MSRV Testing in CI

.github/workflows/build.yml

@@ -11,12 +11,15 @@ env:
 
 jobs:
   test:
+    strategy:
+      matrix:
+        rust-version: ["stable", "1.46.0"]
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
     - uses: actions-rs/toolchain@v1
       with:
-        toolchain: stable
+        toolchain: ${{ matrix.rust-version }}
         profile: minimal
         override: true
         components: rustfmt

src/lib.rs

@@ -11,6 +11,8 @@
 #![forbid(unsafe_code)]
 #![deny(missing_docs)]
 #![cfg_attr(not(feature = "std"), no_std)]
+// Allow identity ops for readability
+#![allow(clippy::identity_op)]
 
 use core::fmt;
 
@@ -94,6 +96,11 @@ impl ConstSlice {
         self.head
     }
 
+    /// Whether the buffer is empty or not.
+    pub const fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
     /// Get the buffer as a slice.
     pub const fn as_slice(&self) -> &[u8] {
         &self.data