Hi Jeff, On 10/17/2018 12:01 AM, Jeff Young wrote:
> I think one of the original justifications of dyn_cast<> was that it was > faster. Do I have that wrong, or do we not believe it to be material? It probably is faster, as comparing values can be inlined, while dynamic_cast<> cannot. Whether it has a measurable impact I can't really tell. What's interesting is that neither gcc nor msvc can cache results of type checks with either system (where I would have expected dynamic_cast<> to come out ahead as the type of an object is generally fairly immutable). Compiler Explorer link: https://godbolt.org/z/HwKrp6 > (Other than that I’d love to get rid of it. It’s bitten me more than once.) We also have a (large) number of instances where people have reimplemented dyn_cast<> by checking the Type() and using static_cast<>, reinterpret_cast<> or a C-style cast afterwards. FWIW, I'd rather store everything in typed containers and have no polymorphism at all, that would probably give the best speedup of all, because we don't even need to look at objects we don't care about. Simon _______________________________________________ Mailing list: https://launchpad.net/~kicad-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~kicad-developers More help : https://help.launchpad.net/ListHelp
