[tialaramex]

I mean, apparently this is confusing, but yes, obviously.

If your Commodore 64 template is dealing with say, foozles that might be 8-byte, 12-byte or 16-byte, the complexity incurred is pretty small, bugs with foozle<16> are likely to be something mere mortals can understand and fix.

On a more complicated system like a cloud Linux setup the template may be for foozles that can be in any colorspace and on a remote machine or locally, and now sometimes the bug with foozle<HSV,remove> involves a fifty line error message because the compiler doesn't realise all that happened is you meant to write foozle<HSV,remote> ...

It's not even as if the C++ committee isn't aware that templates are a problem. Remember template meta-programming wasn't really intended from the outset, and a big part of the point of Concepts was to at last let you write code that compilers can provide readable errors for when it's wrong.

[pjmlp]

The whole issue with Linux and C++ is political, there are other OSes that don't suffer from such issues and gladly accept templates.

https://developer.apple.com/documentation/driverkit

https://docs.microsoft.com/en-us/cpp/build/reference/kernel-...

https://fuchsia.dev/fuchsia-src/development/languages/c-cpp/...

https://genodians.org/nfeske/2019-01-22-conscious-c++

[tialaramex]

I understand that for C++ programmers "That's possible" versus "That's a good idea" is a distinction without a difference, however for the rest of us the fact you can use templates as much as you like in, say, Windows drivers, does not magically mean it's a good idea to write complex templated code in Windows drivers.

The constraints in /kernel like forbidding exceptions are because otherwise they (Microsoft) need to do a bunch of extra work to support your bad idea. But your use of templates has no impact on their work, so knock yourself out adding as much complexity as you like this way.

[pjmlp]

Here is another example, running C++ straight on car firmware free of Linux politics via AUTOSAR certification standard.

https://www.parasoft.com/blog/breaking-down-the-autosar-c14-...

But what do they state specifically? Ah, right.

> "The document allows in particular the usage of dynamic memory, exceptions, templates, inheritance and virtual functions."

https://www.autosar.org/fileadmin/user_upload/standards/adap...

[tialaramex]

It definitely feels like we're talking past each other. I keep telling you why people think it's a bad idea, and you keep showing that you're allowed to do it anyway. We know. That's the difference between impossible and a bad idea.

[stonemetal12]

You keep saying it is a bad idea like it is a given. He keeps saying 5 bazillion programmers are quite successful with your "bad idea" so maybe it isn't so bad. Is there any evidence either way on the effects of templates on code quality?

[pjmlp]

Nope, it is the difference regarding politics of what goes into the Linux kernel and the rest of the world, and it is quite clear to which side each of us belong.

[kaba0]

Why exactly? They are a compile time concept which only generates code for types where it is needed. That C devs instead copy-paste the same code 10s of times, use some shitty slow linked list, or the worst, use textual macros doesn’t make any of them a better tradeoff imo.

[saagarjha]

To be fair, DriverKit runs in userspace. IOKit, its spiritual predecessor, only allowed for the use of Embedded C++.

[pjmlp]

True, but that isn't the case for the other more modern examples.

Also IO Kit is no more, unless one is running an outdated macOS installation.

And talking about the past, maybe discussing about dynamic dispatch of Objective-C messsages on NeXTSTEP drivers with the previous Driver Kit, would also be quite interesting regarding "bloat".

[saagarjha]

IOKit remains the only way to write kernel extensions, which are still supported but discouraged if DriverKit does the job. NeXtTSTEP using Objective-C for drivers was certainly very cute but I guess they just didn’t want to have driver makers learn the language :(

[pjmlp]

> Devices supported on macOS 11 and later require DriverKit. Use IOKit in your apps and services to discover and use devices.

https://developer.apple.com/documentation/iokit

Going forward not for long.