> It's actually really hard to get modern C++ wrong
That's not true. The language is full of footguns, from its basic expressions (signed overflow, integer division-by-zero, and read-before-write are all undefined behaviour) up to concurrency (data-races are undefined behaviour) and everything in between (unsafe arrays, unsafe memory management, alignment, the list goes on). The high-level constructs in modern C++ help, but you're never further than one misstep from undefined behaviour.
Even high-profile codebases by highly skilled teams using all the modern tools, still run into trouble. Even Chromium has security issues arising from the dangers of C++. The push for Rust is out of pragmatism, not trend-chasing or theoretical purity.
Of course, C codebases like the Linux kernel also continue to have these issues.
I'm less optimistic. Even major C++ projects that do everything right, still have issues that would have been prevented had they used a safe language. My go-to example is Chromium.
Rust doesn't prevents logical bugs. Chromium had plenty of those. Most are capable of RCE. They were more dangerous than memory ones because they bypass sandbox in one-click.
As for Windows, The Russians exploited a logical bug in kernel for privilege escalation.
Rust also doesn't prevents overflows, DoS, UaF, OOB.
For example, see CVE-2018-1000657
Another dangerous thing about Rust is Crates. Crates doesn't audit packages for malware and you will face far worse than NPM like situation in future.
> Rust doesn't prevents logical bugs. Chromium had plenty of those.
Right, but that's not the goalpost we're discussing. We're talking about languages that can guarantee safety - the absence of undefined behaviour - not languages that can fully guarantee correctness (e.g. SPARK).
> Rust also doesn't prevents overflows, DoS, UaF, OOB.
In Rust, integer overflow does not cause undefined behaviour. In Safe Rust, undefined behaviour cannot arise from buffer overflows, use-after-free, or out-of-bounds array access. Safe Rust precludes all undefined behaviour, after all. Unsafe Rust may be 'more safe' than C++ in degree, but not in category: it's an unsafe language, as you say.
It wasn’t undefined behavior four years ago either. RFC 560, from 2014, defines this behavior. As far as I can recall, this was mostly a codification of what was already in place; I’m pretty sure it was never UB.
Here's a source. [0] In release builds, overflow results in two's complement wrapping. In debug builds, it results in a panic at runtime. It never results in undefined behaviour.
Safe Rust really is a safe language. That's really what's remarkable about Rust: it has high ambitions for safety and usability and performance, and it's succeeding in achieving them.
(I hear there are some who want to dilute the safety guarantees of Safe Rust. I'm optimistic that they will continue to be ignored.)
That's not true. The language is full of footguns, from its basic expressions (signed overflow, integer division-by-zero, and read-before-write are all undefined behaviour) up to concurrency (data-races are undefined behaviour) and everything in between (unsafe arrays, unsafe memory management, alignment, the list goes on). The high-level constructs in modern C++ help, but you're never further than one misstep from undefined behaviour.
Even high-profile codebases by highly skilled teams using all the modern tools, still run into trouble. Even Chromium has security issues arising from the dangers of C++. The push for Rust is out of pragmatism, not trend-chasing or theoretical purity.
Of course, C codebases like the Linux kernel also continue to have these issues.