Where are the std C/C++ libraries on a mac?

I am sure this question has been asked and answered before; however, a search did not turn it up.

I am looking for standard header files (<>). I am on a Mac (10.10.3) and they are not showing up on my spotlight search (meaning they are installed in one of my "Libraries" directories which are not indexed.

Thanks,
Jon

I would guess they are wherever gcc is located.

That was my first try...

gcc is in /usr/bin (as it should be). /usr/include would be where the include files go; however, I don't see anything in usr (via 'find -L /usr -name "wifi.h" -print'). I know that wifi.h is somewhere as the example complies and it is referenced as '#include <wifi.h>' so it is in the global search path.

I have also checked my ~/Library and /Library folders.

Any other thoughts?

On my system it's:

file:///Applications/Arduino%201.6.4.app/Contents/Java/hardware/tools/avr/avr/include/

Found it... TNX!