llvm-6502/include/Support/DenseMap.h

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//===- DenseMap.h - A dense map implmentation -------------------*- 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 a dense map. A dense 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 SUPPORT_DENSEMAP_H
#define SUPPORT_DENSEMAP_H
#include <vector>
namespace llvm {
template <typename T, typename ToIndexT>
class DenseMap {
typedef typename ToIndexT::argument_type IndexT;
typedef std::vector<T> StorageT;
StorageT storage_;
T nullVal_;
ToIndexT toIndex_;
public:
DenseMap() : nullVal_(T()) { }
explicit DenseMap(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_);
}
};
} // End llvm namespace
#endif