From ee7712de1ad9ce658e1a5b5c134d1529c62263a1 Mon Sep 17 00:00:00 2001
From: Paul Schaaf <paulsimonschaaf@gmail.com>
Date: Thu, 16 Dec 2021 23:43:33 +0100
Subject: [PATCH 1/2] lang: add default impls for AccountSerialize and
 AccountDeserialize

---
 lang/src/lib.rs  |  8 ++++++--
 spl/src/token.rs | 27 ++-------------------------
 2 files changed, 8 insertions(+), 27 deletions(-)

diff --git a/lang/src/lib.rs b/lang/src/lib.rs
index 4cda3d4247..6903667701 100644
--- a/lang/src/lib.rs
+++ b/lang/src/lib.rs
@@ -158,7 +158,9 @@ pub trait ToAccountInfo<'info> {
 /// [`#[account]`](./attr.account.html) attribute.
 pub trait AccountSerialize {
     /// Serializes the account data into `writer`.
-    fn try_serialize<W: Write>(&self, writer: &mut W) -> Result<(), ProgramError>;
+    fn try_serialize<W: Write>(&self, _writer: &mut W) -> Result<(), ProgramError> {
+        Ok(())
+    }
 }
 
 /// A data structure that can be deserialized and stored into account storage,
@@ -173,7 +175,9 @@ pub trait AccountDeserialize: Sized {
     /// For example, if the SPL token program were to implement this trait,
     /// it should be impossible to deserialize a `Mint` account into a token
     /// `Account`.
-    fn try_deserialize(buf: &mut &[u8]) -> Result<Self, ProgramError>;
+    fn try_deserialize(buf: &mut &[u8]) -> Result<Self, ProgramError> {
+        Self::try_deserialize_unchecked(buf)
+    }
 
     /// Deserializes account data without checking the account discriminator.
     /// This should only be used on account initialization, when the bytes of
diff --git a/spl/src/token.rs b/spl/src/token.rs
index 8655321cf0..be1b075287 100644
--- a/spl/src/token.rs
+++ b/spl/src/token.rs
@@ -5,7 +5,6 @@ use anchor_lang::solana_program::program_error::ProgramError;
 use anchor_lang::solana_program::program_pack::Pack;
 use anchor_lang::solana_program::pubkey::Pubkey;
 use anchor_lang::{Accounts, CpiContext};
-use std::io::Write;
 use std::ops::Deref;
 
 pub use spl_token::ID;
@@ -321,21 +320,12 @@ impl TokenAccount {
 }
 
 impl anchor_lang::AccountDeserialize for TokenAccount {
-    fn try_deserialize(buf: &mut &[u8]) -> Result<Self, ProgramError> {
-        TokenAccount::try_deserialize_unchecked(buf)
-    }
-
     fn try_deserialize_unchecked(buf: &mut &[u8]) -> Result<Self, ProgramError> {
         spl_token::state::Account::unpack(buf).map(TokenAccount)
     }
 }
 
-impl anchor_lang::AccountSerialize for TokenAccount {
-    fn try_serialize<W: Write>(&self, _writer: &mut W) -> Result<(), ProgramError> {
-        // no-op
-        Ok(())
-    }
-}
+impl anchor_lang::AccountSerialize for TokenAccount {}
 
 impl anchor_lang::Owner for TokenAccount {
     fn owner() -> Pubkey {
@@ -359,21 +349,12 @@ impl Mint {
 }
 
 impl anchor_lang::AccountDeserialize for Mint {
-    fn try_deserialize(buf: &mut &[u8]) -> Result<Self, ProgramError> {
-        Mint::try_deserialize_unchecked(buf)
-    }
-
     fn try_deserialize_unchecked(buf: &mut &[u8]) -> Result<Self, ProgramError> {
         spl_token::state::Mint::unpack(buf).map(Mint)
     }
 }
 
-impl anchor_lang::AccountSerialize for Mint {
-    fn try_serialize<W: Write>(&self, _writer: &mut W) -> Result<(), ProgramError> {
-        // no-op
-        Ok(())
-    }
-}
+impl anchor_lang::AccountSerialize for Mint {}
 
 impl anchor_lang::Owner for Mint {
     fn owner() -> Pubkey {
@@ -393,10 +374,6 @@ impl Deref for Mint {
 pub struct Token;
 
 impl anchor_lang::AccountDeserialize for Token {
-    fn try_deserialize(buf: &mut &[u8]) -> Result<Self, ProgramError> {
-        Token::try_deserialize_unchecked(buf)
-    }
-
     fn try_deserialize_unchecked(_buf: &mut &[u8]) -> Result<Self, ProgramError> {
         Ok(Token)
     }

From 141a717a2d116e08847be0d89f4f46b6689a82f3 Mon Sep 17 00:00:00 2001
From: Paul Schaaf <paulsimonschaaf@gmail.com>
Date: Fri, 17 Dec 2021 00:07:38 +0100
Subject: [PATCH 2/2] docs: update changelog

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 007a68e42f..48f9ab139a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@ incremented for features.
 
 * lang: Add `programdata_address: Option<Pubkey>` field to `Program` account. Will be populated if account is a program owned by the upgradable bpf loader ([#1125](https://github.com/project-serum/anchor/pull/1125))
 * lang,ts,ci,cli,docs: update solana toolchain to version 1.8.5([#1133](https://github.com/project-serum/anchor/pull/1133))
+* lang: Account wrappers for non-Anchor programs no longer have to implement the `serialize` function because it has a default impl now. Similarly, they no longer have to implement `try_deserialize` which now delegates to `try_deserialize_unchecked` by default([#1156](https://github.com/project-serum/anchor/pull/1156)).
 
 ## [0.19.0] - 2021-12-08