The Decision --- -------- There were a total of 9 people, outside of the library author Emil Dotchevski, who reviewed/commented about the Synapse library during the review period and the Monday following where I accepted a late review and people's responses to that late review. The voting in the Synapse review is: 0 for YES 2 for NO, with one of the two a provisional NO. Among the other people who commented but did not vote I have 2 people who said they definitely liked the library and 2 people who said they definitely did not like the library. Among other commenters I interpreted 2 other people as probably approving of the library as it now is and 1 other person as probably not approving of the library as it now is. Given the actual YES or NO vote, and the small amount of people who took part in the review, and the even smaller amount of people who decided to vote YES or NO for the library, the Synapse library is NOT accepted into Boost. My decision as review manager is based on the review of the library by others and not on my own personal view of whether the library should be accepted or not. Issues ------ I want to use the next part of this decision to summarize the issues brought up largely, but not exclusively, by those who did not see the Synapse library as currently being worthwhile to become a part of Boost. This issues I summarize below may or may not be seen as relevant or not by others but they do represent the areas of criticism of the library made during the review. All the issues were answered by Emil during the review, and I think he did an excellent job of answering reviewers based on how he sees these issues. Some of these issues may be seen as unimportant or trivial or already well answered, but I want to list them all nonetheless. The issues are presented in no particular order of importance. I will refrain from making my own comments about these issues until my own general summary at the end of this review decision: 1) The current Boost signals/signals2 library is adequate for signal/slot processing and another signal/slot library such as Synapse does not provide enough of a usage argument to be added to Boost along with what already exists. 2) The documentation needs to be more expansive on the difference between Boost signals/signals2 and the Synapse library. 3) The end-user should have some sort of control where Synapse stores its information regarding the connection between signal emitters and slots ( signals handlers ). 4) Since Synapse is a C++11 library it should use C++11 standard library constructs across the board rather than their Boost equivalents. 5) There should be some "natural" way in which slots can return a value, ala the signals2 library. 6) A more flexible way of handling the slot lifetimes should be created as an addition to the shared_ptr/weak_ptr way the library currently employs. 7) A means by which a particular thread can be specified ( thread-affinity ) for a particular slot when connected should be created; or a dispatching mechanism, perhaps using asio, for connecting a slot to an emitter. 8) The ability to have signals emitted with more than four parameters should be created. 9) The fact that emitters are identified strictly by address was seen as a weakness in the design since at least theoretically, if not very often practically, it is possible for two different variables to have the same address. Connected to this is that the address of emitters is noted with a "void *" in the public interface, and that was criticized as not C++-like. 10) Connection objects should be movable rather than using shared_ptr. 11) The central dispatching mechanism is too slow for large scale continuous changes which emit signals to be handled by slots in some systems ( a stock market changes type of application was brought up as such an example ). 12) The use of only Boost function as a callable slot is too inflexible. 13) The signal type ( pointer to function whose return type identifies signals ) was seen both as cryptic and inflexible, and a deduced signal type was suggested. 14) Having more than one signal type in Boost in general was seen as a bad situation. 15) More specific information on which compilers should work with Synapse. Summary ------- First of all, thanks to everyone who participated in the review and for Emil for answering and providing explanations for his design and coding decisions. I cannot say it enough but I really hope that more people can be encouraged to look at libraries up for review and make comments, even if they do not want to make an official vote or comment on any particular area in which they do not feel they have adequate knowledge. All comments and personal or technical evaluations are important and help a review manager make a final decision, as well as telling a library author what others think of what he has done. With that said I will not try to hide the fact that I personally view the Synapse approach to signal/slot processing as different enough, and useful enough due to its non-intrusive nature, from signals/signals2 to be a valuable addition to Boost, even while I recognize that there was not enough of a consensus or enough of an interest among others during the review to have that happen now. Among the issue brought forth by others my personal view for possibly improving Synapse to where it might be more acceptable to reviewers and might draw more people's interest as a possibly Boost library in the future pending another review, lies mainly in these numbered issues above: 2), 4), 5), 7), 8), 12), 15). I also feel having the documentation discuss in more detail the major concepts of the library, as a bridge between the Tutorial and the Synopsis, would be very helpful for interesting programmers In Synapse. Of course other people's views may vary greatly, and further discussion of Synapse on the Boost developers mailing list or the Boost users mailing list is, I am sure, welcome to the author of Synapse Emil Dotchevski.