C++ linter based on linear types

Low-level programming requires careful management of system resources, most notably memory. In C++ programmers are encouraged to follow idioms like RAII and smart pointers to handle resources correctly as violating them leads to unsafe code. Typed functional programming languages guarantee safe automatic mem- ory management, but are often sub-optimal in handling system resources. A nice, formal solution to handling resources naturally is linear types. Unfortu- nately, existing languages that support linearity are cumbersome and require explicit, complicated annotations from the programmer. We bridge the two worlds by exploring a novel combination of C++ and linear types. We describe a new type system with linearity for C++ by using constrained qualified types, while requiring no additional input from the programmer. The applied result of our work is called Lily, a static analysis tool for C++ using the Clang compiler infrastructure. Lily can statically detect large, general classes of issues, some of which are not detected by common state-of-the-art tools for C++.