3.6.12.1 Idirafter Option
The -idirafter dir option adds the
directory dir to the list of directories
to be searched for header files during preprocessing. The directory is
searched only after all other search paths (including the standard search
directories as well as those specified by the -I and
-Iquote options) have been searched. If this option
is used more than once, the directories they specify are searched in a
left-to-right order as they appear on the command line.
