c++ object and "undefined reference to" not agree with duplicated [duplicate]

Question

This question already has answers here:

What is an undefined reference/unresolved external symbol error and how do I fix it? (38 answers)

Closed 8 years ago.

Hello all :) It was a forgotten double declaration with a "extern".

Problem

I believe it is a problem of object between differents files or a problem of "&" or "*"

I have the error line:

-lws2_32/tmp/ccBWAJ1F.o: dans la fonction « Z2iav »:/home/myfolder/ia.hpp:217: référence indéfinie vers « union_range »collect2: erreur: ld a retourné 1 code d'état d'exécution

(undefined reference to union_range with 1 code state execution)

I am at 95% sure that the error is from my use of a CarSet object (union_range) in ia.hpp in valeur_main_board_range(moment()+1,union_range)

I have a very close function valeur_main_board(moment()+1) without any error.

ia.hpp

the error is here: int valeur_main = valeur_main_board_range(moment()+1,union_range);

in my file ia.hpp

#include "variable_calcule.hpp"

extern std::set<CardSet> union_range, resultat, range_joueur;
// the error was the "extern" to remove
void ia() 
{
std::set<CardSet> union_range, resultat, range_joueur;
for (int j=0; j<10; j++) 
    {
    range_joueur=range_action(action[0][j][1],j);
    set_union(union_range.begin(),union_range.end(),range_joueur.begin(),range_joueur.end(),std::inserter(resultat,resultat.begin()));
    union_range=resultat;
    }

    int valeur_main = valeur_main_board_range(moment()+1,union_range); // BUG HERE
}

valeur_main_board_range() code (using union_range)

union_range include from #include "variable_calcule.hpp" in include #include "analyse_action.hpp"

#include "CardSet.h"
using namespace pokerstove;
using namespace std;

int valeur_main_board_range(int nb_carte, std::set<CardSet> &range)     { 

int dessus=0;

    [...]

return dessus;  
}   

If I find the answer I will remove unnecessary code for future readers. For the moment I prefer put too much... But if you want I remove or add code just ask :)

Thank you for your reading :)

Answer 1

In presented code snippets I found out union_range only inside function ia where this name is well-defined.

void ia() 
{
analyse_action();
std::set<CardSet> union_range, resultat, range_joueur;

Here union_range is a local variable of type std::set<CardSet>. So you showed irrelevant code.