Added BOOST_HAS_FENV_H detection to Boost.Config (if this macro is defined, then

the standard library/platform provide a POSIX compliant implementation of fenv.h).



[SVN r66693]

include/boost/config/stdlib/sgi.hpp

@@ -40,6 +40,14 @@
 #  define BOOST_NO_STRINGSTREAM
 #endif
 
+#if !defined(CYGWIN) && (defined(unix) || defined(__unix) || defined(__unix__))
+#  include <unistd.h>
+#  if defined(_POSIX_VERSION) || defined(_XOPEN_VERSION)
+#     define BOOST_HAS_FENV_H
+#  endif
+#endif
+
+
 //
 // Assume no std::locale without own iostreams (this may be an
 // incorrect assumption in some cases):