This is using the C++11 override keyword to make the compiler check to
ensure that we are correctly overriding virtual methods when we mean to.
Currently this will not compile without C++11. However, we are planning
on moving to C++11 very soon, and we can fix the macro if we don't.
MSVC likes to warn about using raw pointers as iterators in generic
algorithms because they have been known to lead to problems. When
compiling with that compiler, wrap raw pointers in
stdext::checked_array_pointer to suppress the error and also add a bit
more checking.
We made this change a while ago to help with completion in IDEs.
(Completion was matching a bunch of wrapper macros that were almost
never used anywhere.) Most of the changes are in comments, but there are
a few bad macro definitions.