Merge rust-bitcoin#4568: Remove conversion impl macro for Magic/Network

028a0d6 Remove conversion impl macro for `Magic`/`Network` (rustaceanrob)

Pull request description:

  Closes rust-bitcoin#4560 (or at least one way to close it)

  Handle the coversion of new networks directly in the `From` and `TryFrom` implementations, as new networks are added infrequently.

ACKs for top commit:
  tcharding:
    ACK 028a0d6
  apoelstra:
    ACK 028a0d6; successfully ran local tests

Tree-SHA512: 07b768e229305878849f23e54d3fb4940a736ce44122950e4f4bf68ddeb4f82f2d35020840e8176bd7b562726e46055650ba6de8559bae7559c881b64a437169

Author: apoelstra

bitcoin/src/p2p/mod.rs

@@ -251,40 +251,32 @@ impl FromStr for Magic {
     }
 }
 
-macro_rules! generate_network_magic_conversion {
-    ($(Network::$network:ident$((TestnetVersion::$testnet_version:ident))? => Magic::$magic:ident,)*) => {
-        impl From<Network> for Magic {
-            fn from(network: Network) -> Magic {
-                match network {
-                    $(
-                        Network::$network$((TestnetVersion::$testnet_version))? => Magic::$magic,
-                    )*
-                }
-            }
+impl From<Network> for Magic {
+    fn from(network: Network) -> Self {
+        match network {
+            Network::Bitcoin => Magic::BITCOIN,
+            Network::Testnet(TestnetVersion::V3) => Magic::TESTNET3,
+            Network::Testnet(TestnetVersion::V4) => Magic::TESTNET4,
+            Network::Signet => Magic::SIGNET,
+            Network::Regtest => Magic::REGTEST,
+            // Remember to add the `TryFrom<Magic>` for new networks
         }
+    }
+}
 
-        impl TryFrom<Magic> for Network {
-            type Error = UnknownMagicError;
+impl TryFrom<Magic> for Network {
+    type Error = UnknownMagicError;
 
-            fn try_from(magic: Magic) -> Result<Self, Self::Error> {
-                match magic {
-                    $(
-                        Magic::$magic => Ok(Network::$network$((TestnetVersion::$testnet_version))?),
-                    )*
-                    _ => Err(UnknownMagicError(magic)),
-                }
-            }
+    fn try_from(magic: Magic) -> Result<Self, Self::Error> {
+        match magic {
+            Magic::BITCOIN => Ok(Network::Bitcoin),
+            Magic::TESTNET3 => Ok(Network::Testnet(TestnetVersion::V3)),
+            Magic::TESTNET4 => Ok(Network::Testnet(TestnetVersion::V4)),
+            Magic::SIGNET => Ok(Network::Signet),
+            Magic::REGTEST => Ok(Network::Regtest),
+            _ => Err(UnknownMagicError(magic)),
         }
-    };
-}
-// Generate conversion functions for all known networks.
-// `Network -> Magic` and `Magic -> Network`
-generate_network_magic_conversion! {
-    Network::Bitcoin => Magic::BITCOIN,
-    Network::Testnet(TestnetVersion::V3) => Magic::TESTNET3,
-    Network::Testnet(TestnetVersion::V4) => Magic::TESTNET4,
-    Network::Signet => Magic::SIGNET,
-    Network::Regtest => Magic::REGTEST,
+    }
 }
 
 impl fmt::Display for Magic {