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 "llvm/ADT/STLExtras.h" 24 #include <cassert> 25 #include <functional> 26 #include <vector> 27 28 namespace llvm { 29 30 template <typename T, typename ToIndexT = llvm::identity<unsigned> > 31 class IndexedMap { 32 typedef typename ToIndexT::argument_type IndexT; 33 typedef std::vector<T> StorageT; 34 StorageT storage_; 35 T nullVal_; 36 ToIndexT toIndex_; 37 38 public: 39 IndexedMap() : nullVal_(T()) { } 40 41 explicit IndexedMap(const T& val) : nullVal_(val) { } 42 43 typename StorageT::reference operator[](IndexT n) { 44 assert(toIndex_(n) < storage_.size() && "index out of bounds!"); 45 return storage_[toIndex_(n)]; 46 } 47 48 typename StorageT::const_reference operator[](IndexT n) const { 49 assert(toIndex_(n) < storage_.size() && "index out of bounds!"); 50 return storage_[toIndex_(n)]; 51 } 52 53 void reserve(typename StorageT::size_type s) { 54 storage_.reserve(s); 55 } 56 57 void resize(typename StorageT::size_type s) { 58 storage_.resize(s, nullVal_); 59 } 60 61 void clear() { 62 storage_.clear(); 63 } 64 65 void grow(IndexT n) { 66 unsigned NewSize = toIndex_(n) + 1; 67 if (NewSize > storage_.size()) 68 resize(NewSize); 69 } 70 71 bool inBounds(IndexT n) const { 72 return toIndex_(n) < storage_.size(); 73 } 74 75 typename StorageT::size_type size() const { 76 return storage_.size(); 77 } 78 }; 79 80 } // End llvm namespace 81 82 #endif 83
