ClickHouse/contrib/libpoco/Foundation/include/Poco/HashSet.h
2016-06-07 11:23:15 +03:00

180 lines
3.4 KiB
C++

//
// HashSet.h
//
// $Id: //poco/1.4/Foundation/include/Poco/HashSet.h#1 $
//
// Library: Foundation
// Package: Hashing
// Module: HashSet
//
// Definition of the HashSet class.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_HashSet_INCLUDED
#define Foundation_HashSet_INCLUDED
#include "Poco/Foundation.h"
#include "Poco/LinearHashTable.h"
namespace Poco {
template <class Value, class HashFunc = Hash<Value> >
class HashSet
/// This class implements a set using a LinearHashTable.
///
/// A HashSet can be used just like a std::set.
{
public:
typedef Value ValueType;
typedef Value& Reference;
typedef const Value& ConstReference;
typedef Value* Pointer;
typedef const Value* ConstPointer;
typedef HashFunc Hash;
typedef LinearHashTable<ValueType, Hash> HashTable;
typedef typename HashTable::Iterator Iterator;
typedef typename HashTable::ConstIterator ConstIterator;
HashSet()
/// Creates an empty HashSet.
{
}
HashSet(std::size_t initialReserve):
_table(initialReserve)
/// Creates the HashSet, using the given initialReserve.
{
}
HashSet(const HashSet& set):
_table(set._table)
/// Creates the HashSet by copying another one.
{
}
~HashSet()
/// Destroys the HashSet.
{
}
HashSet& operator = (const HashSet& table)
/// Assigns another HashSet.
{
HashSet tmp(table);
swap(tmp);
return *this;
}
void swap(HashSet& set)
/// Swaps the HashSet with another one.
{
_table.swap(set._table);
}
ConstIterator begin() const
/// Returns an iterator pointing to the first entry, if one exists.
{
return _table.begin();
}
ConstIterator end() const
/// Returns an iterator pointing to the end of the table.
{
return _table.end();
}
Iterator begin()
/// Returns an iterator pointing to the first entry, if one exists.
{
return _table.begin();
}
Iterator end()
/// Returns an iterator pointing to the end of the table.
{
return _table.end();
}
ConstIterator find(const ValueType& value) const
/// Finds an entry in the table.
{
return _table.find(value);
}
Iterator find(const ValueType& value)
/// Finds an entry in the table.
{
return _table.find(value);
}
std::size_t count(const ValueType& value) const
/// Returns the number of elements with the given
/// value, with is either 1 or 0.
{
return _table.count(value);
}
std::pair<Iterator, bool> insert(const ValueType& value)
/// Inserts an element into the set.
///
/// If the element already exists in the set,
/// a pair(iterator, false) with iterator pointing to the
/// existing element is returned.
/// Otherwise, the element is inserted an a
/// pair(iterator, true) with iterator
/// pointing to the new element is returned.
{
return _table.insert(value);
}
void erase(Iterator it)
/// Erases the element pointed to by it.
{
_table.erase(it);
}
void erase(const ValueType& value)
/// Erases the element with the given value, if it exists.
{
_table.erase(value);
}
void clear()
/// Erases all elements.
{
_table.clear();
}
std::size_t size() const
/// Returns the number of elements in the table.
{
return _table.size();
}
bool empty() const
/// Returns true iff the table is empty.
{
return _table.empty();
}
private:
HashTable _table;
};
} // namespace Poco
#endif // Foundation_HashSet_INCLUDED