[Boost-users] Platform-specific Boost filesystem warning

From: Caleb Gingles (nairou_at_[hidden])
Date: 2008-03-07 22:54:05

(Please forgive me if this has already been discussed, I'm new to the list
and wasn't able to find it.)

I'm using Boost 1.34.1 under MSVC8 and am experiencing a compile warning
that I thought was a bit odd.

Whenever I include convenience.hpp, I and up with the following warning:

d:\prgrmmng\libraries\boost_1_34_1\boost\filesystem\convenience.hpp(46) :
warning C4245: 'argument' : conversion from 'int' to
'boost::filesystem::system_error_type', signed/unsigned mismatch

I eventually tracked this down to the following code in path.hpp:

# ifdef BOOST_WINDOWS_API
    typedef unsigned system_error_type;

    BOOST_FILESYSTEM_DECL
    errno_type lookup_errno( system_error_type sys_err_code );
# else
    typedef int system_error_type;

    inline errno_type lookup_errno( system_error_type sys_err_code )
      { return sys_err_code; }
# endif

Why is system_error_type given a different type depending on the platform?