On Apr 23, 2010, at 12:37 PM, Jay Pipes wrote: > On Fri, Apr 23, 2010 at 11:57 AM, Brian Aker <[email protected]> wrote: >> Hi! >> >> This ties into a bigger question of how to return error/information from >> callers. Stewart and I spent a bit of time talking about this at the >> conference (though with no conclusion). The basic idea is to return an >> object that is minimal copy upon return (aka... no memory allocation and the >> hit cost is low). > > Which is precisely why I proposed using std::pair<>'s (or > boost::tuple). There is no copy overhead in most situations (due to > all modern compilers implementing the return value optimization. > Please see: http://en.wikipedia.org/wiki/Return_value_optimization). > This is the reason that the STL's std::map<>::insert() method returns > a std::pair<iterator, bool> as do other STL algorithms.
Sure, but map::insert() will never have a need to return more info than what can fit in std::pair. In your proposed design, if there is ever a need to return more state info, your return type suddenly needs to change. That may not ever happen, so it may be a non-issue. As we discussed on IRC, I propose maintaining private state internal to Cursor, but as you said, anything is better than the way it is now. /Dave _______________________________________________ Mailing list: https://launchpad.net/~drizzle-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~drizzle-discuss More help : https://help.launchpad.net/ListHelp
