Swift泛型树转换为int

class TreeNode<T> {
    var value: T
    var children: [TreeNode<T>]
    
    init(value: T, children: [TreeNode<T>] = []) {
        self.value = value
        self.children = children
    }
}

func convertTreeToInt<T: Numeric>(root: TreeNode<T>) -> TreeNode<Int> {
    let intValue = Int(root.value)
    let intChildren = root.children.map { convertTreeToInt(root: $0) }
    
    return TreeNode<Int>(value: intValue, children: intChildren)
}

let rootNode = TreeNode(value: 5, children: [
    TreeNode(value: 10, children: [
        TreeNode(value: 15),
        TreeNode(value: 20)
    ]),
    TreeNode(value: 30, children: [
        TreeNode(value: 35),
        TreeNode(value: 40)
    ])
])

let intTree = convertTreeToInt(root: rootNode)