Alt text:
A screenshot from the linked article titled "Reflection in C++26", showing reflection as one of the bullet points listed in the "Core Language" section
this post was submitted on 24 Sep 2024
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Java has reflection since version 1.1. It's actually quite useful in situations and most popular frameworks use it. It depends on you if it turns into a footgun.
See my other comment for more detials but it kind of destroys the type safety of the language. In Java for example, it lets you modify private/protected fields and call private/protected methods.
It's also slower than accessing a field normally since you need to do a string lookup (but slightly faster than a hashmap/dictionary) so if you use it over a large enough list it'll cause slowdowns.
Most use cases for it in Java/C# revolve around testing, serialization, and dynamic filtering/sorting. And most of those cases can be handled more safely using macros/attributes (EDIT: and templates as well, though those are also pretty painful to deal with) because that gets handled at compile-time in C/C++.
What macros or attributes provide serialization in C++?
My bad, that's on me, it looks like the C++ libraries I found use either templates or boost's reflection. There might be a way to do it with macros/metaprogramming but I'm not good enough at C/C++ to know.
I'm learning rust and C at the same time and was mixing up rust's features with C's. Rust's answer to reflection is largely compile-time macros/attributes and I mistakenly assumed C's attributes worked similarly since they have the same name.
Ah. Rust's macros and the C preprocessor's exist in vastly different universes. The C preprocessor is literally just a fancy programmatic copy-and-paste tool. Rust macros read the input source code and then execute other source code (the macro definition) to generate new source code that the compiler then reads.
I love Rust, but Rust macros are arguably more of a footgun than compile-time reflection would be, and as amazing as
serdeis (and no, there's nothing comparable in standard-compliant C++ yet), there's a strong argument that compile-time reflection would be a preferable technique for deriving serialization, argument-parsing, and similar feature.