C ++ primer-pe13 -- 10

Summary: The value assignment operator and replication initialization are usually used together. Both of them have merged versions. Sometimes you don't need to worry about them.

In addition, private: Class (const Class &) can prevent the user code from copying this class object,

However, if you can still copy the metadata and members, you can simply declare that they are not defined. This method only prevents the result, but cannot block the call. The call will cause the link to fail.

// Then, how can we use members and friends to test the replication? It will be solved tomorrow.

I recalled the static knowledge point and used the changed static variable to identify the unique ID. for statistics, the initial count is 0 and the initial ID is 1. Therefore, the pre-auto-increment operator is used.

The problem is that the assignment operator forgets the knowledge point?

Employee EM2 = Em1; // It is equivalent to the latter.

Employee EM2 (Em1); // There is no difference between the two. Is operator = ignored here?

# Include "head. H "// ID is unique. To identify class employee {public: // constructor employee (): Name (" "), ID (++ number) {STD:: cout <"defalut-constructor:" <STD: Endl;} employee (STD: String S): name (s), ID (++ number) {STD: cout <"one-parm-constructor:" <STD: Endl;} // copy the constructor employee (const employee &); // value assignment operator employee & operator = (const employee &); // statistic and testing interface static int getcount () {return number;} int GETID () {return ID ;} STD :: String getname () {return name;} PRIVATE: STD: string name; int ID; static int number; // used to mark the ID and count }; // define the relevant member INT: Number = 0; Employee: employee (const employee & EM): Name (EM. name), ID (++ number) {STD: cout <"copy-constructor:" <STD: Endl;} employee & employee :: operator = (const employee & EM) {STD: cout <"assignment:" <STD: Endl; // id = em. ID; // different from the combined value assignment operator, idname = em can be protected. name; return * This ;} Int main () {employee Em1 ("Hu"); // initialize employee EM2 = Em1; // when the value assignment operator is not customized, the default value assignment operation does not change the ID. The custom copy ID cannot be used. This statement does not include assignstd :: cout <"==================" <STD: Endl; employee em3 (Em1 ); // copy and initialize the employee em4; em4 = Em1; // This error occurs when the non-custom value assignment operator is used. The IDS are the same. STD: cout <"ID:" <em1.getid () <":" <em1.getname () <STD: Endl; STD :: cout <"ID:" <em2.getid () <":" <em2.getname () <STD: Endl; STD: cout <"ID: "<em3.getid () <": "<em3.getname () <STD: Endl; STD: cout <" ID: "<em4.getid () <":" <em4.getname () <STD: Endl; STD: cout <"Statistics:" <em1.getcount () <STD: Endl; STD: cout <"Statistics:" <EMPLOYEE: getcount () <STD: Endl ;}