From 903cd4e8010698a36c3cd74b727ba66adb4b40f5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bastian=20K=C3=B6cher?= <bkchr@users.noreply.github.com>
Date: Sat, 11 Jul 2020 20:47:38 +0200
Subject: [PATCH] Clarify some host interfaces (#6626)

---
 substrate/primitives/io/src/lib.rs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/substrate/primitives/io/src/lib.rs b/substrate/primitives/io/src/lib.rs
index c75c8e67cc..dc86ff2d6e 100644
--- a/substrate/primitives/io/src/lib.rs
+++ b/substrate/primitives/io/src/lib.rs
@@ -134,7 +134,7 @@ pub trait Storage {
 	///
 	/// The hashing algorithm is defined by the `Block`.
 	///
-	/// Returns the SCALE encoded hash.
+	/// Returns a `Vec<u8>` that holds the SCALE encoded hash.
 	fn root(&mut self) -> Vec<u8> {
 		self.storage_root()
 	}
@@ -144,7 +144,7 @@ pub trait Storage {
 	///
 	/// The hashing algorithm is defined by the `Block`.
 	///
-	/// Returns an `Some(_)` which holds the SCALE encoded hash or `None` when
+	/// Returns `Some(Vec<u8>)` which holds the SCALE encoded hash or `None` when
 	/// changes trie is disabled.
 	fn changes_root(&mut self, parent_hash: &[u8]) -> Option<Vec<u8>> {
 		self.storage_changes_root(parent_hash)
@@ -306,7 +306,7 @@ pub trait DefaultChildStorage {
 	/// "Commit" all existing operations and compute the resulting child storage root.
 	/// The hashing algorithm is defined by the `Block`.
 	///
-	/// Returns the SCALE encoded hash.
+	/// Returns a `Vec<u8>` that holds the SCALE encoded hash.
 	fn root(
 		&mut self,
 		storage_key: &[u8],
@@ -379,7 +379,8 @@ pub trait Misc {
 
 	/// Extract the runtime version of the given wasm blob by calling `Core_version`.
 	///
-	/// Returns the SCALE encoded runtime version and `None` if the call failed.
+	/// Returns `None` if calling the function failed for any reason or `Some(Vec<u8>)` where
+	/// the `Vec<u8>` holds the SCALE encoded runtime version.
 	///
 	/// # Performance
 	///