相关疑难解决方法(0)

我试图有一个允许隐式转换为某些内置类型的类,比如unsigned long int,因为我试图尽可能正确地做这个(这是我在C++中的第一个重要项目),我遇到了一个奇怪的关于const正确性的问题:

这有效:

#include <iostream>

class CustomizedInt
{
private:
    int data;
public:
    CustomizedInt();
    CustomizedInt(int input);
    operator unsigned long int () const
    {
        unsigned long int output;
        output = (unsigned long int)data;
        return output;
    }
};

CustomizedInt::CustomizedInt()
{
    this->data = 0;
}

CustomizedInt::CustomizedInt(int input)
{
    this->data = input;
}

int main()
{
    CustomizedInt x;
    unsigned long int y = x;

    std::cout << y << std::endl;

    return 0;
}

但是这个:

#include <iostream>

class CustomizedInt
{
private:
    int data;
public:
    CustomizedInt();
    CustomizedInt(int …