Polyglot CheatSheet - Generics

Last Updated: 2023-02-28

Go

Generic functions:

func Index[T comparable](s []T, x T) int

Generic types:

type List[T any] struct {
	next *List[T]
	val  T
}

Rust

// in function
fn foo<T>(list: &[T]) -> T {
}

// in struct
struct Point<T> {
    x: T,
    y: T,
}

// in enum
enum Option<T> {
    Some(T),
    None,
}

// in method
struct Point<T> {
    x: T,
    y: T,
}

impl<T> Point<T> {
    fn x(&self) -> &T {
        &self.x
    }
}

Java

Java Type erasure: enforcing type constraints only at compile time and discarding the element type information at runtime.