use-ink
diff --git a/‎.config/cargo_spellcheck.dic
+2 b/‎.config/cargo_spellcheck.dic
+2
diff --git a/‎.github/workflows/examples.yml
+10-5 b/‎.github/workflows/examples.yml
+10-5
diff --git a/‎.gitlab-ci.yml
+8-8 b/‎.gitlab-ci.yml
+8-8
diff --git a/‎crates/engine/src/ext.rs
+8-5 b/‎crates/engine/src/ext.rs
+8-5
diff --git a/‎crates/env/src/api.rs
+26-17 b/‎crates/env/src/api.rs
+26-17
diff --git a/‎crates/env/src/backend.rs
+21-12 b/‎crates/env/src/backend.rs
+21-12
diff --git a/‎crates/env/src/engine/off_chain/impls.rs
+22-13 b/‎crates/env/src/engine/off_chain/impls.rs
+22-13
@@ -38,6 +38,7 @@ defragmentation
 deploy
 dereferencing
 deserialize/S
+deserialization
 dispatchable/S
 encodable
 evaluable
@@ -106,3 +107,4 @@ natively
 payability
 unpayable
 initializer
+storable
@@ -26,15 +26,20 @@ jobs:
 # Once this is resolved we should re-enable building the examples on windows
 #          - windows-latest
         toolchain:
-          - nightly
+          - stable
         job:
           - build
           - test
     runs-on: ${{ matrix.platform }}
     env:
-      UPGRADEABLE_CONTRACTS:    "forward-calls delegate-calls"
+      UPGRADEABLE_CONTRACTS:    "forward-calls set-code-hash"
       DELEGATOR_SUBCONTRACTS:   "accumulator adder subber"
       RUST_BACKTRACE:           full
+      # We need to enable `RUSTC_BOOTSTRAP` so that the nightly ink!
+      # features still work on stable. This is done automatically by
+      # `cargo-contract`, but in our CI here we also use e.g.
+      # `cargo check` directly.
+      RUSTC_BOOTSTRAP:          "1"
     steps:
 
       - uses: actions/setup-node@v3
@@ -90,12 +95,12 @@ jobs:
                echo "Processing delegator contract: $contract";
                cargo contract ${{ matrix.job }} --verbose --manifest-path examples/delegator/${contract}/Cargo.toml;
            }
-           $upgradeable_contracts = "forward-calls","delegate-calls"
+           $upgradeable_contracts = "forward-calls","set-code-hash"
            foreach ($contract in $upgradeable_contracts) {
                echo "Processing upgradeable contract: $contract";
                cargo contract ${{ matrix.job }} --verbose --manifest-path examples/upgradeable-contracts/${contract}/Cargo.toml;
            }
-           cargo contract ${{ matrix.job }} --verbose --manifest-path examples/upgradeable-contracts/delegate-calls/upgradeable-flipper/Cargo.toml;
+           cargo contract ${{ matrix.job }} --verbose --manifest-path examples/upgradeable-contracts/set-code-hash/updated-incrementer/Cargo.toml;
            foreach ($example in Get-ChildItem  -Directory "examples\*") {
                if ($example -Match 'upgradeable-contracts') { continue }
                echo "Processing example: $example";
@@ -114,7 +119,7 @@ jobs:
                 echo "Processing upgradeable contract: $contract";
                 cargo contract ${{ matrix.job }} --verbose --manifest-path=examples/upgradeable-contracts/$contract/Cargo.toml;
            done
-           cargo contract ${{ matrix.job }} --verbose --manifest-path=examples/upgradeable-contracts/delegate-calls/upgradeable-flipper/Cargo.toml;
+           cargo contract ${{ matrix.job }} --verbose --manifest-path=examples/upgradeable-contracts/set-code-hash/updated-incrementer/Cargo.toml;
            for example in examples/*/; do
                if [ "$example" = "examples/upgradeable-contracts/" ]; then continue; fi;
                echo "Processing example: $example";
 
@@ -33,7 +33,7 @@ variables:
   ALSO_WASM_CRATES:                "env storage storage/derive allocator prelude primitives lang lang/macro lang/ir"
   ALL_CRATES:                      "${PURELY_STD_CRATES} ${ALSO_WASM_CRATES}"
   DELEGATOR_SUBCONTRACTS:          "accumulator adder subber"
-  UPGRADEABLE_CONTRACTS:           "forward-calls delegate-calls"
+  UPGRADEABLE_CONTRACTS:           "forward-calls set-code-hash"
   # We need to enable `RUSTC_BOOTSTRAP` so that the nightly ink!
   # features still work on stable. This is done automatically by
   # `cargo-contract`, but in our CI here we also use e.g.
@@ -127,7 +127,7 @@ examples-fmt:
     - for contract in ${UPGRADEABLE_CONTRACTS}; do
         cargo +nightly fmt --verbose --manifest-path ./examples/upgradeable-contracts/${contract}/Cargo.toml -- --check;
       done
-    - cargo +nightly fmt --verbose --manifest-path ./examples/upgradeable-contracts/delegate-calls/upgradeable-flipper/Cargo.toml -- --check
+    - cargo +nightly fmt --verbose --manifest-path ./examples/upgradeable-contracts/set-code-hash/updated-incrementer/Cargo.toml -- --check
   allow_failure:                   true
 
 clippy-std:
@@ -164,7 +164,7 @@ examples-clippy-std:
     - for contract in ${UPGRADEABLE_CONTRACTS}; do
         cargo +nightly clippy --verbose --all-targets --manifest-path ./examples/upgradeable-contracts/${contract}/Cargo.toml -- -D warnings;
       done
-    - cargo +nightly clippy --verbose --all-targets --manifest-path ./examples/upgradeable-contracts/delegate-calls/upgradeable-flipper/Cargo.toml -- -D warnings;
+    - cargo +nightly clippy --verbose --all-targets --manifest-path ./examples/upgradeable-contracts/set-code-hash/updated-incrementer/Cargo.toml -- -D warnings;
   allow_failure:                   true
 
 examples-clippy-wasm:
@@ -182,7 +182,7 @@ examples-clippy-wasm:
     - for contract in ${UPGRADEABLE_CONTRACTS}; do
         cargo +nightly clippy --verbose --manifest-path ./examples/upgradeable-contracts/${contract}/Cargo.toml --no-default-features --target wasm32-unknown-unknown -- -D warnings;
       done
-    - cargo +nightly clippy --verbose --manifest-path ./examples/upgradeable-contracts/delegate-calls/upgradeable-flipper/Cargo.toml --no-default-features --target wasm32-unknown-unknown -- -D warnings;
+    - cargo +nightly clippy --verbose --manifest-path ./examples/upgradeable-contracts/set-code-hash/updated-incrementer/Cargo.toml --no-default-features --target wasm32-unknown-unknown -- -D warnings;
   allow_failure:                   true
 
 
@@ -281,7 +281,7 @@ docs:
     - cargo doc --no-deps --all-features
         -p scale-info -p ink_metadata
         -p ink_env -p ink_storage -p ink_storage_derive
-        -p ink_primitives -p ink_prelude
+        -p ink_primitives -p ink_prelude -p ink_primitives_derive
         -p ink_lang -p ink_lang_macro -p ink_lang_ir -p ink_lang_codegen
     - mv ${CARGO_TARGET_DIR}/doc ./crate-docs
     # FIXME: remove me after CI image gets nonroot
@@ -352,7 +352,7 @@ examples-test:
     - for contract in ${UPGRADEABLE_CONTRACTS}; do
         cargo test --verbose --manifest-path ./examples/upgradeable-contracts/${contract}/Cargo.toml;
       done
-    - cargo test --verbose --manifest-path ./examples/upgradeable-contracts/delegate-calls/upgradeable-flipper/Cargo.toml;
+    - cargo test --verbose --manifest-path ./examples/upgradeable-contracts/set-code-hash/updated-incrementer/Cargo.toml;
 
 examples-contract-build:
   stage:                           examples
@@ -372,7 +372,7 @@ examples-contract-build:
     - for contract in ${UPGRADEABLE_CONTRACTS}; do
         cargo +stable contract build --manifest-path ./examples/upgradeable-contracts/${contract}/Cargo.toml;
       done
-    - cargo +stable contract build --manifest-path ./examples/upgradeable-contracts/delegate-calls/upgradeable-flipper/Cargo.toml
+    - cargo +stable contract build --manifest-path ./examples/upgradeable-contracts/set-code-hash/updated-incrementer/Cargo.toml
 
 examples-docs:
   stage:                           examples
@@ -395,7 +395,7 @@ examples-docs:
     - for contract in ${UPGRADEABLE_CONTRACTS}; do
         cargo doc --manifest-path ./examples/upgradeable-contracts/${contract}/Cargo.toml --document-private-items --verbose --no-deps;
       done
-    - cargo doc --manifest-path ./examples/upgradeable-contracts/delegate-calls/upgradeable-flipper/Cargo.toml --document-private-items --verbose --no-deps
+    - cargo doc --manifest-path ./examples/upgradeable-contracts/set-code-hash/updated-incrementer/Cargo.toml --document-private-items --verbose --no-deps
 
 
 #### stage:                        ink-waterfall
 
@@ -229,7 +229,7 @@ impl Engine {
 
     /// Writes the encoded value into the storage at the given key.
     /// Returns the size of the previously stored value at the key if any.
-    pub fn set_storage(&mut self, key: &[u8; 32], encoded_value: &[u8]) -> Option<u32> {
+    pub fn set_storage(&mut self, key: &[u8], encoded_value: &[u8]) -> Option<u32> {
         let callee = self.get_callee();
         let account_id = AccountId::from_bytes(&callee[..]);
 
@@ -243,7 +243,7 @@ impl Engine {
     }
 
     /// Returns the decoded contract storage at the key if any.
-    pub fn get_storage(&mut self, key: &[u8; 32], output: &mut &mut [u8]) -> Result {
+    pub fn get_storage(&mut self, key: &[u8], output: &mut &mut [u8]) -> Result {
         let callee = self.get_callee();
         let account_id = AccountId::from_bytes(&callee[..]);
 
@@ -258,7 +258,7 @@ impl Engine {
     }
 
     /// Returns the size of the value stored in the contract storage at the key if any.
-    pub fn contains_storage(&mut self, key: &[u8; 32]) -> Option<u32> {
+    pub fn contains_storage(&mut self, key: &[u8]) -> Option<u32> {
         let callee = self.get_callee();
         let account_id = AccountId::from_bytes(&callee[..]);
 
@@ -269,14 +269,17 @@ impl Engine {
     }
 
     /// Removes the storage entries at the given key.
-    pub fn clear_storage(&mut self, key: &[u8; 32]) {
+    /// Returns the size of the previously stored value at the key if any.
+    pub fn clear_storage(&mut self, key: &[u8]) -> Option<u32> {
         let callee = self.get_callee();
         let account_id = AccountId::from_bytes(&callee[..]);
         self.debug_info.inc_writes(account_id.clone());
         let _ = self
             .debug_info
             .remove_cell_for_account(account_id, key.to_vec());
-        let _ = self.database.remove_contract_storage(&callee, key);
+        self.database
+            .remove_contract_storage(&callee, key)
+            .map(|val| val.len() as u32)
     }
 
     /// Remove the calling account and transfer remaining balance.
 
@@ -39,7 +39,7 @@ use crate::{
     Environment,
     Result,
 };
-use ink_primitives::Key;
+use ink_primitives::traits::Storable;
 
 /// Returns the address of the caller of the executed contract.
 ///
@@ -183,49 +183,58 @@ where
     })
 }
 
-/// Writes the value to the contract storage under the given key and returns
-/// the size of pre-existing value at the specified key if any.
+/// Writes the value to the contract storage under the given storage key and returns the size
+/// of pre-existing value if any.
 ///
 /// # Panics
 ///
 /// - If the encode length of value exceeds the configured maximum value length of a storage entry.
-pub fn set_contract_storage<V>(key: &Key, value: &V) -> Option<u32>
+pub fn set_contract_storage<K, V>(key: &K, value: &V) -> Option<u32>
 where
-    V: scale::Encode,
+    K: scale::Encode,
+    V: Storable,
 {
     <EnvInstance as OnInstance>::on_instance(|instance| {
-        EnvBackend::set_contract_storage::<V>(instance, key, value)
+        EnvBackend::set_contract_storage::<K, V>(instance, key, value)
     })
 }
 
-/// Returns the value stored under the given key in the contract's storage if any.
+/// Returns the value stored under the given storage key in the contract's storage if any.
 ///
 /// # Errors
 ///
 /// - If the decoding of the typed value failed (`KeyNotFound`)
-pub fn get_contract_storage<R>(key: &Key) -> Result<Option<R>>
+pub fn get_contract_storage<K, R>(key: &K) -> Result<Option<R>>
 where
-    R: scale::Decode,
+    K: scale::Encode,
+    R: Storable,
 {
     <EnvInstance as OnInstance>::on_instance(|instance| {
-        EnvBackend::get_contract_storage::<R>(instance, key)
+        EnvBackend::get_contract_storage::<K, R>(instance, key)
     })
 }
 
-/// Checks whether there is a value stored under the given key in
-/// the contract's storage.
+/// Checks whether there is a value stored under the given storage key in the contract's storage.
 ///
 /// If a value is stored under the specified key, the size of the value is returned.
-pub fn contract_storage_contains(key: &Key) -> Option<u32> {
+pub fn contains_contract_storage<K>(key: &K) -> Option<u32>
+where
+    K: scale::Encode,
+{
     <EnvInstance as OnInstance>::on_instance(|instance| {
-        EnvBackend::contract_storage_contains(instance, key)
+        EnvBackend::contains_contract_storage::<K>(instance, key)
     })
 }
 
-/// Clears the contract's storage key entry.
-pub fn clear_contract_storage(key: &Key) {
+/// Clears the contract's storage entry under the given storage key.
+///
+/// If a value was stored under the specified storage key, the size of the value is returned.
+pub fn clear_contract_storage<K>(key: &K) -> Option<u32>
+where
+    K: scale::Encode,
+{
     <EnvInstance as OnInstance>::on_instance(|instance| {
-        EnvBackend::clear_contract_storage(instance, key)
+        EnvBackend::clear_contract_storage::<K>(instance, key)
     })
 }
 
 
@@ -27,7 +27,7 @@ use crate::{
     Environment,
     Result,
 };
-use ink_primitives::Key;
+use ink_primitives::traits::Storable;
 
 /// The flags to indicate further information about the end of a contract execution.
 #[derive(Default)]
@@ -162,26 +162,35 @@ impl CallFlags {
 
 /// Environmental contract functionality that does not require `Environment`.
 pub trait EnvBackend {
-    /// Writes the value to the contract storage under the given key and returns
-    /// the size of the pre-existing value at the specified key if any.
-    fn set_contract_storage<V>(&mut self, key: &Key, value: &V) -> Option<u32>
+    /// Writes the value to the contract storage under the given storage key.
+    ///
+    /// Returns the size of the pre-existing value at the specified key if any.
+    fn set_contract_storage<K, V>(&mut self, key: &K, value: &V) -> Option<u32>
     where
-        V: scale::Encode;
+        K: scale::Encode,
+        V: Storable;
 
-    /// Returns the value stored under the given key in the contract's storage if any.
+    /// Returns the value stored under the given storage key in the contract's storage if any.
     ///
     /// # Errors
     ///
     /// - If the decoding of the typed value failed
-    fn get_contract_storage<R>(&mut self, key: &Key) -> Result<Option<R>>
+    fn get_contract_storage<K, R>(&mut self, key: &K) -> Result<Option<R>>
     where
-        R: scale::Decode;
+        K: scale::Encode,
+        R: Storable;
 
-    /// Returns the size of a value stored under the specified key is returned if any.
-    fn contract_storage_contains(&mut self, key: &Key) -> Option<u32>;
+    /// Returns the size of a value stored under the given storage key is returned if any.
+    fn contains_contract_storage<K>(&mut self, key: &K) -> Option<u32>
+    where
+        K: scale::Encode;
 
-    /// Clears the contract's storage key entry.
-    fn clear_contract_storage(&mut self, key: &Key);
+    /// Clears the contract's storage key entry under the given storage key.
+    ///
+    /// Returns the size of the previously stored value at the specified key if any.
+    fn clear_contract_storage<K>(&mut self, key: &K) -> Option<u32>
+    where
+        K: scale::Encode;
 
     /// Returns the execution input to the executed contract and decodes it as `T`.
     ///
 
@@ -44,7 +44,7 @@ use ink_engine::{
     ext,
     ext::Engine,
 };
-use ink_primitives::Key;
+use ink_primitives::traits::Storable;
 
 /// The capacity of the static buffer.
 /// This is the same size as the ink! on-chain environment. We chose to use the same size
@@ -184,34 +184,43 @@ impl EnvInstance {
 }
 
 impl EnvBackend for EnvInstance {
-    fn set_contract_storage<V>(&mut self, key: &Key, value: &V) -> Option<u32>
+    fn set_contract_storage<K, V>(&mut self, key: &K, value: &V) -> Option<u32>
     where
-        V: scale::Encode,
+        K: scale::Encode,
+        V: Storable,
     {
-        let v = scale::Encode::encode(value);
-        self.engine.set_storage(key.as_ref(), &v[..])
+        let mut v = vec![];
+        Storable::encode(value, &mut v);
+        self.engine.set_storage(&key.encode(), &v[..])
     }
 
-    fn get_contract_storage<R>(&mut self, key: &Key) -> Result<Option<R>>
+    fn get_contract_storage<K, R>(&mut self, key: &K) -> Result<Option<R>>
     where
-        R: scale::Decode,
+        K: scale::Encode,
+        R: Storable,
     {
         let mut output: [u8; 9600] = [0; 9600];
-        match self.engine.get_storage(key.as_ref(), &mut &mut output[..]) {
+        match self.engine.get_storage(&key.encode(), &mut &mut output[..]) {
             Ok(_) => (),
             Err(ext::Error::KeyNotFound) => return Ok(None),
             Err(_) => panic!("encountered unexpected error"),
         }
-        let decoded = scale::Decode::decode(&mut &output[..])?;
+        let decoded = Storable::decode(&mut &output[..])?;
         Ok(Some(decoded))
     }
 
-    fn contract_storage_contains(&mut self, key: &Key) -> Option<u32> {
-        self.engine.contains_storage(key.as_ref())
+    fn contains_contract_storage<K>(&mut self, key: &K) -> Option<u32>
+    where
+        K: scale::Encode,
+    {
+        self.engine.contains_storage(&key.encode())
     }
 
-    fn clear_contract_storage(&mut self, key: &Key) {
-        self.engine.clear_storage(key.as_ref())
+    fn clear_contract_storage<K>(&mut self, key: &K) -> Option<u32>
+    where
+        K: scale::Encode,
+    {
+        self.engine.clear_storage(&key.encode())
     }
 
     fn decode_input<T>(&mut self) -> Result<T>