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For example INotifyPropertyChanged which is used in WPF. The typical implementation is something like this: public string CustomerName {

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?
- gsmecher 5y ago
  I design instrumentation for telescopes, in which C code on an embedded processor peeks and pokes device registers on an nearby FPGA. This C code forms an interface between hardware and the network. In this system, I write a given function in C and surround it with a macro wrapper. This wrapper generates a JSON-RPC equivalent of the C function using the Jansson JSON library [1], complete with argument typechecking and error management. My C code can call the function normally, and an embedded webserver [2] can export it across the network where it's used fairly transparently by a Python stack on a control PC. All three of these "embedded software" elements (the embedded webserver, the JSON library, and the FPGA interface) are very well suited to C. I have recently dabbled in moving parts of it to C++, and have found a few surprising impedance mismatches. (As I mentioned above, C++ still lacks reflection.) The macros, here, are not for "elegance" or any other abstract purpose. They have allowed a ~80% reduction in boilerplate and an equally impressive reduction in the bugs and hassles associated with this kind of low-density, high-sprawl code. [1]: https://digip.org/jansson/ https://digip.org/jansson/ [2]: https://www.gnu.org/software/libmicrohttpd https://www.gnu.org/software/libmicrohttpd

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?

gsmecher 5y ago
I design instrumentation for telescopes, in which C code on an embedded processor peeks and pokes device registers on an nearby FPGA. This C code forms an interface between hardware and the network. In this system, I write a given function in C and surround it with a macro wrapper. This wrapper generates a JSON-RPC equivalent of the C function using the Jansson JSON library [1], complete with argument typechecking and error management. My C code can call the function normally, and an embedded webserver [2] can export it across the network where it's used fairly transparently by a Python stack on a control PC. All three of these "embedded software" elements (the embedded webserver, the JSON library, and the FPGA interface) are very well suited to C. I have recently dabbled in moving parts of it to C++, and have found a few surprising impedance mismatches. (As I mentioned above, C++ still lacks reflection.) The macros, here, are not for "elegance" or any other abstract purpose. They have allowed a ~80% reduction in boilerplate and an equally impressive reduction in the bugs and hassles associated with this kind of low-density, high-sprawl code. [1]: https://digip.org/jansson/ https://digip.org/jansson/ [2]: https://www.gnu.org/software/libmicrohttpd https://www.gnu.org/software/libmicrohttpd