CI: switched to stable toolchain for clippy and fmt, fixed lints

.github/workflows/ci.yml

@@ -136,7 +136,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: Swatinem/rust-cache@v2
-      - uses: dtolnay/rust-toolchain@beta
+      - uses: dtolnay/rust-toolchain@stable
         with:
           components: clippy
       - name: Clippy (argmin-math)
@@ -161,7 +161,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: Swatinem/rust-cache@v2
-      - uses: dtolnay/rust-toolchain@beta
+      - uses: dtolnay/rust-toolchain@stable
         with:
           components: rustfmt
       - run: cargo fmt --all -- --check

crates/argmin-observer-slog/src/lib.rs

@@ -164,7 +164,7 @@ impl SlogLogger {
 
 struct SlogKV<'a>(&'a KV);
 
-impl<'a> slog::KV for SlogKV<'a> {
+impl slog::KV for SlogKV<'_> {
     fn serialize(&self, _record: &Record, serializer: &mut dyn Serializer) -> slog::Result {
         for idx in self.0.kv.iter() {
             serializer.emit_str(Key::from(idx.0.to_string()), &idx.1.to_string())?;

crates/argmin/src/solver/newton/newton_cg.rs

@@ -234,7 +234,7 @@ impl<'a, P, H> CGSubProblem<'a, P, H> {
     }
 }
 
-impl<'a, P, H> Operator for CGSubProblem<'a, P, H>
+impl<P, H> Operator for CGSubProblem<'_, P, H>
 where
     H: ArgminDot<P, P>,
 {

crates/finitediff/src/array/mod.rs

@@ -5,6 +5,9 @@
 // http://opensource.org/licenses/MIT>, at your option. This file may not be
 // copied, modified, or distributed except according to those terms.
 
+// Some types just are complex
+#![allow(clippy::type_complexity)]
+
 pub mod diff;
 pub mod hessian;
 pub mod jacobian;

crates/finitediff/src/vec/mod.rs

@@ -5,6 +5,9 @@
 // http://opensource.org/licenses/MIT>, at your option. This file may not be
 // copied, modified, or distributed except according to those terms.
 
+// Some types just are complex
+#![allow(clippy::type_complexity)]
+
 pub mod diff;
 pub mod hessian;
 pub mod jacobian;