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Only if you can switch to something like Zig, Rust, etc. But a tremendous amount of code bases are already written in plain C. Using preprocessor metaprogrammin

Only if you can switch to something like Zig, Rust, etc. But a tremendous amount of code bases are already written in plain C. Using preprocessor metaprogramming allows you to invoke macros right in the same files in which you write ordinary C code, without the need for integration with other languages.

nicoburns 5y ago
> Using preprocessor metaprogramming allows you to invoke macros right in the same files in which you write ordinary C code C++ effectively lets you do this too. And Zig will let you import and compile C files seamlessly. I suppose you have to switch compilers, but that's not so different to adding the additional pre-processor compiler.
- Hirrolot 5y ago
  C++ can, fair. Still there is a huge amount of developers sticking to plain C, even if they can use C++ (FFmpeg, VLC, Linux, etc.), why do they do that? I think an answer to this question would be pretty much the answer for the initial question. There might be cultural, historical, and other reasons for it. The thing with Zig is that, if I understand it correctly, Zig can't be interleaved with other C code in the same file, which forces you to separate things, loosing convenience. On the other hand, to use Datatype99, you can just #include <datatype99.h> and you're ready to go.
gsmecher 5y ago
To date, C's most proximate (management-friendly, technically similar, programmer-skill-adjacent) competition has been c++. (I'm trying to lay the groundwork for the next statement: I'm not claiming this is good, and excited to see Rust and friends as serious contenders. Stay with me.) Even in c++20, there are things you can do with macros you can't do in the language. This may change when reflection lands in c++2x, but I won't be able to use it for years and widespread adoption won't be possible for another decade.
- spaetzleesser 5y ago
  When I look at a lot of things that are done with reflection in C# I personally would much prefer the preprocessor and macros. Things that could be done in a type safe manner with a macro in a few lines become way more complex when using reflection.
  - mumblemumble 5y ago
    Could I beg of you to give an example? Back when I was working in C#, there were quite a few times when I'd encounter things being done with reflection that I wish had been done with less code and a more type safe manner by just... not using reflection. I always just assumed a lot of that was just bad habits left over from the .NET 1.0 days, back before generics. So I'm curious if there's much overlap there? If it's only a subset, I don't know C as well as I'd like, so it would be interesting to see something that the C preprocessor handles better.
    - spaetzleesser 5y ago
      For example INotifyPropertyChanged which is used in WPF. The typical implementation is something like this: public string CustomerName { get { return this.customerNameValue; } set { if (value != this.customerNameValue) { this.customerNameValue = value; NotifyPropertyChanged(); } } } When you have 20 properties you have a ton of repetitive code. With a preprocessor I could reduce each property to a one liner. You can also do tricks with reflection but that's way more complex to implement.
      - mumblemumble 5y ago
        Yeah, there is that, but I wash hoping to see a great use case for C preprocessor macros. WPF data binding doesn't seem like good candidate for something you're likely to want to do in a C program. Or were you really just meaning to advocate for metaprogramming in general?

nicoburns 5y ago

> Using preprocessor metaprogramming allows you to invoke macros right in the same files in which you write ordinary C code C++ effectively lets you do this too. And Zig will let you import and compile C files seamlessly. I suppose you have to switch compilers, but that's not so different to adding the additional pre-processor compiler.

Hirrolot 5y ago
C++ can, fair. Still there is a huge amount of developers sticking to plain C, even if they can use C++ (FFmpeg, VLC, Linux, etc.), why do they do that? I think an answer to this question would be pretty much the answer for the initial question. There might be cultural, historical, and other reasons for it. The thing with Zig is that, if I understand it correctly, Zig can't be interleaved with other C code in the same file, which forces you to separate things, loosing convenience. On the other hand, to use Datatype99, you can just #include <datatype99.h> and you're ready to go.

gsmecher 5y ago

To date, C's most proximate (management-friendly, technically similar, programmer-skill-adjacent) competition has been c++. (I'm trying to lay the groundwork for the next statement: I'm not claiming this is good, and excited to see Rust and friends as serious contenders. Stay with me.) Even in c++20, there are things you can do with macros you can't do in the language. This may change when reflection lands in c++2x, but I won't be able to use it for years and widespread adoption won't be possible for another decade.

spaetzleesser 5y ago
When I look at a lot of things that are done with reflection in C# I personally would much prefer the preprocessor and macros. Things that could be done in a type safe manner with a macro in a few lines become way more complex when using reflection.
- mumblemumble 5y ago
  Could I beg of you to give an example? Back when I was working in C#, there were quite a few times when I'd encounter things being done with reflection that I wish had been done with less code and a more type safe manner by just... not using reflection. I always just assumed a lot of that was just bad habits left over from the .NET 1.0 days, back before generics. So I'm curious if there's much overlap there? If it's only a subset, I don't know C as well as I'd like, so it would be interesting to see something that the C preprocessor handles better.
  - spaetzleesser 5y ago
    For example INotifyPropertyChanged which is used in WPF. The typical implementation is something like this: public string CustomerName { get { return this.customerNameValue; } set { if (value != this.customerNameValue) { this.customerNameValue = value; NotifyPropertyChanged(); } } } When you have 20 properties you have a ton of repetitive code. With a preprocessor I could reduce each property to a one liner. You can also do tricks with reflection but that's way more complex to implement.
    - mumblemumble 5y ago
      Yeah, there is that, but I wash hoping to see a great use case for C preprocessor macros. WPF data binding doesn't seem like good candidate for something you're likely to want to do in a C program. Or were you really just meaning to advocate for metaprogramming in general?