C++赋值运算符

 1 #include <cstring>
 2 #include <cstdio>
 3 using namespace std;
 4 
 5 class CMyString
 6 {
 7 public:
 8     CMyString(char* pData=nullptr);
 9     CMyString(const CMyString& str);
10     CMyString& operator=(const CMyString& str);
11     ~CMyString();
12 
13     void Print();
14 private:
15     char* m_pData;
16 };
17 
18 CMyString::CMyString(char *pData)
19 {
20     if (pData == nullptr)
21     {
22         m_pData = new char[1];
23         m_pData[0] = '\0';
24     }
25     else
26     {
27         int length = strlen(pData);
28         m_pData = new char[length + 1];
29         strcpy_s(m_pData, length + 1, pData);
30     }
31 }
32 CMyString::CMyString(const CMyString& str)
33 {
34     int length = strlen(str.m_pData);
35     m_pData = new char[length+1];
36     strcpy_s(m_pData, length + 1, str.m_pData);
37 }
38 CMyString::~CMyString()
39 {
40     delete[] m_pData;
41 }
42 CMyString& CMyString::operator=(const CMyString& str)
43 {
44     if (this == &str) return *this;
45     CMyString strTemp(str);
46     char* pTemp = strTemp.m_pData;
47     strTemp.m_pData = m_pData;
48     m_pData = pTemp;
49     return *this;
50 }
51 void CMyString::Print()
52 {
53     printf("%s", m_pData);
54 }

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