Add MSRV and fix new clippy warnings

Cargo.toml

@@ -3,6 +3,7 @@ name = "monty"
 version = "1.0.0"
 edition = "2021"
 authors = ["Jamie Whiting"]
+rust-version = "1.83"
 
 [profile.release]
 panic = 'abort'

Makefile

@@ -14,7 +14,7 @@ default:
 	cargo rustc --release --bin monty --features=embed -- -C target-cpu=native --emit link=$(NAME)
 
 montytest:
-	cargo rustc --release --bin monty --features=uci-minimal,tunable -- -C target-cpu=native --emit link=$(NAME)
+	cargo +stable rustc --release --bin monty --features=uci-minimal,tunable -- -C target-cpu=native --emit link=$(NAME)
 
 noembed:
 	cargo rustc --release --bin monty -- -C target-cpu=native --emit link=$(NAME)

src/tree/half.rs

@@ -29,7 +29,7 @@ impl TreeHalf {
 
         unsafe {
             use std::mem::MaybeUninit;
-            let chunk_size = (size + threads - 1) / threads;
+            let chunk_size = size.div_ceil(threads);
             let ptr = res.nodes.as_mut_ptr().cast();
             let uninit: &mut [MaybeUninit<Node>] = std::slice::from_raw_parts_mut(ptr, size);
 
@@ -83,7 +83,7 @@ impl TreeHalf {
 
     fn clear_ptrs_multi_threaded(&self, threads: usize) {
         std::thread::scope(|s| {
-            let chunk_size = (self.nodes.len() + threads - 1) / threads;
+            let chunk_size = self.nodes.len().div_ceil(threads);
 
             s.spawn(move || {
                 for node_chunk in self.nodes.chunks(chunk_size) {

src/tree/hash.rs

@@ -39,7 +39,7 @@ pub struct HashTable {
 
 impl HashTable {
     pub fn new(size: usize, threads: usize) -> Self {
-        let chunk_size = (size + threads - 1) / threads;
+        let chunk_size = size.div_ceil(threads);
 
         let mut table = HashTable { table: Vec::new() };
         table.table.reserve_exact(size);
@@ -65,7 +65,7 @@ impl HashTable {
     }
 
     pub fn clear(&mut self, threads: usize) {
-        let chunk_size = (self.table.len() + threads - 1) / threads;
+        let chunk_size = self.table.len().div_ceil(threads);
 
         std::thread::scope(|s| {
             for chunk in self.table.chunks_mut(chunk_size) {