Make `bitcoin` mandatory and improve the API?

[Kixunil]

The bitcoin crate currently provides number of useful types that could be returned in Visitor methods instead. This would of course make the dependency mandatory. (But most, if not all, Bitcoin projects will depend on it anyway.) If it's considered too large, perhaps it'll make more sense after crate smashing.

Some noteworthy types:

• &Script
• Sequence
• LockTime
• Amount
• block::Version
• CompactTarget

I'd be happy to help making other types more easily usable with this crate.

[RCasatta]

Totally agree most likely if you use bitcoin_slices you also have bitcoin in the tree, but you can use bitcoin_slices in no_std without an allocator and maybe it's useful in some context...

Is it not possible to achieve a bitcoin-friendly API with a default-enabled feature?
Like with a super trait of Visitor, or Visitor impl, or something else...

[Kixunil]

Oh, yeah, a supertrait of Visitor sounds interesting. What I was mainly thinking about is not duplicating the same API just to support both non-bitcoin and bitcointypes. But I was already thinking of supporting no-alloc inbitcoin. At least Amountcould do it, hashes already do IIRC and I'd be happy to seeScript` as well. I think it'll be easier to do after crate smashing.