member are arrays/lists/vectors of unknown types

[michaeljhkim]

Hi, how do I get the data from a member that is a vector? Keep in mind I do not know what kind of values this vector has

[BlackMATov]

Hello!

The only thing you can do in this regard is to check if the type has an index operator uvalue.has_index_op(). After that, you can take values ​​by index uvalue[42].

The types for which out-of-the-box index operators are defined can be found here: https://github.com/BlackMATov/meta.hpp/blob/main/headers/meta.hpp/meta_detail/value_traits/index_traits.hpp
You can define a specialization of this feature for other array types using the example above.

But keep in mind that this library does not have such abstractions over containers as in RTTR for a variety of reasons, the main one being that it only works in special cases and has big problems in general.

P.S.

Also, you can see another traits here: https://github.com/BlackMATov/meta.hpp/tree/main/headers/meta.hpp/meta_detail/value_traits

[BlackMATov]

You can also mark your members with metadata when binding to differentiate them.

[michaeljhkim]

Hello!

The only thing you can do in this regard is to check if the type has an index operator uvalue.has_index_op(). After that, you can take values ​​by index uvalue[42].

The types for which out-of-the-box index operators are defined can be found here: https://github.com/BlackMATov/meta.hpp/blob/main/headers/meta.hpp/meta_detail/value_traits/index_traits.hpp You can define a specialization of this feature for other array types using the example above.

But keep in mind that this library does not have such abstractions over containers as in RTTR for a variety of reasons, the main one being that it only works in special cases and has big problems in general.

P.S.

Also, you can see another traits here: https://github.com/BlackMATov/meta.hpp/tree/main/headers/meta.hpp/meta_detail/value_traits

Will this suffice for simple iteration? For something like a for loop? How do I get .size() for that? That is really as far as I need to go, no further

[BlackMATov]

Will this suffice for simple iteration? For something like a for loop? How do I get .size() for that? That is really as far as I need to go, no further

I think I can add something like length_traits and specialize it for sequence-like containers.

[michaeljhkim]

I think I can add something like length_traits and specialize it for sequence-like containers.

how difficult would it be to also implement a way to get and set values of that vector? Specifically speaking, I mean how rttr can just sort of get a array like thing where every element is now a variant:

auto view = variant.create_sequential_view();
for (size_t i = 0; i < view.get_size(); ++i)
{
	rttr::variant sub_variant = view.get_value(i);
	view.set_value(i, sub_variant);
}

In meta.hpp, it would be every element being turned into uvalue. I am trying to imitate this behaviour in some way, but it appears I cannot.

[BlackMATov]

Yes, that would be great, but it might be a lot more complicated than it seems at first glance. Anyway, give me a few days, i'm going to think about it in the background.

[michaeljhkim]

Thank you for considering, I will try to find alternative solutions for now

[BlackMATov]

So now we have size_traits and index_traits for uvalue.
This should be enough to iterate over sequence containers.

But we still don't have a way to set values ​​by index, and I'm not sure that I'm ready to implement that, since the concept of traits should be reconsidered, perhaps towards an analog of RTTR views or something similar.

[michaeljhkim]

I think I can probably hack something together, this should be just enough. Thank you very much

[michaeljhkim]

Okay, so I think I did come up with a temporary solution, creating a method that when called will take in uvalues and modify the value at an index.

But then this gave me an idea: why not just get pointers for the elemnts of a vector/array? As in create a uvalue for a pointer for each element? And we only do it if a user activates this feature with a function of somekind.

IDK, I'm just spitballing.

[BlackMATov]

This is an interesting idea, but not flexible enough to include in the library. We need to be able to set values ​​by index with dynamic values. Returning a pointer to an element we need to know the static type to fully work with it, this is not what is needed.

[michaeljhkim]

hmmm, in that case, I'll just leave it alone, since I barely know how this stuff works. The level of abstractions are completely alien to me. I'll keep this issue open just in case.