Configuration question

From: Beman Dawes (bdawes_at_[hidden])
Date: 2002-02-25 10:14:25

For the file system library several of us are working on, there initially 
will be two implementations:  Win32 and POSIX.

It would be nice for users if the correct implementation were selected 
automatically.

For example, say we have an implementation file foo.cpp, which is stable 
and contains something like:

   #if ???? // in effect, #if defined(BOOST_POSIX)
   #  define BOOST_FILE_TO_COMPILE "libs/filesystem/src/foo_posix.cpp"
   #elif ???? // in effect, #if defined(BOOST_WIN32)
   #  define BOOST_FILE_TO_COMPILE "libs/filesystem/src/foo_win32.cpp"
   #else
   #  error Sorry, your platform not supported
   #endif

   #include BOOST_FILE_TO_COMPILE

Questions:

Is this the best general form for solving the problem?

What should ???? actually be?  We can't use BOOST_PLATFORM; it is a string 
rather than an integral expression, and the value is too specific anyhow.

Should we add BOOST_WIN32, BOOST_POSIX, and the like to the Boost config 
system?

--Beman