error C2065: undeclared identifier in template function - c++

Question

I'm a newbie in C++ and i'm trying to put a little project on wheels, but i'm having a hard time with those errors and i don't know what i'm doing wrong. I think, i've included all neccesary header files.
What i'm doing wrong?
Thank you in advance!
d:\files\visual studio 2010\projects\calculator\aplicatie.cpp(31): error C2065: 'CmdAritmetice' : undeclared identifier
d:\files\visual studio 2010\projects\calculator\aplicatie.cpp(31): error C2062: type 'int' unexpected
d:\files\visual studio 2010\projects\calculator\aplicatie.cpp(37): error C2065: 'cmd1' : undeclared identifier
d:\files\visual studio 2010\projects\calculator\aplicatie.cpp(37): error C2228: left of '.Execute' must have class/struct/union
type is ''unknown-type''
Edit
If i modify CmdAritmetice <int, Suma> cmd1("+"); with UI::CmdAritmetice<Calcule::Suma<int>> cmd1("+"); the following errors appear when try to compile:
1>d:\files\visual studio 2010\projects\calculator\aplicatie.cpp(32): error C2440: 'specialization' : cannot convert from 'T (__cdecl *)(T,T)' to 'int (__cdecl *)(int,int)'
1> None of the functions with this name in scope match the target type
1>d:\files\visual studio 2010\projects\calculator\aplicatie.cpp(39): error C2660: 'Calculator::UI::CmdAritmetice<Operatie>::Execute' : function does not take 1 arguments
1> with
1> [
1> Operatie=0x0
1> ]
Main.cpp
#include "aplicatie.h"
using namespace Calculator;
int main()
{
Aplicatie app;
app.Run();
return 0;
}
aplicatie.cpp edited
#include <iostream>
#include "aplicatie.h"
#include "Calcule\operatii.h"
#include "UI\cmdaritmetice.h"
using namespace std;
namespace Calculator{
(...)
void Aplicatie::Run()
{
TestSuma();
CmdAritmetice <int, Suma> cmd1("+"); //here i have errors
cmd1.Execute("Introduceti doua numere intregi (x, y)");
}
void Aplicatie::TestSuma()
{
int x = 10, y = 20;
int r = Calcule::Suma(x,y);
}
}
cmdaritmetice.h
#ifndef ARITMETICE_H
#define ARITMETICE_H
#include "UI\comanda.h"
namespace Calculator{
namespace UI{
template<int Operatie(int, int)>
class CmdAritmetice : public ComandaCalcule
{
public:
CmdAritmetice(const string &nume) : ComandaCalcule(nume)
{
}
void Execute()
{
cout << Nume() << endl;
cout << "Introduceti doua numere intregi (x, y)\n";
int x, y;
cin >> x >> endl;
cin >> y >> endl;
cout << x << " " << Nume() << " " << y << " = " << Operatie (x,y) <<endl;
}
};
}
}
#endif
LE
**operatii.h**
#ifndef OPERATII_H
#define OPERATII_H
namespace Calculator{
namespace Calcule{
template<typename T>
T Suma(T x, T y)
{
return x + y;
}
}
#endif

Answer 1

CmdAritmetice is defined in namespace Calculator::UI while Aplicatie is defined in namespace Calculator. So, you must refer to CmdAritmetice as UI::CmdAritmetice within the Calculator namespace.
As for error saying Suma cannot be found, you haven't posted the definition of Suma, so it's hard to say what's going on there, but check to make sure that that too isn't defined within some nested namespace.
EDIT:
The definition for CmdAritmetice is
template<int Operatie(int, int)>
class CmdAritmetice : public ComandaCalcule
{
// ...
};
So it takes a template argument that is function with the signature int(int, int), i.e. a function that accepts 2 ints and returns an int. Within Aplicatie::Run() you try to instantiate the class as
CmdAritmetice <int, Suma>
Obviously this will not work, the template argument needs to be a function matching the signature you've specified in the definition. Also, references to Suma need to be qualified as Calcule::Suma.
I think what you intend to do is
UI::CmdAritmetice<Calcule::Suma<int>> cmd1("+");