user-defined function as a parameter passed to cpp class constructor

Question

i want to have a class member which is a pointer to undefined typical function .
the function must be performed by user. the user must pass the function as a parameter to class constructor. the function is called in the scope of class methodes. can i do these tasks like this ?

class MyClss
{
    private:    
    bool (*f)();

    public:
    MyClss(bool (*fp)());
    void MyMethod();
}

MyClss::MyClss(bool (*fp)())
{
    f = fp;
}

void MyClss::MyMethod()
{
    // do tasks
    if(f())
    {
        // do tasks
    }
}

Did you try? Did it fail? There's nothing *wrong* with the code you show, other than a missing semi-colon. — StoryTeller - Unslander Monica, Apr 15 '18 at 08:43
Might want to consider [std::function](http://en.cppreference.com/w/cpp/utility/functional/function) — Ed Heal, Apr 15 '18 at 08:44

Mohit · Answer 1 · 2018-04-15T08:51:41.153

0

The code you have given will works fine. See the code below it is the same but using std::function from <functional> header file.

#include <functional>

// The function prototype.
typedef std::function<bool()> MyFunction;

class MyClss
{
    private:    
    MyFunction f;

    public:
    MyClss(MyFunction fp);
    void MyMethod();
};

MyClss::MyClss(MyFunction fp)
{
    f = fp;
}

void MyMethod()
{
    // do tasks
    if(f())
    {
        // do tasks
    }
}

edited Apr 15 '18 at 08:51

answered Apr 15 '18 at 08:48

Mohit

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1

Please read [using std is bad practive](https://stackoverflow.com/questions/1452721/why-is-using-namespace-std-considered-bad-practice) – Ed Heal Apr 15 '18 at 08:51

user-defined function as a parameter passed to cpp class constructor

1 Answers1