Go/Generics

Lesson 1 of 6

Introduction to Generics

Before Go 1.18, writing code that worked for multiple types often required duplicating the entire logic for each type or using empty interfaces and type assertions, which sacrificed type safety and performance.

The Problem: Repetitive Code

Imagine a function that splits a slice in half. Without generics, you would need a version for every type:

func splitIntSlice(s []int) ([]int, []int) { ... }
func splitStringSlice(s []string) ([]string, []string) { ... }

The Solution: Generics

Generics allow you to write abstract code that doesn’t care about the specific type of data it is handling, as long as that data meets certain requirements (constraints).

Why Use Generics?

  1. DRY (Don’t Repeat Yourself): Write logic once and use it for many types.
  2. Library Design: Generics are ideal for utility packages (like slices, maps, or data structures) that should be agnostic to the data they store.
  3. Type Safety: Unlike using interface{}, generics provide compile-time type checking.