Function Pointer 예제

//Function Pointer
// 리턴type(*name)(매개변수)
 
 
class Game
{
public:
    static void Start(int number)
    {
        printf("%d번 게임 시작!!\n", number);
    }
    void Render(int number)
    {
        printf("%d번 렌더링\n", number);
    }
};
 
class Luncher
{
public:
    Luncher() 
    { 
        start_func = Game::Start; 
        render_func = &Game::Render;   // 여기선 레퍼런스랑은 다름, 위치만 정하는거 
    }
    void Execute(int number)
    {
        start_func(10);
        Game game;
        (game.*render_func)(10);
    }
private:
    void(*start_func)(int) = nullptr;
    void(Game::*render_func)(int) = nullptr;
};
 
class Test
{
public:
    static void Tmp()
    {
        printf("Test Tmp\n");
    }
 
    void Tmp2(int a, int b)
    {
        printf("Test Tmp2 %d %d\n", a, b);
    }
 
    std::string Tmp3(std::string str, int a, int b)
    {
        return str + "Tmp3" + std::to_string(10*a + b);
    }
 
};
 
void MoveRight();
void MoveLeft();
std::string Printf(int direction);
 
 
int main()
{
    void(*MoveR)() = MoveRight;
    void(*MoveL)() = MoveLeft;
    MoveR();
    MoveL();
 
    void(*Move[2])() = { MoveRight, MoveLeft };
 
    Move[0]();
    Move[1]();
 
    std::vector<void(*)()> Moves;
    Moves.push_back(MoveLeft);
    Moves.push_back(MoveRight);
    Moves[0]();
    Moves[1]();
 
    std::string(*Func)(int) = Printf;
 
    while (true)
    {
        int direction = -1;
        if (GetAsyncKeyState(VK_LEFT) & 0x8000 == 0x8000)
            direction = 0;
        if (GetAsyncKeyState(VK_RIGHT) & 0x8000 == 0x8000)
            direction = 1;
        if (direction > -1)
        {
            std::string str = Func(direction);
            printf("%s\n", str.c_str());
            break;
        }
    }
 
    Luncher* luncher = new Luncher();
    luncher->Execute(100);
    delete luncher;
 
 
 
    std::function<void()> func0 = nullptr;   // -> void(*func1)() = nullptr;
    func0 = MoveRight;
    if (func0 != nullptr)
        func0();
 
    std::function<void()> funcs[2];
    funcs[0] = MoveRight;
    funcs[1] = std::bind(MoveLeft);
 
    funcs[0]();
    funcs[1]();
 
    std::vector<std::function<void()>> funcss;
    funcss.push_back(MoveRight);
    funcss.push_back(std::bind(MoveLeft));
    funcss.push_back(std::bind(Test::Tmp));
 
    for (auto func_ : funcss)
        func_();
 
    Test test;
    std::function<void()> func1;
    func1 = std::bind(&Test::Tmp);
 
    std::function<void(int, int)> func2;
    func2 = std::bind(&Test::Tmp2, test, std::placeholders::_1, std::placeholders::_2);
    func2(100, 200);
 
    std::function<std::string(std::string, int, int)> func3;
    func3 = std::bind(&Test::Tmp3, test, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3);
 
    std::string str = func3("Test", 300, 700);
    printf("%s\n", str.c_str());
    return 0;
}
 
void MoveRight()
{
    printf("우로 이동\n");
}
 
void MoveLeft()
{
    printf("좌로 이동\n");
}
 
std::string Printf(int direction)
{
    std::string str = "이동방향 : " + std::to_string(direction);
    return str;
}