  Flow-sensitive type systems offer an elegant way to ensure memory-safety in
programming languages. Unfortunately, their adoption in new or existing
languages is often hindered by a painful effort to implement or integrate them
into compilers. This paper presents early results in our effort to alleviate
this task. We introduce Fuel, a type capability-based library that can be
plugged onto a compiler toolchain to check for memory-safety properties. Fuel
builds upon well-established ideas in the domain of capability-based system,
and adds a mechanism leveraging dynamic checks to recover capabilities where
static reasoning is either too difficult or impossible. This approach allows
the analysis to potentially cover situations where a typical type system might
not be expressive enough to statically reason about memory safety.
