1 //===-- llvm/ADT/UniqueVector.h ---------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_ADT_UNIQUEVECTOR_H
11 #define LLVM_ADT_UNIQUEVECTOR_H
20 //===----------------------------------------------------------------------===//
21 /// UniqueVector - This class produces a sequential ID number (base 1) for each
22 /// unique entry that is added. T is the type of entries in the vector. This
23 /// class should have an implementation of operator== and of operator<.
24 /// Entries can be fetched using operator[] with the entry ID.
25 template<class T> class UniqueVector {
27 typedef typename std::vector<T> VectorType;
28 typedef typename VectorType::iterator iterator;
29 typedef typename VectorType::const_iterator const_iterator;
32 // Map - Used to handle the correspondence of entry to ID.
33 std::map<T, unsigned> Map;
35 // Vector - ID ordered vector of entries. Entries can be indexed by ID - 1.
40 /// insert - Append entry to the vector if it doesn't already exist. Returns
41 /// the entry's index + 1 to be used as a unique ID.
42 unsigned insert(const T &Entry) {
43 // Check if the entry is already in the map.
44 unsigned &Val = Map[Entry];
46 // See if entry exists, if so return prior ID.
49 // Compute ID for entry.
50 Val = static_cast<unsigned>(Vector.size()) + 1;
53 Vector.push_back(Entry);
57 /// idFor - return the ID for an existing entry. Returns 0 if the entry is
59 unsigned idFor(const T &Entry) const {
60 // Search for entry in the map.
61 typename std::map<T, unsigned>::const_iterator MI = Map.find(Entry);
63 // See if entry exists, if so return ID.
64 if (MI != Map.end()) return MI->second;
70 /// operator[] - Returns a reference to the entry with the specified ID.
72 const T &operator[](unsigned ID) const {
73 assert(ID-1 < size() && "ID is 0 or out of range!");
74 return Vector[ID - 1];
77 /// \brief Return an iterator to the start of the vector.
78 iterator begin() { return Vector.begin(); }
80 /// \brief Return an iterator to the start of the vector.
81 const_iterator begin() const { return Vector.begin(); }
83 /// \brief Return an iterator to the end of the vector.
84 iterator end() { return Vector.end(); }
86 /// \brief Return an iterator to the end of the vector.
87 const_iterator end() const { return Vector.end(); }
89 /// size - Returns the number of entries in the vector.
91 size_t size() const { return Vector.size(); }
93 /// empty - Returns true if the vector is empty.
95 bool empty() const { return Vector.empty(); }
97 /// reset - Clears all the entries.
105 } // End of namespace llvm
107 #endif // LLVM_ADT_UNIQUEVECTOR_H