Mathematical constants in C++20

by Jens Weller

When I researched the library and language features of C++20 for the Meeting C++ Community survey, this feature catched my eye.

And I thought its such a nice small feature, I should mention it on the blog. As all other C++20 blog posts right now seem to be about coroutines. It also is a nice follow up on an old blog of mine: C++ & π, where I showed the various ways of obtaining pi for C++ in 2013...

Sign Up for the Pure Virtual C++ 2021 Conference

by Sy Brand

Last year we ran the first Pure Virtual C++, a free one-day virtual conference for the whole C++ community. This May we’re doing it again! Sign-up for free on the website to be the first to hear about our program schedule, access our extra on-demand C++ demos, and get more virtual surprises...

C++ coroutines: Building a result holder for movable types

by Raymond Chen

One of the pieces we need for the simple_promise we use to construct a coroutine is what we have been calling the “result holder”. This is basically a variant that starts out empty, and can atomically transition to holding either the result of a successful coroutine, an exception pointer for a failed coroutine...

Starting Jobs with Coroutines

by Rainer Grimm

C++20 has three new keywords to make a coroutine out of a function: co_return, co_yield, and co_await. co_await requires an Awaitable as arguments and starts the Awaiter workflow. Let me show in this post, what that means...

C++ coroutines: Making the promise itself be the shared state, the outline

by Raymond Chen

Last time, we got the idea of putting the result holder state directly inside the coroutine state. This time, we’ll set to work on the implementation...

All C++20 core language features with examples

by Oleksandr Koval

The story behind this article is very simple, I wanted to learn about new C++20 language features and to have a brief summary for all of them on a single page. So, I decided to read all proposals and create this “cheat sheet” that explains and demonstrates each feature. This is not a “best practices” kind of article, it serves only demonstrational purpose. Most examples were inspired or directly taken from corresponding proposals, all credit goes to their authors and to members of ISO C++ committee for their work. Enjoy!

C++ coroutines: Making the promise itself be the shared state, the inspiration

by Raymond Chen

Earlier, we improved our simple coroutine promise by delaying the resumption of awaiting coroutines until local variables have destructed. This time, we’ll look at another improvement...

Organizing the first Meeting C++ online tool fair on April 20th!

by Jens Weller

On the evening of April 20th you'll be able to see demos, meet and chat with different C++ tool vendors at the online C++ tool fair!

Join the event on Meetup.

What auto&& means

by Jonathan Boccara

Since C++11, we have a && in the language, and it can take some time to understand its meaning and all the consequences this can have on your code.

We’ve been through a detailed explanation of lvalues, rvalues and their references, which covers a lot of ground on this topic.

But there is one aspect that we have to talk about: what does auto&&, X&&, or even int&& means in code...

C++ coroutines: What happens if an exception occurs in my return_value?

by Raymond Chen

When I introduced a basic implementation of a promise type, I noted that the return_value method or return_void method is called when the coroutine performs a co_return. But what happens if the return_value or return_void method raises an exception?