Generic ownership for generic Java

Ownership types enforce encapsulation in object-oriented programs by ensuring that objects cannot be leaked beyond object(s) that own them. Existing ownership programming languages either do not sup- port parametric polymorphism (type genericity) or attempt to add it on top of ownership restrictions. Generic Ownership provides per- object ownership on top of a sound generic imperative language. The resulting system not only provides ownership guarantees compara- ble to established systems, but also requires few additional language mechanisms due to full reuse of parametric polymorphism. We formalise the core of Generic Ownership, highlighting that only re- striction of this calls and owner subtype preservation are required to achieve deep ownership. Finally we describe how Ownership Generic Java (OGJ) was implemented as a minimal extension to Generic Java in the hope of bringing ownership types into main- stream programming.