Enumerations and Match statement

Rust makes use of Enumerations and the standard 'match' statement to force user to handle every possible value of an Enum. 'Result' and 'Option' are 2 such examples, that are heavily used in Rust Standard Library.

'Result' enum

'Result' is used when a function might throw an error. It has Ok() and Err() values in it. Each signifying the Success or Failure outcome.

Result<T, Error>

'Option' enum

This is used on situations where a variable can hold a null value.

Option(T)