枚举类型}+变量名是什么意思呢

0: #include <iostream>
1: using namespace std;
2:
3: union SimpleUnion
4: {
5: int num;
6: char alphabet;
7: };
8:
9: struct ComplexType
10: {
11: enum DataType
12: {
13: Int,
14: Char
15: } Type;
16:
17: union Value
18: {
19: int num;
20: char alphabet;
21:
22: Value() {}
23: ~Value() {}
24: }value;
25: };
26:
27: void DisplayComplexType(const ComplexType& obj)
28: {
29: switch (obj.Type)
30: {
31: case ComplexType::Int:
32: cout << "Union contains number: " << obj.value.num << endl;
33: break;
34:
35: case ComplexType::Char:
36: cout << "Union contains character: " << obj.value.alphabet << endl;
37: break;
38: }
39: }
40:
41: int main()
42: {
43: SimpleUnion u1, u2;
44: u1.num = 2100;
45: u2.alphabet = 'C';
46: cout << "sizeof(u1) containing integer: " << sizeof(u1) << endl;
47: cout << "sizeof(u2) containing character: " << sizeof(u2) << endl;
48:
49: ComplexType myData1, myData2;
50: myData1.Type = ComplexType::Int;
51: myData1.value.num = 2017;
52:
53: myData2.Type = ComplexType::Char;
54: myData2.value.alphabet = 'X';
55:
56: DisplayComplexType(myData1);
57: DisplayComplexType(myData2);
58:
59: return 0;
60: }