Is it possible to implement a protocol using generics in a programming language?

In Swift, you can use generics together with protocols, but protocols themselves are not generics. Instead, you can create protocols with associated types, which allow you to specify generic requirements. This enables the implementation of flexible and type-safe interfaces.

Example of a protocol with an associated type:

protocol Container {
    associatedtype Item
    func append(_ item: Item)
    var count: Int { get }
    subscript(i: Int) -> Item { get }
}

struct IntStack: Container {
    var items = [Int]()
    mutating func append(_ item: Int) {
        items.append(item)
    }
    var count: Int {
        return items.count
    }
    subscript(i: Int) -> Int {
        return items[i]
    }
}

Thus, protocols with associated types are a way to implement generic interfaces similar to generics.