Destructors

A destructor is a special member function that is called when the lifetime of an object ends. The purpose of the destructor is to free the resources that the object may have acquired during its lifetime.

# Notes

Calling a destructor directly for an ordinary object, such as a local variable, invokes undefined behavior when the destructor is called again, at the end of scope.

In generic contexts, the destructor call syntax can be used with an object of non-class type; this is known as pseudo-destructor call: see member access operator.

# Example

#include <iostream>
 
struct A
{
    int i;
 
    A(int num) : i(num)
    {
        std::cout << "ctor a" << i << '\n';
    }
 
    ~A()
    {
        std::cout << "dtor a" << i << '\n';
    }
};
 
A a0(0);
 
int main()
{
    A a1(1);
    A* p;
 
    { // nested scope
        A a2(2);
        p = new A(3);
    } // a2 out of scope
 
    delete p; // calls the destructor of a3
}

# Defect reports

# See also

• copy elision
• new
• delete