Just a little information that might be helpful to those concerned about what type the serialization system should use for storing the count of items in a collection. a) the serialization system maintains the concept of "archive version" which gets incremented when changes are made in the the library which could break existing archives. The version number - not to be confused with the version number for any particular class is currently at number 3 and will be incremented to 4 for 1.34. If a change in the collection count type is made, the reading of this number will will depend on the archive version under which the archive was created and adjust accordingly. b) for text base archives it will be hard to notice any change. numbers are renders as - text - which is an inherently variable length format. c) For native binary archives - the length of the count as stored in the archive will change. Currently its the length is the size of unsigned int for the machine that creates the archive. If a change is made to std::size_t then the length will change to the size of this type on the machine which created the archive. Native binary archives meet no requirements for portability accross platforms. If portability is a consideration then native binary archives are not suitable and a different archive class must be used. There is an example of a portable binary archive which stores integers in a variable length format and these are portable across machines as long as the recieving machine has the capability to represent the numbers actually written to the archive. d) the natural candidate for the collection count is std::size_t as that is what the STL uses to specifiy the count of its members. I believe the question has been raised as to whether the serialization system should use this or some special type for this purpose. I don't have a strong opinion. I am surprised that apparently people are using the serialization system with more than 4G objects. Even 4G doubles comes to 32 GB. I would have guessed that the intersection of people doing that and using the serialization system is a null set. So the only questions are a) is the a big enough deal to even bother. b) If it is - should the change be made to std::size_t or is there some reason that it should be made to some other type c)If so, what other type and why? Robert Ramey Kim Barrett wrote:
At 5:33 PM -0500 2/11/06, David Abrahams wrote:
The count should be some type that has a fixed (up to byte-order issues) representation, i.e. something like uint64_t.
Or a variable-length representation, which is what I *think* Matthias chose.
I think that would be even better. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost