🚀 go-pugleaf

Hi

I'm porting code from BCB3 to BCB6, which uses STL string and stream 
classes.
No matter what the include file, I get either "undefined symbol 'string' " & 
"undefined symbol 'ifstream' "
or (if I include oldstl/string.stl) "multiple definitions errors"
The BCB6 headers are below.  The // comments are mine

Should I be using the old Roguewave STl or SPLport ?
How do I get the correct header to load ?
what is macro def  "__cplusplus"   all about

#if !defined(__cplusplus)
# include <_str.h>                                                 //'C' 
string functions, no string class defs
# else /* __cplusplus */
# include <_str.h>
# if defined(__USING_STD_NAMES__)
# ifdef _USE_OLD_RW_STL
# include <oldstl/string.stl>                                   // stub 
redirector for _str.h or oldstl/string.stl
# else
# include <stlport/string>                                      //see below
# endif
# endif /* __USING_STD_NAMES__ */
#endif

contents of stlport/string

# ifndef _STLP_STRING
# define _STLP_STRING
# ifndef _STLP_OUTERMOST_HEADER_ID
#  define _STLP_OUTERMOST_HEADER_ID 0x68
#  include <stl/_prolog.h>                                      //contains 
no class definitions
# endif
#if defined (_STLP_USE_NATIVE_STRING)     .
# if defined (_STLP_MSVC)
#  include <streambuf>
#  include <istream>
# endif
#  include _STLP_NATIVE_HEADER(string)
# endif /* _STLP_USE_NATIVE_STRING */
# if !defined (_STLP_USE_NATIVE_STRING) || defined (_STLP_USE_OWN_NAMESPACE)
# include <stl/_string.h> 
//Standard C++ string class. Including this file gives "undefined symbol 
'string'"
# else
# include <stl/_string_hash.h>                                  //no class 
definitions
# endif /*_STLP_USE_NATIVE_STRING */
// cleanup
# if (_STLP_OUTERMOST_HEADER_ID == 0x68)
#  include <stl/_epilog.h>
#  undef _STLP_OUTERMOST_HEADER_ID
# endif
#endif /* _STLP_STRING */