1 //===- llvm/ADT/IndexedMap.h - An index map implementation ------*- 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 an indexed map. The index map template takes two 11 // types. The first is the mapped type and the second is a functor 12 // that maps its argument to a size_t. On instantiation a "null" value 13 // can be provided to be used as a "does not exist" indicator in the 14 // map. A member function grow() is provided that given the value of 15 // the maximally indexed key (the argument of the functor) makes sure 16 // the map has enough space for it. 17 // 18 //===----------------------------------------------------------------------===// 19 20 #ifndef LLVM_ADT_INDEXEDMAP_H 21 #define LLVM_ADT_INDEXEDMAP_H 22 23 #include <cassert> 24 #include <functional> 25 #include <vector> 26 27 namespace llvm { 28 29 struct IdentityFunctor : public std::unary_function<unsigned, unsigned> { 30 unsigned operator()(unsigned Index) const { 31 return Index; 32 } 33 }; 34 35 template <typename T, typename ToIndexT = IdentityFunctor> 36 class IndexedMap { 37 typedef typename ToIndexT::argument_type IndexT; 38 typedef std::vector<T> StorageT; 39 StorageT storage_; 40 T nullVal_; 41 ToIndexT toIndex_; 42 43 public: 44 IndexedMap() : nullVal_(T()) { } 45 46 explicit IndexedMap(const T& val) : nullVal_(val) { } 47 48 typename StorageT::reference operator[](IndexT n) { 49 assert(toIndex_(n) < storage_.size() && "index out of bounds!"); 50 return storage_[toIndex_(n)]; 51 } 52 53 typename StorageT::const_reference operator[](IndexT n) const { 54 assert(toIndex_(n) < storage_.size() && "index out of bounds!"); 55 return storage_[toIndex_(n)]; 56 } 57 58 void reserve(typename StorageT::size_type s) { 59 storage_.reserve(s); 60 } 61 62 void resize(typename StorageT::size_type s) { 63 storage_.resize(s, nullVal_); 64 } 65 66 void clear() { 67 storage_.clear(); 68 } 69 70 void grow(IndexT n) { 71 unsigned NewSize = toIndex_(n) + 1; 72 if (NewSize > storage_.size()) 73 resize(NewSize); 74 } 75 76 bool inBounds(IndexT n) const { 77 return toIndex_(n) < storage_.size(); 78 } 79 80 typename StorageT::size_type size() const { 81 return storage_.size(); 82 } 83 }; 84 85 } // End llvm namespace 86 87 #endif 88
