[boost] any_function ("Callback" library)

From: Doug Gregor (gregod_at_[hidden])
Date: 2001-01-20 21:40:39

Hello all,
        The Boost "callback" library seemed to die in committee last time, so I 
thought I'd bring another prototype to the table in the hope of getting some 
agreement on the issue. The new prototype is at 

http://www.egroups.com/files/boost/Callback/any_func.zip

Some quick comments/justifications are in order:

- It is called "any_function" because there seemed to be no name consensus 
("callback" was too limiting, "event" wasn't correct, "function_ptr" seems - 
to me - like it sounds limiting) and I don't recall anyone openly disagreeing 
with "any_function".

- It uses cloning. The general consensus seemed to be leaning toward cloning. 

- No virtual functions are used. Instead, static member functions are used to 
dispatch the calls to their targets to keep it typesafe.

I've tested it on MSVC++ 6.0sp4 and GCC 2.95.2. The only difference is in 
initialization:

any_function<int, int, int> f1 = plus<int>(); // 1
any_function<int, int, int> f2 (plus<int>()); // 2

VC++ can handle 2 but not 1; GCC can handle 1 but not 2 :)

        Doug