llvm-6502/include/llvm/ADT/UniqueVector.h

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//===-- llvm/ADT/UniqueVector.h ---------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_UNIQUEVECTOR_H
#define LLVM_ADT_UNIQUEVECTOR_H
#include <cassert>
#include <map>
#include <vector>
namespace llvm {
//===----------------------------------------------------------------------===//
/// UniqueVector - This class produces a sequential ID number (base 1) for each
/// unique entry that is added. T is the type of entries in the vector. This
/// class should have an implementation of operator== and of operator<.
/// Entries can be fetched using operator[] with the entry ID.
template<class T> class UniqueVector {
private:
// Map - Used to handle the correspondence of entry to ID.
std::map<T, unsigned> Map;
// Vector - ID ordered vector of entries. Entries can be indexed by ID - 1.
//
std::vector<T> Vector;
public:
/// insert - Append entry to the vector if it doesn't already exist. Returns
/// the entry's index + 1 to be used as a unique ID.
unsigned insert(const T &Entry) {
// Check if the entry is already in the map.
unsigned &Val = Map[Entry];
// See if entry exists, if so return prior ID.
if (Val) return Val;
// Compute ID for entry.
Val = static_cast<unsigned>(Vector.size()) + 1;
// Insert in vector.
Vector.push_back(Entry);
return Val;
}
/// idFor - return the ID for an existing entry. Returns 0 if the entry is
/// not found.
unsigned idFor(const T &Entry) const {
// Search for entry in the map.
typename std::map<T, unsigned>::const_iterator MI = Map.find(Entry);
// See if entry exists, if so return ID.
if (MI != Map.end()) return MI->second;
// No luck.
return 0;
}
/// operator[] - Returns a reference to the entry with the specified ID.
///
const T &operator[](unsigned ID) const {
assert(ID-1 < size() && "ID is 0 or out of range!");
return Vector[ID - 1];
}
/// size - Returns the number of entries in the vector.
///
size_t size() const { return Vector.size(); }
/// empty - Returns true if the vector is empty.
///
bool empty() const { return Vector.empty(); }
/// reset - Clears all the entries.
///
void reset() {
Map.clear();
Vector.resize(0, 0);
}
};
} // End of namespace llvm
#endif // LLVM_ADT_UNIQUEVECTOR_H