Even if you don't care about the language itself, there is a giant amount of C++ in the wild that won't be reimplemented. Anything that can make that code safer is a huge win.

How much of that existing code, really, is ever going to be updated to the standard of even C++11?

I am working on a device, where the initial code was written in 1995-1997 on a pre cpp98 compiler, the code has recently been updated to cpp11, I am sure we will move to cpp14/17 soon. So this is slowly but steadily moving, even if very conservatively.

On the other hand, Hell would freeze over before you could convince the business to throw the cpp codebase and replace it by anything else, without necessarily a lot of things to show to the customer. And as much as we like to criticize business decisions, here it is probably the right call.

However, if you are startup starting today, it would probably be a good idea to consider other options, that could be used as an advantage against incumbents.

Plenty, AUTOSAR now requires C++14 compliance for example.

Lots of code might not be updated, thing is, with C++20 I still get to compile my pre-C++98 code.

Even taking into account the breaking changes between language revisions, they are quite minor versus writing into another language.

Plus there are still lots of stuff missing, like a proper GUI library that can even compete with MFC, OWL, let alone something like UWP or Qt.

There are 10 million lines of libreoffice code that has been updated to use these features

More than nothing, less than everything.

And that will be still be able to interop with the "everything else" that doesn't get updated.

(Perhaps not seemlessly, but certainly better than a Rust <-> C++ interop.)

A lot of it won’t.

But the interop story between modern cpp and older cpp is much better than the interop story between rust and older cpp.

> I know, C++ is a dirty snowball rolling downhill, gobbling up every feature it can put it's tendrils on, and always has been, but it is getting silly.

That's named evolving and improving. And that's how a language stay alive.

If you never remove features, but keep adding more steadily, 'evolving and improving' is the wrong way to describe it.

C++ did remove features already a couple of times.

gets(), exception specifications, semantic corrections for a couple of cases like decltype vs auto, auto original meaning, std::bind(), and several others

However they don't play a Python 3, and rather take the effort to minimize the impact of those changes.

Removing features from a programming language is almost impossible; it breaks backwards compatibility and so is a hard barrier to upgrading from the old version. Note the 12-year-and-counting struggle to adopt Python 3, or the fact that Perl 6 developers gave up completely trying to get people to upgrade from Perl 5 and just rebranded it as a new language instead.

C++ has opted to avoid those struggles by never removing features; you can disagree with that decision but it was done for good reasons.

I'm speaking strictly technical here, but there have been features that have been removed. Trigraphs (I think), and the register keyword. Moreover, there are objects that are very clearly marked deprecated, like auto_ptr. (Oh, and there is even talk of removing 'volatile' as a keyword.)

The register keyword issue crops up because legacy code included and linked to modern C++ will occasionally have the word "register" affixed to a loop variable. Generally speaking, once you change standards, there is room to drop the old stuff. It's just gradual. Static analyzers do a lot to modernize code now too, so the situation is not as painful as it used to be.

The `volatile` deprecation is more about providing new library features to do the things people (incorrectly) use `volatile` for today. `volatile` will still have legitimate use-cases.

On the other hand, JavaScript very successfully added strict mode that removed features like `eval`. The trick seems to be to ensure that "old code" and "new code" can live side-by-side during a transition period.

Vittorio Romeo has been proposing[0] an "epochs" feature for C++ which would enable modes like "strict." This would let them define things like const-by-default, requiring nulltpr instead of 0, etc. He's facing some resistance by other WG21 members.

[0] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p188...

> the fact that Perl 6 developers gave up completely trying to get people to upgrade from Perl 5 and just rebranded it as a new language instead

This statement does not do justice to the process that led to the renaming of "Perl 6" to "The Raku Programming Language". If you are interested in the process, https://github.com/Raku/problem-solving/issues/81 will give you some of the discussion that happened online.

C++ treats backwards compatibility as important.

New code doesn't have to use old features.

> New code doesn't have to use old features.

Yeah but it's hard to manage in multiple ways. Is there good tooling to help? And it means a lot of references you could normally check are using features you can't use.

Plus none of your libraries are going to agree on what parts to use.

Because as much as I like Rust, it doesn't provide the IDE tooling for mixing language development with Java and .NET stacks, the seamless tooling that for creating COM/UWP components, something like Unreal or Unity for weekend coding hobbies, still builds slower than C++ because cargo doesn't support yet binary dependencies.

For writing memory safe code I already have .NET and JVM set of programming languages, so when I need to go outside of these platforms, I rather pick the tool that provides zero attrition with the existing tooling.

These are all issues that will be fixed, but they aren't yet there.