This just means that affine types aren't the right tool to model memory that you don't have full control over. Which is true, but also represents a very small subset of overall data. Rust provides you with other tools to handle those kinds of situations.
There is a small wart here, which is that (with async Rust) some of these use cases would benefit tremendously from full-fledged linear types, or at least an easy way to run code during async cancellation.
The difference between an affine and a linear type is that the ways in which a linear type is consumed are controllable through encapsulation — for example, imagine you have a type which represents a certain amount of money, and you want to statically prevent the money from being dropped on the floor. Affine types don't prevent that statically, but linear types do. You can still have runtime checks though.
There is a small wart here, which is that (with async Rust) some of these use cases would benefit tremendously from full-fledged linear types, or at least an easy way to run code during async cancellation.
The difference between an affine and a linear type is that the ways in which a linear type is consumed are controllable through encapsulation — for example, imagine you have a type which represents a certain amount of money, and you want to statically prevent the money from being dropped on the floor. Affine types don't prevent that statically, but linear types do. You can still have runtime checks though.