set _XOPEN_SOURCE differently depending on __STDC_VERSION__

#endif

/*

  Solaris include file <sys/feature_tests.h> refers to X/Open document

  Solaris 9 include file <sys/feature_tests.h> refers to X/Open document

    System Interfaces and Headers, Issue 5

  saying we should define _XOPEN_SOURCE=500 to get POSIX.1c prototypes

  saying we should define _XOPEN_SOURCE=500 to get POSIX.1c prototypes,

  but apparently other systems (namely FreeBSD) don't agree.

  Furthermore X/Open has since 2004 "System Interfaces, Issue 6"

  that dictates _XOPEN_SOURCE=600, but Solaris checks for 500.

  So, let's define 500 for solaris only.

  On a newer Solaris 10, the above file recognizes also _XOPEN_SOURCE=600.

  Furthermore, it tests that if a program requires older standard

  (_XOPEN_SOURCE<600 or _POSIX_C_SOURCE<200112L) it cannot be

  run on a new compiler (that defines _STDC_C99) and issues an #error.

  It's also an #error if a program requires new standard (_XOPEN_SOURCE=600

  or _POSIX_C_SOURCE=200112L) and a compiler does not define _STDC_C99.

  To add more to this mess, Sun Studio C compiler defines _STDC_C99 while

  C++ compiler does not!

  So, in a desperate attempt to get correct prototypes for both

  C and C++ code, we define either _XOPEN_SOURCE=600 or _XOPEN_SOURCE=500

  depending on the compiler's announced C standard support.

  Cleaner solutions are welcome.

*/

#ifdef __sun

#if __STDC_VERSION__ - 0 >= 199901L

#define _XOPEN_SOURCE 600

#else

#define _XOPEN_SOURCE 500

#endif

#endif

#if defined(THREAD) && !defined(__WIN__) && !defined(OS2)

#ifndef _POSIX_PTHREAD_SEMANTICS