The newtype sanity rules (a name I came up with):
* Newtypes should have at most one constructor that directly references
the inner field.
* Newtypes should have at most three accessor methods that directly
reference the ineer field: one for owned access, the second for
borrowed and the third for mutably borrowed.
* All other methods should use the methods above to perform operations
on the newtype and not directly access the fields.
This commit makes `Script` and `ScriptBuf` obey these except for
`reserve` and `reserve_exact` since we don't have `as_mut_vec` method.
As a side effect it also adds `const` to `ScriptBuf::from_bytes`.
Enable lint `clippy::return_self_not_must_use` and add attribute
`must_use` as required.
Also run the linter with `clippy::must_use_candidate` enabled and
manually check every warning site.
While we are at it change the current `must_use` usages to have no
message. We can always add a message later if needed.
In functions that act like constructors there is a mixture of the usage
of `creates` and `constructs`.
Replace all occurrences of `creates` with `constructs` in the first line
of docs of constructor like functions.
We want our code to be easy to read and our APIs discoverable, for those
of us who read source files the layout matters.
Put the constructors and getters at the top of the impl block.
Code move only, no logic changes.
Deprecate the `Script::to_bytes` function in favour of `to_vec` as we
are doing elsewhere.
Note that `ScriptBuf` has `into_bytes` because it does not copy.
Potentially this should be deprecated in favour of `into_vec`?
Note that in regards to the `to_` prefix this naming as valid according
to convention because the `Script` type is borrowed and `to_vec` copies
the underlying bytes.