How to init members of an collection based on Element?

I am trying to add an extension, that adds two functions to an array of FloatingPoint types. I added to and extension to get a myDesibe var:

extension FloatingPoint  {
    public var myDescribe:String {
        return String(format:"%.3f",self as! CVarArg)
    }
}

This works fine (or seems to)

On the collection, I want to add two methods/vars. One method returns a string with command delimited values:

public extension Array where Element: FloatingPoint  {
    var myDescribe:String {
        var rvalue = ""
        for (index,entry) in self.enumerated() {
            var format = ",%@"
            if (index == 0) {
                format = "%@"
            }
            rvalue += String(format: format, entry.myDescribe)
        }
        return rvalue
    }
}

That seems to be working fine. The other I wan to pass the command delimited string in, and get an array of the type of elements of the Array. This does not work:

public extension Array where Element: FloatingPoint  {
    var myDescribe:String {
    func fromDescription(desribe:String) -> [Element] {
       var rvalue = [Element]()
        for entry in desribe.components(separatedBy: ",") {
            let trimmed = entry.trimmingCharacters(in: .whitespaces)
            let temp = FloatLiteralType(trimmed) ?? FloatLiteralType.zero
            // Now, how to convert this so I can append this in the array? This is the issue!!
            rvalue.append(temp) // << THIS FAILS, as it wants an Int which I don't `understand`

        }
        
        return rvalue
    }
}

All help is appreciated

Charles