rustlings/exercises/12_options/README.md

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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

Further Information