For now, invoke as:

./mcpp -N -k -C -I- -P testarray.c

This is the c pre-processor but with '#' directives changed to '$' directives,
for use with the C code generated by imptoc.

It is *only* here to convert fred[3][4] into fred[(3)-fredbase1][(4)-fredbase2]
etc. and to insert array bound checks where possible.

#include statements (or indeed any other '#' directives) are passed through,
but maybe not verbatim - they can still be expanded if they contain any '$' macros.

I'm considering a $begin/$end for scoping local symbols, specifically consts,
because C doesn't allow "const" variables in many places where literal constants
are allowed.

However you probably would not want *all* $defines to go out of scope on a $end
so may require new syntax for global $defines vs local ones.

Whether I want to go as far as actually generating code at the end of a procedure
using the macro processor (eg to create %switch tables) I'm not sure yet.

[Note: switch tables could be created using *all* &&lab_001 numbers, and replace
the 'default:' test by just instancing the unused ones before a piece of
error code (i.e.BADSWITCH())

Also (this is a different thing) I'm sort of thinking about #define macros
that can push their parameters onto a local stack for access later by a different
macro, so that things like "until (cond) { ... }" can be transformed into
"do { ... } while (!cond)" although clearly that would be better handled
by the compiler.
 **NEWS** mcpp may already implement what I want -
 it has:  '#pragma push_macro', and '#pragma pop_macro'