llvm-6502/include/llvm/ADT/IndexedMap.h
Chris Lattner 94c002a190 rename DenseMap to IndexedMap.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33749 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-01 05:32:05 +00:00

76 lines
2.2 KiB
C++

//===- llvm/ADT/IndexedMap.h - An index map implementation ------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements an indexed map. The index map template takes two
// types. The first is the mapped type and the second is a functor
// that maps its argument to a size_t. On instantiation a "null" value
// can be provided to be used as a "does not exist" indicator in the
// map. A member function grow() is provided that given the value of
// the maximally indexed key (the argument of the functor) makes sure
// the map has enough space for it.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_INDEXEDMAP_H
#define LLVM_ADT_INDEXEDMAP_H
#include <functional>
#include <vector>
#include <cassert>
namespace llvm {
struct IdentityFunctor : std::unary_function<unsigned, unsigned> {
unsigned operator()(unsigned Index) const {
return Index;
}
};
template <typename T, typename ToIndexT = IdentityFunctor>
class IndexedMap {
typedef typename ToIndexT::argument_type IndexT;
typedef std::vector<T> StorageT;
StorageT storage_;
T nullVal_;
ToIndexT toIndex_;
public:
IndexedMap() : nullVal_(T()) { }
explicit IndexedMap(const T& val) : nullVal_(val) { }
typename StorageT::reference operator[](IndexT n) {
assert(toIndex_(n) < storage_.size() && "index out of bounds!");
return storage_[toIndex_(n)];
}
typename StorageT::const_reference operator[](IndexT n) const {
assert(toIndex_(n) < storage_.size() && "index out of bounds!");
return storage_[toIndex_(n)];
}
void clear() {
storage_.clear();
}
void grow(IndexT n) {
unsigned NewSize = toIndex_(n) + 1;
if (NewSize > storage_.size())
storage_.resize(NewSize, nullVal_);
}
typename StorageT::size_type size() const {
return storage_.size();
}
};
} // End llvm namespace
#endif