Key tools for C++ container library performance are guaranteed copy elision and guaranteed return value optimization. One trick for library writers (which needn't complicate life for library users) is:pic.twitter.com/WFtJx7TGBe
This is the legacy version of twitter.com. We will be shutting it down on June 1, 2020. Please switch to a supported browser, or disable the extension which masks your browser. You can see a list of supported browsers in our Help Center.
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
Add this Tweet to your website by copying the code below. Learn more
Add this video to your website by copying the code below. Learn more
By embedding Twitter content in your website or app, you are agreeing to the Twitter Developer Agreement and Developer Policy.
| Country | Code | For customers of |
|---|---|---|
| United States | 40404 | (any) |
| Canada | 21212 | (any) |
| United Kingdom | 86444 | Vodafone, Orange, 3, O2 |
| Brazil | 40404 | Nextel, TIM |
| Haiti | 40404 | Digicel, Voila |
| Ireland | 51210 | Vodafone, O2 |
| India | 53000 | Bharti Airtel, Videocon, Reliance |
| Indonesia | 89887 | AXIS, 3, Telkomsel, Indosat, XL Axiata |
| Italy | 4880804 | Wind |
| 3424486444 | Vodafone | |
| » See SMS short codes for other countries | ||
This timeline is where you’ll spend most of your time, getting instant updates about what matters to you.
Hover over the profile pic and click the Following button to unfollow any account.
When you see a Tweet you love, tap the heart — it lets the person who wrote it know you shared the love.
The fastest way to share someone else’s Tweet with your followers is with a Retweet. Tap the icon to send it instantly.
Add your thoughts about any Tweet with a Reply. Find a topic you’re passionate about, and jump right in.
Get instant insight into what people are talking about now.
Follow more accounts to get instant updates about topics you care about.
See the latest conversations about any topic instantly.
Catch up instantly on the best stories happening as they unfold.
Key tools for C++ container library performance are guaranteed copy elision and guaranteed return value optimization. One trick for library writers (which needn't complicate life for library users) is:pic.twitter.com/WFtJx7TGBe
Not bad, though you have to add that constructor to every type you want to init this way. C++17 has guaranteed copy elision, so this trick isn't really needed anymore.
Let's say you want to construct an optional<tuple<ts...>> from a tuple<us...>, performing some sort of conversion and test on each element, with the optional's has_value true only if all tests succeed. How would you do this without exceptions or extra copies?
Something like this? https://godbolt.org/z/LgRefo Using -fno-elide-constructors tells the compiler not to optimize constructor elision, but the C++17 version does it anyway because it's guaranteed. I admit your solution means it's impossible to get it wrong, though.
That works, but it requires two passes over any conditional logic: one to evaluate the condition, and another to construct the results. If the later required re-running any tests, and data structures were nested, performance could be n^2 instead of n.
Fair enough. Is this something you've added to UE4's containers?
No, this is my experimental C++ std replacement. Aims to implement a mostly-functional container library with covariance and rich casting, so there’s a lot of interesting container traversal logic.
What's your take on the new ranges stuff coming in C++20?
If one accepts the iterators-over-mutable-containers design of std, ranges are the next logical step in generifying traversal algorithms. Personally though I’d argue for using coroutines to decouple production and consumption or, in Prolog terms, backtracking search.
I think there’s a new optima where one will be able to write very clean logic like backtracking Haskell parser combinators without all of the typical C++ boilerplate.
Yes, coroutines will help a great deal. Still unsure about ranges. Love the idea, but worry about the complexity of implementation. Need more experience with it.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.