protocols/kad/src/kbuckets: Explicitly convert u8 to usize (#1716)

Compiling libp2p-kad for `--target wasm32-unknown-unknown` fails with
the cryptic error message `cannot infer type for type `usize``.
Explicitly converting to `usize` solves the issue.

Co-authored-by: Andronik Ordian <write@reusable.software>

protocols/kad/CHANGELOG.md

@@ -1,3 +1,8 @@
+# 0.22.1 [2020-08-19]
+
+- Explicitly convert from u8 to usize in `BucketIndex::range` to prevent type
+  inference issues ([PR 1716](https://github.com/libp2p/rust-libp2p/pull/1716)).
+
 # 0.22.0 [2020-08-18]
 
 - Store addresses in provider records.

protocols/kad/Cargo.toml

@@ -2,7 +2,7 @@
 name = "libp2p-kad"
 edition = "2018"
 description = "Kademlia protocol for libp2p"
-version = "0.22.0"
+version = "0.22.1"
 authors = ["Parity Technologies <admin@parity.io>"]
 license = "MIT"
 repository = "https://github.com/libp2p/rust-libp2p"

protocols/kad/src/kbucket.rs

@@ -120,7 +120,7 @@ impl BucketIndex {
     /// included in the bucket for this index.
     fn range(&self) -> (Distance, Distance) {
         let min = Distance(U256::pow(U256::from(2), U256::from(self.0)));
-        if self.0 == u8::MAX.into() {
+        if self.0 == usize::from(u8::MAX) {
             (min, Distance(U256::MAX))
         } else {
             let max = Distance(U256::pow(U256::from(2), U256::from(self.0 + 1)) - 1);