MapVector.h revision 289c39965b1b799a22534d759fdf0a26302430d7
1//===- llvm/ADT/MapVector.h - Map with deterministic value order *- 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// 10// This file implements a map that provides insertion order iteration. The 11// interface is purposefully minimal. The key is assumed to be cheap to copy 12// and 2 copies are kept, one for indexing in a DenseMap, one for iteration in 13// a std::vector. 14// 15//===----------------------------------------------------------------------===// 16 17#ifndef LLVM_ADT_MAPVECTOR_H 18#define LLVM_ADT_MAPVECTOR_H 19 20#include "llvm/ADT/ArrayRef.h" 21#include "llvm/ADT/DenseMap.h" 22#include <vector> 23 24namespace llvm { 25 26/// This class implements a map that also provides access to all stored values 27/// in a deterministic order. The values are kept in a std::vector and the 28/// mapping is done with DenseMap from Keys to indexes in that vector. 29template<typename KeyT, typename ValueT, 30 typename MapType = llvm::DenseMap<KeyT, unsigned>, 31 typename VectorType = std::vector<std::pair<KeyT, ValueT> >> 32class MapVector { 33 typedef typename VectorType::size_type SizeType; 34 35 MapType Map; 36 VectorType Vector; 37 38public: 39 typedef typename VectorType::iterator iterator; 40 typedef typename VectorType::const_iterator const_iterator; 41 42 SizeType size() const { 43 return Vector.size(); 44 } 45 46 iterator begin() { 47 return Vector.begin(); 48 } 49 50 const_iterator begin() const { 51 return Vector.begin(); 52 } 53 54 iterator end() { 55 return Vector.end(); 56 } 57 58 const_iterator end() const { 59 return Vector.end(); 60 } 61 62 bool empty() const { 63 return Vector.empty(); 64 } 65 66 void clear() { 67 Map.clear(); 68 Vector.clear(); 69 } 70 71 ValueT &operator[](const KeyT &Key) { 72 std::pair<KeyT, unsigned> Pair = std::make_pair(Key, 0); 73 std::pair<typename MapType::iterator, bool> Result = Map.insert(Pair); 74 unsigned &I = Result.first->second; 75 if (Result.second) { 76 Vector.push_back(std::make_pair(Key, ValueT())); 77 I = Vector.size() - 1; 78 } 79 return Vector[I].second; 80 } 81}; 82 83} 84 85#endif 86