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Comment by thidr0 | Hacker News Reader

At least in C++11 and later, many classes of these memory bugs are eliminated with more modern container and pointer types. It’s not uncommon to have a company policy of not using “new” or “delete” anywhere.

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Equating C with modern C++ is a common sleight of hand for rust evangelists. Most modern C++ projects with a fresh codebase have almost 0 use of new or delete. It turns out that C++ is a lot better than it used to be 10 years ago.

C++ is definitely better but it's still not memory safe. Compared to Rust, you still have little tracking which thread has access to which variable at which time. Even in modern C++, you still have to care about iterator invalidation.

It's far from done, but the GCC static analyzer actually can find iterator invalidation!

Some of it. Because a sound analysis would throw FPs up too frequently, they make the logical decision to use an unsound analysis. This is helpful, but cannot prevent the entire class of issues.

While unique/shared_ptr alleviate some of these issues the STL is still full of UB though, and that can’t be fixed easily.

What proportion of C++ code is "modern"?

The problem is which modern C++ projects?

Android source code is definitely not one of them, and yet Google as ISO C++ contributor should know all about modern C++, right?

Ah, what about Microsoft and their UWP code samples for C++ developers, or the C++/WinRT based libraries?

As advocates from C++ Core Guidelines, surely those samples will be perfect examples from modern C++, right?

Or what about Bloomberg, with heavy contributors like John Lakos?

Maybe they are still in the process of adopting C++11 and C++14, while writing a book about language adoption issues.

I like C++ a lot, but we really need a compiler switch to turn off compiling Vintage C++, it would be marvelous.

Every single codebase you have just cited here (except for the nebulous "advocates from C++ core guidelines") is older than the Rust language. Look at high frequency trading code or maybe recent game engines for good C++ projects - I don't know if any of these are open source.

I 100% agree with breaking C compatibility, breaking ABI compatibility, and turning off vintage C++.

C++/WinRT is from 2015.

C++ Oboe SDK for Android was initially released in 2018.

Android Games Developer SDK was just released last month.

What game engines? Lumberyard , Unreal and Godot certainly not.

Vulkan C++ bindings from Khronos or Dawn for WebGPU? Also not.

The only modern C++ I can find in real life are at CppCon and C++Now talks, and books promoting it.

Even Bjarne Stroustroup has recently on a interview mentioned how he is disappointed how C++ Core Guidelines keep being largely ignored by the community.

There is even, yet again, a paper from him trying to advocate for better C++ on the next C++ mailing.

Having no instances of new or delete does not, in any way, prevent the entire class of memory vulnerabilities. Running off the end of a buffer when processing untrusted data is just as easy. Heck, you can still absolutely get UAF issues even if you never allocate on the heap simply by holding a reference to a stack allocated object past its lifetime. Given how weird the rules around lifetime extension are, this can happy is really really subtle ways.

C++11 is not a safe language. Not even close. It is much much much better than what came before, but it is not safe.

It's still quite easy to have memory safety bugs in modern C++ though.

For example, std::string_view is basically a pointer, as soon as it points to a string that went out of scope you're in trouble if you use it again.

Another one is std::span, that contrary to Microsoft's gsl::span, WG21 decided it was a good idea not to do bounds checking.

The C++98 (Win32/MFC) codebase that I ocassionally touch has a lot of ill-designed abstractions in it, and is full of potential memory problems, but at least one can halfway see what's happening, and a full rebuild of the 30 years old codebase can be done in < 10 minutes.

Not sure if it's worse than the impossible to grok and slow to build C++11+ codebases that I've seen - everything is wrapped in unique_ptr and shared_ptrs, add lots of unused overloaded constructors and methods for every const and copy/move/value construct situation, then add an icing of templates. The trend is to assume that problems are solved by wrapping everything in more layers. But it seems like this ends in maybe fewer memory problems but also a lot less useful functionality, makes it a lot slower to build, and makes it so much harder to add, change and fix stuff.

The best code I've seen uses very, very few C++ features (if any at all) and just gets things done in a straightforward way without celebration.

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