inability to compile in no_std envirnoment

[zzjakub]

Hi!
Your crate looks ideal for my Embassy based project, but unfortunately i wasn't able to compile it after adding it as dependency. I made sure to disable default features, but somehow once_cell that get's pulled by dependencies has std feature enabled.

After an analysis with cargo tree it seems that agnostic-net has agnostic-lite hardcoded with std no matter the features enabled.

I may be wrong, but if that's the cause i can submit a PR.

[al8n]

Hi, yes, currently, the agnostic-net is not work without std, because agnostic-io cannot compile without std (it uses the std::io::Error). I think it is possible to fix it by introducing an associated type Error in the trait definition.

[al8n]

I will refactor the implementation to fully respect Sans-I/O in this week. After the refactoring, the code will support both no-std and no-alloc, so should be compatible with embassy.