[iostreams] Custom allocator support for compression filters

From: Daniel Boehme (Daniel.Boehme1_at_[hidden])
Date: 2024-09-04 13:22:49

Hello everyone,

I'm currently looking into custom allocators with the boost::iostreams::gzip_compressor and now need some help understanding why the code is the way it is.

My problem is that I need to control how zlib internally de-/allocates memory.

It seems to have support for using custom de-/allocation functions. And iostreams seems to have used it some time ago.
However, passing the custom allocator to zlib has been disabled in this commit: https://github.com/boostorg/iostreams/commit/95baf782098f0dee00cc7ca6f62b9b105ca6573f

Does anyone happen to know what has been non-conforming and why it was disabled? I could not find any information about that in the code, on the mailing lists, or anywhere else in the internet.

I'm tempted to submit a patch that enables it, but for that I need to understand the reasons behind that deliberate decision.

Any hint is welcome.

Thank you very much.

Daniel B?hme