T t(2), T t = 2, T t = T(2)三者完全等价

T t(2), T t = 2, T t = T(2)三者完全等价

[cpp]
#include
#include
#include
using namespace std;
class T{
public:
T(){};
T(int t)
{
cout << "复制" << endl;
a = t;
};
T& operator = (const T& t)
{
cout << "赋值" << endl;
a = t.a;
return *this;
}
int a;
};
int main()
{
T t(2);
cout << "------------------"<< endl;
T t1 = 2;
cout << "------------------"<< endl;
T t2 = T(2);
cout << "------------------"<< endl;
T t3;
t3 = t2;
return 0;
}

#include
#include
#include
using namespace std;
class T{
public:
T(){};
T(int t)
{
cout << "复制" << endl;
a = t;
};
T& operator = (const T& t)
{
cout << "赋值" << endl;
a = t.a;
return *this;
}
int a;
};
int main()
{
T t(2);
cout << "------------------"<< endl;
T t1 = 2;
cout << "------------------"<< endl;
T t2 = T(2);
cout << "------------------"<< endl;
T t3;
t3 = t2;
return 0;
}

输出结果为：

复制
------------------
复制
------------------
复制
------------------
赋值