Generics

Generics#

Go 1.18+ has parametric polymorphism via type parameters.

A generic function over any element type.

func Head[T any](xs []T) (T, bool) {
    var zero T
    if len(xs) == 0 { return zero, false }
    return xs[0], true
}

Call site inferring T.

n, ok := Head([]int{1, 2, 3})

Constraints live in the constraints package (now mostly cmp.Ordered plus user-defined sets).

func Max[T cmp.Ordered](a, b T) T {
    if a > b { return a }
    return b
}