UnimplementedFeatureError：类型struct post_office.Message内存[]内存到存储的复制尚不支持

Question

我不知道我的代码有什么问题，有人可以帮我吗？

编译强度> = 0.4.22 <0.7.0; 实用实验性ABIEncoderV2;

合同邮局{

struct Message{
    address owner;
    string msg;
}

struct Msg_box{
    string name;
    address[2] owners;
    Message[] msg_que;
}

mapping(string => Msg_box) msg_boxes;

function create_msg_box(address owner1, address owner2, string memory name) public{
    address[2] memory owners =  [owner1,owner2];
    Message[] memory msg_que;
    Msg_box memory msg_box = Msg_box(name, owners, msg_que);
    msg_boxes[name] = msg_box;
}

function read_msg(string memory msg_box_name)public view returns(string memory){
    Msg_box memory msg_box = msg_boxes[msg_box_name];
    return msg_box.msg_que[msg_box.msg_que.length].msg;
}    

function write_msg(string memory msg_box_name, string memory msg_text)public{
    Message memory msg_object = Message(msg.sender,msg_text);
    msg_boxes[msg_box_name].msg_que.push(msg_object);
}

function get_msg_boxe(string name)public view returns(Msg_box){
    return msg_boxes[name];
}

}