Enforce documentation and no unsafe code

src/fingerprint.rs

@@ -1,18 +1,21 @@
 //! Seed Fingerprints according to ZIP 32
 //!
-//! Implements section `Seed Fingerprints` of Shielded Hierarchical Deterministic Wallets (ZIP 32)
+//! Implements section [Seed Fingerprints] of Shielded Hierarchical Deterministic Wallets (ZIP 32).
 //!
-//! [Section Seed Fingerprints]: https://zips.z.cash/zip-0032#seed-fingerprints
+//! [Seed Fingerprints]: https://zips.z.cash/zip-0032#seed-fingerprints
 use blake2b_simd::Params as Blake2bParams;
 
-pub const ZIP32_SEED_FP_PERSONALIZATION: &[u8; 16] = b"Zcash_HD_Seed_FP";
+const ZIP32_SEED_FP_PERSONALIZATION: &[u8; 16] = b"Zcash_HD_Seed_FP";
+
+/// The fingerprint for a wallet's seed bytes, as defined in [ZIP 32].
+///
+/// [ZIP 32]: https://zips.z.cash/zip-0032#seed-fingerprints
 pub struct SeedFingerprint([u8; 32]);
 
 impl SeedFingerprint {
-    /// Return the seed fingerprint of the wallet as defined in
-    /// <https://zips.z.cash/zip-0032#seed-fingerprints> or None
-    /// if the length of `seed_bytes` is less than 32 or
-    /// greater than 252.
+    /// Derives the fingerprint of the given seed bytes.
+    ///
+    /// Returns `None` if the length of `seed_bytes` is less than 32 or greater than 252.
     pub fn from_seed(seed_bytes: &[u8]) -> Option<SeedFingerprint> {
         let seed_len = seed_bytes.len();
 

src/lib.rs

@@ -2,6 +2,8 @@
 //!
 //! [ZIP 32]: https://zips.z.cash/zip-0032
 
+#![deny(missing_docs)]
+#![deny(unsafe_code)]
 #![deny(rustdoc::broken_intra_doc_links)]
 
 use memuse::{self, DynamicUsage};
@@ -94,6 +96,7 @@ impl ChainCode {
     }
 }
 
+/// The index for a particular diversifier.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub struct DiversifierIndex(pub [u8; 11]);
 
@@ -128,10 +131,12 @@ impl TryFrom<DiversifierIndex> for u32 {
 }
 
 impl DiversifierIndex {
+    /// Constructs the zero index.
     pub fn new() -> Self {
         DiversifierIndex([0; 11])
     }
 
+    /// Increments this index, failing on overflow.
     pub fn increment(&mut self) -> Result<(), ()> {
         for k in 0..11 {
             self.0[k] = self.0[k].wrapping_add(1);