include/util/bitset/bm.h

Go to the documentation of this file.

#ifndef BM__H__INCLUDED__
#define BM__H__INCLUDED__
/*
Copyright(c) 2002-2009 Anatoliy Kuznetsov(anatoliy_kuznetsov at yahoo.com)

Permission is hereby granted, free of charge, to any person 
obtaining a copy of this software and associated documentation 
files (the "Software"), to deal in the Software without restriction, 
including without limitation the rights to use, copy, modify, merge, 
publish, distribute, sublicense, and/or sell copies of the Software, 
and to permit persons to whom the Software is furnished to do so, 
subject to the following conditions:

The above copyright notice and this permission notice shall be included 
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 
OTHER DEALINGS IN THE SOFTWARE.

For more information please visit:  http://bmagic.sourceforge.net

*/


// define BM_NO_STL if you use BM in "STL free" environment and want
// to disable any references to STL headers
#ifndef BM_NO_STL
# include <iterator>
#endif

#ifdef _MSC_VER
#pragma warning( disable : 4311 4312)
#endif



#include "bmconst.h"
#include "bmdef.h"


// Vector based optimizations are incompatible with 64-bit optimization
// which is considered a form of vectorization

#ifdef BMSSE42OPT
# undef BMSSE2OPT
# undef BM64OPT
# define BMVECTOPT
# include "bmsse4.h"
#endif

#ifdef BMSSE2OPT
# undef BM64OPT
# define BMVECTOPT
# include "bmsse2.h"
#endif

#include "bmfwd.h"
#include "bmfunc.h"
#include "bmvmin.h"
#include "encoding.h"
#include "bmalloc.h"
#include "bmblocks.h"

namespace bm
{


#ifdef BMCOUNTOPT

# define BMCOUNT_INC ++count_;
# define BMCOUNT_DEC --count_;
# define BMCOUNT_VALID(x) count_is_valid_ = x;
# define BMCOUNT_SET(x) count_ = x; count_is_valid_ = true;
# define BMCOUNT_ADJ(x) if (x) ++count_; else --count_;

#else

# define BMCOUNT_INC
# define BMCOUNT_DEC
# define BMCOUNT_VALID(x)
# define BMCOUNT_SET(x)
# define BMCOUNT_ADJ(x)

#endif



typedef bm::miniset<bm::block_allocator, bm::set_total_blocks> mem_save_set;


/** @defgroup bmagic BitMagic C++ Library
 *  For more information please visit:  http://bmagic.sourceforge.net
 *  
 */


/** @defgroup bvector The Main bvector<> Group
 *  This is the main group. It includes bvector template: front end of the bm library.
 *  @ingroup bmagic 
 */




/*!
   @brief bitvector with runtime compression of bits.
   @ingroup bvector
*/

template<class Alloc, class MS> 
class bvector
{
public:

    typedef Alloc  allocator_type;
    typedef blocks_manager<Alloc, MS>  blocks_manager_type;
    /** Type used to count bits in the bit vector */
    typedef bm::id_t                   size_type; 

    /** Statistical information about bitset's memory allocation details. */
    struct statistics : public bv_statistics
    {};

    /**
        @brief Class reference implements an object for bit assignment.
        Since C++ does not provide with build-in bit type supporting l-value 
        operations we have to emulate it.

        @ingroup bvector
    */
    class reference
    {
    public:
        reference(bvector<Alloc, MS>& bv, bm::id_t position) 
        : bv_(bv),
          position_(position)
        {}

        reference(const reference& ref)
        : bv_(ref.bv_), 
          position_(ref.position_)
        {
            bv_.set(position_, ref.bv_.get_bit(position_));
        }
        
        operator bool() const
        {
            return bv_.get_bit(position_);
        }

        const reference& operator=(const reference& ref) const
        {
            bv_.set(position_, (bool)ref);
            return *this;
        }

        const reference& operator=(bool value) const
        {
            bv_.set(position_, value);
            return *this;
        }

        bool operator==(const reference& ref) const
        {
            return bool(*this) == bool(ref);
        }

        /*! Bitwise AND. Performs operation: bit = bit AND value */
        const reference& operator&=(bool value) const
        {
            bv_.set_bit_and(position_, value);
            return *this;
        }

        /*! Bitwise OR. Performs operation: bit = bit OR value */
        const reference& operator|=(bool value) const
        {
            if (value != bv_.get_bit(position_))
            {
                bv_.set_bit(position_);
            }
            return *this;
        }

        /*! Bitwise exclusive-OR (XOR). Performs operation: bit = bit XOR value */
        const reference& operator^=(bool value) const
        {
            bv_.set(position_, value != bv_.get_bit(position_));
            return *this;
        }

        /*! Logical Not operator */
        bool operator!() const
        {
            return !bv_.get_bit(position_);
        }

        /*! Bit Not operator */
        bool operator~() const
        {
            return !bv_.get_bit(position_);
        }

        /*! Negates the bit value */
        reference& flip()
        {
            bv_.flip(position_);
            return *this;
        }

    private:
        bvector<Alloc, MS>& bv_;       //!< Reference variable on the parent.
        bm::id_t            position_; //!< Position in the parent bitvector.
    };

    typedef bool const_reference;

    /*!
        @brief Base class for all iterators.
        @ingroup bvector
    */
    class iterator_base
    {
    friend class bvector;
    public:
        iterator_base() : bv_(0), position_(bm::id_max), block_(0) {}

        bool operator==(const iterator_base& it) const
        {
            return (position_ == it.position_) && (bv_ == it.bv_);
        }

        bool operator!=(const iterator_base& it) const
        {
            return ! operator==(it);
        }

        bool operator < (const iterator_base& it) const
        {
            return position_ < it.position_;
        }

        bool operator <= (const iterator_base& it) const
        {
            return position_ <= it.position_;
        }

        bool operator > (const iterator_base& it) const
        {
            return position_ > it.position_;
        }

        bool operator >= (const iterator_base& it) const
        {
            return position_ >= it.position_;
        }

        /**
           \fn bool bm::bvector::iterator_base::valid() const
           \brief Checks if iterator is still valid. Analog of != 0 comparison for pointers.
           \returns true if iterator is valid.
        */
        bool valid() const
        {
            return position_ != bm::id_max;
        }

        /**
           \fn bool bm::bvector::iterator_base::invalidate() 
           \brief Turns iterator into an invalid state.
        */
        void invalidate()
        {
            position_ = bm::id_max;
        }

    public:

        /** Information about current bitblock. */
        struct bitblock_descr
        {
            const bm::word_t*   ptr;      //!< Word pointer.
            unsigned            bits[32]; //!< Unpacked list of ON bits
            unsigned            idx;      //!< Current position in the bit list
            unsigned            cnt;      //!< Number of ON bits
            bm::id_t            pos;      //!< Last bit position before 
        };

        /** Information about current DGAP block. */
        struct dgap_descr
        {
            const gap_word_t*   ptr;       //!< Word pointer.
            gap_word_t          gap_len;   //!< Current dgap length.
        };

    protected:
        bm::bvector<Alloc, MS>* bv_;         //!< Pointer on parent bitvector
        bm::id_t                position_;   //!< Bit position (bit idx)
        const bm::word_t*       block_;      //!< Block pointer.(NULL-invalid)
        unsigned                block_type_; //!< Type of block. 0-Bit, 1-GAP
        unsigned                block_idx_;  //!< Block index

        /*! Block type dependent information for current block. */
        union block_descr
        {
            bitblock_descr   bit_;  //!< BitBlock related info.
            dgap_descr       gap_;  //!< DGAP block related info.
        } bdescr_;
    };

    /*!
        @brief Output iterator iterator designed to set "ON" bits based on
        input sequence of integers (bit indeces).

        STL container can be converted to bvector using this iterator
        Insert iterator guarantees the vector will be dynamically resized
        (set_bit does not do that).

        @note
        If you have many bits to set it is a good idea to use output iterator
        instead of explicitly calling set, because iterator may implement
        some performance specific tricks to make sure bulk insert is fast.

        @ingroup bvector
    */
    class insert_iterator
    {
    public:
#ifndef BM_NO_STL
        typedef std::output_iterator_tag  iterator_category;
#endif
        typedef unsigned value_type;
        typedef void difference_type;
        typedef void pointer;
        typedef void reference;

        insert_iterator(bvector<Alloc, MS>& bvect)
            : bvect_(bvect), 
              max_bit_(bvect.size())
        {
        }
        
        insert_iterator& operator=(bm::id_t n)
        {
            BM_ASSERT(n < bm::id_max);

            if (n >= max_bit_) 
            {
                max_bit_ = n;
                if (n >= bvect_.size()) 
                {
                    bvect_.resize(n + 1);
                }
            }

            bvect_.set(n);
            return *this;
        }
        
        /*! Returns *this without doing anything (no-op) */
        insert_iterator& operator*() { return *this; }
        /*! Returns *this. This iterator does not move (no-op) */
        insert_iterator& operator++() { return *this; }
        /*! Returns *this. This iterator does not move (no-op)*/
        insert_iterator& operator++(int) { return *this; }
        
    protected:
        bm::bvector<Alloc, MS>&   bvect_;
        bm::id_t                  max_bit_;
    };

    /*!
        @brief Constant input iterator designed to enumerate "ON" bits
        @ingroup bvector
    */
    class enumerator : public iterator_base
    {
    public:
#ifndef BM_NO_STL
        typedef std::input_iterator_tag  iterator_category;
#endif
        typedef unsigned   value_type;
        typedef unsigned   difference_type;
        typedef unsigned*  pointer;
        typedef unsigned&  reference;

    public:
        enumerator() : iterator_base() {}
        enumerator(const bvector<Alloc, MS>* bvect, int position)
            : iterator_base()
        { 
            this->bv_ = const_cast<bvector<Alloc, MS>*>(bvect);
            if (position == 0)
            {
                go_first();
            }
            else
            {
                this->invalidate();
            }
        }

        bm::id_t operator*() const
        { 
            return this->position_; 
        }

        enumerator& operator++()
        {
            return this->go_up();
        }

        enumerator operator++(int)
        {
            enumerator tmp = *this;
            this->go_up();
            return tmp;
        }


        void go_first()
        {
            BM_ASSERT(this->bv_);

        #ifdef BMCOUNTOPT
            if (this->bv_->count_is_valid_ && 
                this->bv_->count_ == 0)
            {
                this->invalidate();
                return;
            }
        #endif

            blocks_manager_type* bman = &(this->bv_->blockman_);
            bm::word_t*** blk_root = bman->blocks_root();

            this->block_idx_ = this->position_= 0;
            unsigned i, j;

            for (i = 0; i < bman->top_block_size(); ++i)
            {
                bm::word_t** blk_blk = blk_root[i];

                if (blk_blk == 0) // not allocated
                {
                    this->block_idx_ += bm::set_array_size;
                    this->position_ += bm::bits_in_array;
                    continue;
                }


                for (j = 0; j < bm::set_array_size; ++j,++(this->block_idx_))
                {
                    this->block_ = blk_blk[j];

                    if (this->block_ == 0)
                    {
                        this->position_ += bits_in_block;
                        continue;
                    }

                    if (BM_IS_GAP((*bman), this->block_, this->block_idx_))
                    {
                        this->block_type_ = 1;
                        if (search_in_gapblock())
                        {
                            return;
                        }
                    }
                    else
                    {
                        this->block_type_ = 0;
                        if (search_in_bitblock())
                        {
                            return;
                        }
                    }
            
                } // for j

            } // for i

            this->invalidate();
        }

        enumerator& go_up()
        {
            // Current block search.
            ++this->position_;
            typedef typename iterator_base::block_descr block_descr_type;
            
            block_descr_type* bdescr = &(this->bdescr_);

            switch (this->block_type_)
            {
            case 0:   //  BitBlock
                {

                // check if we can get the value from the 
                // bits cache

                unsigned idx = ++(bdescr->bit_.idx);
                if (idx < bdescr->bit_.cnt)
                {
                    this->position_ = bdescr->bit_.pos + 
                                      bdescr->bit_.bits[idx];
                    return *this; 
                }
                this->position_ += 31 - bdescr->bit_.bits[--idx];

                const bm::word_t* pend = this->block_ + bm::set_block_size;

                while (++(bdescr->bit_.ptr) < pend)
                {
                    bm::word_t w = *(bdescr->bit_.ptr);
                    if (w)
                    {
                        bdescr->bit_.idx = 0;
                        bdescr->bit_.pos = this->position_;
                        bdescr->bit_.cnt = bm::bit_list_4(w, bdescr->bit_.bits); 
                        this->position_ += bdescr->bit_.bits[0];
                        return *this;
                    }
                    else
                    {
                        this->position_ += 32;
                    }
                }
    
                }
                break;

            case 1:   // DGAP Block
                {
                    if (--(bdescr->gap_.gap_len))
                    {
                        return *this;
                    }

                    // next gap is "OFF" by definition.
                    if (*(bdescr->gap_.ptr) == bm::gap_max_bits - 1)
                    {
                        break;
                    }
                    gap_word_t prev = *(bdescr->gap_.ptr);
                    register unsigned val = *(++(bdescr->gap_.ptr));

                    this->position_ += val - prev;
                    // next gap is now "ON"

                    if (*(bdescr->gap_.ptr) == bm::gap_max_bits - 1)
                    {
                        break;
                    }
                    prev = *(bdescr->gap_.ptr);
                    val = *(++(bdescr->gap_.ptr));
                    bdescr->gap_.gap_len = val - prev;
                    return *this;  // next "ON" found;
                }

            default:
                BM_ASSERT(0);

            } // switch


            // next bit not present in the current block
            // keep looking in the next blocks.
            ++(this->block_idx_);
            unsigned i = this->block_idx_ >> bm::set_array_shift;
            unsigned top_block_size = this->bv_->blockman_.top_block_size();
            for (; i < top_block_size; ++i)
            {
                bm::word_t** blk_blk = this->bv_->blockman_.blocks_root()[i];
                if (blk_blk == 0)
                {
                    this->block_idx_ += bm::set_array_size;
                    this->position_ += bm::bits_in_array;
                    continue;
                }

                unsigned j = this->block_idx_ & bm::set_array_mask;

                for(; j < bm::set_array_size; ++j, ++(this->block_idx_))
                {
                    this->block_ = blk_blk[j];

                    if (this->block_ == 0)
                    {
                        this->position_ += bm::bits_in_block;
                        continue;
                    }

                    if (BM_IS_GAP((this->bv_->blockman_), 
                                   this->block_, 
                                   this->block_idx_))
                    {
                        this->block_type_ = 1;
                        if (search_in_gapblock())
                        {
                            return *this;
                        }
                    }
                    else
                    {
                        this->block_type_ = 0;
                        if (search_in_bitblock())
                        {
                            return *this;
                        }
                    }

            
                } // for j

            } // for i


            this->invalidate();
            return *this;
        }


    private:
        bool search_in_bitblock()
        {
            BM_ASSERT(this->block_type_ == 0);
            
            typedef typename iterator_base::block_descr block_descr_type;
            block_descr_type* bdescr = &(this->bdescr_);            

            // now lets find the first bit in block.
            bdescr->bit_.ptr = this->block_;

            const word_t* ptr_end = this->block_ + bm::set_block_size;

            do
            {
                register bm::word_t w = *(bdescr->bit_.ptr);

                if (w)  
                {
                    bdescr->bit_.idx = 0;
                    bdescr->bit_.pos = this->position_;
                    bdescr->bit_.cnt = 
                              bm::bit_list_4(w, bdescr->bit_.bits);
                    this->position_ += bdescr->bit_.bits[0];

                    return true;
                }
                else
                {
                    this->position_ += 32;
                }

            } 
            while (++(bdescr->bit_.ptr) < ptr_end);

            return false;
        }

        bool search_in_gapblock()
        {
            BM_ASSERT(this->block_type_ == 1);

            typedef typename iterator_base::block_descr block_descr_type;
            block_descr_type* bdescr = &(this->bdescr_);            

            bdescr->gap_.ptr = BMGAP_PTR(this->block_);
            unsigned bitval = *(bdescr->gap_.ptr) & 1;

            ++(bdescr->gap_.ptr);

            do
            {
                register unsigned val = *(bdescr->gap_.ptr);

                if (bitval)
                {
                    gap_word_t* first = BMGAP_PTR(this->block_) + 1;
                    if (bdescr->gap_.ptr == first)
                    {
                        bdescr->gap_.gap_len = val + 1;
                    }
                    else
                    {
                        bdescr->gap_.gap_len = 
                             val - *(bdescr->gap_.ptr-1);
                    }
           
                    return true;
                }
                this->position_ += val + 1;

                if (val == bm::gap_max_bits - 1)
                {
                    break;
                }

                bitval ^= 1;
                ++(bdescr->gap_.ptr);

            } while (1);

            return false;
        }

    };
    
    /*!
        @brief Constant input iterator designed to enumerate "ON" bits
        counted_enumerator keeps bitcount, ie number of ON bits starting
        from the position 0 in the bit string up to the currently enumerated bit
        
        When increment operator called current position is increased by 1.
        
        @ingroup bvector
    */
    class counted_enumerator : public enumerator
    {
    public:
#ifndef BM_NO_STL
        typedef std::input_iterator_tag  iterator_category;
#endif
        counted_enumerator() : bit_count_(0){}
        
        counted_enumerator(const enumerator& en)
        : enumerator(en)
        {
            if (this->valid())
                bit_count_ = 1;
        }
        
        counted_enumerator& operator=(const enumerator& en)
        {
            enumerator* me = this;
            *me = en;
            if (this->valid())
                this->bit_count_ = 1;
            return *this;
        }
        
        counted_enumerator& operator++()
        {
            this->go_up();
            if (this->valid())
                ++(this->bit_count_);
            return *this;
        }

        counted_enumerator operator++(int)
        {
            counted_enumerator tmp(*this);
            this->go_up();
            if (this->valid())
                ++bit_count_;
            return tmp;
        }
        
        /*! @brief Number of bits ON starting from the .
        
            Method returns number of ON bits fromn the bit 0 to the current bit 
            For the first bit in bitvector it is 1, for the second 2 
        */
        bm::id_t count() const { return bit_count_; }
        
    private:
        bm::id_t   bit_count_;
    };

    friend class iterator_base;
    friend class enumerator;

public:

#ifdef BMCOUNTOPT
    bvector(strategy          strat      = BM_BIT,
            const gap_word_t* glevel_len = bm::gap_len_table<true>::_len,
            size_type         bv_size    = bm::id_max,
            const Alloc&      alloc      = Alloc()) 
    : count_(0),
      count_is_valid_(true),
      blockman_(glevel_len, bv_size, alloc),
      new_blocks_strat_(strat),
      size_(bv_size)
    {}

    bvector(size_type         bv_size,
            bm::strategy      strat      = BM_BIT,
            const gap_word_t* glevel_len = bm::gap_len_table<true>::_len,
            const Alloc&      alloc = Alloc()) 
    : count_(0),
      count_is_valid_(true),
      blockman_(glevel_len, bv_size, alloc),
      new_blocks_strat_(strat),
      size_(bv_size)
    {}


    bvector(const bm::bvector<Alloc, MS>& bvect)
     : count_(bvect.count_),
       count_is_valid_(bvect.count_is_valid_),
       blockman_(bvect.blockman_),
       new_blocks_strat_(bvect.new_blocks_strat_),
       size_(bvect.size_)
    {}

#else
    /*!
        \brief Constructs bvector class
        \param strat - operation mode strategy, 
                       BM_BIT - default strategy, bvector use plain bitset 
                       blocks, (performance oriented strategy).
                       BM_GAP - memory effitent strategy, bvector allocates 
                       blocks as array of intervals(gaps) and convert blocks 
                       into plain bitsets only when enthropy grows.
        \param glevel_len 
           - pointer on C-style array keeping GAP block sizes. 
            (Put bm::gap_len_table_min<true>::_len for GAP memory saving mode)
        \param bv_size 
          - bvector size (number of bits addressable by bvector), bm::id_max means 
          "no limits" (recommended). 
          bit vector allocates this space dynamically on demand.

        \sa bm::gap_len_table bm::gap_len_table_min set_new_blocks_strat
    */
    bvector(strategy          strat      = BM_BIT,
            const gap_word_t* glevel_len = bm::gap_len_table<true>::_len,
            size_type         bv_size    = bm::id_max,
            const Alloc&      alloc      = Alloc()) 
    : blockman_(glevel_len, bv_size, alloc),
      new_blocks_strat_(strat),
      size_(bv_size)
    {}

    /*!
        \brief Constructs bvector class
    */
    bvector(size_type         bv_size,
            strategy          strat      = BM_BIT,
            const gap_word_t* glevel_len = bm::gap_len_table<true>::_len,
            const Alloc&      alloc      = Alloc()) 
    : blockman_(glevel_len, bv_size, alloc),
      new_blocks_strat_(strat),
      size_(bv_size)
    {}


    bvector(const bvector<Alloc, MS>& bvect)
        :  blockman_(bvect.blockman_),
           new_blocks_strat_(bvect.new_blocks_strat_),
           size_(bvect.size_)
    {}

#endif

    bvector& operator=(const bvector<Alloc, MS>& bvect)
    {
        clear(true); // memory free cleaning
        resize(bvect.size());
        bit_or(bvect);
        return *this;
    }

    reference operator[](bm::id_t n)
    {
        BM_ASSERT(n < size_);
        return reference(*this, n);
    }


    bool operator[](bm::id_t n) const
    {
        BM_ASSERT(n < size_);
        return get_bit(n);
    }

    void operator &= (const bvector<Alloc, MS>& bvect)
    {
        bit_and(bvect);
    }

    void operator ^= (const bvector<Alloc, MS>& bvect)
    {
        bit_xor(bvect);
    }

    void operator |= (const bvector<Alloc, MS>& bvect)
    {
        bit_or(bvect);
    }

    void operator -= (const bvector<Alloc, MS>& bvect)
    {
        bit_sub(bvect);
    }

    bool operator < (const bvector<Alloc, MS>& bvect) const
    {
        return compare(bvect) < 0;
    }

    bool operator <= (const bvector<Alloc, MS>& bvect) const
    {
        return compare(bvect) <= 0;
    }

    bool operator > (const bvector<Alloc, MS>& bvect) const
    {
        return compare(bvect) > 0;
    }

    bool operator >= (const bvector<Alloc, MS>& bvect) const
    {
        return compare(bvect) >= 0;
    }

    bool operator == (const bvector<Alloc, MS>& bvect) const
    {
        return compare(bvect) == 0;
    }

    bool operator != (const bvector<Alloc, MS>& bvect) const
    {
        return compare(bvect) != 0;
    }

    bvector<Alloc, MS> operator~() const
    {
        return bvector<Alloc, MS>(*this).invert();
    }
    
    Alloc get_allocator() const
    {
        return blockman_.get_allocator();
    }


    /*!
       \brief Sets bit n.
       \param n - index of the bit to be set. 
       \param val - new bit value
       \return  TRUE if bit was changed
    */
    bool set_bit(bm::id_t n, bool val = true)
    {
        BM_ASSERT(n < size_);
        return set_bit_no_check(n, val);
    }

    /*!
       \brief Sets bit n using bit AND with the provided value.
       \param n - index of the bit to be set. 
       \param val - new bit value
       \return  TRUE if bit was changed
    */
    bool set_bit_and(bm::id_t n, bool val = true)
    {
        BM_ASSERT(n < size_);
        return and_bit_no_check(n, val);
    }

    /*!
       \brief Sets bit n only if current value is equal to the condition
       \param n - index of the bit to be set. 
       \param val - new bit value
       \param condition - expected current value
       \return TRUE if bit was changed
    */
    bool set_bit_conditional(bm::id_t n, bool val, bool condition)
    {
        BM_ASSERT(n < size_);
        if (val == condition) return false;
        return set_bit_conditional_impl(n, val, condition);
    }


    /*!
        \brief Sets bit n if val is true, clears bit n if val is false
        \param n - index of the bit to be set
        \param val - new bit value
        \return *this
    */
    bvector<Alloc, MS>& set(bm::id_t n, bool val = true)
    {
        set_bit(n, val);
        return *this;
    }



    /*!
       \brief Sets every bit in this bitset to 1.
       \return *this
    */
    bvector<Alloc, MS>& set()
    {
        BMCOUNT_VALID(false)
        set_range(0, size_ - 1, true);
        return *this;
    }


    /*!
        \brief Sets all bits in the specified closed interval [left,right]
        Interval must be inside the bvector's size. 
        This method DOES NOT resize vector.
        
        \param left  - interval start
        \param right - interval end (closed interval)
        \param value - value to set interval in
        
        \return *this
    */
    bvector<Alloc, MS>& set_range(bm::id_t left,
                                  bm::id_t right,
                                  bool     value = true);

    
    /*! Function erturns insert iterator for this bitvector */
    insert_iterator inserter()
    {
        return insert_iterator(*this);
    }


    /*!
       \brief Clears bit n.
       \param n - bit's index to be cleaned.
    */
    void clear_bit(bm::id_t n)
    {
        set(n, false);
    }


    /*!
       \brief Clears every bit in the bitvector.

       \param free_mem if "true" (default) bvector frees the memory,
       otherwise sets blocks to 0.
    */
    void clear(bool free_mem = false)
    {
        blockman_.set_all_zero(free_mem);
        BMCOUNT_SET(0);
    }

    /*!
       \brief Clears every bit in the bitvector.
       \return *this;
    */
    bvector<Alloc, MS>& reset()
    {
        clear();
        return *this;
    }


    /*!
       \brief Returns count of bits which are 1.
       \return Total number of bits ON. 
    */
    bm::id_t count() const;

    /**
        \brief Returns bvector's capacity (number of bits it can store)
    */
    size_type capacity() const 
    {
        return blockman_.capacity();
    }

    /*!
        \brief return current size of the vector (bits)
    */
    size_type size() const 
    {
        return size_;
    }

    /*!
        \brief Change size of the bvector
        \param new_size - new size in bits
    */
    void resize(size_type new_size);

    /*! \brief Computes bitcount values for all bvector blocks
        \param arr - pointer on array of block bit counts
        \return Index of the last block counted. 
        This number +1 gives you number of arr elements initialized during the
        function call.
    */
    unsigned count_blocks(unsigned* arr) const
    {
        bm::word_t*** blk_root = blockman_.get_rootblock();
        typename blocks_manager_type::block_count_arr_func func(blockman_, &(arr[0]));
        for_each_nzblock(blk_root, blockman_.effective_top_block_size(), 
                                   bm::set_array_size, func);
        return func.last_block();
    }

    /*!
       \brief Returns count of 1 bits in the given diapason.
       \param left - index of first bit start counting from
       \param right - index of last bit 
       \param block_count_arr - optional parameter (bitcount by bvector blocks)
              calculated by count_blocks method. Used to improve performance of
              wide range searches
       \return Total number of bits ON. 
    */
    bm::id_t count_range(bm::id_t left, 
                         bm::id_t right, 
                         unsigned* block_count_arr=0) const;


    bm::id_t recalc_count()
    {
        BMCOUNT_VALID(false)
        return count();
    }
    
    /*!
        Disables count cache. Next call to count() or recalc_count()
        restores count caching.
        
        @note Works only if BMCOUNTOPT enabled(defined). 
        Othewise does nothing.
    */
    void forget_count()
    {
        BMCOUNT_VALID(false)    
    }

    /*!
        \brief Inverts all bits.
    */
    bvector<Alloc, MS>& invert();


    /*!
       \brief returns true if bit n is set and false is bit n is 0. 
       \param n - Index of the bit to check.
       \return Bit value (1 or 0)
    */
    bool get_bit(bm::id_t n) const;

    /*!
       \brief returns true if bit n is set and false is bit n is 0. 
       \param n - Index of the bit to check.
       \return Bit value (1 or 0)
    */
    bool test(bm::id_t n) const 
    { 
        return get_bit(n); 
    }

    /*!
       \brief Returns true if any bits in this bitset are set, and otherwise returns false.
       \return true if any bit is set
    */
    bool any() const
    {
    #ifdef BMCOUNTOPT
        if (count_is_valid_ && count_) return true;
    #endif
        
        word_t*** blk_root = blockman_.get_rootblock();
        if (!blk_root) 
            return false;
        typename blocks_manager_type::block_any_func func(blockman_);
        return for_each_nzblock_if(blk_root, 
                                   blockman_.effective_top_block_size(),
                                   bm::set_array_size, 
                                   func);
    }

    /*!
        \brief Returns true if no bits are set, otherwise returns false.
    */
    bool none() const
    {
        return !any();
    }

    /*!
       \brief Flips bit n
       \return *this
    */
    bvector<Alloc, MS>& flip(bm::id_t n) 
    {
        set(n, !get_bit(n));
        return *this;
    }

    /*!
       \brief Flips all bits
       \return *this
    */
    bvector<Alloc, MS>& flip() 
    {
        return invert();
    }

    /*! \brief Exchanges content of bv and this bitvector.
    */
    void swap(bvector<Alloc, MS>& bv)
    {
        if (this != &bv) 
        {
            blockman_.swap(bv.blockman_);
            bm::xor_swap(size_,bv.size_);
    #ifdef BMCOUNTOPT
            BMCOUNT_VALID(false)
            bv.recalc_count();
    #endif
        }
    }


    /*!
       \fn bm::id_t bvector::get_first() const
       \brief Gets number of first bit which is ON.
       \return Index of the first 1 bit.
       \sa get_next, extract_next
    */
    bm::id_t get_first() const { return check_or_next(0); }

    /*!
       \fn bm::id_t bvector::get_next(bm::id_t prev) const
       \brief Finds the number of the next bit ON.
       \param prev - Index of the previously found bit. 
       \return Index of the next bit which is ON or 0 if not found.
       \sa get_first, extract_next
    */
    bm::id_t get_next(bm::id_t prev) const
    {
        return (++prev == bm::id_max) ? 0 : check_or_next(prev);
    }

    /*!
       \fn bm::id_t bvector::extract_next(bm::id_t prev)
       \brief Finds the number of the next bit ON and sets it to 0.
       \param prev - Index of the previously found bit. 
       \return Index of the next bit which is ON or 0 if not found.
       \sa get_first, get_next, 
    */
    bm::id_t extract_next(bm::id_t prev)
    {
        return (++prev == bm::id_max) ? 0 : check_or_next_extract(prev);
    }


    /*!
       @brief Calculates bitvector statistics.

       @param st - pointer on statistics structure to be filled in. 

       Function fills statistics structure containing information about how 
       this vector uses memory and estimation of max. amount of memory 
       bvector needs to serialize itself.

       @sa statistics
    */
    void calc_stat(struct bm::bvector<Alloc, MS>::statistics* st) const;

    /*!
       \brief Logical OR operation.
       \param vect - Argument vector.
    */
    bm::bvector<Alloc, MS>& bit_or(const  bm::bvector<Alloc, MS>& vect)
    {
        BMCOUNT_VALID(false);
        combine_operation(vect, BM_OR);
        return *this;
    }

    /*!
       \brief Logical AND operation.
       \param vect - Argument vector.
    */
    bm::bvector<Alloc, MS>& bit_and(const bm::bvector<Alloc, MS>& vect)
    {
        BMCOUNT_VALID(false);
        combine_operation(vect, BM_AND);
        return *this;
    }

    /*!
       \brief Logical XOR operation.
       \param vect - Argument vector.
    */
    bm::bvector<Alloc, MS>& bit_xor(const bm::bvector<Alloc, MS>& vect)
    {
        BMCOUNT_VALID(false);
        combine_operation(vect, BM_XOR);
        return *this;
    }

    /*!
       \brief Logical SUB operation.
       \param vect - Argument vector.
    */
    bm::bvector<Alloc, MS>& bit_sub(const bm::bvector<Alloc, MS>& vect)
    {
        BMCOUNT_VALID(false);
        combine_operation(vect, BM_SUB);
        return *this;
    }


    /*!
       \brief Sets new blocks allocation strategy.
       \param strat - Strategy code 0 - bitblocks allocation only.
                      1 - Blocks mutation mode (adaptive algorithm)
    */
    void set_new_blocks_strat(strategy strat) 
    { 
        new_blocks_strat_ = strat; 
    }

    /*!
       \brief Returns blocks allocation strategy.
       \return - Strategy code 0 - bitblocks allocation only.
                 1 - Blocks mutation mode (adaptive algorithm)
       \sa set_new_blocks_strat
    */
    strategy  get_new_blocks_strat() const 
    { 
        return new_blocks_strat_; 
    }


    /*! 
        \brief Optimization mode
        Every next level means additional checks (better compression vs time)
        \sa optimize
    */
    enum optmode
    {
        opt_free_0    = 1, ///< Free unused 0 blocks
        opt_free_01   = 2, ///< Free unused 0 and 1 blocks
        opt_compress  = 3  ///< compress blocks when possible
    };

    /*!
       \brief Optimize memory bitvector's memory allocation.
   
       Function analyze all blocks in the bitvector, compresses blocks 
       with a regular structure, frees some memory. This function is recommended
       after a bulk modification of the bitvector using set_bit, clear_bit or
       logical operations.

       Optionally function can calculate vector post optimization statistics
       
       @sa optmode, optimize_gap_size
    */
    void optimize(bm::word_t* temp_block = 0, 
                  optmode opt_mode       = opt_compress,
                  statistics* stat       = 0);

    /*!
       \brief Optimize sizes of GAP blocks

       This method runs an analysis to find optimal GAP levels for the 
       specific vector. Current GAP compression algorithm uses several fixed
       GAP sizes. By default bvector uses some reasonable preset. 
    */
    void optimize_gap_size();


    /*!
        @brief Sets new GAP lengths table. All GAP blocks will be reallocated 
        to match the new scheme.

        @param glevel_len - pointer on C-style array keeping GAP block sizes. 
    */
    void set_gap_levels(const gap_word_t* glevel_len);

    /*!
        \brief Lexicographical comparison with a bitvector.

        Function compares current bitvector with the provided argument 
        bit by bit and returns -1 if our bitvector less than the argument, 
        1 - greater, 0 - equal.
    */
    int compare(const bvector<Alloc, MS>& bvect) const;

    /*! @brief Allocates temporary block of memory. 

        Temp block can be passed to bvector functions requiring some temp memory
        for their operation. (like serialize)
        
        @note method is marked const, but it's not quite true, since
        it can in some cases modify the state of the block allocator
        (if it has a state). (Can be important in MT programs).

        @sa free_tempblock
    */
    bm::word_t* allocate_tempblock() const
    {
        blocks_manager_type* bm = 
            const_cast<blocks_manager_type*>(&blockman_);
        return bm->get_allocator().alloc_bit_block();
    }

    /*! @brief Frees temporary block of memory. 

        @note method is marked const, but it's not quite true, since
        it can in some cases modify the state of the block allocator
        (if it has a state). (Can be important in MT programs).

        @sa allocate_tempblock
    */
    void free_tempblock(bm::word_t* block) const
    {
        blocks_manager_type* bm = 
            const_cast<blocks_manager_type*>(&blockman_);
        bm->get_allocator().free_bit_block(block);
    }

    /**
       \brief Returns enumerator pointing on the first non-zero bit.
    */
    enumerator first() const
    {
        typedef typename bvector<Alloc, MS>::enumerator enumerator_type;
        return enumerator_type(this, 0);
    }

    /**
       \fn bvector::enumerator bvector::end() const
       \brief Returns enumerator pointing on the next bit after the last.
    */
    enumerator end() const
    {
        typedef typename bvector<Alloc, MS>::enumerator enumerator_type;
        return enumerator_type(this, 1);
    }


    const bm::word_t* get_block(unsigned nb) const 
    { 
        return blockman_.get_block(nb); 
    }
    
    void combine_operation(const bm::bvector<Alloc, MS>& bvect, 
                            bm::operation                opcode);
    
private:

    bm::id_t check_or_next(bm::id_t prev) const;
    
    /// check if specified bit is 1, and set it to 0
    /// if specified bit is 0, scan for the next 1 and returns it
    /// if no 1 found returns 0
    bm::id_t check_or_next_extract(bm::id_t prev);

    /**
        \brief Set specified bit without checking preconditions (size, etc)
    */
    bool set_bit_no_check(bm::id_t n, bool val);

    /**
        \brief AND specified bit without checking preconditions (size, etc)
    */
    bool and_bit_no_check(bm::id_t n, bool val);

    bool set_bit_conditional_impl(bm::id_t n, bool val, bool condition);


    void combine_operation_with_block(unsigned nb,
                                      unsigned gap,
                                      bm::word_t* blk,
                                      const bm::word_t* arg_blk,
                                      int arg_gap,
                                      bm::operation opcode);
public:
    void combine_operation_with_block(unsigned nb,
                                      const bm::word_t* arg_blk,
                                      int arg_gap,
                                      bm::operation opcode)
    {
        bm::word_t* blk = const_cast<bm::word_t*>(get_block(nb));
        bool gap = BM_IS_GAP((*this), blk, nb);
        combine_operation_with_block(nb, gap, blk, arg_blk, arg_gap, opcode);
    }
private:
    void combine_count_operation_with_block(unsigned nb,
                                            const bm::word_t* arg_blk,
                                            int arg_gap,
                                            bm::operation opcode)
    {
        const bm::word_t* blk = get_block(nb);
        bool gap = BM_IS_GAP((*this), blk, nb);
        combine_count_operation_with_block(nb, gap, blk, arg_blk, arg_gap, opcode);
    }


    /**
       \brief Extends GAP block to the next level or converts it to bit block.
       \param nb - Block's linear index.
       \param blk - Blocks's pointer 
    */
    void extend_gap_block(unsigned nb, gap_word_t* blk)
    {
        blockman_.extend_gap_block(nb, blk);
    }

    /**
       \brief Set range without validity checking
    */
    void set_range_no_check(bm::id_t left,
                            bm::id_t right,
                            bool     value);
public:

    const blocks_manager_type& get_blocks_manager() const
    {
        return blockman_;
    }

    blocks_manager_type& get_blocks_manager()
    {
        return blockman_;
    }


private:

// This block defines two additional hidden variables used for bitcount
// optimization, in rare cases can make bitvector thread unsafe.
#ifdef BMCOUNTOPT
    mutable id_t      count_;            //!< number of 1 bits in the vector
    mutable bool      count_is_valid_;   //!< actualization flag
#endif

    blocks_manager_type  blockman_;         //!< bitblocks manager
    strategy             new_blocks_strat_; //!< block allocation strategy
    size_type            size_;             //!< size in bits
};





//---------------------------------------------------------------------

template<class Alloc, class MS> 
inline bvector<Alloc, MS> operator& (const bvector<Alloc, MS>& v1,
                                     const bvector<Alloc, MS>& v2)
{
#ifdef BM_USE_EXPLICIT_TEMP
    bvector<Alloc, MS> ret(v1);
    ret.bit_and(v2);
    return ret;
#else    
    return bvector<Alloc, MS>(v1).bit_and(v2);
#endif
}

//---------------------------------------------------------------------

template<class Alloc, class MS> 
inline bvector<Alloc, MS> operator| (const bvector<Alloc, MS>& v1,
                                     const bvector<Alloc>& v2)
{
#ifdef BM_USE_EXPLICIT_TEMP
    bvector<Alloc, MS> ret(v1);
    ret.bit_or(v2);
    return ret;
#else    
    return bvector<Alloc, MS>(v1).bit_or(v2);
#endif
}

//---------------------------------------------------------------------

template<class Alloc, class MS> 
inline bvector<Alloc, MS> operator^ (const bvector<Alloc, MS>& v1,
                                     const bvector<Alloc, MS>& v2)
{
#ifdef BM_USE_EXPLICIT_TEMP
    bvector<Alloc, MS> ret(v1);
    ret.bit_xor(v2);
    return ret;
#else    
    return bvector<Alloc, MS>(v1).bit_xor(v2);
#endif
}

//---------------------------------------------------------------------

template<class Alloc, class MS> 
inline bvector<Alloc, MS> operator- (const bvector<Alloc, MS>& v1,
                                     const bvector<Alloc, MS>& v2)
{
#ifdef BM_USE_EXPLICIT_TEMP
    bvector<Alloc, MS> ret(v1);
    ret.bit_sub(v2);
    return ret;
#else    
    return bvector<Alloc, MS>(v1).bit_sub(v2);
#endif
}




// -----------------------------------------------------------------------

template<typename Alloc, typename MS> 
bvector<Alloc, MS>& bvector<Alloc, MS>::set_range(bm::id_t left,
                                                  bm::id_t right,
                                                  bool     value)
{
    if (right < left)
    {
        return set_range(right, left, value);
    }

    BM_ASSERT(left < size_);
    BM_ASSERT(right < size_);

    BMCOUNT_VALID(false)
    BM_SET_MMX_GUARD

    set_range_no_check(left, right, value);

    return *this;
}

// -----------------------------------------------------------------------

template<typename Alloc, typename MS> 
bm::id_t bvector<Alloc, MS>::count() const
{
#ifdef BMCOUNTOPT
    if (count_is_valid_) return count_;
#endif
    word_t*** blk_root = blockman_.get_rootblock();
    if (!blk_root) 
    {
        BMCOUNT_SET(0);
        return 0;
    }    
    typename blocks_manager_type::block_count_func func(blockman_);
    for_each_nzblock(blk_root, blockman_.effective_top_block_size(), 
                                bm::set_array_size, func);

    BMCOUNT_SET(func.count());
    return func.count();
}

// -----------------------------------------------------------------------

template<typename Alloc, typename MS> 
void bvector<Alloc, MS>::resize(size_type new_size)
{
    if (size_ == new_size) return; // nothing to do
    if (size_ < new_size) // size grows 
    {
        blockman_.reserve(new_size);
        size_ = new_size;
    }
    else // shrink
    {
        set_range(new_size, size_ - 1, false); // clear the tail
        size_ = new_size;
    }
}

// -----------------------------------------------------------------------

template<typename Alloc, typename MS> 
bm::id_t bvector<Alloc, MS>::count_range(bm::id_t left, 
                                         bm::id_t right, 
                                         unsigned* block_count_arr) const
{
    BM_ASSERT(left <= right);

    unsigned count = 0;

    // calculate logical number of start and destination blocks
    unsigned nblock_left  = unsigned(left  >>  bm::set_block_shift);
    unsigned nblock_right = unsigned(right >>  bm::set_block_shift);

    const bm::word_t* block = blockman_.get_block(nblock_left);
    bool left_gap = BM_IS_GAP(blockman_, block, nblock_left);

    unsigned nbit_left  = unsigned(left  & bm::set_block_mask); 
    unsigned nbit_right = unsigned(right & bm::set_block_mask); 

    unsigned r = 
        (nblock_left == nblock_right) ? nbit_right : (bm::bits_in_block-1);

    typename blocks_manager_type::block_count_func func(blockman_);

    if (block)
    {
        if ((nbit_left == 0) && (r == (bm::bits_in_block-1))) // whole block
        {
            if (block_count_arr)
            {
                count += block_count_arr[nblock_left];
            }
            else
            {
                func(block, nblock_left);
            }
        }
        else
        {
            if (left_gap)
            {
                count += gap_bit_count_range(BMGAP_PTR(block), 
                                            (gap_word_t)nbit_left,
                                            (gap_word_t)r);
            }
            else
            {
                count += bit_block_calc_count_range(block, nbit_left, r);
            }
        }
    }

    if (nblock_left == nblock_right)  // in one block
    {
        return count + func.count();
    }

    for (unsigned nb = nblock_left+1; nb < nblock_right; ++nb)
    {
        block = blockman_.get_block(nb);
        if (block_count_arr)
        {
            count += block_count_arr[nb];
        }
        else 
        {
            if (block)
                func(block, nb);
        }
    }
    count += func.count();

    block = blockman_.get_block(nblock_right);
    bool right_gap = BM_IS_GAP(blockman_, block, nblock_right);

    if (block)
    {
        if (right_gap)
        {
            count += gap_bit_count_range(BMGAP_PTR(block),
                                        (gap_word_t)0,
                                        (gap_word_t)nbit_right);
        }
        else
        {
            count += bit_block_calc_count_range(block, 0, nbit_right);
        }
    }

    return count;
}

// -----------------------------------------------------------------------

template<typename Alloc, typename MS>
bvector<Alloc, MS>& bvector<Alloc, MS>::invert()
{
    BMCOUNT_VALID(false)
    BM_SET_MMX_GUARD

    bm::word_t*** blk_root = blockman_.get_rootblock();
    typename blocks_manager_type::block_invert_func func(blockman_);    
    for_each_block(blk_root, blockman_.top_block_size(),
                                bm::set_array_size, func);
    if (size_ == bm::id_max) 
    {
        set_bit_no_check(bm::id_max, false);
    } 
    else
    {
        set_range_no_check(size_, bm::id_max, false);
    }

    return *this;
}

// -----------------------------------------------------------------------

template<typename Alloc, typename MS> 
bool bvector<Alloc, MS>::get_bit(bm::id_t n) const
{    
    BM_ASSERT(n < size_);

    // calculate logical block number
    unsigned nblock = unsigned(n >>  bm::set_block_shift); 

    const bm::word_t* block = blockman_.get_block(nblock);

    if (block)
    {
        // calculate word number in block and bit
        unsigned nbit = unsigned(n & bm::set_block_mask); 
        unsigned is_set;

        if (BM_IS_GAP(blockman_, block, nblock))
        {
            is_set = gap_test(BMGAP_PTR(block), nbit);
        }
        else 
        {
            unsigned nword  = unsigned(nbit >> bm::set_word_shift); 
            nbit &= bm::set_word_mask;

            is_set = (block[nword] & (((bm::word_t)1) << nbit));
        }
        return is_set != 0;
    }
    return false;
}

// -----------------------------------------------------------------------

template<typename Alloc, typename MS> 
void bvector<Alloc, MS>::optimize(bm::word_t* temp_block, 
                                  optmode     opt_mode,
                                  statistics* stat)
{
    word_t*** blk_root = blockman_.blocks_root();

    if (!temp_block)
        temp_block = blockman_.check_allocate_tempblock();

    typename 
        blocks_manager_type::block_opt_func  opt_func(blockman_, 
                                                temp_block, 
                                                (int)opt_mode,
                                                stat);
    if (stat)
    {
        stat->bit_blocks = stat->gap_blocks 
                         = stat->max_serialize_mem 
                         = stat->memory_used 
                         = 0;
        ::memcpy(stat->gap_levels, 
                blockman_.glen(), sizeof(gap_word_t) * bm::gap_levels);
        stat->max_serialize_mem = sizeof(id_t) * 4;

    }

    for_each_nzblock(blk_root, blockman_.effective_top_block_size(),
                               bm::set_array_size, opt_func);

    if (stat)
    {
        unsigned safe_inc = stat->max_serialize_mem / 10; // 10% increment
        if (!safe_inc) safe_inc = 256;
        stat->max_serialize_mem += safe_inc;
        stat->memory_used += sizeof(*this) - sizeof(blockman_);
        stat->memory_used += blockman_.mem_used();
    }
}

// -----------------------------------------------------------------------

template<typename Alloc, typename MS> 
void bvector<Alloc, MS>::optimize_gap_size()
{
    struct bvector<Alloc, MS>::statistics st;
    calc_stat(&st);

    if (!st.gap_blocks)
        return;

    gap_word_t opt_glen[bm::gap_levels];
    ::memcpy(opt_glen, st.gap_levels, bm::gap_levels * sizeof(*opt_glen));

    improve_gap_levels(st.gap_length, 
                            st.gap_length + st.gap_blocks, 
                            opt_glen);
    
    set_gap_levels(opt_glen);
}

// -----------------------------------------------------------------------

template<typename Alloc, typename MS> 
void bvector<Alloc, MS>::set_gap_levels(const gap_word_t* glevel_len)
{
    word_t*** blk_root = blockman_.blocks_root();

    typename 
        blocks_manager_type::gap_level_func  gl_func(blockman_, glevel_len);

    for_each_nzblock(blk_root, blockman_.top_block_size(),
                                bm::set_array_size, gl_func);

    blockman_.set_glen(glevel_len);
}

// -----------------------------------------------------------------------

template<typename Alloc, typename MS> 
int bvector<Alloc, MS>::compare(const bvector<Alloc, MS>& bvect) const
{
    int res;
    unsigned bn = 0;

    unsigned top_blocks = blockman_.effective_top_block_size();
    unsigned bvect_top_blocks = bvect.blockman_.effective_top_block_size();

    if (bvect_top_blocks > top_blocks) top_blocks = bvect_top_blocks;

    for (unsigned i = 0; i < top_blocks; ++i)
    {
        const bm::word_t* const* blk_blk = blockman_.get_topblock(i);
        const bm::word_t* const* arg_blk_blk = 
                                bvect.blockman_.get_topblock(i);

        if (blk_blk == arg_blk_blk) 
        {
            bn += bm::set_array_size;
            continue;
        }

        for (unsigned j = 0; j < bm::set_array_size; ++j, ++bn)
        {
            const bm::word_t* arg_blk = arg_blk_blk ? arg_blk_blk[j] : 0;
            const bm::word_t* blk = blk_blk ? blk_blk[j] : 0;
            if (blk == arg_blk) continue;

            // If one block is zero we check if the other one has at least 
            // one bit ON

            if (!blk || !arg_blk)  
            {
                const bm::word_t*  pblk;
                bool is_gap;

                if (blk)
                {
                    pblk = blk;
                    res = 1;
                    is_gap = BM_IS_GAP((*this), blk, bn);
                }
                else
                {
                    pblk = arg_blk;
                    res = -1;
                    is_gap = BM_IS_GAP(bvect, arg_blk, bn);
                }

                if (is_gap)
                {
                    if (!gap_is_all_zero(BMGAP_PTR(pblk), bm::gap_max_bits))
                    {
                        return res;
                    }
                }
                else
                {
                    bm::wordop_t* blk1 = (wordop_t*)pblk;
                    bm::wordop_t* blk2 = 
                        (wordop_t*)(pblk + bm::set_block_size);
                    if (!bit_is_all_zero(blk1, blk2))
                    {
                        return res;
                    }
                }

                continue;
            }

            bool arg_gap = BM_IS_GAP(bvect, arg_blk, bn);
            bool gap = BM_IS_GAP((*this), blk, bn);

            if (arg_gap != gap)
            {
                bm::wordop_t temp_blk[bm::set_block_size_op]; 
                bm::wordop_t* blk1;
                bm::wordop_t* blk2;

                if (gap)
                {
                    gap_convert_to_bitset((bm::word_t*)temp_blk, 
                                            BMGAP_PTR(blk));

                    blk1 = (bm::wordop_t*)temp_blk;
                    blk2 = (bm::wordop_t*)arg_blk;
                }
                else
                {
                    gap_convert_to_bitset((bm::word_t*)temp_blk, 
                                            BMGAP_PTR(arg_blk));

                    blk1 = (bm::wordop_t*)blk;
                    blk2 = (bm::wordop_t*)temp_blk;

                }                        
                res = bitcmp(blk1, blk2, bm::set_block_size_op);  

            }
            else
            {
                if (gap)
                {
                    res = gapcmp(BMGAP_PTR(blk), BMGAP_PTR(arg_blk));
                }
                else
                {
                    res = bitcmp((bm::wordop_t*)blk, 
                                    (bm::wordop_t*)arg_blk, 
                                    bm::set_block_size_op);
                }
            }

            if (res != 0)
            {
                return res;
            }
        

        } // for j

    } // for i

    return 0;
}


// -----------------------------------------------------------------------

template<typename Alloc, typename MS> 
void bvector<Alloc, MS>::calc_stat(struct bvector<Alloc, MS>::statistics* st) const
{
    st->bit_blocks = st->gap_blocks 
                   = st->max_serialize_mem 
                   = st->memory_used = 0;

    ::memcpy(st->gap_levels, 
             blockman_.glen(), sizeof(gap_word_t) * bm::gap_levels);

    unsigned empty_blocks = 0;
    unsigned blocks_memory = 0;
    gap_word_t* gapl_ptr = st->gap_length;

    st->max_serialize_mem = sizeof(id_t) * 4;

    unsigned block_idx = 0;

    unsigned top_size = blockman_.effective_top_block_size();
    // Walk the blocks, calculate statistics.
    for (unsigned i = 0; i < top_size; ++i)
    {
        const bm::word_t* const* blk_blk = blockman_.get_topblock(i);

        if (!blk_blk) 
        {
            block_idx += bm::set_array_size;
            st->max_serialize_mem += sizeof(unsigned) + 1;
            continue;
        }

        for (unsigned j = 0;j < bm::set_array_size; ++j, ++block_idx)
        {
            const bm::word_t* blk = blk_blk[j];
            if (IS_VALID_ADDR(blk))
            {
                st->max_serialize_mem += empty_blocks << 2;
                empty_blocks = 0;

                if (BM_IS_GAP(blockman_, blk, block_idx)) // gap block
                {
                    ++(st->gap_blocks);

                    bm::gap_word_t* gap_blk = BMGAP_PTR(blk);

                    unsigned mem_used = 
                        bm::gap_capacity(gap_blk, blockman_.glen()) 
                        * sizeof(gap_word_t);

                    *gapl_ptr = gap_length(gap_blk);

                    st->max_serialize_mem += *gapl_ptr * sizeof(gap_word_t);
                    blocks_memory += mem_used;

                    ++gapl_ptr;
                }
                else // bit block
                {
                    ++(st->bit_blocks);
                    unsigned mem_used = sizeof(bm::word_t) * bm::set_block_size;
                    st->max_serialize_mem += mem_used;
                    blocks_memory += mem_used;
                }
            }
            else
            {
                ++empty_blocks;
            }
        }
    }  

    unsigned safe_inc = st->max_serialize_mem / 10; // 10% increment
    if (!safe_inc) safe_inc = 256;
    st->max_serialize_mem += safe_inc;

    // Calc size of different odd and temporary things.

    st->memory_used += sizeof(*this) - sizeof(blockman_);
    st->memory_used += blockman_.mem_used();
    st->memory_used += blocks_memory;
}


// -----------------------------------------------------------------------


template<class Alloc, class MS> 
bool bvector<Alloc, MS>::set_bit_no_check(bm::id_t n, bool val)
{
    // calculate logical block number
    unsigned nblock = unsigned(n >>  bm::set_block_shift); 

    int block_type;

    bm::word_t* blk = 
        blockman_.check_allocate_block(nblock, 
                                        val,
                                        get_new_blocks_strat(), 
                                        &block_type);

    if (!blk) return false;

    // calculate word number in block and bit
    unsigned nbit   = unsigned(n & bm::set_block_mask); 

    if (block_type == 1) // gap
    {
        unsigned is_set;
        unsigned new_block_len;
        
        new_block_len = 
            gap_set_value(val, BMGAP_PTR(blk), nbit, &is_set);
        if (is_set)
        {
            BMCOUNT_ADJ(val)

            unsigned threshold = 
            bm::gap_limit(BMGAP_PTR(blk), blockman_.glen());

            if (new_block_len > threshold) 
            {
                extend_gap_block(nblock, BMGAP_PTR(blk));
            }
            return true;
        }
    }
    else  // bit block
    {
        unsigned nword  = unsigned(nbit >> bm::set_word_shift); 
        nbit &= bm::set_word_mask;

        bm::word_t* word = blk + nword;
        bm::word_t  mask = (((bm::word_t)1) << nbit);

        if (val)
        {
            if ( ((*word) & mask) == 0 )
            {
                *word |= mask; // set bit
                BMCOUNT_INC;
                return true;
            }
        }
        else
        {
            if ((*word) & mask)
            {
                *word &= ~mask; // clear bit
                BMCOUNT_DEC;
                return true;
            }
        }
    }
    return false;
}

// -----------------------------------------------------------------------

template<class Alloc, class MS> 
bool bvector<Alloc, MS>::set_bit_conditional_impl(bm::id_t n, 
                                                  bool     val, 
                                                  bool     condition)
{
    // calculate logical block number
    unsigned nblock = unsigned(n >>  bm::set_block_shift); 

    int block_type;
    bm::word_t* blk = 
        blockman_.check_allocate_block(nblock, 
                                       val,
                                       get_new_blocks_strat(), 
                                       &block_type);
    if (!blk) 
        return false;

    // calculate word number in block and bit
    unsigned nbit   = unsigned(n & bm::set_block_mask); 

    if (block_type == 1) // gap
    {
        bm::gap_word_t* gap_blk = BMGAP_PTR(blk);
        bool old_val = (gap_test(gap_blk, nbit) != 0);

        if (old_val != condition) 
        {
            return false;
        }

        if (val != old_val)
        {
            unsigned is_set;
            unsigned new_block_len = 
                gap_set_value(val, gap_blk, nbit, &is_set);
            BM_ASSERT(is_set);
            BMCOUNT_ADJ(val)

            unsigned threshold = 
                bm::gap_limit(gap_blk, blockman_.glen());
            if (new_block_len > threshold) 
            {
                extend_gap_block(nblock, gap_blk);
            }
            return true;
        }
    }
    else  // bit block
    {
        unsigned nword  = unsigned(nbit >> bm::set_word_shift); 
        nbit &= bm::set_word_mask;

        bm::word_t* word = blk + nword;
        bm::word_t  mask = (((bm::word_t)1) << nbit);
        bool is_set = ((*word) & mask) != 0;

        if (is_set != condition)
        {
            return false;
        }
        if (is_set != val)    // need to change bit
        {
            if (val)          // set bit
            {
                *word |= mask;
                BMCOUNT_INC;
            }
            else               // clear bit
            {
                *word &= ~mask;
                BMCOUNT_DEC;
            }
            return true;
        }
    }
    return false;

}

// -----------------------------------------------------------------------


template<class Alloc, class MS> 
bool bvector<Alloc, MS>::and_bit_no_check(bm::id_t n, bool val)
{
    // calculate logical block number
    unsigned nblock = unsigned(n >>  bm::set_block_shift); 

    int block_type;
    bm::word_t* blk = 
        blockman_.check_allocate_block(nblock, 
                                       val,
                                       get_new_blocks_strat(), 
                                       &block_type);
    if (!blk) return false;

    // calculate word number in block and bit
    unsigned nbit   = unsigned(n & bm::set_block_mask); 

    if (block_type == 1) // gap
    {
        bm::gap_word_t* gap_blk = BMGAP_PTR(blk);
        bool old_val = (gap_test(gap_blk, nbit) != 0);

        bool new_val = val & old_val;
        if (new_val != old_val)
        {
            unsigned is_set;
            unsigned new_block_len = 
                gap_set_value(new_val, gap_blk, nbit, &is_set);
            BM_ASSERT(is_set);
            BMCOUNT_ADJ(val)

            unsigned threshold = 
                bm::gap_limit(gap_blk, blockman_.glen());
            if (new_block_len > threshold) 
            {
                extend_gap_block(nblock, gap_blk);
            }
            return true;
        }
    }
    else  // bit block
    {
        unsigned nword  = unsigned(nbit >> bm::set_word_shift); 
        nbit &= bm::set_word_mask;

        bm::word_t* word = blk + nword;
        bm::word_t  mask = (((bm::word_t)1) << nbit);
        bool is_set = ((*word) & mask) != 0;

        bool new_val = is_set & val;
        if (new_val != val)    // need to change bit
        {
            if (new_val)       // set bit
            {
                *word |= mask;
                BMCOUNT_INC;
            }
            else               // clear bit
            {
                *word &= ~mask;
                BMCOUNT_DEC;
            }
            return true;
        }
    }
    return false;
}


//---------------------------------------------------------------------

template<class Alloc, class MS> 
bm::id_t bvector<Alloc, MS>::check_or_next(bm::id_t prev) const
{
    for (;;)
    {
        unsigned nblock = unsigned(prev >> bm::set_block_shift); 
        if (nblock >= bm::set_total_blocks) 
            break;

        if (blockman_.is_subblock_null(nblock >> bm::set_array_shift))
        {
            prev += (bm::set_blkblk_mask + 1) -
                            (prev & bm::set_blkblk_mask);
        }
        else
        {
            unsigned nbit = unsigned(prev & bm::set_block_mask);
            int no_more_blocks;
            const bm::word_t* block = 
                blockman_.get_block(nblock, &no_more_blocks);

            if (no_more_blocks) 
            {
                BM_ASSERT(block == 0);
                break;
            }

            if (block)
            {
                if (IS_FULL_BLOCK(block)) return prev;
                if (BM_IS_GAP(blockman_, block, nblock))
                {
                    if (bm::gap_find_in_block(BMGAP_PTR(block),
                                                nbit,
                                                &prev))
                    {
                        return prev;
                    }
                }
                else
                {
                    if (bm::bit_find_in_block(block, nbit, &prev)) 
                    {
                        return prev;
                    }
                }
            }
            else
            {
                prev += (bm::set_block_mask + 1) - 
                            (prev & bm::set_block_mask);
            }

        }
        if (!prev) break;
    }

    return 0;
}


//---------------------------------------------------------------------

template<class Alloc, class MS> 
bm::id_t bvector<Alloc, MS>::check_or_next_extract(bm::id_t prev)
{
    for (;;)
    {
        unsigned nblock = unsigned(prev >> bm::set_block_shift); 
        if (nblock >= bm::set_total_blocks) break;

        if (blockman_.is_subblock_null(nblock >> bm::set_array_shift))
        {
            prev += (bm::set_blkblk_mask + 1) -
                            (prev & bm::set_blkblk_mask);
        }
        else
        {
            unsigned nbit = unsigned(prev & bm::set_block_mask);

            int no_more_blocks;
            bm::word_t* block = 
                blockman_.get_block(nblock, &no_more_blocks);

            if (no_more_blocks) 
            {
                BM_ASSERT(block == 0);
                break;
            }


            if (block)
            {
                if (IS_FULL_BLOCK(block))
                {
                    set(prev, false);
                    return prev;
                }
                if (BM_IS_GAP(blockman_, block, nblock))
                {
                    unsigned is_set;
                    unsigned new_block_len = 
                        gap_set_value(0, BMGAP_PTR(block), nbit, &is_set);
                    if (is_set) {
                        BMCOUNT_DEC
                        unsigned threshold = 
                            bm::gap_limit(BMGAP_PTR(block), blockman_.glen());
                        if (new_block_len > threshold) 
                        {
                            extend_gap_block(nblock, BMGAP_PTR(block));
                        }
                        return prev;
                    } else {
                        if (bm::gap_find_in_block(BMGAP_PTR(block),
                                                    nbit,
                                                    &prev))
                        {
                            set(prev, false);
                            return prev;
                        }
                    }
                }
                else // bit block
                {
                    if (bm::bit_find_in_block(block, nbit, &prev)) 
                    {
                        BMCOUNT_DEC

                        unsigned nbit = 
                            unsigned(prev & bm::set_block_mask); 
                        unsigned nword = 
                            unsigned(nbit >> bm::set_word_shift);
                        nbit &= bm::set_word_mask;
                        bm::word_t* word = block + nword;
                        bm::word_t  mask = ((bm::word_t)1) << nbit;
                        *word &= ~mask;

                        return prev;
                    }
                }
            }
            else
            {
                prev += (bm::set_block_mask + 1) - 
                            (prev & bm::set_block_mask);
            }

        }
        if (!prev) break;
    }

    return 0;
}

//---------------------------------------------------------------------

template<class Alloc, class MS> 
void bvector<Alloc, MS>::combine_operation(
                                  const bm::bvector<Alloc, MS>& bvect, 
                                  bm::operation                 opcode)
{
    typedef void (*block_bit_op)(bm::word_t*, const bm::word_t*);
    typedef void (*block_bit_op_next)(bm::word_t*, 
                                        const bm::word_t*, 
                                        bm::word_t*, 
                                        const bm::word_t*);

    unsigned top_blocks = blockman_.top_block_size();
    unsigned bvect_top_blocks = bvect.blockman_.top_block_size();

    if (size_ == bvect.size_) 
    {
        BM_ASSERT(top_blocks >= bvect_top_blocks);
    }
    else
    if (size_ < bvect.size_) // this vect shorter than the arg.
    {
        size_ = bvect.size_;
        // stretch our capacity
        blockman_.reserve_top_blocks(bvect_top_blocks);
        top_blocks = blockman_.top_block_size();
    }
    else 
    if (size_ > bvect.size_) // this vector larger
    {
        if (opcode == BM_AND) // clear the tail with zeros
        {
            set_range(bvect.size_, size_ - 1, false);
            if (bvect_top_blocks < top_blocks)
            {
                // not to scan blocks we already swiped
                top_blocks = bvect_top_blocks;
            }
        }
    }
    
    bm::word_t*** blk_root = blockman_.blocks_root();
    unsigned block_idx = 0;
    unsigned i, j;

    BM_SET_MMX_GUARD

    // calculate effective top size to avoid overscan
    top_blocks = blockman_.effective_top_block_size();
    if (top_blocks < bvect.blockman_.effective_top_block_size())
    {
        if (opcode != BM_AND)
        {
            top_blocks = bvect.blockman_.effective_top_block_size();
        }
    }

    for (i = 0; i < top_blocks; ++i)
    {
        bm::word_t** blk_blk = blk_root[i];

        if (blk_blk == 0) // not allocated
        {
            if (opcode == BM_AND) // 0 AND anything == 0
            {
                block_idx += bm::set_array_size;
                continue; 
            }
            const bm::word_t* const* bvbb = bvect.blockman_.get_topblock(i);
            if (bvbb == 0) // skip it because 0 OP 0 == 0 
            {
                block_idx += bm::set_array_size;
                continue; 
            }
            // 0 - self, non-zero argument
            for (j = 0; j < bm::set_array_size; ++j,++block_idx)
            {
                const bm::word_t* arg_blk = 
                    bvect.blockman_.get_block(i, j);
                if (arg_blk != 0)
                {
                    bool arg_gap = 
                        BM_IS_GAP(bvect.blockman_, arg_blk, block_idx);
                    combine_operation_with_block(block_idx, 0, 0, 
                                                 arg_blk, arg_gap, 
                                                 opcode);
                }

            } // for j
            continue;
        }

        for (j = 0; j < bm::set_array_size; ++j, ++block_idx)
        {            
            bm::word_t* blk = blk_blk[j];
            const bm::word_t* arg_blk = bvect.blockman_.get_block(i, j);
        
            if (arg_blk || blk)
            {
                if (opcode == BM_AND)
                {
                    if (!blk) continue;
                    if (!arg_blk)
                    {
                        if (blk) blockman_.zero_block(block_idx);
                        continue;
                    }
                }

                bool arg_gap = BM_IS_GAP(bvect.blockman_, arg_blk, block_idx);
                bool gap = BM_IS_GAP((*this).blockman_, blk, block_idx);
                combine_operation_with_block(block_idx, gap, blk, 
                                             arg_blk, arg_gap,
                                             opcode);
            }

        } // for j

    } // for i

}


//---------------------------------------------------------------------


template<class Alloc, class MS> 
void 
bvector<Alloc, MS>::combine_operation_with_block(unsigned          nb,
                                                 unsigned          gap,
                                                 bm::word_t*       blk,
                                                 const bm::word_t* arg_blk,
                                                 int               arg_gap,
                                                 bm::operation     opcode)
{
    if (!blk && arg_gap && (opcode == BM_OR || opcode == BM_XOR)) 
    {
        blk = 
            blockman_.check_allocate_block(nb, 
                                        0,
                                        BM_GAP, 
                                        (int*)&gap,
                                        false /*no null return*/);
    }

        if (gap) // our block GAP-type
        {
            if (arg_gap)  // both blocks GAP-type
            {
                gap_word_t tmp_buf[bm::gap_equiv_len * 3]; // temporary result            
                gap_word_t* res;
                unsigned res_len;

                gap_operation_func_type gfunc = 
                    operation_functions<true>::gap_operation(opcode);
                BM_ASSERT(gfunc);
                res = (*gfunc)(BMGAP_PTR(blk), 
                               BMGAP_PTR(arg_blk), 
                               tmp_buf,
                               res_len);
                BM_ASSERT(res == tmp_buf);
                ++res_len;// = bm::gap_length(res);

                BM_ASSERT(!(res == tmp_buf && res_len == 0));

                // if as a result of the operation gap block turned to zero
                // we can now replace it with NULL
                if (gap_is_all_zero(res, bm::gap_max_bits))
                {
                    blockman_.zero_block(nb);
                    return;
                }

                // mutation check

                int level = gap_level(BMGAP_PTR(blk));
                unsigned threshold = blockman_.glen(level)-4;
                int new_level = gap_calc_level(res_len, blockman_.glen());

                if (new_level == -1)
                {
                    blockman_.convert_gap2bitset(nb, res);
                    return;
                }

                if (res_len > threshold)
                {
                    set_gap_level(res, new_level);
                    gap_word_t* new_blk = 
                        blockman_.allocate_gap_block(new_level, res);

                    bm::word_t* p = (bm::word_t*)new_blk;
                    BMSET_PTRGAP(p);

                    blockman_.set_block_ptr(nb, p);
                    blockman_.get_allocator().free_gap_block(BMGAP_PTR(blk), 
                                                            blockman_.glen());
                    return;
                }

                // gap opeartion result is in the temporary buffer
                // we copy it back to the gap_block

                set_gap_level(tmp_buf, level);
                ::memcpy(BMGAP_PTR(blk), tmp_buf, res_len * sizeof(gap_word_t));
                return;
            }
            else // argument is BITSET-type (own block is GAP)
            {
                // since we can not combine blocks of mixed type
                // we need to convert our block to bitset
               
                if (arg_blk == 0)  // Combining against an empty block
                {
                    switch (opcode)
                    {
                    case BM_AND:  // ("Value" AND  0) == 0
                        blockman_.zero_block(nb);
                        return;
                    case BM_OR: case BM_SUB: case BM_XOR:
                        return; // nothing to do
                    }
                }
                gap_word_t* gap_blk = BMGAP_PTR(blk);
                if (opcode == BM_AND)
                {
                    unsigned gap_cnt = gap_bit_count(gap_blk);
                    if (gap_cnt < 128)
                    {
                        gap_word_t tmp_buf[bm::gap_equiv_len * 3];         
                        gap_word_t arr_len = 
                            gap_convert_to_arr(tmp_buf, gap_blk, 
                                               bm::gap_equiv_len-10);
                        BM_ASSERT(gap_cnt == arr_len);
                        blockman_.zero_block(nb);
                        unsigned arr_i = 0;
                        int block_type;
                        blk =
                            blockman_.check_allocate_block(nb,
                                                           true,
                                                           BM_GAP,
                                                           &block_type,
                                                           false //no null return
                                                           );
                        BM_ASSERT(block_type==1); // GAP
                        gap_blk = BMGAP_PTR(blk);
                        unsigned threshold = bm::gap_limit(gap_blk, blockman_.glen());
                        for (; arr_i < arr_len; ++arr_i)
                        {
                            gap_word_t bit_idx = tmp_buf[arr_i];
                            if (bm::test_bit(arg_blk, bit_idx))
                            {
                                unsigned is_set;
                                unsigned new_block_len =
                                    gap_set_value(true, gap_blk, bit_idx, &is_set);
                                BM_ASSERT(is_set);
                                if (new_block_len > threshold) 
                                {
                                    gap_blk = 
                                        blockman_.extend_gap_block(nb, gap_blk);
                                    if (gap_blk == 0) // mutated into bit-block
                                    {
                                        blk = blockman_.check_allocate_block(
                                                         nb,
                                                         true,
                                                         this->get_new_blocks_strat(),
                                                         &block_type,
                                                         false // no null return
                                                         );  
                                        BM_ASSERT(block_type == 0); // BIT
                                        // target block degraded into plain bit-block
                                        for (++arr_i; arr_i < arr_len; ++arr_i)
                                        {
                                            bit_idx = tmp_buf[arr_i];
                                            if (bm::test_bit(arg_blk, bit_idx))
                                            {
                                                or_bit_block(blk, bit_idx, 1);
                                            }
                                        } // for arr_i
                                        return;
                                    } // if gap mutated
                                }
                            } // for arr_i
                        }

                        return;
                    }                    
                } // BM_AND

                blk = blockman_.convert_gap2bitset(nb, gap_blk);
            }
        } 
        else // our block is BITSET-type
        {
            if (arg_gap) // argument block is GAP-type
            {
                if (IS_VALID_ADDR(blk))
                {
                    // special case, maybe we can do the job without 
                    // converting the GAP argument to bitblock
                    gap_operation_to_bitset_func_type gfunc = 
                        operation_functions<true>::gap_op_to_bit(opcode);
                    BM_ASSERT(gfunc);
                    (*gfunc)(blk, BMGAP_PTR(arg_blk));
                    return;
                }
                
                // the worst case we need to convert argument block to 
                // bitset type.
                gap_word_t* temp_blk = (gap_word_t*) blockman_.check_allocate_tempblock();
                arg_blk = 
                    gap_convert_to_bitset_smart((bm::word_t*)temp_blk, 
                                                BMGAP_PTR(arg_blk), 
                                                bm::gap_max_bits);
            
            }   
        }
    
        // Now here we combine two plain bitblocks using supplied bit function.
        bm::word_t* dst = blk;

        bm::word_t* ret; 
        if (dst == 0 && arg_blk == 0)
        {
            return;
        }

        switch (opcode)
        {
        case BM_AND:
            ret = bit_operation_and(dst, arg_blk);
            goto copy_block;
        case BM_XOR:
            ret = bit_operation_xor(dst, arg_blk);
            if (ret && (ret == arg_blk) && IS_FULL_BLOCK(dst))
            {
                ret = blockman_.get_allocator().alloc_bit_block();
#ifdef BMVECTOPT
            VECT_XOR_ARR_2_MASK(ret, 
                                arg_blk, 
                                arg_blk + bm::set_block_size, 
                                bm::all_bits_mask);
#else
                bm::wordop_t* dst_ptr = (wordop_t*)ret;
                const bm::wordop_t* wrd_ptr = (wordop_t*) arg_blk;
                const bm::wordop_t* wrd_end = 
                (wordop_t*) (arg_blk + bm::set_block_size);

                do
                {
                    dst_ptr[0] = bm::all_bits_mask ^ wrd_ptr[0];
                    dst_ptr[1] = bm::all_bits_mask ^ wrd_ptr[1];
                    dst_ptr[2] = bm::all_bits_mask ^ wrd_ptr[2];
                    dst_ptr[3] = bm::all_bits_mask ^ wrd_ptr[3];

                    dst_ptr+=4;
                    wrd_ptr+=4;

                } while (wrd_ptr < wrd_end);
#endif
                break;
            }
            goto copy_block;
        case BM_OR:
            ret = bit_operation_or(dst, arg_blk);
        copy_block:
            if (ret && (ret == arg_blk) && !IS_FULL_BLOCK(ret))
            {
            ret = blockman_.get_allocator().alloc_bit_block();
            bit_block_copy(ret, arg_blk);
            }
            break;

        case BM_SUB:
            ret = bit_operation_sub(dst, arg_blk);
            if (ret && ret == arg_blk)
            {
                ret = blockman_.get_allocator().alloc_bit_block();
#ifdef BMVECTOPT
                VECT_ANDNOT_ARR_2_MASK(ret, 
                                    arg_blk,
                                    arg_blk + bm::set_block_size,
                                    bm::all_bits_mask);
#else

                bm::wordop_t* dst_ptr = (wordop_t*)ret;
                const bm::wordop_t* wrd_ptr = (wordop_t*) arg_blk;
                const bm::wordop_t* wrd_end = 
                (wordop_t*) (arg_blk + bm::set_block_size);

                do
                {
                    dst_ptr[0] = bm::all_bits_mask & ~wrd_ptr[0];
                    dst_ptr[1] = bm::all_bits_mask & ~wrd_ptr[1];
                    dst_ptr[2] = bm::all_bits_mask & ~wrd_ptr[2];
                    dst_ptr[3] = bm::all_bits_mask & ~wrd_ptr[3];

                    dst_ptr+=4;
                    wrd_ptr+=4;

                } while (wrd_ptr < wrd_end);
#endif
            }
            break;
        default:
            BM_ASSERT(0);
            ret = 0;
        }

        if (ret != dst) // block mutation
        {
            blockman_.set_block(nb, ret);
            blockman_.get_allocator().free_bit_block(dst);
        }
}

//---------------------------------------------------------------------

template<class Alloc, class MS> 
void bvector<Alloc, MS>::set_range_no_check(bm::id_t left,
                                            bm::id_t right,
                                            bool     value)
{
    // calculate logical number of start and destination blocks
    unsigned nblock_left  = unsigned(left  >>  bm::set_block_shift);
    unsigned nblock_right = unsigned(right >>  bm::set_block_shift);

    bm::word_t* block = blockman_.get_block(nblock_left);
    bool left_gap = BM_IS_GAP(blockman_, block, nblock_left);

    unsigned nbit_left  = unsigned(left  & bm::set_block_mask); 
    unsigned nbit_right = unsigned(right & bm::set_block_mask); 

    unsigned r = 
        (nblock_left == nblock_right) ? nbit_right :(bm::bits_in_block-1);

        bm::gap_word_t tmp_gap_blk[5] = {0,};

    // Set bits in the starting block

    unsigned nb;
    if ((nbit_left == 0) && (r == bm::bits_in_block - 1)) // full block
    {
        nb = nblock_left;
    }
    else
    {
        gap_init_range_block(tmp_gap_blk,
                            nbit_left, r, value, bm::bits_in_block);

        combine_operation_with_block(nblock_left, 
                                    left_gap, 
                                    block,
                                    (bm::word_t*) tmp_gap_blk,
                                    1,
                                    value ? BM_OR : BM_AND);

        if (nblock_left == nblock_right)  // in one block
            return;
        nb = nblock_left+1;
    }

    // Set (or clear) all full blocks between left and right
    
    unsigned nb_to = nblock_right + (nbit_right ==(bm::bits_in_block-1));
            
    if (value)
    {
        for (; nb < nb_to; ++nb)
        {
            block = blockman_.get_block(nb);
            if (IS_FULL_BLOCK(block)) 
                continue;

            bool is_gap = BM_IS_GAP(blockman_, block, nb);

            blockman_.set_block(nb, FULL_BLOCK_ADDR);
            blockman_.set_block_bit(nb);
            
            if (is_gap)
            {
                blockman_.get_allocator().free_gap_block(BMGAP_PTR(block), 
                                                            blockman_.glen());
            }
            else
            {
                blockman_.get_allocator().free_bit_block(block);
            }
            
        } // for
    }
    else // value == 0
    {
        for (; nb < nb_to; ++nb)
        {
            block = blockman_.get_block(nb);
            if (block == 0)  // nothing to do
                continue;
            bool is_gap = BM_IS_GAP(blockman_, block, nb);
            blockman_.set_block(nb, 0, false /*bit*/);
            //blockman_.set_block_bit(nb);

            if (is_gap) 
            {
                blockman_.get_allocator().free_gap_block(BMGAP_PTR(block),
                                                         blockman_.glen());
            }
            else
            {
                blockman_.get_allocator().free_bit_block(block);
            }

        } // for
    } // if value else 

    if (nb_to > nblock_right)
        return;

    block = blockman_.get_block(nblock_right);
    bool right_gap = BM_IS_GAP(blockman_, block, nblock_right);

    gap_init_range_block(tmp_gap_blk, 
                            0, nbit_right, value, bm::bits_in_block);

    combine_operation_with_block(nblock_right, 
                                    right_gap, 
                                    block,
                                    (bm::word_t*) tmp_gap_blk,
                                    1,
                                    value ? BM_OR : BM_AND);

}

//---------------------------------------------------------------------


} // namespace

#include "bmundef.h"

#ifdef _MSC_VER
#pragma warning( default : 4311 4312)
#endif


#endif

---