Strange problem about constructor

[John]

Hi all:

In my code I define a class with inline constructor. But it does not
work. I describe the class as below:

myclass{
public:
myclass(int a, int b) { r1 = a; r2 = b;}

protected:
int r1;
int r2;
double z;
}

But the constructor does not work. When I declare an object of the
class, the constructor can not correctly initialize the variables.

Then I modify the code as below:

myclass{
public:
myclass(int a, int b);

protected:
int r1;
int r2;
double z;
}

myclass::myclas s(int a, int b) {
r1 = a;
r2 = b;
}

It works. When I declare an object of the class, the constructor can
correctly initialize variables.

What is the problem?

Thanks a lot.

John

[John]

Hi all:

Thanks a lot. I post a simplified version of my code.

---------------
header-file.h
---------------
#include <list>
#include <algorithm>

myclass{
friend class yclass;
public:
myclass(u_int32 _t a, u_int32_t b) { r1 = a; r2 = b;}
protected: //u_int32_t is defined type, a kind of integer.
u_int32_t r1;
u_int32_t r2;
double z;
}

yclass{

public:

.....
void m_insert(u_int3 2_t id, u_int32_t bd);
bool m_lookup(u_int3 2_t id, u_int32_t bd);
void m_purge(void);
void funct(u_int32_t id, u_int32_t bd);

std::list< myclass > myclass_list;

.....
}
-----------------------------------
file.cc
-----------------------------------
#include <header-file.h>

void yclass::m_inser t(u_int32_t d, u_int32_t bd) {
myclass b(d, bd);
std::cout<<"r1: "<<b.r1<<" r2:"<<b.r2<<std ::endl; //LINE 1
b.z = TIME;//a constant.
myclass_list.pu sh_back(b);

std::cout<<"ins ert--d:"<<d<<" bd:"<< bd<<std::endl;
std::list< myclass >::const_iterat or pos;
for (pos = myclass_list.be gin(); pos != myclass_list.en d(); ++pos)
std::cout<<"pos->r1:"<<(*pos).r 1<<" r2:"<<(*pos).r2 <<"
z:"<<pos->z<<std::endl ;

}

bool yclass::m_looku p(u_int32_t d, u_int32_t bd) {
std::list< myclass >::const_iterat or pos;
std::cout<<"loo kup--d:"<<d<<" bd:"<< bd<<std::endl;
for (pos = myclass_list.be gin(); pos != myclass_list.en d(); ++pos){
std::cout<<"(*p os).r1:"<<pos->r1<<" r2:"<< pos->r2<<std::end l;
if (((*pos).r1 == d) && ((*pos).r2 == bd)){
std::cout<<"fin d it"<<std::end l; //LINE 2
return true;
}
}
return false;
}

void yclass::m_purge () {
std::list< myclass >::iterator pos;
for (pos = myclass_list.be gin(); pos != myclass_list.en d(); ++pos){
if((*pos).z <= 10) {
myclass_list.er ase(pos);
--pos;
}
}
}

void funct(u_int32_t id, u_int32_t bd){

.........
if(!m_lookup(id , bd)){
m_insert(id, bd); //LINE 3
}

.........

}

If LINE 3 is executed, e.g., m_insert(2,3), LINE 1 can not output 2
and 3, but two large numbers. So LINE 2 is never executed, since the
list -- myclass_list does not store the correct value. But if I do not
use inline constructor, the output is correct.

I post all the code related to myclass. I hope the bug has been
exposed.

Thanks again for the help.

John
tp*****@mail.ru (New_user) wrote in message news:<d2******* *************** ****@posting.go ogle.com>...

Thanks for reply.
The code is not the original code. I wish I could post the original
code here. But I can not, because the code is large and complex.

Ok, try to minimize and simplify your code so, that it is "simple" and
still buggy. It seems to me, that you should give us more detailed
description of the problem?

For example, compile this:

#include <iostream>

class A
{
public:
A(int a, int b)
{
a_ = a;
b_ = b;
}
int a_;
int b_;
};

int main()
{
A a(1,2);
std::cout<<a.a_ <<" "<<a.b_<<std::e ndl;
}

In this example we have 1 2 in output. And so your example does not
show your problem, right?

[Jeff Flinn]

Forgive the top post, but again the code you provided below is not
compilable, even with cursory examination. ie: myclass{ ... } is not C++,
You need to prefix with the keyword 'class' and terminate the class
declaraton with ';'

Get this code to compile and show us the problem.

Jeff F

"John" <jo*********@ya hoo.com> wrote in message
news:c3******** *************** ***@posting.goo gle.com...

Hi all:

Thanks a lot. I post a simplified version of my code.

---------------
header-file.h
---------------
#include <list>
#include <algorithm>

myclass{
friend class yclass;
public:
myclass(u_int32 _t a, u_int32_t b) { r1 = a; r2 = b;}
protected: //u_int32_t is defined type, a kind of integer.
u_int32_t r1;
u_int32_t r2;
double z;
}

yclass{

public:

.....
void m_insert(u_int3 2_t id, u_int32_t bd);
bool m_lookup(u_int3 2_t id, u_int32_t bd);
void m_purge(void);
void funct(u_int32_t id, u_int32_t bd);

std::list< myclass > myclass_list;

.....
}
-----------------------------------
file.cc
-----------------------------------
#include <header-file.h>

void yclass::m_inser t(u_int32_t d, u_int32_t bd) {
myclass b(d, bd);
std::cout<<"r1: "<<b.r1<<" r2:"<<b.r2<<std ::endl; //LINE 1
b.z = TIME;//a constant.
myclass_list.pu sh_back(b);

std::cout<<"ins ert--d:"<<d<<" bd:"<< bd<<std::endl;
std::list< myclass >::const_iterat or pos;
for (pos = myclass_list.be gin(); pos != myclass_list.en d(); ++pos)
std::cout<<"pos->r1:"<<(*pos).r 1<<" r2:"<<(*pos).r2 <<"
z:"<<pos->z<<std::endl ;

}

bool yclass::m_looku p(u_int32_t d, u_int32_t bd) {
std::list< myclass >::const_iterat or pos;
std::cout<<"loo kup--d:"<<d<<" bd:"<< bd<<std::endl;
for (pos = myclass_list.be gin(); pos != myclass_list.en d(); ++pos){
std::cout<<"(*p os).r1:"<<pos->r1<<" r2:"<< pos->r2<<std::end l;
if (((*pos).r1 == d) && ((*pos).r2 == bd)){
std::cout<<"fin d it"<<std::end l; //LINE 2
return true;
}
}
return false;
}

void yclass::m_purge () {
std::list< myclass >::iterator pos;
for (pos = myclass_list.be gin(); pos != myclass_list.en d(); ++pos){
if((*pos).z <= 10) {
myclass_list.er ase(pos);
--pos;
}
}
}

void funct(u_int32_t id, u_int32_t bd){

.........
if(!m_lookup(id , bd)){
m_insert(id, bd); //LINE 3
}

.........

}

If LINE 3 is executed, e.g., m_insert(2,3), LINE 1 can not output 2
and 3, but two large numbers. So LINE 2 is never executed, since the
list -- myclass_list does not store the correct value. But if I do not
use inline constructor, the output is correct.

I post all the code related to myclass. I hope the bug has been
exposed.

Thanks again for the help.

John
tp*****@mail.ru (New_user) wrote in message

news:<d2******* *************** ****@posting.go ogle.com>...

Thanks for reply.
The code is not the original code. I wish I could post the original
code here. But I can not, because the code is large and complex.

Ok, try to minimize and simplify your code so, that it is "simple" and
still buggy. It seems to me, that you should give us more detailed
description of the problem?

For example, compile this:

#include <iostream>

class A
{
public:
A(int a, int b)
{
a_ = a;
b_ = b;
}
int a_;
int b_;
};

int main()
{
A a(1,2);
std::cout<<a.a_ <<" "<<a.b_<<std::e ndl;
}

In this example we have 1 2 in output. And so your example does not
show your problem, right?

[Victor Bazarov]

"John" <jo*********@ya hoo.com> wrote...

Thanks a lot. I post a simplified version of my code.
Too "simplified " to be useful. Please read the FAQ 5.8.

---------------
header-file.h
---------------
#include <list>
#include <algorithm>
This doesn't seem to be relevant at all.

myclass{
friend class yclass;
public:
myclass(u_int32 _t a, u_int32_t b) { r1 = a; r2 = b;}
protected: //u_int32_t is defined type, a kind of integer.
u_int32_t r1;
u_int32_t r2;
double z;
}

yclass{

public:

.....
void m_insert(u_int3 2_t id, u_int32_t bd);
bool m_lookup(u_int3 2_t id, u_int32_t bd);
void m_purge(void);
void funct(u_int32_t id, u_int32_t bd);

std::list< myclass > myclass_list;

.....
}
-----------------------------------
file.cc
-----------------------------------
#include <header-file.h>

void yclass::m_inser t(u_int32_t d, u_int32_t bd) {
What are the values of these arguments when you step into this
function?
myclass b(d, bd);
What do you see in the debugger when you step over this definition?
std::cout<<"r1: "<<b.r1<<" r2:"<<b.r2<<std ::endl; //LINE 1
b.z = TIME;//a constant.
myclass_list.pu sh_back(b);

std::cout<<"ins ert--d:"<<d<<" bd:"<< bd<<std::endl;
std::list< myclass >::const_iterat or pos;
for (pos = myclass_list.be gin(); pos != myclass_list.en d(); ++pos)
std::cout<<"pos->r1:"<<(*pos).r 1<<" r2:"<<(*pos).r2 <<"
z:"<<pos->z<<std::endl ;

}

bool yclass::m_looku p(u_int32_t d, u_int32_t bd) {
What are the values of the arguments here? Are they correct?
std::list< myclass >::const_iterat or pos;
std::cout<<"loo kup--d:"<<d<<" bd:"<< bd<<std::endl;
What output do you see here?
for (pos = myclass_list.be gin(); pos != myclass_list.en d(); ++pos){
std::cout<<"(*p os).r1:"<<pos->r1<<" r2:"<< pos->r2<<std::end l;
if (((*pos).r1 == d) && ((*pos).r2 == bd)){
std::cout<<"fin d it"<<std::end l; //LINE 2
return true;
}
}
return false;
}

void yclass::m_purge () {
std::list< myclass >::iterator pos;
for (pos = myclass_list.be gin(); pos != myclass_list.en d(); ++pos){
if((*pos).z <= 10) {
myclass_list.er ase(pos);
--pos;
}
}
}
Seems that 'm_purge' is also errelevant.

void funct(u_int32_t id, u_int32_t bd) {

What are the values of 'id' and 'bd' here?

.........
if(!m_lookup(id , bd)){
m_insert(id, bd); //LINE 3
}

.........

}
Who is calling this function? How is it called?

If LINE 3 is executed, e.g., m_insert(2,3), LINE 1 can not output 2
and 3, but two large numbers. So LINE 2 is never executed, since the
list -- myclass_list does not store the correct value. But if I do not
use inline constructor, the output is correct.

I post all the code related to myclass.
No, you didn't post _all_ code. You posted _some_ code. Non-compilable,
first. Incomplete, second.

I hope the bug has been
exposed.

How can it have been? So far only your inattentiveness to requirements
has.

V

[John Harrison]

"John" <jo*********@ya hoo.com> wrote in message
news:c3******** *************** ***@posting.goo gle.com...

Hi all:

Thanks a lot. I post a simplified version of my code.

---------------
header-file.h
---------------
#include <list>
#include <algorithm>

myclass{
friend class yclass;
public:
myclass(u_int32 _t a, u_int32_t b) { r1 = a; r2 = b;}
protected: //u_int32_t is defined type, a kind of integer.
u_int32_t r1;
u_int32_t r2;
double z;
}

yclass{

public:

.....
void m_insert(u_int3 2_t id, u_int32_t bd);
bool m_lookup(u_int3 2_t id, u_int32_t bd);
void m_purge(void);
void funct(u_int32_t id, u_int32_t bd);

std::list< myclass > myclass_list;

.....
}
-----------------------------------
file.cc
-----------------------------------
#include <header-file.h>

void yclass::m_inser t(u_int32_t d, u_int32_t bd) {
myclass b(d, bd);
std::cout<<"r1: "<<b.r1<<" r2:"<<b.r2<<std ::endl; //LINE 1
b.z = TIME;//a constant.
myclass_list.pu sh_back(b);

std::cout<<"ins ert--d:"<<d<<" bd:"<< bd<<std::endl;
std::list< myclass >::const_iterat or pos;
for (pos = myclass_list.be gin(); pos != myclass_list.en d(); ++pos)
std::cout<<"pos->r1:"<<(*pos).r 1<<" r2:"<<(*pos).r2 <<"
z:"<<pos->z<<std::endl ;

}

bool yclass::m_looku p(u_int32_t d, u_int32_t bd) {
std::list< myclass >::const_iterat or pos;
std::cout<<"loo kup--d:"<<d<<" bd:"<< bd<<std::endl;
for (pos = myclass_list.be gin(); pos != myclass_list.en d(); ++pos){
std::cout<<"(*p os).r1:"<<pos->r1<<" r2:"<< pos->r2<<std::end l;
if (((*pos).r1 == d) && ((*pos).r2 == bd)){
std::cout<<"fin d it"<<std::end l; //LINE 2
return true;
}
}
return false;
}

void yclass::m_purge () {
std::list< myclass >::iterator pos;
for (pos = myclass_list.be gin(); pos != myclass_list.en d(); ++pos){
if((*pos).z <= 10) {
myclass_list.er ase(pos);
--pos;
}
}
}

void funct(u_int32_t id, u_int32_t bd){

.........
if(!m_lookup(id , bd)){
m_insert(id, bd); //LINE 3
}

.........

}

If LINE 3 is executed, e.g., m_insert(2,3), LINE 1 can not output 2
and 3, but two large numbers. So LINE 2 is never executed, since the
list -- myclass_list does not store the correct value. But if I do not
use inline constructor, the output is correct.

I post all the code related to myclass. I hope the bug has been
exposed.

Perhaps the problem is related to u_int32_t, how is that defined?

There is nothing wrong with your inline constructor.

john