Options
Type Option represents an optional value: every Option is either Some and contains a value, or None, and does not. Option types are very common in Rust code, as they have a number of uses:
- Initial values
- Return values for functions that are not defined over their entire input range (partial functions)
- Return value for otherwise reporting simple errors, where None is returned on error
- Optional struct fields
- Struct fields that can be loaned or "taken"
- Optional function arguments
- Nullable pointers
- Swapping things out of difficult situations