95fb4e01f9 Document cargo features (Martin Habovstiak)
Pull request description:
This documents cargo features in two ways: explictly in text and in code
using `#[doc(cfg(...))]` attribute where possible. Notably, this is
impossible for `serde` derives. The attribute is contitional and only
activated for docs.rs or explicit local builds.
This change also adds `package.metadata.docs.rs` field to `Cargo.toml`
which instructs docs.rs to build with relevant features and with
`docsrs` config activated enabling `#[doc(cfg(...))] attributes.
I also took the opportunity to fix a few missing spaces in nearby code.
Notes for reviewers:
* To build and look at result locally run: `RUSTDOCFLAGS="--cfg docsrs" cargo +nightly doc --features std,secp-recovery,base64,rand,use-serde,bitcoinconsensus --open` (don't confuse `RUSTDOCFLAGS` with `RUSTFLAGS` - took me a while to figure that out 😞)
* You should see needed features being called out - e.g. in `Script::verify`
* More information and some screenshots: https://github.com/rust-lang/cargo/issues/8103#issuecomment-653154049
* For an example why this matters see: https://github.com/Kixunil/loptos/issues/1😉
* Serde issue: https://github.com/serde-rs/serde/issues/2063
ACKs for top commit:
dr-orlovsky:
ACK 95fb4e01f9
apoelstra:
ACK 95fb4e01f9
Tree-SHA512: 4d6428bfa05cbeb2d8737f0239aa1836b5f36f4b040e1ac5e0862663c4ea783711d122182dd8313913fd593ab224915bd8def5e268b272215bee2c9856a27674
This documents cargo features in two ways: explictly in text and in code
using `#[doc(cfg(...))]` attribute where possible. Notably, this is
impossible for `serde` derives. The attribute is contitional and only
activated for docs.rs or explicit local builds.
This change also adds `package.metadata.docs.rs` field to `Cargo.toml`
which instructs docs.rs to build with relevant features and with
`docsrs` config activated enabling `#[doc(cfg(...))] attributes.
I also took the opportunity to fix a few missing spaces in nearby code.
Instead of using magic numbers we can define constants for the address
prefix bytes. This makes it easier for future readers of the code to see
what these values are if they don't know them and/or see that they are
correct if they do know them.
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
Martin Habovstiak
Andrew Poelstra
Ben Carman
Sanket Kanjalkar
Dr Maxim Orlovsky
Riccardo Casatta
Tobin Harding
Devrandom
Vis Virial
elsirion
Sebastian Geisler
Sebastian