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c++functioncomparatorfunctor

Function which takes function/lambda/class with overloaded() as argument

I need write a function which can take another function/lambda/class with () operator overloaded as a parametr and correctly work with them (like 3th arg of std::sort. What it looks like in terms of C++ syntax?

Solution

  • You can make it a function template (like std::sort) with a template parameter that you assume is callable:

    template<typename Func>
void myFunction(Func f)
{
    f();
}

    Now let's test it:

    void normalFunction()
{
    std::cout << "Normal function.\n";
}

struct Functor {
    void operator()()
    {
        std::cout << "Functor object.\n";
    }
};

int main()
{
    Functor functor;

    myFunction(normalFunction);
    myFunction(functor);
    myFunction([]{ std::cout << "Lambda.\n"; });
}

    This will print:

    Normal function.
Functor object.
Lambda.