Passing string as reference to function pointer c++ - c++

Question

Below is my code
#include "stdafx.h"
#include <string.h>
#include <iostream.h>
using namespace std;
class ToDoCommands
{
public:
void getCommand(string);
};
void ToDoCommands::getCommand(string command)
{
cout<<command; //here i get ping
void (*CommandToCall)(void);
CommandToCall = command; // error here i want something like
// CommandToCall = ping
CommandToCall();
}
void ping(void)
{
cout<<"ping command executed";
}
int main()
{
ToDoCommands obj;
obj.getCommand("ping");
}
The function pointer should refer to function ping dynamically. A string same as function name is passed to getCommand function in main.

Answer 1

C++ just doesn't work that way. If you really need something like that, you'll have to make a table of functions that are indexed by name:
#include <assert.h>
#include <iostream>
#include <map>
#include <string>
using std::cout;
using std::string;
using std::map;
void ping(void)
{
cout << "ping command executed\n";
}
class ToDoCommands
{
public:
typedef void (*FunctionPtr)();
typedef string Name;
void registerFunction(Name name,FunctionPtr);
void callFunction(Name);
private:
map<Name,FunctionPtr> func_map;
};
void ToDoCommands::registerFunction(Name name,FunctionPtr func_ptr)
{
func_map[name] = func_ptr;
}
void ToDoCommands::callFunction(Name name)
{
assert(func_map.find(name)!=func_map.end());
func_map[name]();
}
int main(int argc,char **argv)
{
ToDoCommands to_do_commands;
to_do_commands.registerFunction("ping",ping);
to_do_commands.callFunction("ping");
return 0;
}

Answer 2

void ping(void)
{
// LL DD…DD XX
cout<<"ping command executed"<<endl;
}
class ToDoCommands
{
public:
void getCommand( void (*CommandToCall)(void)); //getCommand(ping)
};
void ToDoCommands::getCommand( void (*CommandToCall)(void) )
{
void (*CommandToCall1)(void);
CommandToCall1 = CommandToCall;
CommandToCall1();
}
int main()
{
ToDoCommands obj;
obj.getCommand( ping );
return 0;
}
i tried this and its working :)