Question

class Simple_String {

int length;

char *c_ptr;

public:

Simple_String(const char *cstr_ = ""); // Default/custom constructor

Simple_String(const Simple_String &original); // Copy constructor

Simple_String & operator= (const Simple_String &rhs); // Assignment operator

~Simple_String(); // Destructor

  /* … */

};

What is the default constructor, copy constructor, assignment operator, and destructor?

Answer 1

class Simple_String {
    int length;
    char *c_ptr;
public:
    Simple_String(const char *cstr_ = ""); // Default/custom constructor
    Simple_String(const Simple_String &original); // Copy constructor
    Simple_String &operator=(const Simple_String &rhs); // Assignment operator
    ~Simple_String(); // Destructor
    /* … */
};

Simple_String::Simple_String(const char *cstr_) {
    length = strlen(cstr_+1)+1;
    c_ptr = new char[length];
    for (int i = 0; i < length; ++i) {
        c_ptr[i] = cstr_[i];
    }
}

Simple_String::Simple_String(const Simple_String &original) {
    length = original.length;
    c_ptr = new char[length];
    for (int i = 0; i < length; ++i) {
        c_ptr[i] = original.c_ptr[i];
    }
}

Simple_String &Simple_String::operator=(const Simple_String &rhs) {
    length = rhs.length;
    c_ptr = new char[length];
    for (int i = 0; i < length; ++i) {
        c_ptr[i] = rhs.c_ptr[i];
    }
    return *this;
}

Simple_String::~Simple_String() {
    delete[] c_ptr;
}