diff --git a/substrate/Cargo.lock b/substrate/Cargo.lock
index 18f18b63d1..f3fc76d630 100644
--- a/substrate/Cargo.lock
+++ b/substrate/Cargo.lock
@@ -211,11 +211,6 @@ name = "bitmask"
 version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "bitvec"
-version = "0.11.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "bitvec"
 version = "0.14.0"
@@ -865,7 +860,7 @@ dependencies = [
  "hashmap_core 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -917,7 +912,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "fork-tree"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1359,7 +1354,7 @@ name = "impl-codec"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2315,7 +2310,7 @@ dependencies = [
  "node-primitives 2.0.0",
  "node-rpc 2.0.0",
  "node-runtime 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -2359,7 +2354,7 @@ dependencies = [
  "node-primitives 2.0.0",
  "node-runtime 2.0.0",
  "node-testing 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
  "srml-balances 2.0.0",
@@ -2384,7 +2379,7 @@ dependencies = [
 name = "node-primitives"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "pretty_assertions 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
@@ -2407,7 +2402,7 @@ dependencies = [
  "node-primitives 2.0.0",
  "node-runtime 2.0.0",
  "node-testing 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
@@ -2435,7 +2430,7 @@ version = "2.0.0"
 dependencies = [
  "integer-sqrt 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "node-primitives 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hex 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2485,7 +2480,7 @@ dependencies = [
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "node-template-runtime 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "substrate-basic-authorship 2.0.0",
@@ -2510,7 +2505,7 @@ dependencies = [
 name = "node-template-runtime"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -2541,7 +2536,7 @@ dependencies = [
  "node-executor 2.0.0",
  "node-primitives 2.0.0",
  "node-runtime 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
  "srml-balances 2.0.0",
@@ -2707,16 +2702,6 @@ name = "parity-bytes"
 version = "0.1.0"
 source = "git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d#b0317f649ab2c665b7987b8475878fc4d2e1f81d"
 
-[[package]]
-name = "parity-codec"
-version = "4.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "arrayvec 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "bitvec 0.11.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "parity-multiaddr"
 version = "0.5.0"
@@ -2750,7 +2735,7 @@ dependencies = [
 
 [[package]]
 name = "parity-scale-codec"
-version = "1.0.4"
+version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "arrayvec 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2758,7 +2743,6 @@ dependencies = [
  "byte-slice-cast 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-scale-codec-derive 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
- "vecarray 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -3316,7 +3300,7 @@ dependencies = [
  "error-chain 0.12.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -3708,7 +3692,7 @@ version = "2.0.0"
 dependencies = [
  "blake2-rfc 0.2.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "criterion 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro-crate 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3730,7 +3714,7 @@ dependencies = [
  "environmental 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "hash-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "libsecp256k1 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-std 2.0.0",
  "substrate-offchain 2.0.0",
@@ -3747,7 +3731,7 @@ dependencies = [
  "integer-sqrt 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "paste 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "primitive-types 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3764,7 +3748,7 @@ name = "sr-sandbox"
 version = "2.0.0"
 dependencies = [
  "assert_matches 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-std 2.0.0",
  "substrate-primitives 2.0.0",
@@ -3776,7 +3760,7 @@ dependencies = [
 name = "sr-staking-primitives"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
 ]
@@ -3793,7 +3777,7 @@ name = "sr-version"
 version = "2.0.0"
 dependencies = [
  "impl-serde 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
@@ -3803,7 +3787,7 @@ dependencies = [
 name = "srml-assets"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -3818,7 +3802,7 @@ name = "srml-aura"
 version = "2.0.0"
 dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3838,7 +3822,7 @@ dependencies = [
 name = "srml-authority-discovery"
 version = "0.1.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -3855,7 +3839,7 @@ dependencies = [
 name = "srml-authorship"
 version = "0.1.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
@@ -3871,7 +3855,7 @@ version = "2.0.0"
 dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3891,7 +3875,7 @@ dependencies = [
 name = "srml-balances"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3908,7 +3892,7 @@ name = "srml-collective"
 version = "2.0.0"
 dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3927,7 +3911,7 @@ dependencies = [
  "assert_matches 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-wasm 0.31.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "pwasm-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3948,7 +3932,7 @@ dependencies = [
 name = "srml-democracy"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3965,7 +3949,7 @@ name = "srml-elections"
 version = "2.0.0"
 dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -3981,7 +3965,7 @@ dependencies = [
 name = "srml-example"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -3997,7 +3981,7 @@ name = "srml-executive"
 version = "2.0.0"
 dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4013,7 +3997,7 @@ dependencies = [
 name = "srml-finality-tracker"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4028,7 +4012,7 @@ dependencies = [
 name = "srml-generic-asset"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4042,7 +4026,7 @@ dependencies = [
 name = "srml-grandpa"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4060,7 +4044,7 @@ dependencies = [
 name = "srml-im-online"
 version = "0.1.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4077,7 +4061,7 @@ dependencies = [
 name = "srml-indices"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "ref_thread_local 0.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4094,7 +4078,7 @@ dependencies = [
 name = "srml-membership"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4108,7 +4092,7 @@ dependencies = [
 name = "srml-metadata"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-std 2.0.0",
  "substrate-primitives 2.0.0",
@@ -4118,7 +4102,7 @@ dependencies = [
 name = "srml-offences"
 version = "1.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4134,7 +4118,7 @@ dependencies = [
 name = "srml-scored-pool"
 version = "1.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4150,7 +4134,7 @@ name = "srml-session"
 version = "2.0.0"
 dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -4169,7 +4153,7 @@ dependencies = [
 name = "srml-staking"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4191,7 +4175,7 @@ dependencies = [
 name = "srml-sudo"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4208,7 +4192,7 @@ version = "2.0.0"
 dependencies = [
  "bitmask 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "once_cell 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "paste 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "pretty_assertions 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4257,7 +4241,7 @@ dependencies = [
 name = "srml-support-test"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "pretty_assertions 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -4272,7 +4256,7 @@ name = "srml-system"
 version = "2.0.0"
 dependencies = [
  "criterion 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "safe-mix 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -4287,7 +4271,7 @@ dependencies = [
 name = "srml-timestamp"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4302,7 +4286,7 @@ dependencies = [
 name = "srml-treasury"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4394,7 +4378,7 @@ dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "node-primitives 2.0.0",
  "node-runtime 2.0.0",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hex 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
@@ -4419,7 +4403,7 @@ dependencies = [
 name = "substrate-application-crypto"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4432,7 +4416,7 @@ dependencies = [
 name = "substrate-authority-discovery-primitives"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
  "substrate-client 2.0.0",
@@ -4444,7 +4428,7 @@ version = "2.0.0"
 dependencies = [
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
  "substrate-consensus-common 2.0.0",
@@ -4514,7 +4498,7 @@ dependencies = [
  "kvdb 0.1.0 (git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d)",
  "kvdb-memorydb 0.1.0 (git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-api-macros 2.0.0",
  "sr-primitives 2.0.0",
@@ -4543,7 +4527,7 @@ dependencies = [
  "kvdb-rocksdb 0.1.4 (git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d)",
  "linked-hash-map 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
@@ -4566,7 +4550,7 @@ dependencies = [
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-timer 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -4595,7 +4579,7 @@ dependencies = [
 name = "substrate-consensus-aura-primitives"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
  "substrate-application-crypto 2.0.0",
@@ -4616,7 +4600,7 @@ dependencies = [
  "num-bigint 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-rational 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "schnorrkel 0.8.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4648,7 +4632,7 @@ dependencies = [
 name = "substrate-consensus-babe-primitives"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "schnorrkel 0.8.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
@@ -4666,7 +4650,7 @@ dependencies = [
  "futures-timer 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libp2p 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
@@ -4684,7 +4668,7 @@ dependencies = [
  "exit-future 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rhododendron 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -4707,7 +4691,7 @@ dependencies = [
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-timer 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
@@ -4742,7 +4726,7 @@ dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libsecp256k1 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-wasm 0.31.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
@@ -4770,7 +4754,7 @@ dependencies = [
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4797,7 +4781,7 @@ dependencies = [
 name = "substrate-finality-grandpa-primitives"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
@@ -4809,7 +4793,7 @@ dependencies = [
 name = "substrate-inherents"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "sr-std 2.0.0",
@@ -4861,7 +4845,7 @@ dependencies = [
  "linked_hash_set 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "lru-cache 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "quickcheck 0.8.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4902,7 +4886,7 @@ dependencies = [
  "hyper 0.12.33 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper-tls 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
@@ -4963,7 +4947,7 @@ dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "pretty_assertions 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "primitive-types 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4995,7 +4979,7 @@ dependencies = [
  "jsonrpc-derive 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "jsonrpc-pubsub 13.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hex 2.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -5061,7 +5045,7 @@ dependencies = [
  "node-primitives 2.0.0",
  "node-runtime 2.0.0",
  "parity-multiaddr 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -5126,7 +5110,7 @@ version = "2.0.0"
 dependencies = [
  "env_logger 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "substrate-primitives 2.0.0",
 ]
@@ -5139,7 +5123,7 @@ dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "substrate-panic-handler 2.0.0",
  "substrate-primitives 2.0.0",
@@ -5175,7 +5159,7 @@ version = "2.0.0"
 dependencies = [
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "hash-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
  "substrate-client-db 2.0.0",
@@ -5193,7 +5177,7 @@ dependencies = [
  "cfg-if 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "memory-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-io 2.0.0",
  "sr-primitives 2.0.0",
@@ -5225,7 +5209,7 @@ dependencies = [
 name = "substrate-test-runtime-client"
 version = "2.0.0"
 dependencies = [
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-primitives 2.0.0",
  "substrate-test-client 2.0.0",
@@ -5241,7 +5225,7 @@ dependencies = [
  "env_logger 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-preview 0.3.0-alpha.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
@@ -5255,7 +5239,7 @@ version = "2.0.0"
 dependencies = [
  "derive_more 0.14.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-client 2.0.0",
@@ -5274,7 +5258,7 @@ dependencies = [
  "hex-literal 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "keccak-hasher 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "memory-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-std 2.0.0",
  "substrate-primitives 2.0.0",
  "trie-bench 0.16.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -5675,7 +5659,7 @@ name = "transaction-factory"
 version = "0.0.1"
 dependencies = [
  "log 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-primitives 2.0.0",
  "substrate-cli 2.0.0",
  "substrate-client 2.0.0",
@@ -5693,7 +5677,7 @@ dependencies = [
  "hash-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "keccak-hasher 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "memory-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "trie-db 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "trie-root 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "trie-standardmap 0.15.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -5885,16 +5869,6 @@ name = "vec_map"
 version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "vecarray"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "parity-codec 4.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.97 (registry+https://github.com/rust-lang/crates.io-index)",
- "typenum 1.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "vergen"
 version = "3.0.4"
@@ -6287,7 +6261,6 @@ dependencies = [
 "checksum bindgen 0.47.3 (registry+https://github.com/rust-lang/crates.io-index)" = "df683a55b54b41d5ea8ebfaebb5aa7e6b84e3f3006a78f010dadc9ca88469260"
 "checksum bitflags 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3d155346769a6855b86399e9bc3814ab343cd3d62c7e985113d46a0ec3c281fd"
 "checksum bitmask 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5da9b3d9f6f585199287a473f4f8dfab6566cf827d15c00c219f53c645687ead"
-"checksum bitvec 0.11.3 (registry+https://github.com/rust-lang/crates.io-index)" = "b67491e1cc6f37da6c4415cd743cb8d2e2c65388acc91ca3094a054cbf3cbd0c"
 "checksum bitvec 0.14.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9633b74910e1870f50f5af189b08487195cdb83c0e27a71d6f64d5e09dd0538b"
 "checksum blake2 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "91721a6330935673395a0607df4d49a9cb90ae12d259f1b3e0a3f6e1d486872e"
 "checksum blake2-rfc 0.2.18 (registry+https://github.com/rust-lang/crates.io-index)" = "5d6d530bdd2d52966a6d03b7a964add7ae1a288d25214066fd4b600f0f796400"
@@ -6515,10 +6488,9 @@ dependencies = [
 "checksum owning_ref 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "cdf84f41639e037b484f93433aa3897863b561ed65c6e59c7073d7c561710f37"
 "checksum owning_ref 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "49a4b8ea2179e6a2e27411d3bca09ca6dd630821cf6894c6c7c8467a8ee7ef13"
 "checksum parity-bytes 0.1.0 (git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d)" = "<none>"
-"checksum parity-codec 4.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2900f06356edf90de66a2922db622b36178dca71e85625eae58d0d9cc6cff2ac"
 "checksum parity-multiaddr 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "045b3c7af871285146300da35b1932bb6e4639b66c7c98e85d06a32cbc4e8fa7"
 "checksum parity-multihash 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "df3a17dc27848fd99e4f87eb0f8c9baba6ede0a6d555400c850ca45254ef4ce3"
-"checksum parity-scale-codec 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "00fd14ff806ad82cea9a8f909bb116443d92efda7c9acd4502690af64741ad81"
+"checksum parity-scale-codec 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "65582b5c02128a4b0fa60fb3e070216e9c84be3e4a8f1b74bc37e15a25e58daf"
 "checksum parity-scale-codec-derive 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a81f3cd93ed368a8e41c4e79538e99ca6e8f536096de23e3a0bc3e782093ce28"
 "checksum parity-send-wrapper 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "aa9777aa91b8ad9dd5aaa04a9b6bcb02c7f1deb952fca5a66034d5e63afc5c6f"
 "checksum parity-util-mem 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2005637ccf93dbb60c85081ccaaf3f945f573da48dcc79f27f9646caa3ec1dc"
@@ -6697,7 +6669,6 @@ dependencies = [
 "checksum utf8-ranges 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "9d50aa7650df78abf942826607c62468ce18d9019673d4a2ebe1865dbb96ffde"
 "checksum vcpkg 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "33dd455d0f96e90a75803cfeb7f948768c08d70a6de9a8d2362461935698bf95"
 "checksum vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
-"checksum vecarray 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "d4d68a73b7d7d950c6558b6009e9fba229fb67562bda9fd02198f614f4ecf83f"
 "checksum vergen 3.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "6aba5e34f93dc7051dfad05b98a18e9156f27e7b431fe1d2398cb6061c0a1dba"
 "checksum version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "914b1a6776c4c929a602fafd8bc742e06365d4bcbe48c30f9cca5824f70dc9dd"
 "checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
diff --git a/substrate/node/runtime/src/lib.rs b/substrate/node/runtime/src/lib.rs
index a487a4a89e..5260a3ef43 100644
--- a/substrate/node/runtime/src/lib.rs
+++ b/substrate/node/runtime/src/lib.rs
@@ -80,7 +80,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	// implementation changes and behavior does not, then leave spec_version as
 	// is and increment impl_version.
 	spec_version: 153,
-	impl_version: 153,
+	impl_version: 154,
 	apis: RUNTIME_API_VERSIONS,
 };
 
diff --git a/substrate/srml/democracy/src/lib.rs b/substrate/srml/democracy/src/lib.rs
index f1265438f2..4853d192c4 100644
--- a/substrate/srml/democracy/src/lib.rs
+++ b/substrate/srml/democracy/src/lib.rs
@@ -24,11 +24,11 @@ use sr_primitives::traits::{Zero, Bounded, CheckedMul, CheckedDiv, EnsureOrigin,
 use sr_primitives::weights::SimpleDispatchInfo;
 use codec::{Encode, Decode, Input, Output, Error};
 use srml_support::{
-	decl_module, decl_storage, decl_event, ensure,
-	StorageValue, StorageMap, Parameter, Dispatchable, EnumerableStorageMap,
+	decl_module, decl_storage, decl_event, ensure, AppendableStorageMap, StorageValue, StorageMap,
+	Parameter, Dispatchable, EnumerableStorageMap,
 	traits::{
-		Currency, ReservableCurrency, LockableCurrency, WithdrawReason, LockIdentifier,
-		OnFreeBalanceZero, Get
+		Currency, ReservableCurrency, LockableCurrency, WithdrawReason, LockIdentifier, Get,
+		OnFreeBalanceZero
 	}
 };
 use srml_support::dispatch::Result;
@@ -377,9 +377,8 @@ decl_module! {
 			PublicPropCount::put(index + 1);
 			<DepositOf<T>>::insert(index, (value, vec![who.clone()]));
 
-			let mut props = Self::public_props();
-			props.push((index, (*proposal).clone(), who));
-			<PublicProps<T>>::put(props);
+			let new_prop = (index, (*proposal).clone(), who);
+			<PublicProps<T>>::append_or_put([new_prop].into_iter());
 
 			Self::deposit_event(RawEvent::Proposed(index, value));
 		}
@@ -788,7 +787,7 @@ impl<T: Trait> Module<T> {
 	fn do_vote(who: T::AccountId, ref_index: ReferendumIndex, vote: Vote) -> Result {
 		ensure!(Self::is_active_referendum(ref_index), "vote given for invalid referendum.");
 		if !<VoteOf<T>>::exists(&(ref_index, who.clone())) {
-			<VotersFor<T>>::mutate(ref_index, |voters| voters.push(who.clone()));
+			<VotersFor<T>>::append_or_insert(ref_index, [who.clone()].into_iter());
 		}
 		<VoteOf<T>>::insert(&(ref_index, who), vote);
 		Ok(())
@@ -926,9 +925,9 @@ impl<T: Trait> Module<T> {
 			if info.delay.is_zero() {
 				Self::enact_proposal(info.proposal, index);
 			} else {
-				<DispatchQueue<T>>::mutate(
+				<DispatchQueue<T>>::append_or_insert(
 					now + info.delay,
-					|q| q.push(Some((info.proposal, index)))
+					[Some((info.proposal, index))].into_iter()
 				);
 			}
 		} else {
diff --git a/substrate/srml/elections/src/lib.rs b/substrate/srml/elections/src/lib.rs
index f615fdee38..9c49b9055b 100644
--- a/substrate/srml/elections/src/lib.rs
+++ b/substrate/srml/elections/src/lib.rs
@@ -28,7 +28,7 @@ use sr_primitives::traits::{Zero, One, StaticLookup, Bounded, Saturating};
 use sr_primitives::weights::SimpleDispatchInfo;
 use runtime_io::print;
 use srml_support::{
-	StorageValue, StorageMap,
+	StorageValue, StorageMap, AppendableStorageMap, DecodeLengthStorageMap,
 	dispatch::Result, decl_storage, decl_event, ensure, decl_module,
 	traits::{
 		Currency, ExistenceRequirement, Get, LockableCurrency, LockIdentifier,
@@ -714,15 +714,15 @@ impl<T: Trait> Module<T> {
 	///
 	/// The voter index must be provided as explained in [`voter_at`] function.
 	fn do_set_approvals(who: T::AccountId, votes: Vec<bool>, index: VoteIndex, hint: SetIndex) -> Result {
-		let candidates = Self::candidates();
+		let candidates_len = <Self as Store>::Candidates::decode_len().unwrap_or(0_usize);
 
 		ensure!(!Self::presentation_active(), "no approval changes during presentation period");
 		ensure!(index == Self::vote_index(), "incorrect vote index");
-		ensure!(!candidates.is_empty(), "amount of candidates to receive approval votes should be non-zero");
+		ensure!(!candidates_len.is_zero(), "amount of candidates to receive approval votes should be non-zero");
 		// Prevent a vote from voters that provide a list of votes that exceeds the candidates length
 		// since otherwise an attacker may be able to submit a very long list of `votes` that far exceeds
 		// the amount of candidates and waste more computation than a reasonable voting bond would cover.
-		ensure!(candidates.len() >= votes.len(), "amount of candidate votes cannot exceed amount of candidates");
+		ensure!(candidates_len >= votes.len(), "amount of candidate votes cannot exceed amount of candidates");
 
 		// Amount to be locked up.
 		let mut locked_balance = T::Currency::total_balance(&who);
@@ -755,10 +755,10 @@ impl<T: Trait> Module<T> {
 				CellStatus::Head | CellStatus::Occupied => {
 					// Either occupied or out-of-range.
 					let next = Self::next_nonfull_voter_set();
-					let mut set = Self::voters(next);
+					let set_len = <Voters<T>>::decode_len(next).unwrap_or(0_usize);
 					// Caused a new set to be created. Pay for it.
 					// This is the last potential error. Writes will begin afterwards.
-					if set.is_empty() {
+					if set_len == 0 {
 						let imbalance = T::Currency::withdraw(
 							&who,
 							T::VotingFee::get(),
@@ -769,8 +769,10 @@ impl<T: Trait> Module<T> {
 						// NOTE: this is safe since the `withdraw()` will check this.
 						locked_balance -= T::VotingFee::get();
 					}
-					Self::checked_push_voter(&mut set, who.clone(), next);
-					<Voters<T>>::insert(next, set);
+					if set_len + 1 == VOTER_SET_SIZE {
+						NextVoterSet::put(next + 1);
+					}
+					<Voters<T>>::append_or_insert(next, [Some(who.clone())].into_iter())
 				}
 			}
 
@@ -908,18 +910,6 @@ impl<T: Trait> Module<T> {
 		Ok(())
 	}
 
-	fn checked_push_voter(set: &mut Vec<Option<T::AccountId>>, who: T::AccountId, index: u32) {
-		let len = set.len();
-
-		// Defensive only: this should never happen. Don't push since it will break more things.
-		if len == VOTER_SET_SIZE { return; }
-
-		set.push(Some(who));
-		if len + 1 == VOTER_SET_SIZE {
-			NextVoterSet::put(index + 1);
-		}
-	}
-
 	/// Get the set and vector index of a global voter index.
 	///
 	/// Note that this function does not take holes into account.
diff --git a/substrate/srml/support/Cargo.toml b/substrate/srml/support/Cargo.toml
index 2befc11b19..cf8c90993a 100644
--- a/substrate/srml/support/Cargo.toml
+++ b/substrate/srml/support/Cargo.toml
@@ -6,7 +6,7 @@ edition = "2018"
 
 [dependencies]
 serde = { version = "1.0", optional = true, features = ["derive"] }
-codec = { package = "parity-scale-codec", version = "1.0.0", default-features = false, features = ["derive"] }
+codec = { package = "parity-scale-codec", version = "1.0.5", default-features = false, features = ["derive"] }
 srml-metadata = { path = "../metadata", default-features = false }
 sr-std = { path = "../../core/sr-std", default-features = false }
 runtime_io = { package = "sr-io", path = "../../core/sr-io", default-features = false }
diff --git a/substrate/srml/support/procedural/src/storage/impls.rs b/substrate/srml/support/procedural/src/storage/impls.rs
index d5f73f5d39..d67bc5a116 100644
--- a/substrate/srml/support/procedural/src/storage/impls.rs
+++ b/substrate/srml/support/procedural/src/storage/impls.rs
@@ -43,6 +43,8 @@ pub(crate) struct Impls<'a, I: Iterator<Item=syn::Meta>> {
 	pub instance_opts: &'a InstanceOpts,
 	pub type_infos: DeclStorageTypeInfos<'a>,
 	pub fielddefault: TokenStream2,
+	pub default_delegator_ident: syn::Ident,
+	pub default_delegator_return: TokenStream2,
 	pub prefix: String,
 	pub cratename: &'a syn::Ident,
 	pub name: &'a syn::Ident,
@@ -60,6 +62,8 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 			instance_opts,
 			type_infos,
 			fielddefault,
+			default_delegator_ident,
+			default_delegator_return,
 			prefix,
 			name,
 			attrs,
@@ -116,6 +120,17 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 
 		// generator for value
 		quote! {
+			#visibility struct #default_delegator_ident<#struct_trait>(
+				#scrate::rstd::marker::PhantomData<(#trait_and_instance)>
+			) #where_clause;
+			impl<#impl_trait> #scrate::traits::StorageDefault<#typ>
+				for #default_delegator_ident<#trait_and_instance> #where_clause
+			{
+				fn default() -> Option<#typ> {
+					#default_delegator_return
+				}
+			}
+
 			#( #[ #attrs ] )*
 			#visibility struct #name<#struct_trait>(
 				#scrate::rstd::marker::PhantomData<(#trait_and_instance)>
@@ -125,6 +140,7 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 				for #name<#trait_and_instance> #where_clause
 			{
 				type Query = #value_type;
+				type Default = #default_delegator_ident<#trait_and_instance>;
 
 				/// Get the storage key.
 				fn key() -> &'static [u8] {
@@ -168,6 +184,8 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 			instance_opts,
 			type_infos,
 			fielddefault,
+			default_delegator_ident,
+			default_delegator_return,
 			prefix,
 			name,
 			attrs,
@@ -230,6 +248,17 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 
 		// generator for map
 		quote!{
+			#visibility struct #default_delegator_ident<#struct_trait>(
+				#scrate::rstd::marker::PhantomData<(#trait_and_instance)>
+			) #where_clause;
+			impl<#impl_trait> #scrate::traits::StorageDefault<#typ>
+				for #default_delegator_ident<#trait_and_instance> #where_clause
+			{
+				fn default() -> Option<#typ> {
+					#default_delegator_return
+				}
+			}
+
 			#( #[ #attrs ] )*
 			#visibility struct #name<#struct_trait>(
 				#scrate::rstd::marker::PhantomData<(#trait_and_instance)>
@@ -239,8 +268,8 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 				for #name<#trait_and_instance> #where_clause
 			{
 				type Query = #value_type;
-
 				type Hasher = #scrate::#hasher;
+				type Default = #default_delegator_ident<#trait_and_instance>;
 
 				/// Get the prefix key in storage.
 				fn prefix() -> &'static [u8] {
@@ -283,6 +312,10 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 			impl<#impl_trait> #scrate::storage::hashed::generator::AppendableStorageMap<#kty, #typ>
 				for #name<#trait_and_instance> #where_clause
 			{}
+
+			impl<#impl_trait> #scrate::storage::hashed::generator::DecodeLengthStorageMap<#kty, #typ>
+				for #name<#trait_and_instance> #where_clause
+			{}
 		}
 	}
 
@@ -295,6 +328,8 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 			instance_opts,
 			type_infos,
 			fielddefault,
+			default_delegator_ident,
+			default_delegator_return,
 			prefix,
 			name,
 			attrs,
@@ -567,12 +602,23 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 
 			#structure
 
+			#visibility struct #default_delegator_ident<#struct_trait>(
+				#scrate::rstd::marker::PhantomData<(#trait_and_instance)>
+			) #where_clause;
+			impl<#impl_trait> #scrate::traits::StorageDefault<#typ>
+				for #default_delegator_ident<#trait_and_instance> #where_clause
+			{
+				fn default() -> Option<#typ> {
+					#default_delegator_return
+				}
+			}
+
 			impl<#impl_trait> #scrate::storage::hashed::generator::StorageMap<#kty, #typ>
 				for #name<#trait_and_instance> #where_clause
 			{
 				type Query = #value_type;
-
 				type Hasher = #scrate::#hasher;
+				type Default = #default_delegator_ident<#trait_and_instance>;
 
 				/// Get the prefix key in storage.
 				fn prefix() -> &'static [u8] {
@@ -730,6 +776,10 @@ impl<'a, I: Iterator<Item=syn::Meta>> Impls<'a, I> {
 					})
 				}
 			}
+
+			impl<#impl_trait> #scrate::storage::hashed::generator::DecodeLengthStorageMap<#kty, #typ>
+				for #name<#trait_and_instance> #where_clause
+			{}
 		}
 	}
 
diff --git a/substrate/srml/support/procedural/src/storage/transformation.rs b/substrate/srml/support/procedural/src/storage/transformation.rs
index eb479a2664..039bf8c8f6 100644
--- a/substrate/srml/support/procedural/src/storage/transformation.rs
+++ b/substrate/srml/support/procedural/src/storage/transformation.rs
@@ -762,10 +762,26 @@ fn decl_storage_items(
 		} = sline;
 
 		let type_infos = get_type_infos(storage_type);
+		let fielddefault = default_value.inner
+			.as_ref()
+			.map(|d| &d.expr)
+			.map(|d| quote!( #d ))
+			.unwrap_or_else(|| quote!{ Default::default() });
 		let kind = type_infos.kind.clone();
 		// Propagate doc attributes.
 		let attrs = attrs.inner.iter().filter_map(|a| a.parse_meta().ok()).filter(|m| m.name() == "doc");
 
+		// create default value delegator
+		let default_delegator_ident = Ident::new(
+			&format!("{}{}", name.to_string(), "DefaultDelegator"),
+			proc_macro2::Span::call_site(),
+		);
+		let default_delegator_return = if !type_infos.is_option {
+			quote! { Some(#fielddefault) }
+		} else {
+			quote! { #fielddefault }
+		};
+
 		let i = impls::Impls {
 			scrate,
 			visibility,
@@ -774,8 +790,9 @@ fn decl_storage_items(
 			traittype,
 			instance_opts,
 			type_infos,
-			fielddefault: default_value.inner.as_ref().map(|d| &d.expr).map(|d| quote!( #d ))
-				.unwrap_or_else(|| quote!{ Default::default() }),
+			fielddefault,
+			default_delegator_ident,
+			default_delegator_return,
 			prefix: build_prefix(cratename, name),
 			name,
 			attrs,
diff --git a/substrate/srml/support/src/lib.rs b/substrate/srml/support/src/lib.rs
index 16e3ca5de9..9ebd848fca 100644
--- a/substrate/srml/support/src/lib.rs
+++ b/substrate/srml/support/src/lib.rs
@@ -62,7 +62,8 @@ mod double_map;
 pub mod traits;
 
 pub use self::storage::{
-	StorageValue, StorageMap, EnumerableStorageMap, StorageDoubleMap, AppendableStorageMap
+	StorageValue, StorageMap, EnumerableStorageMap, StorageDoubleMap, AppendableStorageMap,
+	DecodeLengthStorageMap,
 };
 pub use self::hashable::Hashable;
 pub use self::dispatch::{Parameter, Dispatchable, Callable, IsSubType};
diff --git a/substrate/srml/support/src/storage/hashed/generator.rs b/substrate/srml/support/src/storage/hashed/generator.rs
index f8b8fb5483..27b459e3ff 100644
--- a/substrate/srml/support/src/storage/hashed/generator.rs
+++ b/substrate/srml/support/src/storage/hashed/generator.rs
@@ -14,12 +14,14 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-//! Abstract storage to use on HashedStorage trait
+//! Abstract storage to use on HashedStorage trait. Please refer to the
+//! [top level docs](../../index.html) for more detailed documentation about storage traits and functions.
 
 use crate::codec::{self, Encode};
-use crate::rstd::prelude::{Vec, Box};
+use crate::rstd::{prelude::{Vec, Box}, iter::FromIterator};
 #[cfg(feature = "std")]
 use crate::storage::unhashed::generator::UnhashedStorage;
+use crate::traits::{StorageDefault, Len};
 use runtime_io::{twox_64, twox_128, blake2_128, twox_256, blake2_256};
 
 pub trait StorageHasher: 'static {
@@ -164,6 +166,9 @@ impl<H: StorageHasher> HashedStorage<H> for sr_primitives::StorageOverlay {
 pub trait StorageValue<T: codec::Codec> {
 	/// The type that get/take returns.
 	type Query;
+	/// Something that can provide the default value of this storage type.
+	type Default: StorageDefault<T>;
+
 
 	/// Get the storage key.
 	fn key() -> &'static [u8];
@@ -202,24 +207,75 @@ pub trait StorageValue<T: codec::Codec> {
 	/// Append the given items to the value in the storage.
 	///
 	/// `T` is required to implement `codec::EncodeAppend`.
-	fn append<S: HashedStorage<Twox128>, I: codec::Encode>(
-		items: &[I], storage: &mut S
-	) -> Result<(), &'static str> where T: codec::EncodeAppend<Item=I> {
+	fn append<'a, S, I, R>(
+		items: R,
+		storage: &mut S,
+	) -> Result<(), &'static str> where
+		S: HashedStorage<Twox128>,
+		I: 'a + codec::Encode,
+		T: codec::EncodeAppend<Item=I>,
+		R: IntoIterator<Item=&'a I>,
+		R::IntoIter: ExactSizeIterator,
+	{
 		let new_val = <T as codec::EncodeAppend>::append(
-			storage.get_raw(Self::key()).unwrap_or_default(),
+			// if the key exists, directly append to it.
+			storage.get_raw(Self::key()).unwrap_or_else(|| {
+				// otherwise, try and read a proper __provided__ default.
+				Self::Default::default().map(|v| v.encode())
+					// or just use the Rust's `default()` value.
+					.unwrap_or_default()
+			}),
 			items,
 		).map_err(|_| "Could not append given item")?;
 		storage.put_raw(Self::key(), &new_val);
 		Ok(())
 	}
+
+	/// Safely append the given items to the value in the storage. If a codec error occurs, then the
+	/// old (presumably corrupt) value is replaced with the given `items`.
+	///
+	/// `T` is required to implement `codec::EncodeAppend`.
+	fn append_or_put<'a, S, I, R>(
+		items: R,
+		storage: &mut S,
+	) where
+		S: HashedStorage<Twox128>,
+		I: 'a + codec::Encode + Clone,
+		T: codec::EncodeAppend<Item=I> + FromIterator<I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator,
+	{
+		Self::append(items.clone(), storage)
+			.unwrap_or_else(|_| Self::put(&items.into_iter().cloned().collect(), storage));
+	}
+
+	/// Read the length of the value in a fast way, without decoding the entire value.
+	///
+	/// `T` is required to implement `Codec::DecodeLength`.
+	///
+	/// Note that `0` is returned as the default value if no encoded value exists at the given key.
+	/// Therefore, this function cannot be used as a sign of _existence_. use the `::exists()`
+	/// function for this purpose.
+	fn decode_len<S: HashedStorage<Twox128>>(storage: &mut S) -> Result<usize, &'static str>
+		where T: codec::DecodeLength, T: Len
+	{
+		// attempt to get the length directly.
+		if let Some(k) = storage.get_raw(Self::key()) {
+			<T as codec::DecodeLength>::len(&k).map_err(|e| e.what())
+		} else {
+			Ok(Self::Default::default().map(|v| v.len()).unwrap_or(0))
+		}
+	}
 }
 
 /// A strongly-typed map in storage.
 pub trait StorageMap<K: codec::Codec, V: codec::Codec> {
 	/// The type that get/take returns.
 	type Query;
-
+	/// Hasher type
 	type Hasher: StorageHasher;
+	/// Something that can provide the default value of this storage type.
+	type Default: StorageDefault<V>;
 
 	/// Get the prefix key in storage.
 	fn prefix() -> &'static [u8];
@@ -295,16 +351,69 @@ pub trait EnumerableStorageMap<K: codec::Codec, V: codec::Codec>: StorageMap<K,
 pub trait AppendableStorageMap<K: codec::Codec, V: codec::Codec>: StorageMap<K, V> {
 	/// Append the given items to the value in the storage.
 	///
-	/// `T` is required to implement `codec::EncodeAppend`.
-	fn append<S: HashedStorage<Self::Hasher>, I: codec::Encode>(
-		key : &K, items: &[I], storage: &mut S
-	) -> Result<(), &'static str> where V: codec::EncodeAppend<Item=I> {
+	/// `V` is required to implement `codec::EncodeAppend`.
+	fn append<'a, S, I, R>(
+		key : &K,
+		items: R,
+		storage: &mut S,
+	) -> Result<(), &'static str> where
+		S: HashedStorage<Self::Hasher>,
+		I: 'a + codec::Encode,
+		V: codec::EncodeAppend<Item=I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator,
+	{
 		let k = Self::key_for(key);
 		let new_val = <V as codec::EncodeAppend>::append(
-			storage.get_raw(&k[..]).unwrap_or_default(),
+			storage.get_raw(&k[..]).unwrap_or_else(|| {
+				// otherwise, try and read a proper __provided__ default.
+				Self::Default::default().map(|v| v.encode())
+					// or just use the default value.
+					.unwrap_or_default()
+			}),
 			items,
 		).map_err(|_| "Could not append given item")?;
 		storage.put_raw(&k[..], &new_val);
 		Ok(())
 	}
+
+	/// Safely append the given items to the value in the storage. If a codec error occurs, then the
+	/// old (presumably corrupt) value is replaced with the given `items`.
+	///
+	/// `T` is required to implement `codec::EncodeAppend`.
+	fn append_or_insert<'a, S, I, R>(
+		key : &K,
+		items: R,
+		storage: &mut S,
+	) where
+		S: HashedStorage<Self::Hasher>,
+		I: 'a + codec::Encode + Clone,
+		V: codec::EncodeAppend<Item=I> + crate::rstd::iter::FromIterator<I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator,
+	{
+		Self::append(key, items.clone(), storage)
+			.unwrap_or_else(|_| Self::insert(key, &items.into_iter().cloned().collect(), storage));
+	}
+}
+
+/// A storage map with a decodable length.
+pub trait DecodeLengthStorageMap<K: codec::Codec, V: codec::Codec>: StorageMap<K, V> {
+	/// Read the length of the value in a fast way, without decoding the entire value.
+	///
+	/// `T` is required to implement `Codec::DecodeLength`.
+	///
+	/// Note that `0` is returned as the default value if no encoded value exists at the given key.
+	/// Therefore, this function cannot be used as a sign of _existence_. use the `::exists()`
+	/// function for this purpose.
+	fn decode_len<S: HashedStorage<Self::Hasher>>(key: &K, storage: &mut S) -> Result<usize, &'static str>
+		where V: codec::DecodeLength, V: Len
+	{
+		let k = Self::key_for(key);
+		if let Some(v) = storage.get_raw(&k[..]) {
+			<V as codec::DecodeLength>::len(&v).map_err(|e| e.what())
+		} else {
+			Ok(Self::Default::default().map(|v| v.len()).unwrap_or(0))
+		}
+	}
 }
diff --git a/substrate/srml/support/src/storage/mod.rs b/substrate/srml/support/src/storage/mod.rs
index 385fad42eb..aa3faee878 100644
--- a/substrate/srml/support/src/storage/mod.rs
+++ b/substrate/srml/support/src/storage/mod.rs
@@ -17,10 +17,11 @@
 //! Stuff to do with the runtime's storage.
 
 use crate::rstd::prelude::*;
-use crate::rstd::borrow::Borrow;
+use crate::rstd::{borrow::Borrow, iter::FromIterator};
 use codec::{Codec, Encode, Decode, KeyedVec, EncodeAppend};
 use hashed::generator::{HashedStorage, StorageHasher};
 use unhashed::generator::UnhashedStorage;
+use crate::traits::{StorageDefault, Len};
 
 #[macro_use]
 pub mod storage_items;
@@ -107,6 +108,8 @@ impl UnhashedStorage for RuntimeStorage {
 pub trait StorageValue<T: Codec> {
 	/// The type that get/take return.
 	type Query;
+	/// Something that can provide the default value of this storage type.
+	type Default: StorageDefault<T>;
 
 	/// Get the storage key.
 	fn key() -> &'static [u8];
@@ -136,12 +139,39 @@ pub trait StorageValue<T: Codec> {
 	/// Append the given item to the value in the storage.
 	///
 	/// `T` is required to implement `codec::EncodeAppend`.
-	fn append<I: Encode>(items: &[I]) -> Result<(), &'static str>
-		where T: EncodeAppend<Item=I>;
+	fn append<'a, I, R>(items: R) -> Result<(), &'static str> where
+		I: 'a + Encode,
+		T: EncodeAppend<Item=I>,
+		R: IntoIterator<Item=&'a I>,
+		R::IntoIter: ExactSizeIterator;
+
+	/// Append the given items to the value in the storage.
+	///
+	/// `T` is required to implement `Codec::EncodeAppend`.
+	///
+	/// Upon any failure, it replaces `items` as the new value (assuming that the previous stored
+	/// data is simply corrupt and no longer usable).
+	///
+	/// ### WARNING
+	///
+	/// use with care; if your use-case is not _exactly_ as what this function is doing,
+	/// you should use append and sensibly handle failure within the runtime code if it happens.
+	fn append_or_put<'a, I, R>(items: R) where
+		I: 'a + Encode + Clone,
+		T: EncodeAppend<Item=I> + FromIterator<I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator;
+
+	/// Read the length of the value in a fast way, without decoding the entire value.
+	///
+	/// `T` is required to implement `Codec::DecodeLength`.
+	fn decode_len() -> Result<usize, &'static str>
+		where T: codec::DecodeLength, T: Len;
 }
 
 impl<T: Codec, U> StorageValue<T> for U where U: hashed::generator::StorageValue<T> {
 	type Query = U::Query;
+	type Default = U::Default;
 
 	fn key() -> &'static [u8] {
 		<U as hashed::generator::StorageValue<T>>::key()
@@ -167,17 +197,35 @@ impl<T: Codec, U> StorageValue<T> for U where U: hashed::generator::StorageValue
 	fn take() -> Self::Query {
 		U::take(&mut RuntimeStorage)
 	}
-	fn append<I: Encode>(items: &[I]) -> Result<(), &'static str>
-		where T: EncodeAppend<Item=I>
+	fn append<'a, I, R>(items: R) -> Result<(), &'static str> where
+		I: 'a + Encode,
+		T: EncodeAppend<Item=I>,
+		R: IntoIterator<Item=&'a I>,
+		R::IntoIter: ExactSizeIterator,
 	{
 		U::append(items, &mut RuntimeStorage)
 	}
+	fn append_or_put<'a, I, R>(items: R) where
+		I: 'a + Encode + Clone,
+		T: EncodeAppend<Item=I> + FromIterator<I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator,
+	{
+		U::append_or_put(items, &mut RuntimeStorage)
+	}
+	fn decode_len() -> Result<usize, &'static str>
+		where T: codec::DecodeLength, T: Len
+	{
+		U::decode_len(&mut RuntimeStorage)
+	}
 }
 
 /// A strongly-typed map in storage.
 pub trait StorageMap<K: Codec, V: Codec> {
 	/// The type that get/take return.
 	type Query;
+	/// Something that can provide the default value of this storage type.
+	type Default: StorageDefault<V>;
 
 	/// Get the prefix key in storage.
 	fn prefix() -> &'static [u8];
@@ -213,6 +261,7 @@ pub trait StorageMap<K: Codec, V: Codec> {
 
 impl<K: Codec, V: Codec, U> StorageMap<K, V> for U where U: hashed::generator::StorageMap<K, V> {
 	type Query = U::Query;
+	type Default = U::Default;
 
 	fn prefix() -> &'static [u8] {
 		<U as hashed::generator::StorageMap<K, V>>::prefix()
@@ -260,18 +309,85 @@ pub trait AppendableStorageMap<K: Codec, V: Codec>: StorageMap<K, V> {
 	/// Append the given item to the value in the storage.
 	///
 	/// `T` is required to implement `codec::EncodeAppend`.
-	fn append<KeyArg: Borrow<K>, I: Encode>(key: KeyArg, items: &[I]) -> Result<(), &'static str>
-		where V: EncodeAppend<Item=I>;
+	fn append<'a, KeyArg, I, R>(
+		key: KeyArg,
+		items: R,
+	) -> Result<(), &'static str> where
+		KeyArg: Borrow<K>,
+		I: 'a + codec::Encode,
+		V: EncodeAppend<Item=I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator;
+
+	/// Append the given items to the value in the storage.
+	///
+	/// `T` is required to implement `codec::EncodeAppend`.
+	///
+	/// Upon any failure, it replaces `items` as the new value (assuming that the previous stored
+	/// data is simply corrupt and no longer usable).
+	///
+	/// WARNING: use with care; if your use-case is not _exactly_ as what this function is doing,
+	/// you should use append and sensibly handle failure within the runtime code if it happens.
+	fn append_or_insert<'a, KeyArg, I, R>(
+		key: KeyArg,
+		items: R,
+	) where
+		KeyArg: Borrow<K>,
+		I: 'a + codec::Encode + Clone,
+		V: codec::EncodeAppend<Item=I> + FromIterator<I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator;
 }
 
 impl<K: Codec, V: Codec, U> AppendableStorageMap<K, V> for U
 	where U: hashed::generator::AppendableStorageMap<K, V>
 {
-	fn append<KeyArg: Borrow<K>, I: Encode>(key: KeyArg, items: &[I]) -> Result<(), &'static str>
-		where V: EncodeAppend<Item=I>
+	fn append<'a, KeyArg, I, R>(
+		key: KeyArg,
+		items: R,
+	) -> Result<(), &'static str> where
+		KeyArg: Borrow<K>,
+		I: 'a + codec::Encode,
+		V: EncodeAppend<Item=I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator,
 	{
 		U::append(key.borrow(), items, &mut RuntimeStorage)
 	}
+
+	fn append_or_insert<'a, KeyArg, I, R>(
+		key: KeyArg,
+		items: R,
+	) where
+		KeyArg: Borrow<K>,
+		I: 'a + codec::Encode + Clone,
+		V: codec::EncodeAppend<Item=I> + FromIterator<I>,
+		R: IntoIterator<Item=&'a I> + Clone,
+		R::IntoIter: ExactSizeIterator,
+	{
+		U::append_or_insert(key.borrow(), items, &mut RuntimeStorage)
+	}
+}
+
+/// A storage map with a decodable length.
+pub trait DecodeLengthStorageMap<K: Codec, V: Codec>: StorageMap<K, V> {
+	/// Read the length of the value in a fast way, without decoding the entire value.
+	///
+	/// `T` is required to implement `Codec::DecodeLength`.
+	///
+	/// Has the same logic as [`StorageValue`](trait.StorageValue.html).
+	fn decode_len<KeyArg: Borrow<K>>(key: KeyArg) -> Result<usize, &'static str>
+		where V: codec::DecodeLength, V: Len;
+}
+
+impl <K: Codec, V: Codec, U> DecodeLengthStorageMap<K, V> for U
+	where U: hashed::generator::DecodeLengthStorageMap<K, V>
+{
+	fn decode_len<KeyArg: Borrow<K>>(key: KeyArg) -> Result<usize, &'static str>
+		where V: codec::DecodeLength, V: Len
+	{
+		U::decode_len(key.borrow(), &mut RuntimeStorage)
+	}
 }
 
 /// A storage map that can be enumerated.
diff --git a/substrate/srml/support/src/storage/storage_items.rs b/substrate/srml/support/src/storage/storage_items.rs
index 06cb8fc55b..a2a5c3229f 100644
--- a/substrate/srml/support/src/storage/storage_items.rs
+++ b/substrate/srml/support/src/storage/storage_items.rs
@@ -172,6 +172,7 @@ macro_rules! __storage_items_internal {
 
 		impl $crate::storage::hashed::generator::StorageValue<$ty> for $name {
 			type Query = $gettype;
+			type Default = ();
 
 			/// Get the storage key.
 			fn key() -> &'static [u8] {
@@ -221,8 +222,8 @@ macro_rules! __storage_items_internal {
 
 		impl $crate::storage::hashed::generator::StorageMap<$kty, $ty> for $name {
 			type Query = $gettype;
-
 			type Hasher = $crate::Blake2_256;
+			type Default = ();
 
 			/// Get the prefix key in storage.
 			fn prefix() -> &'static [u8] {
@@ -795,18 +796,41 @@ mod test3 {
 
 #[cfg(test)]
 #[allow(dead_code)]
-mod test_map_vec_append {
+mod test_append_and_len {
+	use crate::storage::{AppendableStorageMap, DecodeLengthStorageMap, StorageMap, StorageValue};
+	use runtime_io::{with_externalities, TestExternalities};
+	use codec::{Encode, Decode};
+
 	pub trait Trait {
 		type Origin;
 		type BlockNumber;
 	}
+
 	decl_module! {
 		pub struct Module<T: Trait> for enum Call where origin: T::Origin {}
 	}
+
+	#[derive(PartialEq, Eq, Clone, Encode, Decode)]
+	struct NoDef(u32);
+
 	crate::decl_storage! {
 		trait Store for Module<T: Trait> as Test {
+			NoDefault: Option<NoDef>;
+
 			JustVec: Vec<u32>;
+			JustVecWithDefault: Vec<u32> = vec![6, 9];
+			OptionVec: Option<Vec<u32>>;
+			OptionVecWithDefault: Option<Vec<u32>> = Some(vec![6, 9]);
+
 			MapVec: map u32 => Vec<u32>;
+			MapVecWithDefault: map u32 => Vec<u32> = vec![6, 9];
+			OptionMapVec: map u32 => Option<Vec<u32>>;
+			OptionMapVecWithDefault: map u32 => Option<Vec<u32>> = Some(vec![6, 9]);
+
+			LinkedMapVec: linked_map u32 => Vec<u32>;
+			LinkedMapVecWithDefault: linked_map u32 => Vec<u32> = vec![6, 9];
+			OptionLinkedMapVec: linked_map u32 => Option<Vec<u32>>;
+			OptionLinkedMapVecWithDefault: linked_map u32 => Option<Vec<u32>> = Some(vec![6, 9]);
 		}
 	}
 
@@ -818,20 +842,115 @@ mod test_map_vec_append {
 	}
 
 	#[test]
-	fn append_works() {
-		use crate::storage::{AppendableStorageMap, StorageMap, StorageValue};
-		use runtime_io::{with_externalities, TestExternalities};
-
+	fn default_for_option() {
 		with_externalities(&mut TestExternalities::default(), || {
-			let _ = MapVec::append(1, &[1, 2, 3]);
-			let _ = MapVec::append(1, &[4, 5]);
+			assert_eq!(OptionVecWithDefault::get(), Some(vec![6, 9]));
+			assert_eq!(OptionVec::get(), None);
+			assert_eq!(JustVec::get(), vec![]);
+		});
+	}
+
+	#[test]
+	fn append_works() {
+		with_externalities(&mut TestExternalities::default(), || {
+			let _ = MapVec::append(1, [1, 2, 3].iter());
+			let _ = MapVec::append(1, [4, 5].iter());
 			assert_eq!(MapVec::get(1), vec![1, 2, 3, 4, 5]);
 
-			let _ = JustVec::append(&[1, 2, 3]);
-			let _ = JustVec::append(&[4, 5]);
+			let _ = JustVec::append([1, 2, 3].iter());
+			let _ = JustVec::append([4, 5].iter());
 			assert_eq!(JustVec::get(), vec![1, 2, 3, 4, 5]);
 		});
 	}
+
+	#[test]
+	fn append_works_for_default() {
+		with_externalities(&mut TestExternalities::default(), || {
+			assert_eq!(JustVecWithDefault::get(), vec![6, 9]);
+			let _ = JustVecWithDefault::append([1].iter());
+			assert_eq!(JustVecWithDefault::get(), vec![6, 9, 1]);
+
+			assert_eq!(MapVecWithDefault::get(0), vec![6, 9]);
+			let _ = MapVecWithDefault::append(0, [1].iter());
+			assert_eq!(MapVecWithDefault::get(0), vec![6, 9, 1]);
+
+			assert_eq!(OptionVec::get(), None);
+			let _ = OptionVec::append([1].iter());
+			assert_eq!(OptionVec::get(), Some(vec![1]));
+		});
+	}
+
+	#[test]
+	fn append_or_put_works() {
+		with_externalities(&mut TestExternalities::default(), || {
+			let _ = MapVec::append_or_insert(1, [1, 2, 3].iter());
+			let _ = MapVec::append_or_insert(1, [4, 5].iter());
+			assert_eq!(MapVec::get(1), vec![1, 2, 3, 4, 5]);
+
+			let _ = JustVec::append_or_put([1, 2, 3].iter());
+			let _ = JustVec::append_or_put([4, 5].iter());
+			assert_eq!(JustVec::get(), vec![1, 2, 3, 4, 5]);
+		});
+	}
+
+	#[test]
+	fn len_works() {
+		with_externalities(&mut TestExternalities::default(), || {
+			JustVec::put(&vec![1, 2, 3, 4]);
+			OptionVec::put(&vec![1, 2, 3, 4, 5]);
+			MapVec::insert(1, &vec![1, 2, 3, 4, 5, 6]);
+			LinkedMapVec::insert(2, &vec![1, 2, 3]);
+
+			assert_eq!(JustVec::decode_len().unwrap(), 4);
+			assert_eq!(OptionVec::decode_len().unwrap(), 5);
+			assert_eq!(MapVec::decode_len(1).unwrap(), 6);
+			assert_eq!(LinkedMapVec::decode_len(2).unwrap(), 3);
+		});
+	}
+
+	#[test]
+	fn len_works_for_default() {
+		with_externalities(&mut TestExternalities::default(), || {
+			// vec
+			assert_eq!(JustVec::get(), vec![]);
+			assert_eq!(JustVec::decode_len(), Ok(0));
+
+			assert_eq!(JustVecWithDefault::get(), vec![6, 9]);
+			assert_eq!(JustVecWithDefault::decode_len(), Ok(2));
+
+			assert_eq!(OptionVec::get(), None);
+			assert_eq!(OptionVec::decode_len(), Ok(0));
+
+			assert_eq!(OptionVecWithDefault::get(), Some(vec![6, 9]));
+			assert_eq!(OptionVecWithDefault::decode_len(), Ok(2));
+
+			// map
+			assert_eq!(MapVec::get(0), vec![]);
+			assert_eq!(MapVec::decode_len(0), Ok(0));
+
+			assert_eq!(MapVecWithDefault::get(0), vec![6, 9]);
+			assert_eq!(MapVecWithDefault::decode_len(0), Ok(2));
+
+			assert_eq!(OptionMapVec::get(0), None);
+			assert_eq!(OptionMapVec::decode_len(0), Ok(0));
+
+			assert_eq!(OptionMapVecWithDefault::get(0), Some(vec![6, 9]));
+			assert_eq!(OptionMapVecWithDefault::decode_len(0), Ok(2));
+
+			// linked map
+			assert_eq!(LinkedMapVec::get(0), vec![]);
+			assert_eq!(LinkedMapVec::decode_len(0), Ok(0));
+
+			assert_eq!(LinkedMapVecWithDefault::get(0), vec![6, 9]);
+			assert_eq!(LinkedMapVecWithDefault::decode_len(0), Ok(2));
+
+			assert_eq!(OptionLinkedMapVec::get(0), None);
+			assert_eq!(OptionLinkedMapVec::decode_len(0), Ok(0));
+
+			assert_eq!(OptionLinkedMapVecWithDefault::get(0), Some(vec![6, 9]));
+			assert_eq!(OptionLinkedMapVecWithDefault::decode_len(0), Ok(2));
+		});
+	}
 }
 
 
diff --git a/substrate/srml/support/src/traits.rs b/substrate/srml/support/src/traits.rs
index 37262cdfcb..a5e52f5f66 100644
--- a/substrate/srml/support/src/traits.rs
+++ b/substrate/srml/support/src/traits.rs
@@ -26,6 +26,28 @@ use crate::sr_primitives::ConsensusEngineId;
 
 use super::for_each_tuple;
 
+/// A trait that can return the default value of a storage item. This must only ever be implemented
+/// for a special delegator struct for each storage item
+pub trait StorageDefault<V>: Sized {
+	/// Return the default value of type `V`. `None`, if `V` does not have a proper default value.
+	fn default() -> Option<V>;
+}
+
+// FIXME #1466 This is needed for `storage_items!`. Should be removed once it is deprecated.
+impl<T: Default> StorageDefault<T> for () { fn default() -> Option<T> { Some(Default::default()) } }
+
+/// Anything that can have a `::len()` method.
+pub trait Len {
+	/// Return the length of data type.
+	fn len(&self) -> usize;
+}
+
+impl<T: IntoIterator + Clone,> Len for T where <T as IntoIterator>::IntoIter: ExactSizeIterator {
+	fn len(&self) -> usize {
+		self.clone().into_iter().len()
+	}
+}
+
 /// A trait for querying a single fixed value from a type.
 pub trait Get<T> {
 	/// Return a constant value.
diff --git a/substrate/srml/system/src/lib.rs b/substrate/srml/system/src/lib.rs
index d0b36ae14d..2343af8bec 100644
--- a/substrate/srml/system/src/lib.rs
+++ b/substrate/srml/system/src/lib.rs
@@ -578,7 +578,7 @@ impl<T: Trait> Module<T> {
 		// We perform early return if we've reached the maximum capacity of the event list,
 		// so `Events<T>` seems to be corrupted. Also, this has happened after the start of execution
 		// (since the event list is cleared at the block initialization).
-		if <Events<T>>::append(&[event]).is_err() {
+		if <Events<T>>::append([event].into_iter()).is_err() {
 			// The most sensible thing to do here is to just ignore this event and wait until the
 			// new block.
 			return;