Merge #216: add Address::is_liquid

17578d7 add Address::is_liquid (Riccardo Casatta)

Pull request description:

  User code can already compare against AddressParams, but it seems easier to find a method to check if the address is liquid. Even tough is less general because you can't discriminate between elements and liquid testnet, most of the time wallets are interested only in the mainnet or not discrimination.

ACKs for top commit:
  apoelstra:
    ACK 17578d7 successfully ran local tests; sure

Tree-SHA512: e2d47a1ed8880c3c54ddb9c8812f0ae0bc321f74747eb2b45c1078f1afe63a73c910849d2c75b8af6f41600163fd6b156d5ac72e9c263c2a99f3a0fcee217643

src/address.rs

@@ -223,6 +223,11 @@ impl Address {
         self.blinding_pubkey.is_some()
     }
 
+    /// Return if the address is for the Liquid network
+    pub fn is_liquid(&self) -> bool {
+        self.params == &AddressParams::LIQUID
+    }
+
     /// Creates a pay to (compressed) public key hash address from a public key
     /// This is the preferred non-witness type address
     #[inline]