Module show_notes::e008

Just like something else

• Date: 2015-12-27
• Subject: Generics, traits, and shared behavior in Rust.
• Audio

Notes

In this episode we cover—at a very high level—two more fundamental concepts in Rust programming: generics and traits.

Generics gives us the ability to write types and functions which can be used with more than one type. Traits give us the ability to specify behavior which can be implemented for more than one type. The combination gives us powerful tools for higher-level programming constructs in Rust.

Comments on source code

Now that we have a handle on how tests work, we’ll use them to validate the behavior of our code going forward. This is great: we can show that the tests do what we think.

To today’s point, though: we actually know even apart from whether the tests run successfully that these generic functions and the associated traits are behaving as we want. Failure with generics is a compile-time error, not a runtime error.

Links

• Rust Book
  • Generics
  • Traits – includes a discussion of trait bounds and *generic traits
• Rust by Example
  • Generics
  • Traits
  • Generic traits
  • Traits bounds
• Generics and traits in use in Diesel

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• Chris Palmer
• Derek Morr
• Luca Schmid
• Micael Bergeron
• Ralph Giles (“rillian”)
• reddraggone9
• William Roe

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Structs

• GenericContainer
  This is just a container which can hold any two types.
• SimpleType
  A simple type to illustrate trait implementation.

Enums

• Maybe
  This is Option<T>, but using Haskell’s names instead.

Functions

• a_generic
  Demonstrate a function generic over any type.
• a_generic_printable
  Demonstrate a function with a trait bound on a generic.