-Wunused-local-typedefs is a new warning flag of gcc-4.7, and it will enabled
by -Wall since gcc-4.8 (not yet released).
The fix is a big set of removals of unused typedefs (or comments, or moves,
depending on the context).
Using :
for i in * ; do cd $i ; for f in examples/*/*.cpp ; do ( head -1 $f | grep file | grep -v '\.cpp' ) && echo $f && perl -pi.bak -e 's/\.C$/.cpp/' $f ; done ; cd .. ; done