How to pass and execute anonymous function as parameter in C++11?

Question

The code I\'m looking for is like following.

bool Func1(int Arg1, C++11LambdaFunc Arg2){
    if(Arg1 > 0){
        return Arg2(Arg1);
    }
}

Answer 1

First solution:

You can make your Func1() function a function template:

template
bool Func1(int Arg1, T&& Arg2){
    if(Arg1 > 0){
        return Arg2(Arg1);
    }

    return false; // <== DO NOT FORGET A return STATEMENT IN A VALUE-RETURNING
                  //     FUNCTION, OR YOU WILL GET UNDEFINED BEHAVIOR IF FLOWING
                  //     OFF THE END OF THE FUNCTION WITHOUT RETURNING ANYTHING
}

You could then invoke it as you desire:

int main()
{
    Func1(12, [](int D) -> bool { return D < 0; } );
}

Second solution:

If you do not want to use templates, an alternative (that would bring some run-time overhead) is to use std::function:

#include 

bool Func1(int Arg1, std::function Arg2){
    if(Arg1 > 0){
        return Arg2(Arg1);
    }

    return false;
}

Once again, this would allow you to call Func1() the way you desire:

int main()
{
    Func1(12, [](int D) -> bool { return D < 0; } );
}