[boost] Dynamic bitset library - compilation problem on windows (boost 1_37_0onwards)

Subject: [boost] Dynamic bitset library - compilation problem on windows (boost 1_37_0onwards)
From: Aniket Bhat (anbhat_at_[hidden])
Date: 2009-05-13 11:43:48

I am seeing problems with msvc when compiling a simple code snippet that
instantiates a dynamic_bitset with a uint64_t. The problem occurs when
instantiating a template specialization for the resize function for
uint64_t. There was a change made to the block_width_type typedef from an
int in 1_36_0 to block_type in 1_37_0. This change seems to have broken
support for uint64_t data-types on 32-bit windows systems or any other types
which are bigger than size_t on a given platform.

Code snippet:

#include <boost/dynamic_bitset.hpp>

#include <iostream>

#if defined (__GNUC__)

#if !defined (SUNOS_OS)

typedef unsigned long long uint64_t;

#endif

#else

typedef unsigned __int64   uint64_t;

#endif

typedef uint64_t myType;

boost::dynamic_bitset<myType>::size_type

foo()

{

    unsigned int blockHandles(10);

    return (boost::dynamic_bitset<myType>::size_type
)(blockHandles*sizeof(myType)*8);

}

int main(int argc,char**argv)

{

      boost::dynamic_bitset<myType>::size_type t = foo();

      boost::dynamic_bitset<myType> m_myBitSet;

      m_myBitSet.resize(12,false);

}

Compilation error:

Compiling...

TestBitSet.cpp

c:\p3_dev_boost\common\lib\boost_1_39_0\boost\dynamic_bitset\dynamic_bitset.hpp(673)
: error C2220: warning treated as error - no 'object' file generated

c:\p3_dev_boost\common\lib\boost_1_39_0\boost\dynamic_bitset\dynamic_bitset.hpp(649)
: while compiling class template member function 'void
boost::dynamic_bitset<Block>::resize(boost::dynamic_bitset<Block>::size_type,bool)'

        with

        [

            Block=myType

        ]

        c:\documents and settings\abhat\my
documents\aniket\projects\dynamic_bitset\testbitset\testbitset.cpp(17) : see
reference to class template instantiation 'boost::dynamic_bitset<Block>'
being compiled

        with

        [

            Block=myType

        ]

c:\p3_dev_boost\common\lib\boost_1_39_0\boost\dynamic_bitset\dynamic_bitset.hpp(673)
: warning C4244: 'initializing' : conversion from 'unsigned __int64' to
'const boost::dynamic_bitset<Block>::size_type', possible loss of data

        with

        [

            Block=myType

        ]

The resize function (dynamic_bitset.hpp:673) calls count_extra_bits() which
returns a size_type instead of block_width_type resulting in possible loss
of data. At all other places this function is called within the header, it
returns a block_width_type. I am not sure if it has to return a size_type in
this particular case for a specific reason?

Thanks,

Aniket.