I don't know why it was decided to concatenate at first, but I don't think there's any reason to do this (other than we have 1K+ kata that relies on the setup). Maybe I'm missing something.

I can see a few reasons for this, but I believe the most probable one is handling of templates in C++. Templates have to be defined in every translation unit, and that's why they're always located in header files. If a solution would need to define a template, it would be not enough for a solution to be a cpp file (i.e. a separate translation unit), because tests would not be able to use it.

Ah, I see. If it was possible to have solution.h and solution.cpp, the test can include solution.h to be compiled separately and linked. Since we can't do that, we don't have a choice.

I don't think we need a separate page for the template snippet. There's nothing much to explain further, and the new reusable one is self-explanatory.

Solution snippet is not the only one affected by this issue. It applies also to, for example, preloaded, which might want to define global/static data in a cpp part, and declare it in a header file.

Ah, I see. If it was possible to have solution.h and solution.cpp, the test can include solution.h to be compiled separately and linked. Since we can't do that, we don't have a choice.

It could be done, but in kinda awkward way: snippets could contain some kind of markers which would separate "header" part and ".cpp part", and runner would split them into files appropriately. It's clunky, awkward, but in 99% not necessary, and some default behavior would suffice (no markers and store everything as a cpp file, compile, and link). Only those who need it, could use something like:

/*============ solution.h ============*/
// ... declarations, template definitions

/*===========solution.cpp============*/
// ... implementation part

Not that I like this solution, but it is one of solutions.

I don't think we need a separate page for the template snippet. There's nothing much to explain further, and the new reusable one is self-explanatory.

Ok so I will remove the link to the "solution template" page for now, and later I will turn the "solution template" page into "how to train on cpp kata locally" and add the link back.

Doesn't this contradict with the above?

Codewars does not strictly enforce any of them, just use whatever set of guidelines you like, but when you do, use it consistently.

Maybe we should have a small set of rules that content creators are expected to follow based on this list.

I meant the first paragraph to be related to things like naming conventions, placement of braces, and other minuscule things people like to fight about over the Internet.
The latter paragraph i meant to relate to more serious / not just aestethic language best practices.
Maybe my wording is off, and just do not know how to express myself clearly. One is code style, and the other is language practices.

I tried to reword both points, I am not sure if it's better though.