Question

I want to call destructor of an instance (proc) always before my program ends, especially after return 1 or exit() in main.

I found C++ function atexit(), but it requires pointer to void function with no argument, so the code below cannot be compiled. How I can solve it, please?

Destructor of my instance requires MySQL connection.

#include <WinSock.h>
#include <iostream>
#include <cstdio>
#include <stdio.h>
#include <mysql.h>
#include <string>

// Declarations for Mysql DB

using namespace std;

class Process {
  public:
     ~Process();
};

Process::~Process ()
{
    // Interaction with DB
}

int main(void) 
{
  // Join to DB

  atexit(proc.~Process); // Call desctructor of instance proc before program ends

  Process proc;

  // App code

  return 0;
}

Answer 1

proc has automatic duration, i.e. when exiting main, it will be destroyed automatically (and the destructor invoked) – you don’t need the atexit business..

Unless as @Rob mentions below, you call exit() in your code somewhere… if that’s the case, then you’ll have to allocate Process on the heap, provide a function that atexit can call which is aware of this instance, and delete it there…