Generic types

Context

You can define generic structs, interfaces, and type aliases. The type parameter appears after the type name in square brackets. Generic types can have methods, but methods cannot have additional type parameters (the receiver’s parameters are fixed).

Example

Define a generic Stack[T] with push and pop methods.

Code example

package main

import "fmt"

type Stack[T any] struct {
    items []T
}

func (s *Stack[T]) Push(item T) {
    s.items = append(s.items, item)
}

func (s *Stack[T]) Pop() (T, bool) {
    if len(s.items) == 0 {
        var zero T
        return zero, false
    }
    last := s.items[len(s.items)-1]
    s.items = s.items[:len(s.items)-1]
    return last, true
}

func main() {
    intStack := Stack[int]{}
    intStack.Push(10)
    intStack.Push(20)
    fmt.Println(intStack.Pop()) // 20, true
    fmt.Println(intStack.Pop()) // 10, true
    fmt.Println(intStack.Pop()) // 0, false
}

Output

20 true
10 true
0 false

Useful links

• Go spec: Generic types
• Go generics tutorial