c++ my understanding of temporary variables

Temporary variable is a variable that is released if there is no variable to receive it

class A
{
public:
    A()
    {
        std::cout << " 1 A() \n";
    }

    A(const A& aa)
    {         std::cout << "copy construction\n";     }

 

    ~A()
    {
        std::cout << " 2 ~A() \n";
    }
};

//When the type returned by the function is a value, the return is a temporary variable

A TestA()
{
    return A();
}

//When the variable is returned, the copy structure will be called to generate a temporary variable

A TestA2()
{
    A aa1= A();
    return aa1;
}

 

int main()
{      A(); //Release if there is no variable receiving

 TestA()；
    system("pause");
}

 

When returning variables, it’s best to return temporary variables or references instead of variables.