Check in CI compatibility with MSRV (#741)

.github/workflows/rust.yml

@@ -1,6 +1,8 @@
 name: RocksDB CI
 
 on: [push, pull_request]
+env:
+  RUST_VERSION: 1.60.0
 
 jobs:
   fmt:
@@ -12,7 +14,7 @@ jobs:
       - name: Install rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: ${{ env.RUST_VERSION }}
           components: rustfmt
           profile: minimal
           override: true
@@ -31,7 +33,7 @@ jobs:
       - name: Install rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: ${{ env.RUST_VERSION }}
           components: clippy
           profile: minimal
           override: true
@@ -69,7 +71,7 @@ jobs:
       - name: Install rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: ${{ matrix.rust || 'stable' }}
+          toolchain: ${{ env.RUST_VERSION }}
           target: ${{ matrix.target }}
           profile: minimal
           override: true

Cargo.toml

@@ -3,6 +3,7 @@ name = "rocksdb"
 description = "Rust wrapper for Facebook's RocksDB embeddable database"
 version = "0.20.0"
 edition = "2018"
+rust-version = "1.60"
 authors = ["Tyler Neely <t@jujit.su>", "David Greenberg <dsg123456789@gmail.com>"]
 repository = "https://github.com/rust-rocksdb/rust-rocksdb"
 license = "Apache-2.0"

librocksdb-sys/Cargo.toml

@@ -2,6 +2,7 @@
 name = "librocksdb-sys"
 version = "0.10.0+7.9.2"
 edition = "2018"
+rust-version = "1.60"
 authors = ["Karl Hobley <karlhobley10@gmail.com>", "Arkadiy Paronyan <arkadiy@ethcore.io>"]
 license = "MIT/Apache-2.0/BSD-3-Clause"
 description = "Native bindings to librocksdb"

src/transactions/transaction_db.rs

@@ -57,7 +57,7 @@ type DefaultThreadMode = crate::MultiThreaded;
 /// {
 ///     let db: TransactionDB = TransactionDB::open_default(path).unwrap();
 ///     db.put(b"my key", b"my value").unwrap();
-///     
+///
 ///     // create transaction
 ///     let txn = db.transaction();
 ///     txn.put(b"key2", b"value2");
@@ -359,11 +359,9 @@ impl<T: ThreadMode> TransactionDB<T> {
         name: &str,
         opts: &Options,
     ) -> Result<*mut ffi::rocksdb_column_family_handle_t, Error> {
-        let Ok(cf_name) = CString::new(name.as_bytes()) else {
-            return Err(Error::new(
-                "Failed to convert path to CString when creating cf".to_owned(),
-            ));
-        };
+        let cf_name = CString::new(name.as_bytes()).map_err(|_| {
+            Error::new("Failed to convert path to CString when creating cf".to_owned())
+        })?;
 
         Ok(unsafe {
             ffi_try!(ffi::rocksdb_transactiondb_create_column_family(