Class function with own namespace that calls a global function with a pointer to the same class [duplicate]

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• Resolve header include circular dependencies 8 answers

I have these files:

pi_utilities.h

#ifndef UTILITIES_H_
#define UTILITIES_H_

#include "pi_dfa.h"

struct ir_statistical_measures
{
    // True positive, and so on.
    int tp = 0;
    int tn = 0;
    int fp = 0;
    int fn = 0;

    int dim_positive=0; 
    int dim_negative=0; 

    double accuracy  = 0; //(number in [0 1])
    double precision = 0;
    double recall = 0;
    double f_measure = 0;
    double matthews = 0;
    double specificity = 0; //this is recall- or true negative rate
    double bcr = 0;
};


void compute_ir_stats(const pi::dfa* dfa1 ,const pi::dfa* target,const set<vector<MYTYPE>> &test_set,ir_statistical_measures &stats);
#endif

pi_utilities.cpp

#include "pi_utilities.h"

void compute_ir_stats(const pi::dfa* dfa1 ,const pi::dfa* target,const set<vector<MYTYPE>> &test_set,ir_statistical_measures &stats)
{
}

pi_dfa.h

#ifndef DFA_H_
#define DFA_H_

#include <string>
#include <vector>
#include <set>

#include "pi_utilities.h"

typedef unsigned short int MYTYPE;

using namespace std;

extern struct ir_statistical_measures &stats; //I say to compiler that definition isn't here

namespace pi
{
   class dfa
   {
        public:
        bool compare_dfa(const dfa *dfa_to_compare,string method,ir_statistical_measures &stats1,ir_statistical_measures &stats2) const;


    };
}
#endif

pi_dfa.cpp

#include "pi_dfa.h"



bool pi::dfa::compare_dfa(const dfa *dfa_to_compare , string method , ir_statistical_measures &stats1 , ir_statistical_measures &stats2) const
{
   set<vector<MYTYPE>> test_set;
   compute_ir_stats(dfa_to_compare,this,test_set,stats1); 

   return true;
}

main.cpp

#include "pi_dfa.h"

int main()
{
   pi::dfa* L_dfa=NULL;  
   L_dfa = new pi::dfa();
   pi::dfa* O_dfa=new pi::dfa();

   bool value_return;
   struct ir_statistical_measures test_set_ir_statistical_measures; //struct defined in pi_utilities.h
   struct ir_statistical_measures test_set_ir_statistical_measures2;
   value_return = L_dfa->compare_dfa(O_dfa,"method",test_set_ir_statistical_measures,test_set_ir_statistical_measures2);
}

I would call from a function of a class a global method. This method has a struct defined in the "global space" and this rason bring me to include an extern declaration in pi_dfa.h for the struct: I don't know if it's right. Furthermore the called global function has a pointer to a member of the class dfa. But i get these compile errors:

pi_utilities.h:27:29: error: ‘pi’ does not name a type
 void compute_ir_stats(const pi::dfa* dfa1 ,const pi::dfa* target,const set<vector<MYTYPE>> &test_set,ir_statistical_measures &stats);
                             ^
pi_utilities.h:27:36: error: expected unqualified-id before ‘*’ token
 void compute_ir_stats(const pi::dfa* dfa1 ,const pi::dfa* target,const set<vector<MYTYPE>> &test_set,ir_statistical_measures &stats);
                                    ^
pi_utilities.h:27:36: error: expected ‘)’ before ‘*’ token
pi_utilities.h:27:36: error: expected initializer before ‘*’ token
pi_dfa.cpp: In member function ‘bool pi::dfa::compare_dfa(const pi::dfa*, std::string, ir_statistical_measures&, ir_statistical_measures&) const’:
pi_dfa.cpp:8:56: error: ‘compute_ir_stats’ was not declared in this scope
    compute_ir_stats(dfa_to_compare,this,test_set,stats1); 
                                                        ^
In file included from pi_dfa.h:8:0,
                 from main.cpp:1:
pi_utilities.h:27:29: error: ‘pi’ does not name a type
 void compute_ir_stats(const pi::dfa* dfa1 ,const pi::dfa* target,const set<vector<MYTYPE>> &test_set,ir_statistical_measures &stats);
                             ^
pi_utilities.h:27:36: error: expected unqualified-id before ‘*’ token
 void compute_ir_stats(const pi::dfa* dfa1 ,const pi::dfa* target,const set<vector<MYTYPE>> &test_set,ir_statistical_measures &stats);
                                    ^
pi_utilities.h:27:36: error: expected ‘)’ before ‘*’ token
pi_utilities.h:27:36: error: expected initializer before ‘*’ token

Maybe there is a namespace problem or other. I made some attemps but I was not able to fix problems and compile. How could I fix it?

I'm using C++11 (The code here is rearranged to a minimal executable version)