c++中显式与隐式类型转换发生在构造函数（略）与operator type（）中

头文件

#pragma once
#include 
class StringInt
{
	int i;
	std::string str;
public:
	StringInt(int i = -1);

	StringInt(std::string s = "");

	explicit operator int() const;//将自定义类型显式转换为int类型
	explicit operator std::string() const;//将自定义类型显式转换为std::string类型

	~StringInt();
};

cpp文件

#include "StringInt.h"



StringInt::StringInt(int i):i(i)
{
	str = "";
}

StringInt::StringInt(std::string s):str(s)
{
	i = -1;
}

StringInt::operator int() const
{
	return i;
}

StringInt::operator std::string() const
{
	return str;
}

StringInt::~StringInt()
{
}

主函数

void test_stringInt() 
{
	StringInt p1("s");
	StringInt p2(12);
	int a = static_cast(p1) + static_cast(p2);
	std::cout << a<<" ";
	std::cout << static_cast(p1) << " " << static_cast(p2);

}