考虑下面的代码:了解C++动态分配
class CString
{
private:
char* buff;
size_t len;
public:
CString(const char* p):len(0), buff(nullptr)
{
cout << "Constructor called!"<<endl;
if (p!=nullptr)
{
len= strlen(p);
if (len>0)
{
buff= new char[len+1];
strcpy_s(buff, len+1, p);
}
}
}
CString (const CString& s)
{
cout << "Copy constructor called!"<<endl;
len= s.len;
buff= new char[len+1];
strcpy_s(buff, len+1, s.buff);
}
CString& operator = (const CString& rhs)
{
cout << "Assignment operator called!"<<endl;
if (this != &rhs)
{
len= rhs.len;
delete[] buff;
buff= new char[len+1];
strcpy_s(buff, len+1, rhs.buff);
}
return *this;
}
CString operator + (const CString& rhs) const
{
cout << "Addition operator called!"<<endl;
size_t lenght= len+rhs.len+1;
char* tmp = new char[lenght];
strcpy_s(tmp, lenght, buff);
strcat_s(tmp, lenght, rhs.buff);
return CString(tmp);
}
~CString()
{
cout << "Destructor called!"<<endl;
delete[] buff;
}
};
int main()
{
CString s1("Hello");
CString s2("World");
CString s3 = s1+s2;
}
我的问题是,我不知道如何删除加法运算功能(char* tmp = new char[length]
)分配的内存。我无法在构造函数中执行此操作(我尝试了delete[] p
),因为它也是从主函数调用的,并将字符数组作为参数分配给堆中的参数......我怎样才能解决这个问题?
你还需要在你的赋值运算符的工作(它不安全(喜欢复制和交换Idium))。见下文。 – 2011-01-10 20:59:00