Re: [Boost-users] [boost::function] Retrieving function objects / Determining function type

From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2008-07-14 12:04:03

AMDG

Ruediger Berlich wrote:
> is it possible to get direct access to a function object encapsulated in
> boost::function ?

If you know that type of the function object, you can use target.

>  And is it possible to determine whether boost::function
> has indeed stored a function object rather than, say, a function pointer ?
>   

You can get the typeid of the type that a boost::function contains
using the function target_type.

#include <iostream>
#include <boost/function.hpp>

void f() {
    std::cout << "Calling f" << std::endl;
}

int main() {
    boost::function<void()> func = &f;
    if(func.target_type() == typeid(void(*)())) {
        func();
    }
    if(void(**target)() = func.target<void(*)()>()) {
        (*target)();
    }
}

In Christ,
Steven Watanabe