If you're curious, that feature is called bounded polymorphism [1]. It's supported by Java and Rust, too, and I'm sure other languages as well. As mattnewport s

If you're curious, that feature is called bounded polymorphism [1]. It's supported by Java and Rust, too, and I'm sure other languages as well. As mattnewport said, something similar is in the works for C++. [1] http://wiki.c2.com/?BoundedPolymorphism http://wiki.c2.com/?BoundedPolymorphism