no_std support for subxt

[melynx]

Currently there isn't any no_std support for substrate-subxt making it really difficult to craft extrinsics from within a restricted environment. Is there any planned support for no_std / alloc environments?

[DemiMarie]

I am not aware of any such plans on Parity’s end, though community contributions would be welcome. That said, much of the client code is likely to be completely rewritten at some point. Currently, each extrinsic requires manual effort in this repo, which just does not scale. In the future, the client code will be generated from the chain metadata.

[jsdw]

Nowadays we have a subxt-core crate which contains the no-std compatible subset of subxt functionality (it does require alloc though; I think for non-alloc cases you're probably going to have to do something more manual as needed since we rely on it quite a lot!)

So I'll close this, and we can open new issues to address things missing from subxt-core or whatever :)