illegal call of non-static member function - c++

Question

I'm having trouble with this function below:
char* GetPlayerNameEx(int playerid)
{
char Name[MAX_PLAYER_NAME], i = 0;
GetPlayerName(playerid, Name, sizeof(Name));
std::string pName (Name);
while(i == 0 || i != pName.npos)
{
if(i != 0) i++;
int Underscore = pName.find("_", i);
Name[Underscore] = ' ';
}
return Name;
}
declaration:
char* GetPlayerNameEx(int playerid);
usage:
sprintf(string, "%s", CPlayer::GetPlayerNameEx(playerid));
Now my problem here is
Removed personal information.
If this has anything to do whith it which I doubt it does, this function is contained within a "Class" header (Declartion).
Also I have no idea why but I can't get the "Code" box to fit over correctly.

Answer 1

Illegal call of non-static member function means that you are trying to call the function without using an object of the class that contains the function.
The solution should be to make the function a static function.
This is normally what causes the error C2352:
class MyClass {
public:
void MyFunc() {}
static void MyFunc2() {}
};
int main() {
MyClass::MyFunc(); // C2352
MyClass::MyFunc2(); // OK
}
If making it static is not an option for you, then you have to create an instance of the class CPlayer.
Like this:
CPlayer myPlayer;
myPlayer.GetPlayerNameEx(playerid);

Answer 2

You cannot create these functions as static (without a lot of tweaking) because you are attempting to modify the data of a specific instance. To fix your problem:
class CPlayer
{
public:
// public members
// since you are operating on class member data, you cannot declare these as static
// if you wanted to declare them as static, you would need some way of getting an actual instance of CPlayer
char* GetPlayerNameEx(int playerId);
char* GetPlayerName(int playerId, char* name, int size);
private:
// note: using a std::string would be better
char m_Name[MAX_PLAYER_NAME];
};
// note: returning a string would be better here
char* CPlayer::GetPlayerNameEx(int playerId)
{
char* Name = new char[MAX_PLAYER_NAME];
memset(Name, MAX_PLAYER_NAME, 0);
GetPlayerName(playerId, m_Name, sizeof(m_Name));
std::string sName(m_Name);
std::replace(sName.begin(), sName.end(), '_', ' ');
::strncpy(sName.c_str(), Name, MAX_PLAYER_NAME);
return Name;
}
// in your usage
CPlayer player;
// ...
sprintf(string, "%s", player.GetPlayerNameEx(playerid));

Answer 3

CPlayer::GetPlayerNameEx(playerid)
You can't use the scope (::) operator on a class type to call a function unless it is a static function. To call a function on an object, you actually have to create the memory for that object first (via making a CPlayer variable somewhere) and then calling the function on that object.
Static functions are global and specifically do not mess with member variables of the class (unless they are also static) which makes them valid to call without the scope of an actual object instance.