Thread: is it uncommon to explicitly call the destructor of an object.

While I'm sure it's not significant, what if you're working with a temporary string to append it to a larger string, when you're done with the temp, would it be pretty useless to explicitly call the destructor or is it just uncommon. Or any other objects that are made to be temporary.

Or should I just dynamically allocate?

You'll probably use the temporary in a small scope. At the end of the scope the string destruction will be called automatically for you, and you can reuse the memory.

If you really are short of memory, you can create a smaller scope just by putting the desired lifetime of the string between a pair of curly brackets

Code:

//some code
{ //just a new scope
std::string temp(1000000, 0); //large temporary string
//some more code
} //end of scope, temp is gone

You can explicitly call your own destructor, if you want your destructor to print something like:

Code:

destructor called

as an example...

If you run this program from command prompt, you'll see that the destructor gets called twice. This doesn't look good, if it were to do something important. (You'll probably need special precautions when coding the destructor, making it more complicated than it needs to be.)

Code:

#include <iostream>

class A
{
    public:
        A() {std::cout << "constuctor called" << std::endl;}
        ~A() {std::cout << "destructor called" << std::endl;}
};

int main()
{
    A a;
    a.~A();
}

This is simpler to use and you can still see "destructor called" before std::cin.get()

Code:

#include <iostream>

class A
{
    public:
        A() {std::cout << "constuctor called" << std::endl;}
        ~A() {std::cout << "destructor called" << std::endl;}
};

int main()
{
    {
        A a;
    }
    std::cin.get();
}

>> You can explicitly call your own destructor, if you want your destructor to print something like

Even if you want your destructor to print something, there is still no reason to call it explicitly. Read the link.

I was originally thinking along the lines of the temporary scope rather than calling it explicitly, just wondering, thanks for the links.