StreamReader before this commit is trying to repeatedly parse big object like
blocks at every read, causing useless overhead.
consensus_encode deal with partial data by simply blocking.
After this changes it doesn't look what remain of the StreamReader is really giving
value, so it's deprecated
Based on the original work by Justin Moon.
*MSRV unchanged from 1.29.0.*
When `std` is off, `no-std` must be on, and we use the [`alloc`](https://doc.rust-lang.org/alloc/) and core2 crates. The `alloc` crate requires the user define a global allocator.
* Import from `core` and `alloc` instead of `std`
* `alloc` only used if `no-std` is on
* Create `std` feature
* Create `no-std` feature which adds a core2 dependency to polyfill `std::io` features. This is an experimental feature and should be
used with caution.
* CI runs tests `no-std`
* MSRV for `no-std` is 1.51 or so
Dr Maxim Orlovsky
Riccardo Casatta
Devrandom
Margarita Kitic
Elias Rohrer