Call the destructor more than one time

we can call the destructor as like function, but we can't call the constructor like this.

class Shape
{
   public:
       Shape(){ cout<<" Shape"<
       virtual ~Shape(){ cout<<" ~  Shape"<
};
class Circle : public Shape
{
   public:
      Circle() { cout<<"Circle"<< endl; }
      ~Circle(){ cout<<" ~ Circle" << endl; }
};

int main()
{

   Circle *ptr = new Circle();
   ptr->~Circle();
   ptr->~Circle();

   return 1;
}

output:-

# ./a.out

 Shape

Circle

 ~ Circle

 ~  Shape

 ~  Shape

while calling the destructor function first time , its calling the base call destructor also ( if its virtual ) . but after that not calling the base class destructor.

How to resolve the IPv6 Address from domain name in C++ ?

In general, we are using gethostbyname or gethostbyname_r for resolving IPAddress from domain name. These system calls are not supporting IPv6 format.

For resolve IPv6Address from domain name, we need to use gethostbyname2_r function.

struct in6_addr aadrv6;
struct hostent *host;
char* pszHostName = “localhost6.localdomain6”;
char strIPAddr[50];
char buffer[2048];
int iError = 0,hrr;

iError = gethostbyname2_r( pszHostName, AF_INET6, &hostbuf,buffer, 2048,&host,&hrr );

if( iError == 0 && host != NULL )
{
    memcpy( &aadrv6 , host->h_addr_list[0], sizeof( in6_addr ) );
   if( inet_ntop ( AF_INET6, &aadrv6, strIPAddr, INET6_ADDRSTRLEN ) != NULL )
   {
        printf("IPv6Address: %s\n", strIPAddr);
    }
}

output:
#./a.out
IPv6Address: ::1