On Fri, 12 Oct 2007 08:56:50 +0200, Marco Costalba <mcostalba@gmail.com> wrote:
On 10/12/07, Marco Costalba <mcostalba@gmail.com> wrote:
So I would say a _possible_ policy is to not allow to register say
set(f6);
if is already registered a function with a "compatible" signature.
This is wrong.
I would have said:
" a _possible_ policy is that a call like
f.set(f6);
overwrites any exsisting function with the same signature *or with a compatible signature*"
Not sure to have understood your question. Anyway this is the assignment policy followed by the latest version of my implementation: http://archives.free.net.ph/message/20071011.214216.2c194f99.en.html Let be "ov" an instantiation of the overload template class for a given set of signatures "ss" used as template arguments: - if the passed functor "f" is a free function or a member function then: - if "f" is not overloaded and its signature is included in "ss" then the new target (i.e. "f") overwrites the target related to the matching signature; - if the signature of "f" is not included in "ss" a compile time error is produced; - if "f" is overloaded an "unresolved overloaded function type" compile time error is produced; (we can't rely on the Mesonides' trick, or equivalent for free functions, because they require to know the function name in advance); this is the same behaviour followed by boost.function; note: when I say that a function member signature is included in "ss" I actually mean that the signature of it's `equivalent` free function is included in "ss"; - if the passed functor "f" is a function object (possibly overloaded or polymorfic) then: - let be "rs" the set of signatures that are defined by its overload resolution set (or it would be better to say "by the overload resolution set of f::operator()" ); note that for a polymorfic object function "rs" is an infinite set; - if the intersection between "rs" and "ss" is empty the assignment fails and a compile time error is produced; - if the intersection between "rs" and "ss" is not empty then the new target (i.e. "f") overwrites all the targets related to the signatures included in the intersection. I hope to have answered to your question. Regards, Marco -- Using Opera's revolutionary e-mail client: http://www.opera.com/mail/