Destructor Problem

This is a discussion on Destructor Problem within the C++ Programming forums, part of the General Programming Boards category; Hi, I compile the following program using Microsoft Visual C++ 6.0: Create.h Code: #ifndef CREATE_H #define CREATE_H class CreateAndDestroy { ...

  1. #1
    Registered User
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    Apr 2007
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    7

    Destructor Problem

    Hi, I compile the following program using Microsoft Visual C++ 6.0:

    Create.h
    Code:
    #ifndef CREATE_H
    #define CREATE_H
    
    class CreateAndDestroy
    {
    public:
    	CreateAndDestroy(int, char *);
    	~CreateAndDestroy();
    
    private:
    	int object_id;
    	char *message;
    };
    
    #endif
    Create.cpp
    Code:
    #include <iostream>
    #include "Create.h"
    
    using namespace std;
    
    CreateAndDestroy::CreateAndDestroy(int object_number, char *messageptr)
    {
    	object_id = object_number;
    	message = messageptr;
    
    	cout << "Object " << object_id << " constructor runs " << message << endl;
    }
    
    CreateAndDestroy::~CreateAndDestroy()
    {
    	if (object_id == 1 || object_id == 6)
    	{
    		cout << "\n";
    	}
    	else
    	{
    		cout << "";
    	}
    
    	cout << "Object " << object_id << " destructor runs " << message << endl;
    }
    TestCreate.cpp
    Code:
    #include <iostream>
    #include "Create.h"
    
    using namespace std;
    
    void create()
    {
    	cout << endl << "CREATE FUNCTION: EXECUTION BEGINS" << endl;
    	CreateAndDestroy fifth(5, "(local automatic in create)");
    	static CreateAndDestroy sixth(6, "(local static in create)");
    	CreateAndDestroy seventh(7, "(local automatic in create)");
    	cout << endl << "CREATE FUNCTION: EXECUTION ENDS" << endl;
    }
    
    CreateAndDestroy first(1, "(global before main)");
    
    int main()
    {
    	cout << endl << "MAIN FUNCTION: EXECUTION BEGINS" << endl;
    	CreateAndDestroy second(2, "(local automatic in main)");
    	static CreateAndDestroy third(3, "(local static in main)");
    	create();
    	cout << endl << "MAIN FUNCTION: EXECUTION RESUMES" << endl;
    	CreateAndDestroy fourth(4, "(local automatic in main)");
    	cout << endl << "MAIN FUNCTION: EXECUTION ENDS" << endl;
    	return 0;
    }
    While the program is working, the result is not the one that I expect. Somehow, the destructor of object 1 is not getting called. I have debugged the program several time, but I cannot find the answer why destructor of object 1 is not getting called. Here is the result of the program:

    Object 1 constructor runs (global before main)

    MAIN FUNCTION: EXECUTION BEGINS
    Object 2 constructor runs (local automatic in main)
    Object 3 constructor runs (local static in main)

    CREATE FUNCTION: EXECUTION BEGINS
    Object 5 constructor runs (local automatic in create)
    Object 6 constructor runs (local static in create)
    Object 7 constructor runs (local automatic in create)

    CREATE FUNCTION: EXECUTION ENDS
    Object 7 destructor runs (local automatic in create)
    Object 5 destructor runs (local automatic in create)

    MAIN FUNCTION: EXECUTION RESUMES
    Object 4 constructor runs (local automatic in main)

    MAIN FUNCTION: EXECUTION ENDS
    Object 4 destructor runs (local automatic in main)
    Object 2 destructor runs (local automatic in main)

    Object 6 destructor runs (local static in create)
    Object 3 destructor runs (local static in main)
    Press any key to continue

    Can you help me find the answer? Thank you for your help in advance.

  2. #2
    ZuK
    ZuK is offline
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    Location
    Austria
    Posts
    1,990
    I think this is a problem with your c library. That destructor will run after main has returned that's why you don't see the output statement.
    I think MS library behaves this way.
    Try setting a breakpoint in the destructor. It should be executed.
    Kurt

  3. #3
    Massively Single Player AverageSoftware's Avatar
    Join Date
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    Location
    Buffalo, NY
    Posts
    141
    It might be possible that cout is being destroyed before your global object is, and thus it can't print. Try using printf instead.
    There is no greater sign that a computing technology is worthless than the association of the word "solution" with it.

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