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about static vector (of pointers) member function

 
 
Josefo
Guest
Posts: n/a
 
      05-19-2007

Hello, is someone so kind to tell me why I am getting the following
errors ?


vector_static_function.c:20: error: expected constructor, destructor,
or type conversion before '.' token
vector_static_function.c:21: error: expected constructor, destructor,
or type conversion before '.' token


when compiling this:


// about static vector (of pointers) member function

#include <iostream>
#include <vector>
using namespace std;

class G4PreCompoundModel
{
public:
static vector<int*> * GetCreatorModels()
{ return &G4PreCompoundModel::theCreatorModels; }

// private:

static vector<int*> theCreatorModels;

};

int uno=1, dos=2;
G4PreCompoundModel::theCreatorModels.push_back(&un o);
G4PreCompoundModel::theCreatorModels.push_back(&do s);

int main ()
{
G4PreCompoundModel::GetCreatorModels();
return 0;
}

Thanks in advance amd best regards

Jose Manuel

 
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Gianni Mariani
Guest
Posts: n/a
 
      05-19-2007
Josefo wrote:
> Hello, is someone so kind to tell me why I am getting the following
> errors ?
>
>
> vector_static_function.c:20: error: expected constructor, destructor,
> or type conversion before '.' token
> vector_static_function.c:21: error: expected constructor, destructor,
> or type conversion before '.' token
>
>
> when compiling this:
>
>
> // about static vector (of pointers) member function
>
> #include <iostream>
> #include <vector>
> using namespace std;
>
> class G4PreCompoundModel
> {
> public:
> static vector<int*> * GetCreatorModels()
> { return &G4PreCompoundModel::theCreatorModels; }
>
> // private:
>
> static vector<int*> theCreatorModels;
>
> };
>
> int uno=1, dos=2;
> G4PreCompoundModel::theCreatorModels.push_back(&un o);

^^^^^^^ what is this supposed to be ? A statement is not allowed here,
it must be in a function block.

Look up your C++ book on how to define static data members and how to
initialize them.

> G4PreCompoundModel::theCreatorModels.push_back(&do s);
>
> int main ()
> {
> G4PreCompoundModel::GetCreatorModels();
> return 0;
> }
>
> Thanks in advance amd best regards
>
> Jose Manuel
>

 
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Salt_Peter
Guest
Posts: n/a
 
      05-19-2007
On May 19, 1:46 pm, Josefo <(E-Mail Removed)> wrote:
> Hello, is someone so kind to tell me why I am getting the following
> errors ?
>
> vector_static_function.c:20: error: expected constructor, destructor,
> or type conversion before '.' token
> vector_static_function.c:21: error: expected constructor, destructor,
> or type conversion before '.' token
>
> when compiling this:
>
> // about static vector (of pointers) member function
>
> #include <iostream>
> #include <vector>
> using namespace std;
>
> class G4PreCompoundModel
> {
> public:
> static vector<int*> * GetCreatorModels()
> { return &G4PreCompoundModel::theCreatorModels; }
>
> // private:
>
> static vector<int*> theCreatorModels;


Where is the definition for this static member?

>
> };
>
> int uno=1, dos=2;
> G4PreCompoundModel::theCreatorModels.push_back(&un o);
> G4PreCompoundModel::theCreatorModels.push_back(&do s);


These push_back() calls are not allowed outside main() or another
function. You can't code anything else but a declaration or a
definition in a namespace (in this case: the global namespace).

>
> int main ()
> {
> G4PreCompoundModel::GetCreatorModels();
> return 0;
>
> }
>
> Thanks in advance amd best regards
>
> Jose Manuel



 
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John Harrison
Guest
Posts: n/a
 
      05-20-2007
Josefo wrote:
> Hello, is someone so kind to tell me why I am getting the following
> errors ?
>
>
> vector_static_function.c:20: error: expected constructor, destructor,
> or type conversion before '.' token
> vector_static_function.c:21: error: expected constructor, destructor,
> or type conversion before '.' token
>
>
> when compiling this:
>
>
> // about static vector (of pointers) member function
>
> #include <iostream>
> #include <vector>
> using namespace std;
>
> class G4PreCompoundModel
> {
> public:
> static vector<int*> * GetCreatorModels()
> { return &G4PreCompoundModel::theCreatorModels; }
>
> // private:
>
> static vector<int*> theCreatorModels;
>
> };
>
> int uno=1, dos=2;
> G4PreCompoundModel::theCreatorModels.push_back(&un o);
> G4PreCompoundModel::theCreatorModels.push_back(&do s);
>
> int main ()
> {
> G4PreCompoundModel::GetCreatorModels();
> return 0;
> }
>
> Thanks in advance amd best regards
>
> Jose Manuel
>


Here's how to write your code so that it works, (basically your design
has static in the wrong place)

class G4PreCompoundModel
{
public:
static G4PreCompoundModel& GetCreatorModels()
{
static G4PreCompoundModel theModel;
return theModel;
}

private:
G4PreCompoundModel()
{
uno = 1;
dos = 2;
theCreatorModels.push_back(&uno);
theCreatorModels.push_back(&dos);
}

int uno;
int dos;
vector<int*> theCreatorModels;

};

Now all you have to do is add whatever methods you require to
G4PreCompoundModel.

john
 
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Josefo
Guest
Posts: n/a
 
      05-21-2007
On May 20, 8:45 am, John Harrison <(E-Mail Removed)> wrote:
> Josefo wrote:
> > Hello, is someone so kind to tell me why I am getting the following
> > errors ?

>
> > vector_static_function.c:20: error: expected constructor, destructor,
> > or type conversion before '.' token
> > vector_static_function.c:21: error: expected constructor, destructor,
> > or type conversion before '.' token

>
> > when compiling this:

>
> > // about static vector (of pointers) member function

>
> > #include <iostream>
> > #include <vector>
> > using namespace std;

>
> > class G4PreCompoundModel
> > {
> > public:
> > static vector<int*> * GetCreatorModels()
> > { return &G4PreCompoundModel::theCreatorModels; }

>
> > // private:

>
> > static vector<int*> theCreatorModels;

>
> > };

>
> > int uno=1, dos=2;
> > G4PreCompoundModel::theCreatorModels.push_back(&un o);
> > G4PreCompoundModel::theCreatorModels.push_back(&do s);

>
> > int main ()
> > {
> > G4PreCompoundModel::GetCreatorModels();
> > return 0;
> > }

>
> > Thanks in advance amd best regards

>
> > Jose Manuel

>
> Here's how to write your code so that it works, (basically your design
> has static in the wrong place)
>
> class G4PreCompoundModel
> {
> public:
> static G4PreCompoundModel& GetCreatorModels()
> {
> static G4PreCompoundModel theModel;
> return theModel;
> }
>
> private:
> G4PreCompoundModel()
> {
> uno = 1;
> dos = 2;
> theCreatorModels.push_back(&uno);
> theCreatorModels.push_back(&dos);
> }
>
> int uno;
> int dos;
> vector<int*> theCreatorModels;
>
> };
>
> Now all you have to do is add whatever methods you require to
> G4PreCompoundModel.
>
> john


Thanks, John for your assistance. A sent a reply yesterday, but it
does not appear published. Therefore, I write it again (sorry in
advance if it shows up duplicated).Well, when I received your
suggestion I had already more or less "elegantly" (or efficiently)
solved the problem. Here you have the code:


///begin of the code
// about static vector (of pointers) member function
//19/05/07...my solution

#include <iostream>
#include <vector>
using namespace std;

class G4PreCompoundModel
{
public:
static int uno, dos;

static vector<int*> * GetCreatorModels()
{ return &
G4PreCompoundModel::theCreatorModels; }

// private:

static vector<int*> theCreatorModels;

private:
static bool __init;
static bool init() {
theCreatorModels.push_back(&uno);
theCreatorModels.push_back(&dos);
return true;
}
};
int G4PreCompoundModel::uno=1;
int G4PreCompoundModel::dos=2;
vector<int*> G4PreCompoundModel::theCreatorModels;
bool G4PreCompoundModel::__init = G4PreCompoundModel::init();

int main ()
{
int uno=1,dos=2;
vector<int*> * p=G4PreCompoundModel::GetCreatorModels();
cout<<"The returned pointer 'p' (to vector of pointers to integers)=
"<<p<<endl;

int ** p1;
int ** p2;
p1=&((*p).at(0))+1;
p2=&((*p).at(1));

if(uno==*((*p).at(0)) && dos==*((*p).at(1)))

cout<<"Ok...uno =*((*p).at(0)) = "<<*((*p).at(0))<<" and dos =
*((*p).at(1)) ="<<*((*p).at(1))<<endl;
if (p1==p2)
{cout<<"Right!..the pointers (to vector member pointers to integers)
are sequential!!"<<endl;
cout<<"&((*p).at(0))+1="<<&((*p).at(0))+1<<"
&((*p).at(1))="<<p2<<endl;}
cout<<"The vector member pointers (to integers..) are not sequential
(why shoud they?):"<<endl;
cout<<"(*p).at(0) = "<<(*p).at(0)<<" (*p).at(1) =
"<<(*p).at(1)<<endl;
return 0;
}

////// end of the code



When implementing your suggestion I had to comment the /private
declaration in G4PreCompoundModel class in order to have acces to its
constructor and hence to ints vector members. Here you hacve it:


///begin of the code
// about static vector (of pointers) member function
//20/05/07...John Allison's solution

#include <iostream>
#include <vector>
using namespace std;
class G4PreCompoundModel
{
public:
static G4PreCompoundModel& GetCreatorModels()
{
static G4PreCompoundModel theModel;
return theModel;
}

// private:
G4PreCompoundModel()
{
uno = 1;
dos = 2;
theCreatorModels.push_back(&uno);
theCreatorModels.push_back(&dos);
}

int uno;
int dos;
vector<int*> theCreatorModels;

};


int main ()
{
int uno=1,dos=2;
int * puno;
int * pdos;
puno =G4PreCompoundModel::GetCreatorModels().theCreator Models.at(0);
pdos =G4PreCompoundModel::GetCreatorModels().theCreator Models.at(1);



if(uno==*puno && dos==*pdos)
cout<<"Ok...uno =*puno = "<<*puno<<" and dos = *pdos
="<<*pdos<<endl;
if (&puno+1==&pdos) {
cout<<"The pointers (to vector member pointers to integers) are
sequential:"<<endl;
cout<<"&puno+1="<<&puno+1<<" &pdos="<<&pdos<<endl;
cout<< "why they are not????"<<endl;}
else
{ cout<<" The pointers (to vector member pointers to integers) are
NOT sequential:"<<endl;
cout<<"&puno+1="<<&puno+1<<" &pdos="<<&pdos<<endl;
cout<< "why ????"<<endl;}
cout<<"The vector member pointers (to integers..) are not sequential
(why shoud they?):"<<endl;
cout<<"puno = "<<puno<<" pdos = "<<pdos<<endl;

return 0;
}

///end of the code

But which puzzles me is the fact that the pointers to the vector
members (also pointers to integers, by he way) are not
sequential...and they are sequential when constructucted in "my
way" (my code). Can you tell me why?? Cheers and many thanks in
advance

Jose Manuel
Jose Manuel

 
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