Memory Allocation Function per Document

[J-Richter]

Currently memory allocation functions can only be set globally with set_memory_management_functions.
We use it to allocate separate mmap regions to a very large xml document. But this does not scale with more than one document. It is not easy to have separate memory allocators per document.
This is the enhancement request to have document specific memory allocation/deallocation functions.

[LuridHound]

I would like to create PR addressing this issue.

but first - @J-Richter - do you have any branch / near final version of the code?
or you've simply created an issue?

[J-Richter]

I just created the issue. I didn't implement the feature.