How to Use Generics with Methods in Go (And the Limitations)

Use generics in Go methods by adding type parameters to the function signature with the func keyword, constrained by interface{} or specific type constraints.

func ToInt[P interface{ ~int }](p P) int { return int(p) }

Limitations include the inability to use generic methods on non-generic types without explicit instantiation, and the requirement that type parameters must be specified at the call site or inferred by the compiler.

Generics let you write functions that work with any data type while keeping type safety. Think of it like a reusable mold that can shape different materials without breaking. You use this when you need the same logic for integers, strings, or custom types without rewriting the code.