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]

@timur_audio Read the paper https://t.co/qNL9wUuk1u

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

[CPPAlliance @CPPAlliance]

What if your function could tell the compiler: "don't call me with a negative number"?

And what if the compiler could actually enforce that at debug time, at test time, or even in production?

C++26 just made that part of the language 🧵👇

[CPPAlliance @CPPAlliance]

Contracts (P2900) ship in C++26. Preconditions, postconditions, and assertions built into the language, not hidden in comments

Four enforcement modes: ignore, observe, enforce, quick_enforce. Your call, per build

By @timur_audio, Joshua Berne, and Andrzej Krzemieński

[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