C++:How to pass reference-to-function into another function?

问题

I have been reading about function pointers and about using them as parameters for other functions. My question is how would you pass a function by reference without using pointers? I have been trying to find the answer on the Internet but I haven't found a good answer. I know that you can pass variables by reference like this: void funct(int& anInt);. How would you do something similar to this but instead of a reference to a variable a reference to a function was the parameter? Also how would you use a reference to the function in a function body?

回答1:

#include <iostream>
using namespace std;

void doCall( void (&f)(int) )
{
    f( 42 );
}

void foo( int x )
{
    cout << "The answer might be " << x << "." << endl;
}

int main()
{
    doCall( foo );
}

Cheers & hth.,

来源：https://stackoverflow.com/questions/7142883/chow-to-pass-reference-to-function-into-another-function