C++26 Status Quo I’d previously written about how difficult it is to extend support for using class types as constant template parameters. These are the template parameters formerly known as non-type template parameters. But it turns out that since C++98, we had three kinds of template param...
Last week, C++26 was finalized in Sofia, Bulgaria — and C++26 will include all of the reflection papers that we were pushing for: P2996R13: Reflection for C++26 P3394R4: Annotations for Reflection P3293R3: Splicing a Base Class Subobject P3491R3: define_static_{string,object,array} P1...
Frequently, whenever the topic of Reflection comes up, I see a lot of complains specifically about the new syntax being added to support Reflection in C++26. I’ve always thought of that as being largely driven by unfamiliarity — this syntax is new, unfamiliar, and thus bad. I thought I’d take a d...
Recently, I watched Andrew Kelley’s talk on Practical Data Oriented Design. It goes into some of the architectural changes he’s been making to the Zig compiler, with pretty significant performance benefit. Would definitely recommend checking out the talk, even if you’re like me and have never wri...
There was a StackOverflow question recently that led me to want to write a new post about Ranges. Specifically, I wanted to write about some situations in which Ranges do more work than it seems like they should have to. And then what we can do to avoid doing that extra work. I’ll offer solutions...
I was reading through the latest mailing, and a sentence caught my eye in P3661 (“Attributes, annotations, labels”), emphasis mine: Attributes turned out to be unsuitable for the role of “small features”, “small modifications to bigger features” or annotations from other languages. The need f...
I recently ran into an interesting bug that I thought was worth sharing. The Setup We have an abstract base class, with polymorphic equality: struct Base { virtual ~Base() = default; virtual auto operator==(Base const&) const -> bool = 0; }; And then we have a bunch of derived...
One of the reasons that I’m excited for Reflection in C++ is that it can permit you to implement, as a library, many things that previously required language features. In this post, I’m going to walk through implementing P2786R8 (“Trivial Relocatability For C++26”). Or, at least, just the tri...
One of the things I like to do is compare how different languages solve the same problem — especially when they end up having very different approaches. It’s always educational. In this case, a bunch of us have been working hard on trying to get reflection — a really transformative language featu...
Setting the Stage Previously, I tried to answer the question: what’s so hard about constexpr allocation?. Today, we continue what will become a series of posts about attempting to explain the issues behind a bunch of hard problems we’re trying to solve. The next problem: class types as non-type ...