solana: Add SPL Multisig wrapper for InterfaceAccount

Author: nvsriram

solana/programs/example-native-token-transfers/src/lib.rs

@@ -20,6 +20,7 @@ pub mod messages;
 pub mod peer;
 pub mod queue;
 pub mod registered_transceiver;
+pub mod spl_multisig;
 pub mod transceivers;
 pub mod transfer;
 

solana/programs/example-native-token-transfers/src/spl_multisig.rs

@@ -0,0 +1,37 @@
+use anchor_lang::{prelude::*, solana_program::program_pack::Pack, Ids, Owners};
+use anchor_spl::token_interface::TokenInterface;
+use std::ops::Deref;
+
+/// Anchor does not have a SPL Multisig wrapper as a part of the token interface:
+/// https://docs.rs/anchor-spl/0.29.0/src/anchor_spl/token_interface.rs.html
+/// Thus, we have to write our own wrapper to use with `InterfaceAccount`
+
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct SplMultisig(spl_token_2022::state::Multisig);
+
+impl AccountDeserialize for SplMultisig {
+    fn try_deserialize_unchecked(buf: &mut &[u8]) -> anchor_lang::Result<Self> {
+        spl_token_2022::state::Multisig::unpack(buf)
+            .map(|t| SplMultisig(t))
+            .map_err(Into::into)
+    }
+}
+
+impl AccountSerialize for SplMultisig {}
+
+impl Owners for SplMultisig {
+    fn owners() -> &'static [Pubkey] {
+        TokenInterface::ids()
+    }
+}
+
+impl Deref for SplMultisig {
+    type Target = spl_token_2022::state::Multisig;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[cfg(feature = "idl-build")]
+impl anchor_lang::IdlBuild for SplMultisig {}