from http://dl.rust-lang.org/doc/tutorial.html http://dl.rust-lang.org/doc/tutorial.html "7.3 What to be aware of Rust has three "realms" in which objects can

from http://dl.rust-lang.org/doc/tutorial.html http://dl.rust-lang.org/doc/tutorial.html "7.3 What to be aware of Rust has three "realms" in which objects can be allocated: the stack, the local heap, and the exchange heap. These realms have corresponding pointer types: the borrowed pointer (&T), the shared box (@T), and the unique box (~T). These three sigils will appear repeatedly as we explore the language. Learning the appropriate role of each is key to using Rust effectively." It's 3 different types, not 2.