text: //  (C) Copyright John Maddock 2001.
  //  (C) Copyright Jens Maurer 2001.
  //  Use, modification and distribution are subject to the
  //  Boost Software License, Version 1.0. (See accompanying file
  //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  
  //  See http://www.boost.org for most recent version.
  
  //  config for libstdc++ v3
  //  not much to go in here:
  
  #define BOOST_GNU_STDLIB 1
  
  #ifdef __GLIBCXX__
  #define BOOST_STDLIB "GNU libstdc++ version " BOOST_STRINGIZE(__GLIBCXX__)
  #else
  #define BOOST_STDLIB "GNU libstdc++ version " BOOST_STRINGIZE(__GLIBCPP__)
  #endif
  
  #if !defined(_GLIBCPP_USE_WCHAR_T) && !defined(_GLIBCXX_USE_WCHAR_T)
  #  define BOOST_NO_CWCHAR
  #  define BOOST_NO_CWCTYPE
  #  define BOOST_NO_STD_WSTRING
  #  define BOOST_NO_STD_WSTREAMBUF
  #endif
  
  #if defined(__osf__) && !defined(_REENTRANT) \
    && ( defined(_GLIBCXX_HAVE_GTHR_DEFAULT) || defined(_GLIBCPP_HAVE_GTHR_DEFAULT) )
  // GCC 3 on Tru64 forces the definition of _REENTRANT when any std lib header
  // file is included, therefore for consistency we define it here as well.
  #  define _REENTRANT
  #endif
  
  #ifdef __GLIBCXX__ // gcc 3.4 and greater:
  #  if defined(_GLIBCXX_HAVE_GTHR_DEFAULT) \
          || defined(_GLIBCXX__PTHREADS)
        //
        // If the std lib has thread support turned on, then turn it on in Boost
        // as well.  We do this because some gcc-3.4 std lib headers define _REENTANT
        // while others do not...
        //
  #     define BOOST_HAS_THREADS
  #  else
  #     define BOOST_DISABLE_THREADS
  #  endif
  #elif defined(__GLIBCPP__) \
          && !defined(_GLIBCPP_HAVE_GTHR_DEFAULT) \
          && !defined(_GLIBCPP__PTHREADS)
     // disable thread support if the std lib was built single threaded:
  #  define BOOST_DISABLE_THREADS
  #endif
  
  #if (defined(linux) || defined(__linux) || defined(__linux__)) && defined(__arm__) && defined(_GLIBCPP_HAVE_GTHR_DEFAULT)
  // linux on arm apparently doesn't define _REENTRANT
  // so just turn on threading support whenever the std lib is thread safe:
  #  define BOOST_HAS_THREADS
  #endif
  
  #if !defined(_GLIBCPP_USE_LONG_LONG) \
      && !defined(_GLIBCXX_USE_LONG_LONG)\
      && defined(BOOST_HAS_LONG_LONG)
  // May have been set by compiler/*.hpp, but "long long" without library
  // support is useless.
  #  undef BOOST_HAS_LONG_LONG
  #endif
  
  // Apple doesn't seem to reliably defined a *unix* macro
  #if !defined(CYGWIN) && (  defined(__unix__)  \
                          || defined(__unix)    \
                          || defined(unix)      \
                          || defined(__APPLE__) \
                          || defined(__APPLE)   \
                          || defined(APPLE))
  #  include <unistd.h>
  #endif
  
  #if defined(__GLIBCXX__) || (defined(__GLIBCPP__) && __GLIBCPP__>=20020514) // GCC >= 3.1.0
  #  define BOOST_STD_EXTENSION_NAMESPACE __gnu_cxx
  #  define BOOST_HAS_SLIST
  #  define BOOST_HAS_HASH
  #  define BOOST_SLIST_HEADER <ext/slist>
  # if !defined(__GNUC__) || __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 3)
  #   define BOOST_HASH_SET_HEADER <ext/hash_set>
  #   define BOOST_HASH_MAP_HEADER <ext/hash_map>
  # else
  #   define BOOST_HASH_SET_HEADER <backward/hash_set>
  #   define BOOST_HASH_MAP_HEADER <backward/hash_map>
  # endif
  #endif
  
  //  stdlibc++ C++0x support is detected via __GNUC__, __GNUC_MINOR__, and possibly
  //  __GNUC_PATCHLEVEL__ at the suggestion of Jonathan Wakely, one of the stdlibc++
  //  developers. He also commented:
  //
  //       "I'm not sure how useful __GLIBCXX__ is for your purposes, for instance in
  //       GCC 4.2.4 it is set to 20080519 but in GCC 4.3.0 it is set to 20080305.
  //       Although 4.3.0 was released earlier than 4.2.4, it has better C++0x support
  //       than any release in the 4.2 series."
  //
  //  Another resource for understanding stdlibc++ features is:
  //  http://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#manual.intro.status.standard.200x
  
  //  C++0x headers in GCC 4.3.0 and later
  //
  #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 3) || !defined(__GXX_EXPERIMENTAL_CXX0X__)
  #  define BOOST_NO_0X_HDR_ARRAY
  #  define BOOST_NO_0X_HDR_REGEX
  #  define BOOST_NO_0X_HDR_TUPLE
  #  define BOOST_NO_STD_UNORDERED  // deprecated; see following
  #  define BOOST_NO_0X_HDR_UNORDERED_MAP
  #  define BOOST_NO_0X_HDR_UNORDERED_SET
  #endif
  
  //  C++0x headers in GCC 4.4.0 and later
  //
  #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 4) || !defined(__GXX_EXPERIMENTAL_CXX0X__)
  #  define BOOST_NO_0X_HDR_CHRONO
  #  define BOOST_NO_0X_HDR_CONDITION_VARIABLE
  #  define BOOST_NO_0X_HDR_FORWARD_LIST
  #  define BOOST_NO_0X_HDR_INITIALIZER_LIST
  #  define BOOST_NO_0X_HDR_MUTEX
  #  define BOOST_NO_0X_HDR_RATIO
  #  define BOOST_NO_0X_HDR_SYSTEM_ERROR
  #else
  #  define BOOST_HAS_TR1_COMPLEX_INVERSE_TRIG 
  #  define BOOST_HAS_TR1_COMPLEX_OVERLOADS 
  #endif
  
  #if (!defined(_GLIBCXX_HAS_GTHREADS) || !defined(_GLIBCXX_USE_C99_STDINT_TR1)) && (!defined(BOOST_NO_0X_HDR_CONDITION_VARIABLE) || !defined(BOOST_NO_0X_HDR_MUTEX))
  #  define BOOST_NO_0X_HDR_CONDITION_VARIABLE
  #  define BOOST_NO_0X_HDR_MUTEX
  #endif
  
  //  C++0x features in GCC 4.5.0 and later
  //
  #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 5) || !defined(__GXX_EXPERIMENTAL_CXX0X__)
  #  define BOOST_NO_NUMERIC_LIMITS_LOWEST
  #  define BOOST_NO_0X_HDR_FUTURE
  #  define BOOST_NO_0X_HDR_RANDOM
  #endif
  
  //  C++0x features in GCC 4.5.0 and later
  //
  #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6) || !defined(__GXX_EXPERIMENTAL_CXX0X__)
  #  define BOOST_NO_0X_HDR_TYPEINDEX
  #endif
  //  C++0x headers not yet (fully!) implemented
  //
  #  define BOOST_NO_0X_HDR_THREAD
  #  define BOOST_NO_0X_HDR_TYPE_TRAITS
  #  define BOOST_NO_0X_HDR_CODECVT
  
  //  --- end ---
  