the SetVector.
64  iterator begin() {
65    return vector_.begin();
66  }
67
68  /// @brief Get a const_iterator to the beginning of the SetVector.
69  const_iterator begin() const {
70    return vector_.begin();
71  }
72
73  /// @brief Get an iterator to the end of the SetVector.
74  iterator end() {
75    return vector_.end();
76  }
77
78  /// @brief Get a const_iterator to the end of the SetVector.
79  const_iterator end() const {
80    return vector_.end();
81  }
82
83  /// @brief Return the last element of the SetVector.
84  const T &back() const {
85    assert(!empty() && "Cannot call back() on empty SetVector!");
86    return vector_.back();
87  }
88
89  /// @brief Index into the SetVector.
90  const_reference operator[](size_type n) const {
91    assert(n < vector_.size() && "SetVector access out of range!");
92    return vector_[n];
93  }
94
95  /// @returns true iff the element was inserted into the SetVector.
96  /// @brief Insert a new element into the SetVector.
97  bool insert(const value_type &X) {
98    bool result = set_.insert(X).second;
99    if (result)
100      vector_.push_back(X);
101    return result;
102  }
103
104  /// @brief Insert a range of elements into the SetVector.
105  template<typename It>
106  void insert(It Start, It End) {
107    for (; Start != End; ++Start)
108      if (set_.insert(*Start).second)
109        vector_.push_back(*Start);
110  }
111
112  /// @brief Remove an item from the set vector.
113  void remove(const value_type& X) {
114    if (0 < set_.erase(X)) {
115      iterator I = find(vector_.begin(),vector_.end(),X);
116      if (I != vector_.end())
117        vector_.erase(I);
118    }
119  }
120
121
122  /// @returns 0 if the element is not in the SetVector, 1 if it is.
123  /// @brief Count the number of elements of a given key in the SetVector.
124  size_type count(const key_type &key) const {
125    return set_.count(key);
126  }
127
128  /// @brief Completely clear the SetVector
129  void clear() {
130    set_.clear();
131    vector_.clear();
132  }
133
134  /// @brief Remove the last element of the SetVector.
135  void pop_back() {
136    assert(!empty() && "Cannot remove an element from an empty SetVector!");
137    set_.erase(back());
138    vector_.pop_back();
139  }
140
141private:
142  set_type set_;         ///< The set.
143  vector_type vector_;   ///< The vector.
144};
145
146} // End llvm namespace
147
148// vim: sw=2 ai
149#endif
150