--- Log opened Mon May 30 00:00:38 2022
03:44 < darosior> sipa: (context: https://github.com/bitcoin/bitcoin/pull/24860#discussion_r883686621) if you don't mind giving a C++ lesson, could you further explain to me why we cannot use a lambda? You mention that they are non-assignable, ok, and that the set operations require moving the comparator around. But how comes that moving the comparator around
03:44 < darosior> require it to be assignable?
03:44 < darosior> I had actually tried using a lambda previously but admittedly didn't entirely understand why it failed.
05:01 <@sipa> the set holds an internal variable of type Comparator
05:02 <@sipa> and when std::swap is invoked on the std::set, that involves an assignment to that internal conparator
05:02 <@sipa> but if it is of type lambda, it has no operator=
05:17 <@sipa> (but the swap is not the only problem; i think the set merge or something else also requires a comparator assignment)
05:21 <@sipa> it'd be nice if somehow the ctx variable could be treated as sort of a global from the perspective of the comparator class (as its lifetime is longer than the class definition) so it wouldn't require a copy of the ctx pointer in every set, but there doesn't seem to be a way in c++ to do that
05:36 < darosior> Thanks
--- Log closed Tue May 31 00:00:38 2022