調用CPP構造與重載>>運算

Question

我很新的C++，我想知道，如果以下是可能的：

考慮你有

class Client { 
public: 
    Client(string firstname, string lastname); 
// ... 
} 

你可以重載>>運營商用剛剛輸入的輸入生成一個新對象？

像

istream& operator>> (istream& is, Client* client) { 
    cout << "First Name: "; 
    is >> client->firstName; 
    cout << "Last Name: "; 
    is >> client->lastName; 
    return is; 
} 

？

什麼是正確的方式來創建一個基於用戶輸入使用重載>>運算符的對象，你會怎麼做？ 如果我想這樣做，這樣，我會寫

Client* client; 
cin >> client; 

但在那一刻，客戶端已創建...

感謝

Answer 1

你可以像下面這樣做（需要通過引用傳遞客戶端的指針，然後讀取到臨時變量並創建客戶端）：

istream& operator >> (istream& is, Client * &client) { 
    string firstname, lastname; 
    cout << "First Name: "; 
    is >> firstname; 
    cout << "Last Name: "; 
    is >> lastname; 
    client = new Client(firstname, lastname); 
    return is; 
} 

Client* client; 
cin >> client; 
// use client 
delete client; 

但我不會建議一般。更清潔的方式是有

istream& operator >> (istream& is, Client &client) { 
    cout << "First Name: "; 
    is >> client.firstname; 
    cout << "Last Name: "; 
    is >> client.lastname; 
    return is; 
} 

Client client; 
cin >> client; 
// use client 
// client destroyed on scope exit