[boost] [1.44] [filesystem] filesystem::path construction problems in version 3

19 Aug 2010


      It seems Boost.Filesystem v. 3 in Boost 1.44 has some problems in 
filesystem::path construction.

    Firstly it does not work well when a C array is given to the 
constructor. Problem is illustrated with following code:

----------------------------------------
#include <cstdio>
#include <string>
#define BOOST_FILESYSTEM_VERSION 3
#include <boost/filesystem.hpp>


int main( int argc, char* argv[] )
{
    char big[100];
    char* small = "d:/foo/";

    boost::filesystem::path pathFromSmall( small );
    pathFromSmall /= "bar.txt";
    std::printf( "%s\n", pathFromSmall.string< std::string >().c_str() );

    std::strcpy( big, small );

    boost::filesystem::path pathFromBig( big );
    pathFromBig /= "bar.txt";
    std::printf( "%s\n", pathFromBig.string< std::string >().c_str() );

    return 0;
}
----------------------------------------

    Secondly filesystem::path accepts to much in its constructors. Currently 
it accepts even shared_ptr. This is illustrated by following code which was 
fine in 1.43 while in 1.44 it results in compilation error (VS 2010) of 
ambiguous call to "fun".

----------------------------------------
#define BOOST_FILESYSTEM_VERSION 3
#include <boost/filesystem.hpp>
#include <boost/smart_ptr.hpp>


class Base
{
};

class Derived : public Base
{
};


void fun( const boost::filesystem::path& _path )
{
}

void fun( const boost::shared_ptr< Base >& _pBase )
{
}


int main( int argc, char* argv[] )
{
    boost::shared_ptr< Derived > pDerived( new Derived() );
    fun( pDerived );

    return 0;
}
----------------------------------------

    Adam Badura