1 //===-- llvm/ADT/UniqueVector.h ---------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by James M. Laskey and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_ADT_UNIQUEVECTOR_H
11 #define LLVM_ADT_UNIQUEVECTOR_H
19 //===----------------------------------------------------------------------===//
20 /// UniqueVector - This class produces a sequential ID number (base 1) for each
21 /// unique entry that is added. T is the type of entries in the vector. This
22 /// class should have an implementation of operator== and of operator<.
23 /// Entries can be fetched using operator[] with the entry ID.
24 template<class T> class UniqueVector {
26 // Map - Used to handle the correspondence of entry to ID.
27 std::map<T, unsigned> Map;
29 // Vector - ID ordered vector of entries. Entries can be indexed by ID - 1.
31 std::vector<T> Vector;
34 /// insert - Append entry to the vector if it doesn't already exist. Returns
35 /// the entry's index + 1 to be used as a unique ID.
36 unsigned insert(const T &Entry) {
37 // Check if the entry is already in the map.
38 unsigned &Val = Map[Entry];
40 // See if entry exists, if so return prior ID.
43 // Compute ID for entry.
44 Val = Vector.size() + 1;
47 Vector.push_back(Entry);
51 /// idFor - return the ID for an existing entry. Returns 0 if the entry is
53 unsigned idFor(const T &Entry) const {
54 // Search for entry in the map.
55 typename std::map<T, unsigned>::const_iterator MI = Map.find(Entry);
57 // See if entry exists, if so return ID.
58 if (MI != Map.end()) return MI->second;
64 /// operator[] - Returns a reference to the entry with the specified ID.
66 const T &operator[](unsigned ID) const {
67 assert(ID-1 < size() && "ID is 0 or out of range!");
68 return Vector[ID - 1];
71 /// size - Returns the number of entries in the vector.
73 size_t size() const { return Vector.size(); }
75 /// empty - Returns true if the vector is empty.
77 bool empty() const { return Vector.empty(); }
79 /// reset - Clears all the entries.
87 } // End of namespace llvm
89 #endif // LLVM_ADT_UNIQUEVECTOR_H