spirit's file_iterator truncates file size value on Windows x64 (VC8.0express)

[peter.myerscough-jackopson@…]

I have written a grammar to read in a file. I am using spirit's file_iterator class to enable the parse(...) function to read directly from the file and I get the following warning:

1> XXX\boost\boost_1_34_0\boost/spirit/iterator/impl/file_iterator.ipp(276) : warning C4244: 'return' : conversion from '__w64 int' to 'long', possible loss of data
1>        XXX\boost\boost_1_34_0\boost/spirit/iterator/impl/file_iterator.ipp(276) : while compiling class template member function 'long boost::spirit::fileiter_impl::mmap_file_iterator<CharT>::distance(const boost::spirit::fileiter_impl::mmap_file_iterator<CharT> &) const'
1>        with
1>        [
1>            CharT=char
1>        ]
1>        XXX\boost\boost_1_34_0\boost/spirit/iterator/file_iterator.hpp(118) : see reference to class template instantiation 'boost::spirit::fileiter_impl::mmap_file_iterator<CharT>' being compiled
1>        with
1>        [
1>            CharT=char
1>        ]
1>        XXX\boost\boost_1_34_0\boost/spirit/iterator/file_iterator.hpp(152) : see reference to class template instantiation 'boost::spirit::fileiter_impl::file_iter_generator<CharT,BaseIteratorT>' being compiled
1>        with
1>        [
1>            CharT=char,
1>            BaseIteratorT=boost::spirit::fileiter_impl::mmap_file_iterator<char>
1>        ]
1>        .\myfile.cpp(121) : see reference to class template instantiation 'boost::spirit::file_iterator<>' being compiled

This would be a problem for me if my file's were large, but they are not. Essentially in the file_iterator.ipp function the

long distance(const mmap_file_iterator& iter) const

is wrong as the difference between pointers on a 64bit windows computer is not a long. I think this needs to change to:

ptrdiff_t distance(const mmap_file_iterator& iter) const

I have tried this in my copy of the file, but the warning moves to the files/classes that use the function. I am also not sure about the other considerations for this function's return type, so I haven't proposed a patch.

I am compiling on Windows XP Pro x64, using MSVC++ 8.0 express edition (with SP1) on Xeon CPUs. I'm pretty sure the problem was also present without SP1.

[Hartmut Kaiser]

Fixed in Boost CVS::HEAD.

[Thomas Witt]

Reopened for consideration in 1.34.1.

[Hartmut Kaiser]

Patch for boost/spirit/iterator/file_iterator.hpp

[Hartmut Kaiser]

patch for boost/spirit/iterator/impl/file_iterator.ipp

[Thomas Witt]

Patch applied to RC_1_34_0.