Merge branch 'master' into create_ci

.travis.yml

@@ -7,7 +7,7 @@ rust:
   # - stable
   # - beta
   - nightly
-  - nightly-2019-08-30
+  - nightly-2019-10-04
 
 matrix:
   allow_failures:

core/Cargo.toml

@@ -24,16 +24,22 @@ ink_utils = { path = "../utils/", default-features = false }
 
 scale = { package = "parity-scale-codec", version = "1.0", default-features = false, features = ["derive", "full"] }
 type-metadata = { git = "https://github.com/type-metadata/type-metadata.git", default-features = false, features = ["derive"], optional = true }
+derive_more = { version = "0.15", default-features = false, features = ["no_std"] }
+smallvec = { version = "0.6.10", default-features = false, features = ["union"] }
+cfg-if = "0.1"
 
 [features]
 default = ["test-env"]
-test-env = ["std"]
+test-env = [
+    "std",
+]
 std = [
     "ink_abi/std",
     "ink_alloc/std",
     "ink_utils/std",
     "scale/std",
     "type-metadata/std",
+    "smallvec/std",
 ]
 ink-generate-abi = [
     "ink_abi",

core/src/byte_utils.rs

@@ -25,7 +25,7 @@ fn invert_bytes(bytes: &mut [u8]) {
 
 /// Negate the given bytes inplace.
 ///
-/// Interprets the bytes as twos-complement number.
+/// Interprets the bytes as big endian twos-complement number.
 pub fn negate_bytes(bytes: &mut [u8]) {
     invert_bytes(bytes);
     bytes_add_bytes(bytes, &[0x01]);