Re: [Rpm-maint] [rpm-software-management/rpm] Add API for clone rpmps iterator (func rpmpsiClone) (#1359)
Closed #1359. -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/rpm-software-management/rpm/pull/1359#event-3930984309___ Rpm-maint mailing list Rpm-maint@lists.rpm.org http://lists.rpm.org/mailman/listinfo/rpm-maint
Re: [Rpm-maint] [rpm-software-management/rpm] Add API for clone rpmps iterator (func rpmpsiClone) (#1359)
After mulling over this some more... as per above comments, sorry but no. There are several key iterators where we couldn't support this even if we wanted to, so adding it for one or two would only make both the C API and the C++ wrapper more inconsistent instead of improving it. -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/rpm-software-management/rpm/pull/1359#issuecomment-717901144___ Rpm-maint mailing list Rpm-maint@lists.rpm.org http://lists.rpm.org/mailman/listinfo/rpm-maint
Re: [Rpm-maint] [rpm-software-management/rpm] Add API for clone rpmps iterator (func rpmpsiClone) (#1359)
I wanted to create standard forward (or input) C++ iterator which satisfies copy-constructible, copy-assignable and can be incremented (pre-increment, post-increment). -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/rpm-software-management/rpm/pull/1359#issuecomment-694802602___ Rpm-maint mailing list Rpm-maint@lists.rpm.org http://lists.rpm.org/mailman/listinfo/rpm-maint
Re: [Rpm-maint] [rpm-software-management/rpm] Add API for clone rpmps iterator (func rpmpsiClone) (#1359)
Usually the C++ Compiler removes the copy creation (see https://en.wikipedia.org/wiki/Copy_elision#Return_value_optimization). But yes, I don't see why postincrement needs to be supported, preincrement should be enough. -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/rpm-software-management/rpm/pull/1359#issuecomment-694781781___ Rpm-maint mailing list Rpm-maint@lists.rpm.org http://lists.rpm.org/mailman/listinfo/rpm-maint
Re: [Rpm-maint] [rpm-software-management/rpm] Add API for clone rpmps iterator (func rpmpsiClone) (#1359)
This is actually a text-book example of operator overloading considered harmful. Assuming this was added and a wrapper uses it for post-increment operator: we've managed to turn what is essentially an integer increment at the fooNext() rpm API into malloc, assign, increment reference (possibly taking additional locks while doing so), free and decrement reference (again possible taking additional locks), which is not only slow but also harmful in that it's an invitation for memory fragmentation. And since all that mumbo-jumbo is masqueraded into a deceptively simple ++ instead of some next() call, guess which one people are going to use? If it can't be sanely implemented, it's better not to offer the choice. -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/rpm-software-management/rpm/pull/1359#issuecomment-694700370___ Rpm-maint mailing list Rpm-maint@lists.rpm.org http://lists.rpm.org/mailman/listinfo/rpm-maint
Re: [Rpm-maint] [rpm-software-management/rpm] Add API for clone rpmps iterator (func rpmpsiClone) (#1359)
That looks like such a hideously ineffective way of incrementing that people are better off not having it, IMO. Real world use-cases outside the syntactic sugar category might be easier to sell. Furthermore, there are some key iterators where this can't be implemented at all as the iterator is part of the structure itself (at least rpmds and rpmtd, the latter isn't even reference counted, and there might be others that I don't recall). -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/rpm-software-management/rpm/pull/1359#issuecomment-694653660___ Rpm-maint mailing list Rpm-maint@lists.rpm.org http://lists.rpm.org/mailman/listinfo/rpm-maint
