CPPAlliance

Our mission is to make the C++ programming language accessible and useful to anyone who wishes to learn and apply the language.

[CPPAlliance @CPPAlliance]

@BarryRevzin Read the paper https://t.co/39K7jfUINp

See all the papers https://t.co/LjmG01hP7R

[CPPAlliance @CPPAlliance]

C++ just got a new operator

It looks like this: ^^

The committee calls it "the cat-ears operator." It's the gateway to the biggest language change since templates 🧵👇

[CPPAlliance @CPPAlliance]

C++26 ships compile time reflection (P2996). The ^^ operator turns any entity (type, function, enumerator) into a compile-time mirror you can inspect and transform

Enum-to-string? One function. JSON serialization? No macros. By @BarryRevzin and six co-authors

[CPPAlliance @CPPAlliance]

https://t.co/YvDnzOLfmy

[CPPAlliance @CPPAlliance]

You have a variant<Dog, Cat, Raccoon>

You also have an enum { Dog, Cat, Raccoon } that you manually keep in sync with it

One day someone adds Fox to the variant but forgets the enum. The switch compiles and the bug ships

What if the enum wrote itself? 🧵👇

[CPPAlliance @CPPAlliance]

Read the paper https://t.co/stXetVRD4j

See all the papers https://t.co/LjmG01hP7R

[CPPAlliance @CPPAlliance]

@FalcoVinnie Read the paper https://t.co/fSiHCXXngf

See all the papers https://t.co/LjmG01hP7R

[CPPAlliance @CPPAlliance]

When you write co_await f() in C++, three questions need answers:

Which thread resumes you? Should you stop? Where does the frame get allocated?

Right now every coroutine library answers these differently. There's a proposal to unify them

[CPPAlliance @CPPAlliance]

P4003 by @FalcoVinnie, Mungo Gill, and Steve Gerbino proposes IoAwaitable: a minimal coroutine execution protocol

Implemented on three platforms. Designed as a companion to std::execution, not a replacement

[CPPAlliance @CPPAlliance]

@__phantomderp Read the paper https://t.co/1ttELAjorW

See all the papers https://t.co/LjmG01hP7R

[CPPAlliance @CPPAlliance]

Every C++ developer has a cursed shell script somewhere that converts a binary file into a C array so it can be compiled in

bin2c. xxd. Platform specific linker hacks. Custom CMake incantations

C++26 just killed all of them. One preprocessor directive

[CPPAlliance @CPPAlliance]

C++26 ships #embed. Pull any file into your binary at compile time. Shaders, fonts, certs, model weights. One directive, no tooling hacks

By @__phantomderp, who's been pushing this since 2018. Already in GCC 16.1 and Clang

[CPPAlliance @CPPAlliance]

Read the paper https://t.co/BZyrlNr9Hn

See all the papers https://t.co/rG2PnfCzmi

[CPPAlliance @CPPAlliance]

Seven authors. Forwarded to EWG with committee consensus. And the title is a question most C++ developers assumed would never be asked officially:

"Should C++ be a memory-safe language?"

The debate is now open and it's already contentious

[CPPAlliance @CPPAlliance]

P3874 makes the case for a subset-of-superset strategy: new code gets a compiler enforced, UB-free subset. Existing code stays untouched

Not everyone agrees. The committee chose safety profiles over Safe C++. But this paper argues profiles alone won't get there. The debate continues