MSVC's STL doesn't let iterators go before begin() (#98)
MSVC's STL doesn't let iterators go before begin() (#98)

* MSVC's STL doesn't let iterators go before begin()

This is the case even of the iterator is not
dereferenced. Fix #94.

* cleanup

google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament,google/filament