Rust Structs, Enums, Match and Box

Flashcards covering structs, enums, match statements, and Box<T> in Rust.

Struct

A complex type defined by the user that can contain any number of fields of any type.

Instantiating a struct

Can be done primitively by instantiating all of its fields.

Tuple Structs

Useful for naming and differentiating one tuple from others, especially when naming each field in a regular struct would be verbose or redundant.

Struct Methods

Functions defined within the context of a struct using 'impl'. They can take '&self' (immutable reference), '&mut self' (mutable reference), or 'self' (ownership) as arguments.

Static Functions in Structs

Often used for constructors that return a new instance of the struct. 'Self' is an alias for the type in the 'impl' block.

Enum

Used for saying a value is one of a possible set of values (enumeration constants).

Enums with data

Group the data right next to the type.

Box

A smart pointer that stores data on the heap, allowing for enums with recursive types to have a known size at compile time.

Option

Rust’s solution for null checks. An enum that holds Some(T) or None, helping the user with checking of possibly non-existent data.

Option API shortcuts

unwrap() extracts the value in Some, crashing if None; expect("str") does the same but prints an error message; isok() returns true if Some; isnone() returns true if None.

Match Statement

Used to compare a value against a series of patterns and execute code based on the matching pattern. Must be exhaustive to avoid errors.

Catch-all statements in Match

'other' catches the value from a match statement. '_' matches the pattern

Matching with if statement

Allows for additional conditions to be checked within a match arm.

If let shorthand

A concise way to run code when a value matches a single pattern, particularly useful with Options.