[Boost-users] boost::function and equality operators?

From: Alo Sarv (alo17_at_[hidden])
Date: 2004-11-12 15:45:17

Hi

I was just transforming my event engine from another callback functors
lib to boost::function, and discovered that boost::function has
explicitly forbidden operator== and operator!=. My question is why is
this done, and what could be possible workarounds?

Thanks in advance,
Alo Sarv.

Example:

#include <boost/function.hpp>
#include <cassert>
void foo() {}
void bar() {}
int main() {
        // won't compile if these are used in the below asserts
//      boost::function<void()> f(&foo);
//      boost::function<void()> g(&bar);
//      boost::function<void()> h(&foo);
        // works with raw function pointers
         void (*f)() = &foo;
         void (*g)() = &bar;
         void (*h)() = &foo;
         assert(f == h);
         assert(f != g);
         assert(g != h);
}