dynamic_bitset.hpp

Go to the documentation of this file.

/*
 * Copyright (c) 2017 Patrick P. Frey
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
#ifndef _STRUS_DYNAMIC_BITSET_HPP_INCLUDED
#define _STRUS_DYNAMIC_BITSET_HPP_INCLUDED
#include "strus/base/bitset.hpp"

#if defined __GNUC__
#define STRUS_GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
#endif

#undef STRUS_USE_STD_DYNAMIC_BITSET
#if __cplusplus >= 201103L
#if defined __clang__
#define STRUS_USE_STD_DYNAMIC_BITSET
#elif defined __GNUC__
#if STRUS_GCC_VERSION >= 40900
#define STRUS_USE_STD_DYNAMIC_BITSET
#endif // STRUS_GCC_VERSION
#endif // __clang__
#endif // __cplusplus

#ifdef STRUS_USE_STD_DYNAMIC_BITSET
#include <vector>
#include <algorithm>
namespace strus {

class dynamic_bitset
{
public:
        dynamic_bitset( std::size_t size_)
                :m_indices( (size_+(ElementDim-1)) / ElementDim, -1),m_elements(){}
        dynamic_bitset( const dynamic_bitset& o)
                :m_indices(o.m_indices),m_elements(o.m_elements){}
        void set( std::size_t n, bool val = true)
        {
                int hi = n / ElementDim;
                int li = n % ElementDim;
                int idx = m_indices[ hi];
                if (idx == -1)
                {
                        idx = m_indices[ hi] = m_elements.size();
                        m_elements.push_back( bitset<ElementDim>());
                }
                m_elements[ idx].set( li, val);
        }
        bool test( std::size_t n) const
        {
                int hi = n / ElementDim;
                int li = n % ElementDim;
                int idx = m_indices[ hi];
                if (idx == -1) return false;
                return m_elements.at(idx).test( li);
        }
        void reset()
        {
                m_elements.clear();
                std::fill( m_indices.begin(), m_indices.end(), -1);
        }

private:
        enum {ElementDim=256};
        std::vector<int> m_indices;
        std::vector<bitset<ElementDim> > m_elements;
};
}//namespace

#else //STRUS_USE_STD_DYNAMIC_BITSET
#include <boost/dynamic_bitset.hpp>

namespace strus {

class dynamic_bitset
        :public boost::dynamic_bitset<>
{
public:
        dynamic_bitset( std::size_t size_)
                :boost::dynamic_bitset<>( size_){}
        dynamic_bitset( const dynamic_bitset& o)
                :boost::dynamic_bitset<>( o){}
};

}//namespace
#endif //STRUS_USE_STD_DYNAMIC_BITSET

#endif