Pass a Function as an argument in C++

[Mr.Macdonald]

can you show me an example of it?

[StOoZ]

you can use a function pointer...

void func(int (*p)(int)) {}

this function takes an argument of a function that takes an int , and return an int...
for example:

int sxt(int k) {...}

func(sxt);

[dwhitney67]

You can also try "functor" objects.

Example:

#include <iostream>

class Echo
{
public:
int operator()(int value )
{
return value;
}
};

class MultiplyByTwo
{
public:
int operator()(int value )
{
return value*2;
}
};

template< typename F >
void function( F f, int value )
{
std::cout << "value = " << f(5) << std::endl;
}

int main()
{
Echo echo;
MultiplyByTwo mult;

function( echo, 5 );
function( mult, 5 );

return 0;
}

[dribeas]

You can also try "functor" objects.


+1

Also consider using libraries: boost::function (functors), boost::bind (creating functors bound to existing functions/methods) to remove some of the hassle of creating the functors. I am really fond of boost::signals combined with boost::bind and boost::function :)

David