Update our `rust-secp256k1` dependency to the latest version.
Requires doing:
- Add a new variant to `Error` for the case where parity of the internal
key is an invalid value (not 0 or 1).
- Use non-deprecated const
Rust convention is to use `to_` for conversion methods that convert from
an owned type to an owned `Copy` type. `into_` is for owned to owned
non-`Copy` types.
Re-name conversion methods that use `into_` for `Copy` types to use
`to_`, no need to deprecate these ones because they are unreleased.
Currently we calculate the parity during `tap_tweak` but do not return
it, this means others must re-do work done inside `tap_tweak` in order
to calculate the parity. We can just return the parity along with the
tweaked key.
Keeping inline with the method on `UntweakedPublicKey` that outputs a
`TweakedPublicKey` we can use the same name, for the same reasons.
Use `dangerous_assume_tweaked` as the constructor name to highlight the
fact that this constructor should probably not be being used.
We currently run `tweak_add_check` and use the result as a conditional
branch, the error path of which uses `unreachable`. This usage of
`unreachable` is non-typical. An 'unreachable' statement is by
definition supposed to be unreachable, it is not clear why we would need
to have a conditional branch to check an unreachable statement.
Use `debug_assert!` so programmer errors get caught in un-optimised
builds but in optimised builds the call to `tweak_add_check` is not even
done.
Ambiguous TweakedPublicKey and UntweakedPublicKey type aliases and methods to convert
Use structs for Untweaked and Tweaked key type
swap dangerous api to work on tweaked keys
remove unecessary allocations and rename methods
Use type alias for UntweakedPublicKey
TweakedPublicKey::new(...) method added
minor naming and doc changes
Docs can always do with a bit of love.
Clean up the module level (`//!`) rustdocs for all public modules.
I claim uniform is better than any specific method/style. I tried to fit
in with what ever was either most sane of most prevalent, therefore
attaining uniformity without unnecessary code churn (one exception being
the changes to headings described below).
Notes:
* Headings - use heading as a regular sentence for all modules e.g.,
```
//! Bitcoin network messages.
```
as opposed to
```
//! # Bitcoin Network Messages
```
It was not clear which style to use so I picked a 'random' mature
project and copied their style.
* Added 'This module' in _most_ places as the start of the module
description, however I was not religious about this one.
* Fixed line length if necessary since most of our code seems to follow
short (80 char) line lengths for comments anyways.
* Added periods and fixed obvious (and sometimes not so obvious)
grammatically errors.
* Added a trailing `//!` to every block since this was almost universal
already. I don't really like this one but I'm guessing it is Andrew's
preferred style since its on the copyright notices as well.