Rust is a bigger language.
There are other languages aiming to be small and a better c. Zig comes to mind.
I mean i can hardly imagine any language being BIGGER (as in more language features) than C++ (except C++ 2030 standard ;)
The biggest chunck of ISO C++ is describing the standard library.
Just wait Rust to get 40 years of language improvements, while you try to link 5 different epochs on the same executable.
Imagine PHP, but not memory safe. Mistakes cause segfaults, memory leaks, and can enable attackers write memory they shouldn't be able to access. To top it off, a lot of libraries are still written in "PHP4 style" and you've got to make use of them. C++ is really hard.
Both C and C++ require consideration of memory semantics, and they are both "hard" in this sense. You have to allocate and free memory deliberately and be conscious about what memory you're passing around. C is much simpler in design than C++. It doesn't have as many features, so it's harder to trip over. It doesn't necessarily make it easier to program, though.
Rust targets the same domains that C and C++ do: systems programing (operating systems and drivers), real time programming (robotics and control software), graphics and games, etc. These are places where explicit memory management is important. Rust does so while being much easier to write. The language leverages new programming language theory and design to protect memory from being written incorrectly. The memory semantics are baked into the language design and checked at compile time. Bad code (in terms of memory and async) simply doesn't compile.
Rust does this while being just as fast as C and C++.
In addition, Rust has a ton of modern features that make it feel like Ruby. Functional idioms, zero-cost abstractions, a modern trait-based type system, generics, macros, and a beautiful package manager and package ecosystem that is better than Ruby and npm.
Rust is going to beat both of these languages.
I think looking at this as a battle is not helpful to understanding the situation. In order to supplant C/C++, Rust (and Rust programmers) will need to operate in harmony with the existing ecosystem for decades.
This interoperability means that Rust programmers will need to also be good C/C++ programmers. Its not a binary OR, its more like diffusion.
Just as an example, the primary (or earliest) use of Rust is in Firefox. But Firefox is still a C++ project.
- C has broader support for designated initializers
- C allows implicitly casting void* to any other pointer type
- C has fewer keywords, e.g. you can use "friend" or "class" as identifier
- ...
Despite all this, it's true enough that one can easily write C code that also compiles as C++.
C has generics?
Go into pointer qualifiers and const with _Generic and you'll see that it's a mess to do anything serious with it. But it's handy for type-generic math (tgmath.h style) and that's seems to be about it.
Simplicity is a feature, and one that C++ aggressively avoids.