Function/Method pointers Pushed to a Deque - c++

Question

I am making a Queue for running functions. I put the functions that require being called into a std::deque<bool(*)()> Then I later on cycle through the deque calling each function and letting it run, sometimes even doing things based on the return.
The problem I am having is actually with regards to placing these functions inside of the deque.
I have this deque inside a class called A2_Game. I also have a class called Button.
My code resembles the following:
class Button
{
bool DoInput();
}
class A2_Game
{
std::deque<bool(*)()> Input_Functions;
bool EnterName()
}
A2_Game::OtherMethod()
{
Button* btn1 = new Button();
Input_Functions.push_back(&A2_Game::EnterName); //The compiler told me to do this and it still won't compile the line..
Input_Functions.push_back(btn1->DoInput);
//Loop
}
I cannot determine how to fix my compile errors. I suspect some of you may be able to just tell me outright what needs to be changed/done in order to get this to compile, by looking at what I've shown here. In case that is !true then here are the compile errors.
error C2664: 'std::deque<_Ty>::push_back' : cannot convert parameter 1 from 'bool (__thiscall A2_Game::* )(void)' to 'bool (__cdecl *const &)(void)'
error C3867: 'Button::Doinput': function call missing argument list; use '&Button::Doinput' to create a pointer to member

Answer 1

if you want to push back functions you can use std::function (or boost if your compiler doesn't support c++11)
std::deque<std::function<bool()> > function_list;
Button* btn1 = new Button();
function_list.push_back([this](){return EnterName();});
function_list.push_back([btn1](){return btn1->DoInput();});
make sure everything in the lambda is still going to be valid when you call it from the function_list.
EDIT:
boost equivalent
std::deque<boost::function<bool()> > function_list;
Button* btn1 = new Button();
function_list.push_back(boost::bind(&A2_Game::EnterName,this));
function_list.push_back(boost::bind(&Button::DoInput,btn1));

Answer 2

The problem is that the signature of the class methods don't match with the function signature bool (*)(). The signatures of the two methods are bool (Button::*)(); or bool (A2_Game::*)(); respectively. (The actual class to which the method belongs is part of its signature!)
The solution here is to use functors/function objects. Functors are wrapper objects around "callable elements" that are useful if you want to treat functions like objects (in a OOP sense). If you have boost at hand your code could look similar to this (code compiles):
#include <boost/function.hpp>
#include <deque>
class Button
{
public:
bool DoInput() { return true; }
};
class A2_Game
{
public:
typedef boost::function<bool()> Functor;
std::deque<Functor> Input_Functions;
bool EnterName() { return true; }
void OtherMethod();
};
void A2_Game::OtherMethod()
{
Button* btn1 = new Button();
Input_Functions.push_back(boost::bind(&A2_Game::EnterName, this));
Input_Functions.push_back(boost::bind(&Button::DoInput, btn1));
}
boost::bind combines a function pointer with the reference to an actual class instance and returns an function object of the same type as A2_Game::Functor.
Note that boost::function has been integrated into the C++11 standard (see here), so if your project supports C++11 simply use #include <functional> and std instead of boost namespaces.