"Reflective" programming...

In almost every other language:
1. obj.GetType().GetProperties()
or
for k, v in pairs(obj) do something end
or
fieldnames(typeof(obj))
or
Object.entries(obj)

2. Enjoy.

In C++: 💀
1. Use the extern keyword to trick compilers into believing some fake objects of your chosen type actually exist.

2. Use the famous C++ type loophole or structured binding to extract fields from your fake objects.

3. Figure out a way to suppress those annoying compiler warnings that were generated because of your how much of a bad practice your code is.

4. Extract type and field names from strings generated by compiler magic (__PRETTY_FUNCTION__, __FUNCSIG__) or from the extremely new feature std::source_location (people hate you because their Windows XP compilers can't handle your code)

5. Realize your code still does not work for classes that have private or protected fields.

6. Decide it's time to become a language lawyer and make OOPers angry by breaking encapsulation and stealing private fields from their classes using explicit template instantiation

7. Realize your code will never work outside of MSVC, GCC or CLANG and will always be reliant on undefined behaviors.

8. Live forever in doubt and fear that new changes to the compiler magic you abused will one day break your code.

9. SUFFER IN HELL as you start getting 5000 lines worth of template errors after switching to a new compiler.

The most normal C++ program be like:

// prints "Hello, World!"
namespace{decltype(+*"")(*main)()=[]()->decltype(main()){return{};};}
decltype(main())(main(decltype(main())={},decltype(&*"")_[]={})){
extern decltype(&"") puts;
reinterpret_cast<decltype(::main())(*)(decltype(&*""))>(&puts)("Hello, World!");
return(decltype(::main()){});
}