What Is Google’s New Carbon Language and Why It Could Replace C++?

Carbon is Google’s latest internally‑built programming language, presented as an experimental successor to C++ at Cpp North in Toronto.

Google has a history of creating influential languages such as Go for server‑side development and Dart for Flutter, and Carbon follows that tradition.

Carbon aims to improve developer productivity and leverage modern language design while offering seamless, bidirectional interoperability with existing C++ code, making migration from C++ to Carbon straightforward.

Key design goals include performance‑critical software, safety, and ease of use. The language introduces several novel features:

Compile‑time expression types

Structural types

No null pointers, using Optional(T*) Arrays as value types with slice support

Tag‑based union sum types

Value categories limited to lvalues and rvalues, eliminating reference types

Move operator ~x Conditional expression if c then t else f Lossless implicit conversions

Pattern matching

Named return values

Removal of multiple inheritance

Interface‑based generic constraints, composition, associated types, specialization, dynamic dispatch, variadic generics

Full two‑way interop with C++

Official package manager, documentation, and toolchain

TODO: stronger type system for memory safety

TODO: lifetimes and move semantics

TODO: structured metaprogramming

TODO: Rust‑like error handling with Result and try operator

TODO: abstract machine, lambdas, coroutines, concurrency

Overall, Carbon can be seen as a Rust‑like language without ownership, lifetimes, or borrow checking, combined with class‑based single inheritance and mixins.