This could be really useful for me but the presentation breaks (at least on Chrome). By the time you're halfway down the list it's hard to tell which header's row belongs to which compiler's column.
It would be nice to see a POSIX.1-2008 section too -- many of the headers listed as "POSIX.1-2001 optional" are required in POSIX.1-2008. (e.g., <aio.h>, <cpio.h>, <dlfcn.h>, <iconv.h>, <langinfo.h>... and <pthread.h>, which is probably the most commonly used 2001-optional/2008-required header).
It'd be great to see a metric of "completeness". For instance, while <semaphore.h> declares support for unnamed semaphores on OS X, the platform does not have them.
This is really nice, I just have one question, ( maybe I have overlooked it), where is the test-suite for gathering the data?´, as to which headerfiles are workable or not?
Is there a configure script there?
I mean, I am on Snow Leopard, and I have no trouble using unistd.h which is marked as flawed on the graph.
All I see that is that it is a survey, I wonder what kind of tests that are used to draw the conclusions. I also see for instances that the regexp.h file is absent for OS X Lion, which is reworked to work wide wide characters. But, the header files may fail in ways I don't know about, that is why I ask for the tests that makes up for the results.
If you'll look at the code in the link posted previously, it appears that it is testing for the presence of the headers rather than functionality inside of them.
