拷贝构造函数与赋值

拷贝构造函数

String(const String& other) =delete;

赋值

void operator=(const String& )=delete;

只要产生新对象其实就是调用了拷贝构造函数

class String {
private:
    char *m_Buffer;
    unsigned int m_Size;

public:
    String(const char *string) {
        m_Size = strlen(string);
        m_Buffer = new char[m_Size + 1];
        memcpy(m_Buffer, string, m_Size);
        m_Buffer[m_Size] = 0;
    }

    String() {
    }

    String(const String &other)
        : m_Size(other.m_Size) {
        m_Buffer = new char[m_Size + 1];
        memcpy(m_Buffer, other.m_Buffer, m_Size + 1);
        m_Buffer[m_Size] = 0;
    }

    String &operator=(const String &other) {
        m_Size = other.m_Size;
        m_Buffer = new char[m_Size + 1];
        memcpy(m_Buffer, other.m_Buffer, m_Size + 1);
        return *this;
    }

    ~String() {
        std::cout << "Dleteted String: " << m_Buffer << std::endl;
        delete[] m_Buffer;
    }

    char &operator[](unsigned int index) const {
        return m_Buffer[index];
    }

    friend std::ostream &operator<<(std::ostream &stream, const String &string);
};

std::ostream &operator<<(std::ostream &stream, const String &string) {
    stream << string.m_Buffer;
    return stream;
}

int main() {
    String string("12345");
    String second;
    second = string;
    second[2] = 'a';
    std::cout << string << std::endl;
    std::cout << second << std::endl;
    return 0;
}