Recently we fixed a bunch of feature gates to use `rand-std` instead
of `rand` but in doing so did not notice that the same feature gates
were using `alloc` which is meaningless if `std` is enabled.
Feature gate on `std` if we are using `rand-std`.
Our API often involves a `Secp256k1` parameter, when users enable the
`global-context` feature they must then pass `SECP256K1` into these
functions. This is kind of clunky since the global is by definition
available everywhere.
Make the API more ergonomic for `global-context` builds by adding
various API functions/methods that use the global context implicitly.
Currently various features fail to build when enabled without default
features. This is because many tests need feature gating.
Feature gating the import statements quickly turns into spaghetti when
trying to cover all combinations of two features correctly, instead just
allow unused imports on `tests` modules where needed.
Add correct feature requirements to the examples so they also can be run
without default features.
Improve the CI script by doing:
- Add `std` to the feature matrix.
- Add `--no-default-features` to test runs in the CI script.
Currently we have an implementation of `Debug` (also used by `Display`)
for `Signature` that first converts the sig to a `SerializedSignature`
then prints it as hex.
We would like to have an implementation of `Debug` for
`SerializedSignature`, this cannot be derived because of the `data: [u8;
field]`. We can manually implement `Debug` for `SerializedSignature`
exactly as it is currently done for `Signature` and call this new
implementation from `Signature::fmt()`.
This code path is already tested in `lib.rs` in the test function
`signature_display`.
This documents the Cargo features making sure docs.rs shows warning for
feature-gated items. They are also explicitly spelled out in the crate
documentation.
With the introduction of Schnorr signatures, exporting a `Signature`
type without any further qualification is ambiguous. To minimize the
ambiguity, the `ecdsa` module is public which should encourage users
to refer to its types as `ecdsa::Signature` and `ecdsa::SerializedSignature`.
To reduce ambiguity in the APIs on `Secp256k1`, we deprecate several
fucntions and introduce new variants that explicitly mention the use of
the ECDSA signature algorithm.
Due to the move of `Signature` and `SerializedSignature` to a new module,
this patch is a breaking change. The impact is minimal though and fixing the
compile errors encourages a qualified naming of the type.