Switch to LGPL instead

[XVilka]

To be able to use this as library.

We are considering this for https://github.com/radareorg/radare2/issues/6093

[catb0t]

In its current state, this project is an unfinished, highly experimental toy.

It lacks a lot of basic functionality, and the functionality it does have is currently naively implemented using a lot of copies/frees (instead of in-place data changes, because of strong const correctness), and the most simple algorithms possible, to teach myself the principles.

On top of all that, its core premise is probably wrong, and whatever strategies are used by GMP, Boost, etc to fit large numbers in small amounts of memory should probably be used instead of simple arrays, but currently aren't used.

However, if you are still interested, it can be made production-efficient, especially with contributions.

[catb0t]

Your application is specifically for the representation of wider hardware types, so a purpose-built library which can use wider hardware types when available, but falls back to a platform-independent representation otherwise, would probably be best. That might be fun to work on.