Class MaybeUnique

generator/compat.h:27–31

// clang 3.6 uses unique_ptr in many places that was not using it before
template<typename T> struct MaybeUnique {
    T *val;
    operator T*() { return val; }
    template <typename X> operator std::unique_ptr<X> () && {  return std::unique_ptr<X>(val); }
};
template<typename T> MaybeUnique<T> maybe_unique(T* val) { return {val}; }

#ifndef LLVM_FALLTHROUGH