Convert the FeaturedAddress tuple to a struct

Not only did we already have multiple booleans in it, yet it theoretically
could expand in the future. Not only is this more explicit, it actually cleans
some existing code.

coins/monero/src/wallet/address.rs

@@ -24,7 +24,7 @@ pub enum AddressType {
   Standard,
   Integrated([u8; 8]),
   Subaddress,
-  Featured(bool, Option<[u8; 8]>, bool),
+  Featured { subaddress: bool, payment_id: Option<[u8; 8]>, guaranteed: bool },
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Zeroize)]
@@ -56,26 +56,27 @@ pub enum AddressSpec {
   Standard,
   Integrated([u8; 8]),
   Subaddress(SubaddressIndex),
-  Featured(Option<SubaddressIndex>, Option<[u8; 8]>, bool),
+  Featured { subaddress: Option<SubaddressIndex>, payment_id: Option<[u8; 8]>, guaranteed: bool },
 }
 
 impl AddressType {
   pub fn subaddress(&self) -> bool {
-    matches!(self, AddressType::Subaddress) || matches!(self, AddressType::Featured(true, ..))
+    matches!(self, AddressType::Subaddress) ||
+      matches!(self, AddressType::Featured { subaddress: true, .. })
   }
 
   pub fn payment_id(&self) -> Option<[u8; 8]> {
     if let AddressType::Integrated(id) = self {
       Some(*id)
-    } else if let AddressType::Featured(_, id, _) = self {
-      *id
+    } else if let AddressType::Featured { payment_id, .. } = self {
+      *payment_id
     } else {
       None
     }
   }
 
   pub fn guaranteed(&self) -> bool {
-    matches!(self, AddressType::Featured(_, _, true))
+    matches!(self, AddressType::Featured { guaranteed: true, .. })
   }
 }
 
@@ -137,7 +138,7 @@ impl<B: AddressBytes> AddressMeta<B> {
       AddressType::Standard => bytes.0,
       AddressType::Integrated(_) => bytes.1,
       AddressType::Subaddress => bytes.2,
-      AddressType::Featured(..) => bytes.3,
+      AddressType::Featured { .. } => bytes.3,
     }
   }
 
@@ -146,7 +147,7 @@ impl<B: AddressBytes> AddressMeta<B> {
     AddressMeta { _bytes: PhantomData, network, kind }
   }
 
-  // Returns an incomplete type in the case of Integrated/Featured addresses
+  // Returns an incomplete instantiation in the case of Integrated/Featured addresses
   fn from_byte(byte: u8) -> Result<Self, AddressError> {
     let mut meta = None;
     for network in [Network::Mainnet, Network::Testnet, Network::Stagenet] {
@@ -155,7 +156,9 @@ impl<B: AddressBytes> AddressMeta<B> {
         _ if byte == standard => Some(AddressType::Standard),
         _ if byte == integrated => Some(AddressType::Integrated([0; 8])),
         _ if byte == subaddress => Some(AddressType::Subaddress),
-        _ if byte == featured => Some(AddressType::Featured(false, None, false)),
+        _ if byte == featured => {
+          Some(AddressType::Featured { subaddress: false, payment_id: None, guaranteed: false })
+        }
         _ => None,
       } {
         meta = Some(AddressMeta::new(network, kind));
@@ -200,7 +203,7 @@ impl<B: AddressBytes> ToString for Address<B> {
     let mut data = vec![self.meta.to_byte()];
     data.extend(self.spend.compress().to_bytes());
     data.extend(self.view.compress().to_bytes());
-    if let AddressType::Featured(subaddress, payment_id, guaranteed) = self.meta.kind {
+    if let AddressType::Featured { subaddress, payment_id, guaranteed } = self.meta.kind {
       // Technically should be a VarInt, yet we don't have enough features it's needed
       data.push(
         u8::from(subaddress) + (u8::from(payment_id.is_some()) << 1) + (u8::from(guaranteed) << 2),
@@ -233,7 +236,7 @@ impl<B: AddressBytes> Address<B> {
       .ok_or(AddressError::InvalidKey)?;
     let mut read = 65;
 
-    if matches!(meta.kind, AddressType::Featured(..)) {
+    if matches!(meta.kind, AddressType::Featured { .. }) {
       if raw[read] >= (2 << 3) {
         Err(AddressError::UnknownFeatures)?;
       }
@@ -242,8 +245,11 @@ impl<B: AddressBytes> Address<B> {
       let integrated = ((raw[read] >> 1) & 1) == 1;
       let guaranteed = ((raw[read] >> 2) & 1) == 1;
 
-      meta.kind =
-        AddressType::Featured(subaddress, Some([0; 8]).filter(|_| integrated), guaranteed);
+      meta.kind = AddressType::Featured {
+        subaddress,
+        payment_id: Some([0; 8]).filter(|_| integrated),
+        guaranteed,
+      };
       read += 1;
     }
 
@@ -258,7 +264,7 @@ impl<B: AddressBytes> Address<B> {
     if let AddressType::Integrated(ref mut id) = meta.kind {
       id.copy_from_slice(&raw[(read - 8) .. read]);
     }
-    if let AddressType::Featured(_, Some(ref mut id), _) = meta.kind {
+    if let AddressType::Featured { payment_id: Some(ref mut id), .. } = meta.kind {
       id.copy_from_slice(&raw[(read - 8) .. read]);
     }