text: This is the mail archive of the libstdc++@sources.redhat.com mailing list for the libstdc++ project.
  The libio errors due to _XOPEN_SOURCE=500, etc. not being defined stem from the following fragment in more libio source files: #ifndef _POSIX_SOURCE # define _POSIX_SOURCE #endif This is preventing AIX from defining the macros it normally would. Given that the fragments occur as the very first CPP definitions in the file, this would seem to assume systems where the value is defined on the commandline because it does not allow any system headers to define it (which is the problem it is creating for AIX). From the ChangeLog entries, Ulrich tried to fix this, but the current structure of the code does not allow the portability necessary to conditionally define this at the appropriate time. David