import Foundation

protocol SomeProtocol<Thing>
{
	associatedtype Thing

	func doSomething()
}

struct SomeStruct<Thing>:SomeProtocol
{
	let thing:Thing

	func doSomething()
	{
		print( "=> \(thing)" )
	}
}

struct SomeClass
{
	var someThing:any SomeProtocol

	func run()
	{
		self.someThing.doSomething()
	}
}

let someStructInstance1 = SomeStruct(thing:"What is the answer to the ultimate question?")
let someStructInstance2 = SomeStruct(thing:42)
let someStructInstance3 = SomeStruct(thing:someStructInstance1)
let someStructInstance4 = SomeStruct(thing:someStructInstance2)
let someStructInstance5 = SomeStruct(thing:[someStructInstance1,someStructInstance2,someStructInstance3,someStructInstance4])

var someClassInstance = SomeClass( someThing:someStructInstance1 )
someClassInstance.run()
someClassInstance.someThing = someStructInstance2
someClassInstance.run()
someClassInstance.someThing = someStructInstance3
someClassInstance.run()
someClassInstance.someThing = someStructInstance4
someClassInstance.run()
someClassInstance.someThing = someStructInstance5
someClassInstance.run()

/*
Output:

=> What is the answer to the ultimate question?
=> 42
=> SomeStruct<String>(thing: "What is the answer to the ultimate question?")
=> SomeStruct<Int>(thing: 42)
=> [__lldb_expr_24.SomeStruct<Swift.String>(thing: "What is the answer to the ultimate question?"), __lldb_expr_24.SomeStruct<Swift.Int>(thing: 42), __lldb_expr_24.SomeStruct<__lldb_expr_24.SomeStruct<Swift.String>>(thing: __lldb_expr_24.SomeStruct<Swift.String>(thing: "What is the answer to the ultimate question?")), __lldb_expr_24.SomeStruct<__lldb_expr_24.SomeStruct<Swift.Int>>(thing: __lldb_expr_24.SomeStruct<Swift.Int>(thing: 42))]

*/