Issue 3223: First phase of migration to Rust Edition 2024

Update cargo dependencies Apply cargo fix --edition Change cargo.toml edition property to `2024` ^ Conflicts: ^ Cargo.lock ^ src/ffi.rs ^ Conflicts: ^ src/offset_table.rs ^ src/raw_block.rs
2026-04-02 15:55:45 -04:00
parent daaab1cb37
commit efbddeaeee
32 changed files with 389 additions and 395 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -204,9 +204,9 @@ checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 [[package]]
 name = "bitflags"
-version = "2.11.1"
+version = "2.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c4512299f36f043ab09a583e57bceb5a5aab7a73db1805848e8fef3c9e8c78b3"
+checksum = "84d7ced0ae9557296835c32bf1b1e02b44c746701f898460fb000d7eaa84f00a"
 [[package]]
 name = "bitvec"
@@ -279,12 +279,12 @@ checksum = "37b2a672a2cb129a2e41c10b1224bb368f9f37a2b16b612598138befd7b37eb5"
 [[package]]
 name = "cc"
-version = "1.2.62"
+version = "1.2.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1dce859f0832a7d088c4f1119888ab94ef4b5d6795d1ce05afb7fe159d79f98"
+checksum = "556e016178bb5662a08681bbe0f00f8e17631781a4dfc8c45e466e4b185ec27f"
 dependencies = [
 "find-msvc-tools",
- "shlex",
+ "shlex 2.0.1",
 ]
 [[package]]
@@ -525,7 +525,7 @@ version = "0.28.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "829d955a0bb380ef178a640b91779e3987da38c9aea133b20614cfed8cdea9c6"
 dependencies = [
- "bitflags 2.11.1",
+ "bitflags 2.12.1",
 "crossterm_winapi",
 "mio",
 "parking_lot",
@@ -613,9 +613,9 @@ checksum = "a74858bcfe44b22016cb49337d7b6f04618c58e5dbfdef61b06b8c434324a0bc"
 [[package]]
 name = "dashu"
-version = "0.4.2"
+version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85b3e5ac1e23ff1995ef05b912e2b012a8784506987a2651552db2c73fb3d7e0"
+checksum = "dc8621924e1a1d2e19f3ea55c7b553a90b1f63a0a5c0a3f5b44afce841d08aa0"
 dependencies = [
 "dashu-base",
 "dashu-float",
@@ -627,15 +627,15 @@ dependencies = [
 [[package]]
 name = "dashu-base"
-version = "0.4.1"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0b80bf6b85aa68c58ffea2ddb040109943049ce3fbdf4385d0380aef08ef289"
+checksum = "fab3f0756c8585395280bd81b384cd28bbd66d6b00e66124ecfd1f644938b38c"
 [[package]]
 name = "dashu-float"
-version = "0.4.3"
+version = "0.4.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85078445a8dbd2e1bd21f04a816f352db8d333643f0c9b78ca7c3d1df71063e7"
+checksum = "85d913daa4f8193f709a2b5cc87a8be649dac8d816f7f049fb0a38e8b9e5d23b"
 dependencies = [
 "dashu-base",
 "dashu-int",
@@ -648,9 +648,9 @@ dependencies = [
 [[package]]
 name = "dashu-int"
-version = "0.4.1"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee99d08031ca34a4d044efbbb21dff9b8c54bb9d8c82a189187c0651ffdb9fbf"
+checksum = "d6a93d93dc2aca9a071e6ecb2af883441e8b34357a1037bc536e1c52b0d3c713"
 dependencies = [
 "cfg-if",
 "dashu-base",
@@ -663,15 +663,15 @@ dependencies = [
 [[package]]
 name = "dashu-macros"
-version = "0.4.1"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "93381c3ef6366766f6e9ed9cf09e4ef9dec69499baf04f0c60e70d653cf0ab10"
+checksum = "a89dbf51c81b22b30a0a30a4fcff84c4af8bdcd7a6159a556007b0b2dabc1e79"
 dependencies = [
 "dashu-base",
 "dashu-float",
 "dashu-int",
 "dashu-ratio",
- "paste",
+ "pastey",
 "proc-macro2",
 "quote",
 "rustversion",
@@ -679,9 +679,9 @@ dependencies = [
 [[package]]
 name = "dashu-ratio"
-version = "0.4.1"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "47e33b04dd7ce1ccf8a02a69d3419e354f2bbfdf4eb911a0b7465487248764c9"
+checksum = "b689daf8ea2221461973a29752a648e2971a377acefbf20df88e063f491032c7"
 dependencies = [
 "dashu-base",
 "dashu-float",
@@ -758,7 +758,7 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1e0e367e4e7da84520dedcac1901e4da967309406d1e51017ae1abfb97adbd38"
 dependencies = [
- "bitflags 2.11.1",
+ "bitflags 2.12.1",
 "block2",
 "libc",
 "objc2",
@@ -766,9 +766,9 @@ dependencies = [
 [[package]]
 name = "displaydoc"
-version = "0.2.5"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "97369cbbc041bc366949bc74d34658d6cda5621039731c6310521892a3a20ae0"
+checksum = "1ac70aa55017e108007fbaf5aa0f54b021c98f92ff8af59d42eda9da96e3dd4f"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -1711,9 +1711,9 @@ dependencies = [
 [[package]]
 name = "libredox"
-version = "0.1.16"
+version = "0.1.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e02f3bb43d335493c96bf3fd3a321600bf6bd07ed34bc64118e9293bdffea46c"
+checksum = "f02ab6bace2054fb888a3c16f990117b579d14a3088e472d63c6011fa185c9d3"
 dependencies = [
 "libc",
 ]
@@ -1747,9 +1747,9 @@ dependencies = [
 [[package]]
 name = "log"
-version = "0.4.30"
+version = "0.4.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "616ec5685824bcc94416c6d4a7a446eea774a31efd7062c8480ba6fd06d7a6e5"
+checksum = "113b30b4cd05f7c06868fdb2854f66a7b9fece9a48425351cd532e810d74024f"
 [[package]]
 name = "mac"
@@ -1790,9 +1790,9 @@ dependencies = [
 [[package]]
 name = "memchr"
-version = "2.8.0"
+version = "2.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
+checksum = "6b947ae49db0d222b1dbc6b113ce7248a3fc3a6ca21b696717bfc000ba4484d8"
 [[package]]
 name = "memmap2"
@@ -1830,9 +1830,9 @@ dependencies = [
 [[package]]
 name = "mio"
-version = "1.2.0"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "50b7e5b27aa02a74bac8c3f23f448f8d87ff11f92d3aac1a6ed369ee08cc56c1"
+checksum = "02bd0af71c67b473010cbbc60715ee815645a4dc942899111f494b4b737d6fda"
 dependencies = [
 "libc",
 "log",
@@ -1928,7 +1928,7 @@ version = "0.31.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf20d2fde8ff38632c426f1165ed7436270b44f199fc55284c38276f9db47c3d"
 dependencies = [
- "bitflags 2.11.1",
+ "bitflags 2.12.1",
 "cfg-if",
 "cfg_aliases",
 "libc",
@@ -2031,7 +2031,7 @@ version = "0.10.80"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a45fa2aa886c42762255da344f0a0d313e254066c46aad76f300c3d3da62d967"
 dependencies = [
- "bitflags 2.11.1",
+ "bitflags 2.12.1",
 "cfg-if",
 "foreign-types",
 "libc",
@@ -2135,10 +2135,10 @@ dependencies = [
 ]
 [[package]]
-name = "paste"
+name = "pastey"
-version = "1.0.15"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
+checksum = "2ee67f1008b1ba2321834326597b8e186293b049a023cdef258527550b9935b4"
 [[package]]
 name = "percent-encoding"
@@ -2472,7 +2472,7 @@ version = "0.5.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed2bf2547551a7053d6fdfafda3f938979645c44812fbfcda098faae3f1a362d"
 dependencies = [
- "bitflags 2.11.1",
+ "bitflags 2.12.1",
 ]
 [[package]]
@@ -2614,7 +2614,7 @@ version = "0.38.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fdb5bc1ae2baa591800df16c9ca78619bf65c0488b41b96ccec5d11220d8c154"
 dependencies = [
- "bitflags 2.11.1",
+ "bitflags 2.12.1",
 "errno",
 "libc",
 "linux-raw-sys 0.4.15",
@@ -2627,7 +2627,7 @@ version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b6fe4565b9518b83ef4f91bb47ce29620ca828bd32cb7e408f0062e9930ba190"
 dependencies = [
- "bitflags 2.11.1",
+ "bitflags 2.12.1",
 "errno",
 "libc",
 "linux-raw-sys 0.12.1",
@@ -2698,7 +2698,7 @@ version = "18.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4a990b25f351b25139ddc7f21ee3f6f56f86d6846b74ac8fad3a719a287cd4a0"
 dependencies = [
- "bitflags 2.11.1",
+ "bitflags 2.12.1",
 "cfg-if",
 "clipboard-win",
 "home",
@@ -2728,15 +2728,6 @@ dependencies = [
 "winapi-util",
 ]
 [[package]]
 name = "scc"
 version = "2.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "46e6f046b7fef48e2660c57ed794263155d713de679057f2d0c169bfc6e756cc"
 dependencies = [
 "sdd",
 ]
 [[package]]
 name = "schannel"
 version = "0.1.29"
@@ -2848,19 +2839,13 @@ dependencies = [
 "web-sys",
 ]
 [[package]]
 name = "sdd"
 version = "3.0.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "490dcfcbfef26be6800d11870ff2df8774fa6e86d047e3e8c8a76b25655e41ca"
 [[package]]
 name = "security-framework"
 version = "3.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b7f4bc775c73d9a02cde8bf7b2ec4c9d12743edf609006c7facc23998404cd1d"
 dependencies = [
- "bitflags 2.11.1",
+ "bitflags 2.12.1",
 "core-foundation 0.10.1",
 "core-foundation-sys",
 "libc",
@@ -2883,7 +2868,7 @@ version = "0.26.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fd568a4c9bb598e291a08244a5c1f5a8a6650bee243b5b0f8dbb3d9cc1d87fe8"
 dependencies = [
- "bitflags 2.11.1",
+ "bitflags 2.12.1",
 "cssparser",
 "derive_more",
 "fxhash",
@@ -2979,24 +2964,23 @@ dependencies = [
 [[package]]
 name = "serial_test"
-version = "3.4.0"
+version = "3.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "911bd979bf1070a3f3aa7b691a3b3e9968f339ceeec89e08c280a8a22207a32f"
+checksum = "699f4197115b8a7e7ff19c9a315a4bd6fffec26cc4626ef45ecaea389e081c6d"
 dependencies = [
 "futures-executor",
 "futures-util",
 "log",
 "once_cell",
 "parking_lot",
 "scc",
 "serial_test_derive",
 ]
 [[package]]
 name = "serial_test_derive"
-version = "3.4.0"
+version = "3.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0a7d91949b85b0d2fb687445e448b40d322b6b3e4af6b44a29b21d9a5f33e6d9"
+checksum = "94e153fc76e1c6a068703d6d29c508a0b15c061c4b7e43da59cc097bc342673c"
 dependencies = [
 "proc-macro2",
 "quote",
@@ -3050,6 +3034,12 @@ version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
 [[package]]
 name = "shlex"
 version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8fadd59c855ef2080decdef8ff161eb6661b86933c9d82e5ba29dc602a55aba"
 [[package]]
 name = "signal-hook"
 version = "0.3.18"
@@ -3148,9 +3138,9 @@ dependencies = [
 [[package]]
 name = "socket2"
-version = "0.6.3"
+version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3a766e1110788c36f4fa1c2b71b387a7815aa65f88ce0229841826633d93723e"
+checksum = "52d1cfed4120b4d927bf7c0f86d2087a4a7d6027c906d9f9d525a80573b9be51"
 dependencies = [
 "libc",
 "windows-sys 0.61.2",
@@ -3415,7 +3405,7 @@ dependencies = [
 "parking_lot",
 "pin-project-lite",
 "signal-hook-registry",
- "socket2 0.6.3",
+ "socket2 0.6.4",
 "tokio-macros",
 "windows-sys 0.61.2",
 ]
@@ -3561,7 +3551,7 @@ dependencies = [
 "humantime-serde",
 "rayon",
 "serde",
- "shlex",
+ "shlex 1.3.0",
 "snapbox",
 "toml_edit",
 ]
@@ -3587,9 +3577,9 @@ dependencies = [
 [[package]]
 name = "typenum"
-version = "1.20.0"
+version = "1.20.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "40ce102ab67701b8526c123c1bab5cbe42d7040ccfd0f64af1a385808d2f43de"
+checksum = "b6f5e870be6c3b371b77fe0ee0bafb859fa4964b4404c27de1d380043c4dda20"
 [[package]]
 name = "unicase"
@@ -3605,9 +3595,9 @@ checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 [[package]]
 name = "unicode-segmentation"
-version = "1.13.2"
+version = "1.13.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9629274872b2bfaf8d66f5f15725007f635594914870f65218920345aa11aa8c"
+checksum = "c6f5d3c3b1bf09027a88a6bc961fc00497d651009560b5463668dc81b0fa87a8"
 [[package]]
 name = "unicode-width"
@@ -3659,9 +3649,9 @@ checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 [[package]]
 name = "uuid"
-version = "1.23.1"
+version = "1.23.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ddd74a9687298c6858e9b88ec8935ec45d22e8fd5e6394fa1bd4e99a87789c76"
+checksum = "d258b83ceec21034727ecee8c382cfa6c3e133699b0742c64571814fb420c9f7"
 dependencies = [
 "js-sys",
 "wasm-bindgen",
@@ -3845,7 +3835,7 @@ version = "0.244.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "47b807c72e1bac69382b3a6fb3dbe8ea4c0ed87ff5629b8685ae6b9a611028fe"
 dependencies = [
- "bitflags 2.11.1",
+ "bitflags 2.12.1",
 "hashbrown 0.15.5",
 "indexmap",
 "semver",
@@ -4271,7 +4261,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9d66ea20e9553b30172b5e831994e35fbde2d165325bec84fc43dbf6f4eb9cb2"
 dependencies = [
 "anyhow",
- "bitflags 2.11.1",
+ "bitflags 2.12.1",
 "indexmap",
 "log",
 "serde",
@@ -4347,18 +4337,18 @@ dependencies = [
 [[package]]
 name = "zerocopy"
-version = "0.8.48"
+version = "0.8.50"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eed437bf9d6692032087e337407a86f04cd8d6a16a37199ed57949d415bd68e9"
+checksum = "3b065d4f0e55f82fae73202e189638116a87c55ab6b8e6c2721e13dd9d854ad1"
 dependencies = [
 "zerocopy-derive",
 ]
 [[package]]
 name = "zerocopy-derive"
-version = "0.8.48"
+version = "0.8.50"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70e3cd084b1788766f53af483dd21f93881ff30d7320490ec3ef7526d203bad4"
+checksum = "0b631b19d36a892ab55420c92dbc83ccd79274f25be714855d3074aa71cab639"
 dependencies = [
 "proc-macro2",
 "quote",
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,7 +2,7 @@
 name = "scryer-prolog"
 version = "0.10.0"
 authors = ["Mark Thom <markjordanthom@gmail.com>"]
-edition = "2021"
+edition = "2024"
 description = "A modern Prolog implementation written mostly in Rust."
 readme = "README.md"
 repository = "https://github.com/mthom/scryer-prolog"
--- a/benches/setup.rs
+++ b/benches/setup.rs
@@ -70,7 +70,7 @@ impl PrologBenchmark {
    }
    #[cfg(not(all(target_arch = "wasm32", target_os = "unknown")))]
-    pub fn setup(&self) -> impl FnMut() -> Vec<LeafAnswer> {
+    pub fn setup(&self) -> impl FnMut() -> Vec<LeafAnswer> + use<> {
        let mut machine = self.make_machine();
        let query = self.query;
        move || {
--- a/src/arena.rs
+++ b/src/arena.rs
@@ -281,14 +281,14 @@ pub trait ArenaAllocated {
    unsafe fn typed_ptr(ptr: UntypedArenaPtr) -> TypedArenaPtr<Self>
    where
        Self::Payload: Sized,
-    {
+    { unsafe {
        TypedArenaPtr(NonNull::new_unchecked(
            ptr.get_ptr()
                .byte_add(Self::header_offset_from_payload())
                .cast_mut()
                .cast::<Self::Payload>(),
        ))
-    }
+    }}
    #[allow(clippy::missing_safety_doc)]
    fn alloc(arena: &mut Arena, value: Self::Payload) -> TypedArenaPtr<Self>
@@ -496,7 +496,7 @@ impl Arena {
    }
 }
-unsafe fn drop_slab_in_place(value: NonNull<AllocSlab>, tag: ArenaHeaderTag) {
+unsafe fn drop_slab_in_place(value: NonNull<AllocSlab>, tag: ArenaHeaderTag) { unsafe {
    macro_rules! drop_typed_slab_in_place {
        ($payload: ty, $value: expr) => {
            <$payload as ArenaAllocated>::dealloc($value.cast::<TypedAllocSlab<$payload>>())
@@ -580,7 +580,7 @@ unsafe fn drop_slab_in_place(value: NonNull<AllocSlab>, tag: ArenaHeaderTag) {
            unreachable!("NullStream is never arena allocated!");
        }
    }
-}
+}}
 impl Drop for Arena {
    fn drop(&mut self) {
--- a/src/arithmetic.rs
+++ b/src/arithmetic.rs
@@ -361,7 +361,7 @@ pub(crate) fn rnd_i(n: &'_ Number, arena: &mut Arena) -> Result<Number, EvalErro
                )))
            }
        }
-        Number::Rational(ref r) => {
+        Number::Rational(r) => {
            let floor = r.floor();
            if let Ok(value) = Fixnum::build_with_checked(&floor) {
@@ -384,9 +384,9 @@ impl From<Fixnum> for Integer {
 pub(crate) fn rnd_f(n: &Number) -> f64 {
    match n {
        &Number::Fixnum(n) => n.get_num() as f64,
-        Number::Integer(ref n) => n.to_f64().value(),
+        Number::Integer(n) => n.to_f64().value(),
        &Number::Float(OrderedFloat(f)) => f,
-        Number::Rational(ref r) => r.to_f64().value(),
+        Number::Rational(r) => r.to_f64().value(),
    }
 }
@@ -514,33 +514,33 @@ impl PartialEq for Number {
    fn eq(&self, rhs: &Self) -> bool {
        match (self, rhs) {
            (&Number::Fixnum(n1), &Number::Fixnum(n2)) => n1.eq(&n2),
-            (&Number::Fixnum(n1), Number::Integer(ref n2)) => n1.get_num().num_eq(&**n2),
+            (&Number::Fixnum(n1), Number::Integer(n2)) => n1.get_num().num_eq(&**n2),
-            (Number::Integer(ref n1), &Number::Fixnum(n2)) => n1.num_eq(&n2.get_num()),
+            (Number::Integer(n1), &Number::Fixnum(n2)) => n1.num_eq(&n2.get_num()),
-            (&Number::Fixnum(n1), Number::Rational(ref n2)) => {
+            (&Number::Fixnum(n1), Number::Rational(n2)) => {
                Integer::from(n1.get_num()).num_eq(&**n2)
            }
-            (Number::Rational(ref n1), &Number::Fixnum(n2)) => {
+            (Number::Rational(n1), &Number::Fixnum(n2)) => {
                n1.num_eq(&Integer::from(n2.get_num()))
            }
            (&Number::Fixnum(n1), &Number::Float(n2)) => OrderedFloat(n1.get_num() as f64).eq(&n2),
            (&Number::Float(n1), &Number::Fixnum(n2)) => n1.eq(&OrderedFloat(n2.get_num() as f64)),
-            (Number::Integer(ref n1), Number::Integer(ref n2)) => n1.eq(n2),
+            (Number::Integer(n1), Number::Integer(n2)) => n1.eq(n2),
-            (Number::Integer(ref n1), Number::Float(n2)) => {
+            (Number::Integer(n1), Number::Float(n2)) => {
                OrderedFloat(n1.to_f64().value()).eq(n2)
            }
-            (&Number::Float(n1), Number::Integer(ref n2)) => {
+            (&Number::Float(n1), Number::Integer(n2)) => {
                n1.eq(&OrderedFloat(n2.to_f64().value()))
            }
-            (Number::Integer(ref n1), Number::Rational(ref n2)) => n1.num_eq(&**n2),
+            (Number::Integer(n1), Number::Rational(n2)) => n1.num_eq(&**n2),
-            (Number::Rational(ref n1), Number::Integer(ref n2)) => n1.num_eq(&**n2),
+            (Number::Rational(n1), Number::Integer(n2)) => n1.num_eq(&**n2),
-            (Number::Rational(ref n1), &Number::Float(n2)) => {
+            (Number::Rational(n1), &Number::Float(n2)) => {
                OrderedFloat(n1.to_f64().value()).eq(&n2)
            }
-            (&Number::Float(n1), Number::Rational(ref n2)) => {
+            (&Number::Float(n1), Number::Rational(n2)) => {
                n1.eq(&OrderedFloat(n2.to_f64().value()))
            }
            (&Number::Float(f1), &Number::Float(f2)) => f1.eq(&f2),
-            (Number::Rational(ref r1), Number::Rational(ref r2)) => r1.eq(r2),
+            (Number::Rational(r1), Number::Rational(r2)) => r1.eq(r2),
        }
    }
 }
@@ -607,7 +607,7 @@ impl Ord for Number {
            (&Number::Float(n1), &Number::Fixnum(n2)) => n1.cmp(&OrderedFloat(n2.get_num() as f64)),
            (&Number::Integer(n1), &Number::Integer(n2)) => (*n1).cmp(&*n2),
            (&Number::Integer(n1), Number::Float(n2)) => OrderedFloat(n1.to_f64().value()).cmp(n2),
-            (&Number::Float(n1), Number::Integer(ref n2)) => {
+            (&Number::Float(n1), Number::Integer(n2)) => {
                n1.cmp(&OrderedFloat(n2.to_f64().value()))
            }
            (&Number::Integer(n1), &Number::Rational(n2)) => {
--- a/src/atom_table.rs
+++ b/src/atom_table.rs
@@ -388,9 +388,11 @@ impl Atom {
 }
 unsafe fn write_to_ptr(string: &str, ptr: *mut u8) { 
-    ptr::write(ptr as *mut _, AtomHeader::build_with(string.len() as u64));
+    unsafe { ptr::write(ptr as *mut _, AtomHeader::build_with(string.len() as u64)); }
    unsafe {
        let str_ptr = ptr.add(mem::size_of::<AtomHeader>());
        ptr::copy_nonoverlapping(string.as_ptr(), str_ptr, string.len());
    }
 }
 impl PartialOrd for Atom {
--- a/src/codegen.rs
+++ b/src/codegen.rs
@@ -345,10 +345,10 @@ impl<'a> AddToFreeList<'a, QueryInstruction> for CodeGenerator {
 fn structure_cell(term: &Term) -> Option<&Cell<RegType>> {
    match term {
-        &Term::Cons(ref cell, ..)
+        Term::Cons(cell, ..)
-        | &Term::Clause(ref cell, ..)
+        | Term::Clause(cell, ..)
-        | Term::PartialString(ref cell, ..)
+        | Term::PartialString(cell, ..)
-        | Term::CompleteString(ref cell, ..) => Some(cell),
+        | Term::CompleteString(cell, ..) => Some(cell),
        _ => None,
    }
 }
@@ -401,18 +401,18 @@ impl CodeGenerator {
            &Term::AnonVar => {
                Self::add_or_increment_void_instr::<Target>(target);
            }
-            &Term::Cons(ref cell, ..)
+            Term::Cons(cell, ..)
-            | &Term::Clause(ref cell, ..)
+            | Term::Clause(cell, ..)
-            | Term::PartialString(ref cell, ..)
+            | Term::PartialString(cell, ..)
-            | Term::CompleteString(ref cell, ..) => {
+            | Term::CompleteString(cell, ..) => {
                self.marker
                    .mark_non_var::<Target>(Level::Deep, term_loc, cell, target);
                target.push_back(Target::clause_arg_to_instr(cell.get()));
            }
-            Term::Literal(_, ref constant) => {
+            Term::Literal(_, constant) => {
                target.push_back(Target::constant_subterm(*constant));
            }
-            Term::Var(ref cell, ref var_ptr) => {
+            Term::Var(cell, var_ptr) => {
                self.deep_var_instr::<Target>(
                    cell,
                    var_ptr.to_var_num().unwrap(),
@@ -572,7 +572,7 @@ impl CodeGenerator {
                Term::Literal(_, Literal::Atom(..)) => {
                    instr!("$succeed")
                }
-                Term::Var(ref vr, ref name) => {
+                Term::Var(vr, name) => {
                    self.marker.reset_arg(1);
                    let r = self.marker.mark_non_callable(
@@ -600,7 +600,7 @@ impl CodeGenerator {
                Term::Literal(..) => {
                    instr!("$succeed")
                }
-                Term::Var(ref vr, ref name) => {
+                Term::Var(vr, name) => {
                    self.marker.reset_arg(1);
                    let r = self.marker.mark_non_callable(
@@ -621,7 +621,7 @@ impl CodeGenerator {
                | Term::CompleteString(..) => {
                    instr!("$succeed")
                }
-                Term::Var(ref vr, ref name) => {
+                Term::Var(vr, name) => {
                    self.marker.reset_arg(1);
                    let r = self.marker.mark_non_callable(
@@ -733,7 +733,7 @@ impl CodeGenerator {
                Term::Literal(_, Literal::Integer(_)) | Term::Literal(_, Literal::Fixnum(_)) => {
                    instr!("$succeed")
                }
-                Term::Var(ref vr, name) => {
+                Term::Var(vr, name) => {
                    self.marker.reset_arg(1);
                    let r = self.marker.mark_non_callable(
@@ -828,7 +828,7 @@ impl CodeGenerator {
                    self.marker
                        .mark_anon_var::<QueryInstruction>(Level::Shallow, term_loc, code);
-                    if let Term::Var(ref vr, ref var) = &terms[1] {
+                    if let Term::Var(vr, var) = &terms[1] {
                        let var_num = var.to_var_num().unwrap();
                        // if var is an anonymous variable, insert
--- a/src/debray_allocator.rs
+++ b/src/debray_allocator.rs
@@ -158,7 +158,7 @@ impl DebrayAllocator {
        for var_num in subsumed_hits {
            match &mut self.var_data.records[var_num].allocation {
-                VarAlloc::Perm(_, ref mut allocation) => {
+                VarAlloc::Perm(_, allocation) => {
                    if let PermVarAllocation::Done {
                        shallow_safety,
                        deep_safety,
@@ -551,7 +551,7 @@ impl DebrayAllocator {
                } else if let Some(&temp_var_num) = self.shallow_temp_mappings.get(&self.arg_c) {
                    match &mut self.var_data.records[temp_var_num].allocation {
                        VarAlloc::Temp {
-                            ref mut to_perm_var_num,
+                            to_perm_var_num,
                            ..
                        } => {
                            *to_perm_var_num = Some(var_num);
@@ -560,7 +560,7 @@ impl DebrayAllocator {
                    }
                }
            }
-            VarAlloc::Temp { ref mut safety, .. } => {
+            VarAlloc::Temp { safety, .. } => {
                *safety = VarSafetyStatus::GloballyUnneeded;
            }
            _ => {
@@ -581,7 +581,7 @@ impl DebrayAllocator {
            VarAlloc::Perm(
                _,
                PermVarAllocation::Done {
-                    ref mut shallow_safety,
+                    shallow_safety,
                    ..
                },
            ) => {
@@ -617,7 +617,7 @@ impl DebrayAllocator {
            VarAlloc::Perm(
                _,
                PermVarAllocation::Done {
-                    ref mut deep_safety,
+                    deep_safety,
                    ..
                },
            ) => {
@@ -631,7 +631,7 @@ impl DebrayAllocator {
                    Target::unsafe_subterm_to_value(r)
                }
            }
-            VarAlloc::Temp { ref mut safety, .. } => {
+            VarAlloc::Temp { safety, .. } => {
                if self
                    .branch_stack
                    .safety_unneeded_in_branch(safety, &branch_designator)
@@ -874,7 +874,7 @@ impl Allocator for DebrayAllocator {
        self.arity = args.len();
        for (idx, arg) in args.iter().enumerate() {
-            if let Term::Var(_, ref var) = arg {
+            if let Term::Var(_, var) = arg {
                let var_num = var.to_var_num().unwrap();
                let r = self.get_binding(var_num);
--- a/src/ffi.rs
+++ b/src/ffi.rs
@@ -53,27 +53,27 @@ pub struct FunctionImpl {
 }
 impl FunctionImpl {
-    unsafe fn call_void(&self, args: &[Arg], _: &mut Arena) -> Result<Value, FfiError> {
+    unsafe fn call_void(&self, args: &[Arg], _: &mut Arena) -> Result<Value, FfiError> { unsafe {
        self.cif.call_return_into(self.code_ptr, args, Ret::void());
        Ok(Value::Number(Number::Fixnum(Fixnum::build_with(0))))
-    }
+    }}
    unsafe fn call_int<T>(&self, args: &[Arg], arena: &mut Arena) -> Result<Value, FfiError>
    where
        Integer: From<T>,
        T: Copy + TryInto<i64> + MightNotFitInFixnum,
-    {
+    { unsafe {
        let n = self.cif.call::<T>(self.code_ptr, args);
        Ok(Value::Number(fixnum!(Number, n, arena)))
-    }
+    }}
    unsafe fn call_float<T>(&self, args: &[Arg], _: &mut Arena) -> Result<Value, FfiError>
    where
        T: Into<f64>,
-    {
+    { unsafe {
        let n = self.cif.call::<T>(self.code_ptr, args);
        Ok(Value::Number(Number::Float(OrderedFloat(n.into()))))
-    }
+    }}
    unsafe fn call_ptr(&self, args: &[Arg], arena: &mut Arena) -> Result<Value, FfiError> {
        let ptr = unsafe { self.cif.call::<*mut c_void>(self.code_ptr, args) };
@@ -197,14 +197,14 @@ impl StructImpl {
            ptr: NonNull<c_void>,
            layout: &mut Layout,
            val: T,
-        ) -> Result<(), FfiError> {
+        ) -> Result<(), FfiError> { unsafe {
            let (new_layout, offset) = layout
                .extend(Layout::new::<T>())
                .map_err(|_| FfiError::LayoutError)?;
            *layout = new_layout;
            ptr.byte_offset(offset as isize).cast::<T>().write(val);
            Ok(())
-        }
+        }}
        for arg in args {
            unsafe {
@@ -258,14 +258,14 @@ impl StructImpl {
            unsafe fn read_primitive<T>(
                ptr: *mut c_void,
                layout: &mut Layout,
-            ) -> Result<T, FfiError> {
+            ) -> Result<T, FfiError> { unsafe {
                let (new_layout, offset) = layout
                    .extend(Layout::new::<T>())
                    .map_err(|_| FfiError::LayoutError)?;
                *layout = new_layout;
                let n = std::ptr::read::<T>(ptr.byte_offset(offset as isize).cast());
                Ok(n)
-            }
+            }}
            unsafe fn read_int<T>(
                ptr: *mut c_void,
@@ -275,10 +275,10 @@ impl StructImpl {
            where
                T: Copy + TryInto<i64> + MightNotFitInFixnum,
                Integer: From<T>,
-            {
+            { unsafe {
                let n = read_primitive::<T>(ptr, layout)?;
                Ok(Value::Number(fixnum!(Number, n, arena)))
-            }
+            }}
            unsafe fn read_float<T>(
                ptr: *mut c_void,
@@ -286,10 +286,10 @@ impl StructImpl {
            ) -> Result<Value, FfiError>
            where
                T: Into<f64>,
-            {
+            { unsafe {
                let n = read_primitive::<T>(ptr, layout)?;
                Ok(Value::Number(Number::Float(OrderedFloat(n.into()))))
-            }
+            }}
            let mut layout = Layout::from_size_align(0, 1).map_err(|_| FfiError::LayoutError)?;
@@ -788,10 +788,10 @@ impl ForeignFunctionTable {
        where
            T: Copy + TryInto<i64> + MightNotFitInFixnum,
            Integer: From<T>,
-        {
+        { unsafe {
            let n = ptr.cast::<T>().read();
            Value::Number(fixnum!(Number, n, arena))
-        }
+        }}
        let ptr = ptr.as_ptr()?;
@@ -924,7 +924,7 @@ impl Value {
    fn as_ptr(&mut self) -> Result<*mut c_void, FfiError> {
        match self {
-            Value::CString(ref mut cstr) => Ok(cstr.as_ptr().cast_mut().cast()),
+            Value::CString(cstr) => Ok(cstr.as_ptr().cast_mut().cast()),
            Value::Number(Number::Fixnum(fixnum)) => Ok(std::ptr::with_exposed_provenance_mut(
                fixnum.get_num() as usize,
            )),
--- a/src/forms.rs
+++ b/src/forms.rs
@@ -389,15 +389,15 @@ impl ClauseInfo for Rule {
 impl ClauseInfo for PredicateClause {
    fn name(&self) -> Option<Atom> {
        match self {
-            PredicateClause::Fact(ref term, ..) => term.head.name(),
+            PredicateClause::Fact(term, ..) => term.head.name(),
-            PredicateClause::Rule(ref rule, ..) => rule.name(),
+            PredicateClause::Rule(rule, ..) => rule.name(),
        }
    }
    fn arity(&self) -> usize {
        match self {
-            PredicateClause::Fact(ref term, ..) => term.head.arity(),
+            PredicateClause::Fact(term, ..) => term.head.arity(),
-            PredicateClause::Rule(ref rule, ..) => rule.arity(),
+            PredicateClause::Rule(rule, ..) => rule.arity(),
        }
    }
 }
@@ -582,7 +582,7 @@ pub(crate) fn fetch_op_spec_from_existing(
    op_desc: Option<OpDesc>,
    op_dir: &OpDir,
 ) -> Option<OpDesc> {
-    if let Some(ref op_desc) = &op_desc {
+    if let Some(op_desc) = &op_desc {
        if op_desc.arity() != arity {
            /* it's possible to extend operator functors with
             * additional terms. When that happens,
@@ -843,9 +843,9 @@ impl Number {
    pub(crate) fn is_positive(&self) -> bool {
        match self {
            Number::Fixnum(n) => n.get_num() > 0,
-            Number::Integer(ref n) => n.is_positive(),
+            Number::Integer(n) => n.is_positive(),
            Number::Float(f) => f.is_sign_positive(),
-            Number::Rational(ref r) => r.is_positive(),
+            Number::Rational(r) => r.is_positive(),
        }
    }
@@ -853,9 +853,9 @@ impl Number {
    pub(crate) fn is_negative(&self) -> bool {
        match self {
            Number::Fixnum(n) => n.get_num() < 0,
-            Number::Integer(ref n) => n.is_negative(),
+            Number::Integer(n) => n.is_negative(),
            &Number::Float(OrderedFloat(f)) => f.is_sign_negative() && f != -0f64,
-            Number::Rational(ref r) => r.is_negative(),
+            Number::Rational(r) => r.is_negative(),
        }
    }
@@ -863,9 +863,9 @@ impl Number {
    pub(crate) fn is_zero(&self) -> bool {
        match self {
            Number::Fixnum(n) => n.get_num() == 0,
-            Number::Integer(ref n) => n.is_zero(),
+            Number::Integer(n) => n.is_zero(),
            &Number::Float(OrderedFloat(f)) => f == 0.0 || f == -0.0,
-            Number::Rational(ref r) => r.is_zero(),
+            Number::Rational(r) => r.is_zero(),
        }
    }
@@ -920,9 +920,9 @@ impl OptArgIndexKey {
    #[inline]
    pub(crate) fn set_switch_on_term_loc(&mut self, value: usize) {
        match self {
-            OptArgIndexKey::Literal(_, ref mut loc, ..)
+            OptArgIndexKey::Literal(_, loc, ..)
-            | OptArgIndexKey::Structure(_, ref mut loc, ..)
+            | OptArgIndexKey::Structure(_, loc, ..)
-            | OptArgIndexKey::List(_, ref mut loc) => {
+            | OptArgIndexKey::List(_, loc) => {
                *loc = value;
            }
            OptArgIndexKey::None => {}
@@ -934,9 +934,9 @@ impl AddAssign<usize> for OptArgIndexKey {
    #[inline]
    fn add_assign(&mut self, n: usize) {
        match self {
-            OptArgIndexKey::Literal(_, ref mut o, ..)
+            OptArgIndexKey::Literal(_, o, ..)
-            | OptArgIndexKey::List(_, ref mut o)
+            | OptArgIndexKey::List(_, o)
-            | OptArgIndexKey::Structure(_, ref mut o, ..) => {
+            | OptArgIndexKey::Structure(_, o, ..) => {
                *o += n;
            }
            OptArgIndexKey::None => {}
--- a/src/heap_print.rs
+++ b/src/heap_print.rs
@@ -387,7 +387,7 @@ fn negated_op_needs_bracketing(
    op_dir: &OpDir,
    op: &Option<DirectedOp>,
 ) -> bool {
-    if let Some(ref op) = op {
+    if let Some(op) = op {
        op.is_negative_sign()
            && iter.leftmost_leaf_has_property(op_dir, |addr| {
                match Number::try_from((addr, f64_tbl)) {
@@ -1452,7 +1452,7 @@ impl<'a, Outputter: HCValueOutputter> HCPrinter<'a, Outputter> {
                    });
                for op in &[op, parent_op] {
-                    if let Some(ref op) = &op {
+                    if let Some(op) = &op {
                        if op.is_left()
                            && (op.is_prefix() || requires_space(&op.as_atom().as_str(), "("))
                        {
--- a/src/indexing.rs
+++ b/src/indexing.rs
@@ -167,7 +167,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
            .push(IndexingLine::IndexedChoice(third_level_index));
        match &mut self.indexing_code[self.offset] {
-            IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(ref mut constants)) => {
+            IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(constants)) => {
                constants.insert(
                    constant,
                    IndexingCodePtr::Internal(indexing_code_len - self.offset),
@@ -196,7 +196,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
            .push(IndexingLine::DynamicIndexedChoice(third_level_index));
        match &mut self.indexing_code[self.offset] {
-            IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(ref mut constants)) => {
+            IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(constants)) => {
                constants.insert(
                    constant,
                    IndexingCodePtr::Internal(indexing_code_len - self.offset),
@@ -210,22 +210,22 @@ impl<'a> IndexingCodeMergingPtr<'a> {
    fn extend_indexed_choice(&mut self, index: usize) {
        match &mut self.indexing_code[self.offset] {
-            IndexingLine::IndexedChoice(ref mut indexed_choice_instrs)
+            IndexingLine::IndexedChoice(indexed_choice_instrs)
                if self.append_or_prepend.is_append() =>
            {
                uncap_choice_seq_with_trust(indexed_choice_instrs.make_contiguous());
                indexed_choice_instrs.push_back(IndexedChoiceInstruction::Trust(index));
            }
-            IndexingLine::IndexedChoice(ref mut indexed_choice_instrs) => {
+            IndexingLine::IndexedChoice(indexed_choice_instrs) => {
                uncap_choice_seq_with_try(indexed_choice_instrs.make_contiguous());
                indexed_choice_instrs.push_front(IndexedChoiceInstruction::Try(index));
            }
-            IndexingLine::DynamicIndexedChoice(ref mut indexed_choice_instrs)
+            IndexingLine::DynamicIndexedChoice(indexed_choice_instrs)
                if self.append_or_prepend.is_append() =>
            {
                indexed_choice_instrs.push_back(index);
            }
-            IndexingLine::DynamicIndexedChoice(ref mut indexed_choice_instrs) => {
+            IndexingLine::DynamicIndexedChoice(indexed_choice_instrs) => {
                indexed_choice_instrs.push_front(index);
            }
            _ => {
@@ -244,7 +244,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
            let indexing_code_len = self.indexing_code.len();
            match &mut self.indexing_code[self.offset] {
-                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)) => {
+                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, c, ..)) => {
                    match *c {
                        IndexingCodePtr::Fail if self.is_dynamic => {
                            *c = IndexingCodePtr::DynamicExternal(index);
@@ -322,7 +322,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
            let indexing_code_len = self.indexing_code.len();
            match &mut self.indexing_code[self.offset] {
-                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)) => {
+                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, c, ..)) => {
                    match *c {
                        IndexingCodePtr::Fail if self.is_dynamic => {
                            *c = IndexingCodePtr::DynamicExternal(index);
@@ -445,7 +445,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
            .push(IndexingLine::IndexedChoice(third_level_index));
        match &mut self.indexing_code[self.offset] {
-            IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(ref mut structures)) => {
+            IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(structures)) => {
                structures.insert(
                    key,
                    IndexingCodePtr::Internal(indexing_code_len - self.offset),
@@ -474,7 +474,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
            .push(IndexingLine::DynamicIndexedChoice(third_level_index));
        match &mut self.indexing_code[self.offset] {
-            IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(ref mut structures)) => {
+            IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(structures)) => {
                structures.insert(
                    key,
                    IndexingCodePtr::Internal(indexing_code_len - self.offset),
@@ -496,7 +496,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
                    _,
                    _,
                    _,
-                    ref mut s,
+                    s,
                )) => match *s {
                    IndexingCodePtr::Fail if self.is_dynamic => {
                        *s = IndexingCodePtr::DynamicExternal(index);
@@ -559,7 +559,7 @@ impl<'a> IndexingCodeMergingPtr<'a> {
        let indexing_code_len = self.indexing_code.len();
        match &mut self.indexing_code[self.offset] {
-            IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, _, ref mut l, _)) => {
+            IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, _, l, _)) => {
                match *l {
                    IndexingCodePtr::Fail if self.is_dynamic => {
                        *l = IndexingCodePtr::DynamicExternal(index);
@@ -632,7 +632,7 @@ pub(crate) fn merge_clause_index(
    );
    match &opt_arg_index_key {
-        OptArgIndexKey::Literal(_, index_loc, constant, ref overlapping_constants) => {
+        OptArgIndexKey::Literal(_, index_loc, constant, overlapping_constants) => {
            let offset = new_clause_loc - index_loc + 1;
            merging_ptr.index_constant(HeapCellValue::from(*constant), offset);
@@ -676,7 +676,7 @@ pub(crate) fn remove_constant_indices(
    let iter = once(&constant).chain(overlapping_constants.iter());
    match &mut indexing_code[index] {
-        IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)) => {
+        IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, c, ..)) => {
            match *c {
                IndexingCodePtr::DynamicExternal(_) | IndexingCodePtr::External(_) => {
                    *c = IndexingCodePtr::Fail;
@@ -701,7 +701,7 @@ pub(crate) fn remove_constant_indices(
        loop {
            match &mut indexing_code[index] {
                IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(
-                    ref mut constants,
+                    constants,
                )) => {
                    constants_index = index;
@@ -720,7 +720,7 @@ pub(crate) fn remove_constant_indices(
                        }
                    }
                }
-                IndexingLine::IndexedChoice(ref mut indexed_choice_instrs) => {
+                IndexingLine::IndexedChoice(indexed_choice_instrs) => {
                    StaticCodeIndices::remove_instruction_with_offset(
                        indexed_choice_instrs,
                        offset,
@@ -734,13 +734,13 @@ pub(crate) fn remove_constant_indices(
                                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(
                                    _,
                                    _,
-                                    ref mut c,
+                                    c,
                                    ..,
                                )) => {
                                    *c = ext;
                                }
                                IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(
-                                    ref mut constants,
+                                    constants,
                                )) => {
                                    constants.insert(constant, ext);
                                }
@@ -753,7 +753,7 @@ pub(crate) fn remove_constant_indices(
                    break;
                }
-                IndexingLine::DynamicIndexedChoice(ref mut indexed_choice_instrs) => {
+                IndexingLine::DynamicIndexedChoice(indexed_choice_instrs) => {
                    DynamicCodeIndices::remove_instruction_with_offset(
                        indexed_choice_instrs,
                        offset,
@@ -767,13 +767,13 @@ pub(crate) fn remove_constant_indices(
                                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(
                                    _,
                                    _,
-                                    ref mut c,
+                                    c,
                                    ..,
                                )) => {
                                    *c = ext;
                                }
                                IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(
-                                    ref mut constants,
+                                    constants,
                                )) => {
                                    constants.insert(constant, ext);
                                }
@@ -794,11 +794,11 @@ pub(crate) fn remove_constant_indices(
    }
    match &indexing_code[constants_index] {
-        IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(ref constants))
+        IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(constants))
            if constants.is_empty() =>
        {
            match &mut indexing_code[0] {
-                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, ref mut c, ..)) => {
+                IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, c, ..)) => {
                    *c = IndexingCodePtr::Fail;
                }
                _ => {
@@ -819,7 +819,7 @@ pub(crate) fn remove_structure_index(
    let mut index = 0;
    match &mut indexing_code[index] {
-        IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, _, _, ref mut s)) => {
+        IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, _, _, s)) => {
            match *s {
                IndexingCodePtr::DynamicExternal(_) | IndexingCodePtr::External(_) => {
                    *s = IndexingCodePtr::Fail;
@@ -842,7 +842,7 @@ pub(crate) fn remove_structure_index(
    loop {
        match &mut indexing_code[index] {
-            IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(ref mut structures)) => {
+            IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(structures)) => {
                structures_index = index;
                match structures.get(&(name, arity)).cloned() {
@@ -859,7 +859,7 @@ pub(crate) fn remove_structure_index(
                    }
                }
            }
-            IndexingLine::IndexedChoice(ref mut indexed_choice_instrs) => {
+            IndexingLine::IndexedChoice(indexed_choice_instrs) => {
                StaticCodeIndices::remove_instruction_with_offset(indexed_choice_instrs, offset);
                if indexed_choice_instrs.len() == 1 {
@@ -872,12 +872,12 @@ pub(crate) fn remove_structure_index(
                                _,
                                _,
                                _,
-                                ref mut s,
+                                s,
                            )) => {
                                *s = ext;
                            }
                            IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(
-                                ref mut structures,
+                                structures,
                            )) => {
                                structures.insert((name, arity), ext);
                            }
@@ -890,7 +890,7 @@ pub(crate) fn remove_structure_index(
                break;
            }
-            IndexingLine::DynamicIndexedChoice(ref mut indexed_choice_instrs) => {
+            IndexingLine::DynamicIndexedChoice(indexed_choice_instrs) => {
                DynamicCodeIndices::remove_instruction_with_offset(indexed_choice_instrs, offset);
                if indexed_choice_instrs.len() == 1 {
@@ -903,12 +903,12 @@ pub(crate) fn remove_structure_index(
                                _,
                                _,
                                _,
-                                ref mut s,
+                                s,
                            )) => {
                                *s = ext;
                            }
                            IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(
-                                ref mut structures,
+                                structures,
                            )) => {
                                structures.insert((name, arity), ext);
                            }
@@ -928,7 +928,7 @@ pub(crate) fn remove_structure_index(
    }
    match &indexing_code[structures_index] {
-        IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(ref structures))
+        IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(structures))
            if structures.is_empty() =>
        {
            match &mut indexing_code[0] {
@@ -937,7 +937,7 @@ pub(crate) fn remove_structure_index(
                    _,
                    _,
                    _,
-                    ref mut s,
+                    s,
                )) => {
                    *s = IndexingCodePtr::Fail;
                }
@@ -954,7 +954,7 @@ pub(crate) fn remove_list_index(indexing_code: &mut [IndexingLine], offset: usiz
    let mut index = 0;
    match &mut indexing_code[index] {
-        IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, _, ref mut l, _)) => {
+        IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, _, _, l, _)) => {
            match *l {
                IndexingCodePtr::DynamicExternal(_) | IndexingCodePtr::External(_) => {
                    *l = IndexingCodePtr::Fail;
@@ -974,7 +974,7 @@ pub(crate) fn remove_list_index(indexing_code: &mut [IndexingLine], offset: usiz
    }
    match &mut indexing_code[index] {
-        IndexingLine::IndexedChoice(ref mut indexed_choice_instrs) => {
+        IndexingLine::IndexedChoice(indexed_choice_instrs) => {
            StaticCodeIndices::remove_instruction_with_offset(indexed_choice_instrs, offset);
            if indexed_choice_instrs.len() == 1 {
@@ -986,7 +986,7 @@ pub(crate) fn remove_list_index(indexing_code: &mut [IndexingLine], offset: usiz
                            _,
                            _,
                            _,
-                            ref mut l,
+                            l,
                            _,
                        )) => {
                            *l = ext;
@@ -998,7 +998,7 @@ pub(crate) fn remove_list_index(indexing_code: &mut [IndexingLine], offset: usiz
                }
            }
        }
-        IndexingLine::DynamicIndexedChoice(ref mut indexed_choice_instrs) => {
+        IndexingLine::DynamicIndexedChoice(indexed_choice_instrs) => {
            DynamicCodeIndices::remove_instruction_with_offset(indexed_choice_instrs, offset);
            if indexed_choice_instrs.len() == 1 {
@@ -1010,7 +1010,7 @@ pub(crate) fn remove_list_index(indexing_code: &mut [IndexingLine], offset: usiz
                            _,
                            _,
                            _,
-                            ref mut l,
+                            l,
                            _,
                        )) => {
                            *l = ext;
@@ -1034,7 +1034,7 @@ pub(crate) fn remove_index(
    clause_loc: usize,
 ) {
    match opt_arg_index_key {
-        OptArgIndexKey::Literal(_, _, constant, ref overlapping_constants) => {
+        OptArgIndexKey::Literal(_, _, constant, overlapping_constants) => {
            remove_constant_indices(*constant, *overlapping_constants, indexing_code, clause_loc);
        }
        OptArgIndexKey::Structure(_, _, name, arity) => {
@@ -1525,11 +1525,11 @@ impl<I: Indexer> CodeOffsets<I> {
            &mut prelude,
        );
-        if let IndexingCodePtr::Internal(ref mut i) = &mut str_loc {
+        if let IndexingCodePtr::Internal(i) = &mut str_loc {
            *i += emitted_switch_on_constant as usize; // con_loc.is_internal() as usize;
        }
-        if let IndexingCodePtr::Internal(ref mut i) = &mut lst_loc {
+        if let IndexingCodePtr::Internal(i) = &mut lst_loc {
            *i += emitted_switch_on_constant as usize; // con_loc.is_internal() as usize;
            *i += emitted_switch_on_structure as usize; // str_loc.is_internal() as usize;
        }
--- a/src/instructions.rs
+++ b/src/instructions.rs
@@ -251,7 +251,7 @@ impl Instruction {
    #[inline]
    pub fn to_indexing_line_mut(&mut self) -> Option<&mut Vec<IndexingLine>> {
        match self {
-            Instruction::IndexingCode(ref mut indexing_code) => Some(indexing_code),
+            Instruction::IndexingCode(indexing_code) => Some(indexing_code),
            _ => None,
        }
    }
@@ -259,7 +259,7 @@ impl Instruction {
    #[inline]
    pub fn to_indexing_line(&self) -> Option<&Vec<IndexingLine>> {
        match self {
-            Instruction::IndexingCode(ref indexing_code) => Some(indexing_code),
+            Instruction::IndexingCode(indexing_code) => Some(indexing_code),
            _ => None,
        }
    }
@@ -1372,12 +1372,12 @@ impl Instruction {
 impl CompareNumber {
    pub fn set_terms(&mut self, l_at_1: ArithmeticTerm, l_at_2: ArithmeticTerm) {
        match self {
-            CompareNumber::NumberGreaterThan(ref mut at_1, ref mut at_2)
+            CompareNumber::NumberGreaterThan(at_1, at_2)
-            | CompareNumber::NumberLessThan(ref mut at_1, ref mut at_2)
+            | CompareNumber::NumberLessThan(at_1, at_2)
-            | CompareNumber::NumberGreaterThanOrEqual(ref mut at_1, ref mut at_2)
+            | CompareNumber::NumberGreaterThanOrEqual(at_1, at_2)
-            | CompareNumber::NumberLessThanOrEqual(ref mut at_1, ref mut at_2)
+            | CompareNumber::NumberLessThanOrEqual(at_1, at_2)
-            | CompareNumber::NumberNotEqual(ref mut at_1, ref mut at_2)
+            | CompareNumber::NumberNotEqual(at_1, at_2)
-            | CompareNumber::NumberEqual(ref mut at_1, ref mut at_2) => {
+            | CompareNumber::NumberEqual(at_1, at_2) => {
                *at_1 = l_at_1;
                *at_2 = l_at_2;
            }
--- a/src/iterators.rs
+++ b/src/iterators.rs
@@ -103,11 +103,11 @@ impl<'a> QueryIterator<'a> {
    fn extend_state(&mut self, lvl: Level, term: &'a QueryTerm) {
        match term {
-            QueryTerm::Clause(ref cell, ClauseType::CallN(_), ref terms, _) => {
+            QueryTerm::Clause(cell, ClauseType::CallN(_), terms, _) => {
                self.state_stack
                    .push(TermIterState::Clause(lvl, 1, cell, atom!("$call"), terms));
            }
-            QueryTerm::Clause(ref cell, ref ct, ref terms, _) => {
+            QueryTerm::Clause(cell, ct, terms, _) => {
                self.state_stack
                    .push(TermIterState::Clause(lvl, 0, cell, ct.name(), terms));
            }
@@ -419,7 +419,7 @@ impl<'a> Iterator for ClauseIterator<'a> {
                            self.state_stack
                                .push(ClauseIteratorState::RemainingBranches(branch_nums, arms, 0));
                        }
-                        ChunkedTerms::Chunk { ref terms } => {
+                        ChunkedTerms::Chunk { terms } => {
                            return Some(ClauseItem::Chunk { terms });
                        }
                    }
--- a/src/machine/attributed_variables.rs
+++ b/src/machine/attributed_variables.rs
@@ -62,7 +62,7 @@ impl MachineState {
            .attr_var_init
            .bindings
            .iter()
-            .map(|(ref h, _)| attr_var_as_cell!(*h));
+            .map(|(h, _)| attr_var_as_cell!(*h));
        let var_list_addr = sized_iter_to_heap_list(&mut self.heap, size, iter)?;
        let iter = self.attr_var_init.bindings.drain(0..).map(|(_, ref v)| *v);
--- a/src/machine/compile.rs
+++ b/src/machine/compile.rs
@@ -80,19 +80,19 @@ fn derelictize_try_me_else(
 ) -> Option<usize> {
    match &mut code[index] {
        Instruction::DynamicElse(_, _, NextOrFail::Next(0)) => None,
-        Instruction::DynamicElse(_, _, NextOrFail::Next(ref mut o)) => {
+        Instruction::DynamicElse(_, _, NextOrFail::Next(o)) => {
            retraction_info.push_record(RetractionRecord::ReplacedDynamicElseOffset(index, *o));
            Some(mem::replace(o, 0))
        }
        Instruction::DynamicInternalElse(_, _, NextOrFail::Next(0)) => None,
-        Instruction::DynamicInternalElse(_, _, NextOrFail::Next(ref mut o)) => {
+        Instruction::DynamicInternalElse(_, _, NextOrFail::Next(o)) => {
            retraction_info.push_record(RetractionRecord::ReplacedDynamicElseOffset(index, *o));
            Some(mem::replace(o, 0))
        }
        Instruction::DynamicElse(_, _, NextOrFail::Fail(_))
        | Instruction::DynamicInternalElse(_, _, NextOrFail::Fail(_)) => None,
        Instruction::TryMeElse(0) => None,
-        Instruction::TryMeElse(ref mut o) => {
+        Instruction::TryMeElse(o) => {
            retraction_info.push_record(RetractionRecord::ModifiedTryMeElse(index, *o));
            Some(mem::replace(o, 0))
        }
@@ -275,7 +275,7 @@ fn merge_indexed_subsequences(
            .unwrap(),
    );
-    if let Instruction::TryMeElse(ref mut o) = &mut code[inner_try_me_else_loc] {
+    if let Instruction::TryMeElse(o) = &mut code[inner_try_me_else_loc] {
        retraction_info.push_record(RetractionRecord::ModifiedTryMeElse(
            inner_try_me_else_loc,
            *o,
@@ -324,7 +324,7 @@ fn merge_indexed_subsequences(
            );
        }
        None => {
-            if let Instruction::TryMeElse(ref mut o) = &mut code[outer_threaded_choice_instr_loc] {
+            if let Instruction::TryMeElse(o) = &mut code[outer_threaded_choice_instr_loc] {
                retraction_info
                    .push_record(RetractionRecord::ModifiedTryMeElse(inner_trust_me_loc, *o));
@@ -472,7 +472,7 @@ fn set_switch_var_offset(
    let target_indexing_line = code[index_loc].to_indexing_line_mut().unwrap();
    let old_v = match &mut target_indexing_line[0] {
-        IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, ref mut v, ..)) => match *v {
+        IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(_, v, ..)) => match *v {
            IndexingCodePtr::DynamicExternal(_) => {
                mem::replace(v, IndexingCodePtr::DynamicExternal(offset))
            }
@@ -497,7 +497,7 @@ fn internalize_choice_instr_at(
    match &mut code[instr_loc] {
        Instruction::DynamicElse(_, _, NextOrFail::Fail(_))
        | Instruction::DynamicInternalElse(_, _, NextOrFail::Fail(_)) => {}
-        Instruction::DynamicElse(_, _, ref mut o @ NextOrFail::Next(0)) => {
+        Instruction::DynamicElse(_, _, o @ NextOrFail::Next(0)) => {
            retraction_info.push_record(RetractionRecord::ReplacedDynamicElseOffset(instr_loc, 0));
            *o = NextOrFail::Fail(0);
        }
@@ -516,7 +516,7 @@ fn internalize_choice_instr_at(
                }
            }
        }
-        Instruction::DynamicInternalElse(_, _, ref mut o @ NextOrFail::Next(0)) => {
+        Instruction::DynamicInternalElse(_, _, o @ NextOrFail::Next(0)) => {
            retraction_info.push_record(RetractionRecord::ReplacedDynamicElseOffset(instr_loc, 0));
            *o = NextOrFail::Fail(0);
        }
@@ -564,7 +564,7 @@ fn thread_choice_instr_at_to(
 ) {
    loop {
        match &mut code[instr_loc] {
-            Instruction::TryMeElse(ref mut o) | Instruction::RetryMeElse(ref mut o)
+            Instruction::TryMeElse(o) | Instruction::RetryMeElse(o)
                if target_loc >= instr_loc =>
            {
                retraction_info.push_record(RetractionRecord::ReplacedChoiceOffset(instr_loc, *o));
@@ -572,8 +572,8 @@ fn thread_choice_instr_at_to(
                *o = target_loc - instr_loc;
                return;
            }
-            Instruction::DynamicElse(_, _, NextOrFail::Next(ref mut o))
+            Instruction::DynamicElse(_, _, NextOrFail::Next(o))
-            | Instruction::DynamicInternalElse(_, _, NextOrFail::Next(ref mut o))
+            | Instruction::DynamicInternalElse(_, _, NextOrFail::Next(o))
                if target_loc >= instr_loc =>
            {
                retraction_info
@@ -588,7 +588,7 @@ fn thread_choice_instr_at_to(
            Instruction::TryMeElse(o) | Instruction::RetryMeElse(o) => {
                instr_loc += *o;
            }
-            Instruction::RevJmpBy(ref mut o) if instr_loc >= target_loc => {
+            Instruction::RevJmpBy(o) if instr_loc >= target_loc => {
                retraction_info.push_record(RetractionRecord::ModifiedRevJmpBy(instr_loc, *o));
                *o = instr_loc - target_loc;
@@ -631,7 +631,7 @@ fn thread_choice_instr_at_to(
            Instruction::DynamicInternalElse(_, _, NextOrFail::Fail(o)) if *o > 0 => {
                instr_loc += *o;
            }
-            Instruction::TrustMe(ref mut o) if target_loc >= instr_loc => {
+            Instruction::TrustMe(o) if target_loc >= instr_loc => {
                retraction_info.push_record(
                    RetractionRecord::AppendedTrustMe(instr_loc, *o, false),
                    //choice_instr.is_default()),
@@ -657,7 +657,7 @@ fn remove_non_leading_clause(
    retraction_info: &mut RetractionInfo,
 ) -> Option<IndexPtr> {
    match &mut code[non_indexed_choice_instr_loc] {
-        Instruction::RetryMeElse(ref mut o) => {
+        Instruction::RetryMeElse(o) => {
            let o = *o;
            thread_choice_instr_at_to(
@@ -680,7 +680,7 @@ fn remove_non_leading_clause(
                None
            }
-            Instruction::TryMeElse(ref mut o) => {
+            Instruction::TryMeElse(o) => {
                retraction_info.push_record(RetractionRecord::ModifiedTryMeElse(
                    preceding_choice_instr_loc,
                    *o,
@@ -730,7 +730,7 @@ fn remove_leading_unindexed_clause(
    retraction_info: &mut RetractionInfo,
 ) -> Option<IndexPtr> {
    match &mut code[non_indexed_choice_instr_loc] {
-        Instruction::TryMeElse(ref mut o) => {
+        Instruction::TryMeElse(o) => {
            if *o > 0 {
                retraction_info.push_record(RetractionRecord::ModifiedTryMeElse(
                    non_indexed_choice_instr_loc,
@@ -935,10 +935,10 @@ fn prepend_compiled_clause(
                let prepend_queue_len = prepend_queue.len();
                match &mut prepend_queue[1] {
-                    Instruction::TryMeElse(ref mut o) if *o == 0 => {
+                    Instruction::TryMeElse(o) if *o == 0 => {
                        *o = prepend_queue_len - 2;
                    }
-                    Instruction::DynamicInternalElse(_, _, ref mut o @ NextOrFail::Next(0)) => {
+                    Instruction::DynamicInternalElse(_, _, o @ NextOrFail::Next(0)) => {
                        *o = NextOrFail::Fail(prepend_queue_len - 2);
                    }
                    _ => {
@@ -1632,8 +1632,8 @@ impl<'a, LS: LoadState<'a>> Loader<'a, LS> {
        };
        match &mut self.wam_prelude.code[clause_loc] {
-            Instruction::DynamicElse(_, ref mut d, _)
+            Instruction::DynamicElse(_, d, _)
-            | Instruction::DynamicInternalElse(_, ref mut d, _) => {
+            | Instruction::DynamicInternalElse(_, d, _) => {
                *d = Death::Finite(LS::machine_st(&mut self.payload).global_clock);
            }
            _ => unreachable!(),
--- a/src/machine/dispatch.rs
+++ b/src/machine/dispatch.rs
@@ -1365,8 +1365,8 @@ impl Machine {
        let p = self.machine_st.p;
        let indexed_choice_instrs = match &self.code[p] {
-            Instruction::IndexingCode(ref indexing_code) => match &indexing_code[oi as usize] {
+            Instruction::IndexingCode(indexing_code) => match &indexing_code[oi as usize] {
-                IndexingLine::DynamicIndexedChoice(ref indexed_choice_instrs) => {
+                IndexingLine::DynamicIndexedChoice(indexed_choice_instrs) => {
                    indexed_choice_instrs
                }
                _ => unreachable!(),
@@ -1376,7 +1376,7 @@ impl Machine {
        loop {
            match &indexed_choice_instrs.get(ii as usize) {
-                Some(&offset) => match &self.code[p + offset - 1] {
+                &Some(&offset) => match &self.code[p + offset - 1] {
                    &Instruction::DynamicInternalElse(birth, death, next_or_fail) => {
                        if birth < self.machine_st.cc && Death::Finite(self.machine_st.cc) <= death
                        {
@@ -2670,7 +2670,7 @@ impl Machine {
                            self.machine_st.backtrack();
                        }
                    }
-                    Instruction::CallNumberLessThanOrEqual(ref at_1, ref at_2) => {
+                    Instruction::CallNumberLessThanOrEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2692,7 +2692,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::ExecuteNumberLessThanOrEqual(ref at_1, ref at_2) => {
+                    Instruction::ExecuteNumberLessThanOrEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2714,7 +2714,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::CallNumberEqual(ref at_1, ref at_2) => {
+                    Instruction::CallNumberEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2736,7 +2736,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::ExecuteNumberEqual(ref at_1, ref at_2) => {
+                    Instruction::ExecuteNumberEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2758,7 +2758,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::CallNumberNotEqual(ref at_1, ref at_2) => {
+                    Instruction::CallNumberNotEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2780,7 +2780,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::ExecuteNumberNotEqual(ref at_1, ref at_2) => {
+                    Instruction::ExecuteNumberNotEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2802,7 +2802,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::CallNumberGreaterThanOrEqual(ref at_1, ref at_2) => {
+                    Instruction::CallNumberGreaterThanOrEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2824,7 +2824,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::ExecuteNumberGreaterThanOrEqual(ref at_1, ref at_2) => {
+                    Instruction::ExecuteNumberGreaterThanOrEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2846,7 +2846,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::CallNumberGreaterThan(ref at_1, ref at_2) => {
+                    Instruction::CallNumberGreaterThan(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2868,7 +2868,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::ExecuteNumberGreaterThan(ref at_1, ref at_2) => {
+                    Instruction::ExecuteNumberGreaterThan(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2890,7 +2890,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::CallNumberLessThan(ref at_1, ref at_2) => {
+                    Instruction::CallNumberLessThan(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2912,7 +2912,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::ExecuteNumberLessThan(ref at_1, ref at_2) => {
+                    Instruction::ExecuteNumberLessThan(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2934,7 +2934,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::DefaultCallNumberLessThanOrEqual(ref at_1, ref at_2) => {
+                    Instruction::DefaultCallNumberLessThanOrEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2955,7 +2955,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::DefaultExecuteNumberLessThanOrEqual(ref at_1, ref at_2) => {
+                    Instruction::DefaultExecuteNumberLessThanOrEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2976,7 +2976,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::DefaultCallNumberNotEqual(ref at_1, ref at_2) => {
+                    Instruction::DefaultCallNumberNotEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -2997,7 +2997,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::DefaultExecuteNumberNotEqual(ref at_1, ref at_2) => {
+                    Instruction::DefaultExecuteNumberNotEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -3018,7 +3018,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::DefaultCallNumberEqual(ref at_1, ref at_2) => {
+                    Instruction::DefaultCallNumberEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -3039,7 +3039,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::DefaultExecuteNumberEqual(ref at_1, ref at_2) => {
+                    Instruction::DefaultExecuteNumberEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -3060,7 +3060,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::DefaultCallNumberGreaterThanOrEqual(ref at_1, ref at_2) => {
+                    Instruction::DefaultCallNumberGreaterThanOrEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -3081,7 +3081,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::DefaultExecuteNumberGreaterThanOrEqual(ref at_1, ref at_2) => {
+                    Instruction::DefaultExecuteNumberGreaterThanOrEqual(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -3102,7 +3102,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::DefaultCallNumberGreaterThan(ref at_1, ref at_2) => {
+                    Instruction::DefaultCallNumberGreaterThan(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -3123,7 +3123,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::DefaultExecuteNumberGreaterThan(ref at_1, ref at_2) => {
+                    Instruction::DefaultExecuteNumberGreaterThan(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -3144,7 +3144,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::DefaultCallNumberLessThan(ref at_1, ref at_2) => {
+                    Instruction::DefaultCallNumberLessThan(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -3165,7 +3165,7 @@ impl Machine {
                            }
                        }
                    }
-                    Instruction::DefaultExecuteNumberLessThan(ref at_1, ref at_2) => {
+                    Instruction::DefaultExecuteNumberLessThan(at_1, at_2) => {
                        let n1 = try_or_throw!(
                            self.machine_st,
                            self.machine_st.get_number(at_1),
@@ -3640,7 +3640,7 @@ impl Machine {
                    &Instruction::Proceed => {
                        self.machine_st.p = self.machine_st.cp;
                    }
-                    Instruction::IndexingCode(ref indexing_lines) => {
+                    Instruction::IndexingCode(indexing_lines) => {
                        match &indexing_lines[self.machine_st.oip as usize] {
                            IndexingLine::Indexing(_) => {
                                self.execute_switch_on_term();
@@ -3649,7 +3649,7 @@ impl Machine {
                                    self.machine_st.backtrack();
                                }
                            }
-                            IndexingLine::IndexedChoice(ref indexed_choice) => {
+                            IndexingLine::IndexedChoice(indexed_choice) => {
                                match indexed_choice[self.machine_st.iip as usize] {
                                    IndexedChoiceInstruction::Try(offset) => {
                                        backtrack_on_resource_error!(
--- a/src/machine/heap.rs
+++ b/src/machine/heap.rs
@@ -57,7 +57,7 @@ struct InnerHeap {
 }
 impl InnerHeap {
-    unsafe fn grow(&mut self) -> bool {
+    unsafe fn grow(&mut self) -> bool { unsafe {
        let new_cap = if self.byte_cap == 0 {
            256 * 256 * 8
        } else {
@@ -88,7 +88,7 @@ impl InnerHeap {
        } else {
            false
        }
-    }
+    }}
 }
 unsafe impl Send for Heap {}
@@ -101,7 +101,7 @@ pub struct HeapStringScan<'a> {
 }
 // The heap_slice should be inside the heap
-unsafe fn scan_slice_to_str(heap_slice: &[u8]) -> HeapStringScan<'_> {
+unsafe fn scan_slice_to_str(heap_slice: &[u8]) -> HeapStringScan<'_> { unsafe {
    let string_len = heap_slice
        .iter()
        .position(|b| *b == 0u8)
@@ -120,11 +120,11 @@ unsafe fn scan_slice_to_str(heap_slice: &[u8]) -> HeapStringScan<'_> {
        string: std::str::from_utf8_unchecked(str_slice),
        tail_idx,
    }
-}
+}}
 // Same as scan_slice_to_str but assumes that the slice is from the start of a string.
 // Can be used on strings out of the heap.
-unsafe fn scan_slice_to_str_from_start(heap_slice: &[u8]) -> HeapStringScan<'_> {
+unsafe fn scan_slice_to_str_from_start(heap_slice: &[u8]) -> HeapStringScan<'_> { unsafe {
    let string_len = heap_slice
        .iter()
        .position(|b| *b == 0u8)
@@ -142,7 +142,7 @@ unsafe fn scan_slice_to_str_from_start(heap_slice: &[u8]) -> HeapStringScan<'_>
        string: std::str::from_utf8_unchecked(str_slice),
        tail_idx,
    }
-}
+}}
 #[derive(Debug, Clone, Copy)]
 pub(crate) enum PStrContinuable {
@@ -585,9 +585,9 @@ impl Heap {
    }
    #[inline(always)]
-    unsafe fn grow(&mut self) -> bool {
+    unsafe fn grow(&mut self) -> bool { unsafe {
        self.inner.grow()
-    }
+    }}
    #[inline]
    fn resource_error_offset(&self) -> usize {
--- a/src/machine/load_state.rs
+++ b/src/machine/load_state.rs
@@ -34,7 +34,7 @@ pub(super) fn set_code_index<'a, LS: LoadState<'a>>(
                    RetractionRecord::ReplacedUserPredicate(key, replaced)
                }
            }
-            CompilationTarget::Module(ref module_name) => {
+            CompilationTarget::Module(module_name) => {
                if IndexPtrTag::Undefined == code_idx_ptr.tag() {
                    *code_idx_ptr = code_ptr;
                    RetractionRecord::AddedModulePredicate(*module_name, key)
@@ -98,7 +98,7 @@ pub(super) fn add_op_decl(
            CompilationTarget::User => {
                retraction_info.push_record(RetractionRecord::ReplacedUserOp(*op_decl, op_desc));
            }
-            CompilationTarget::Module(ref module_name) => {
+            CompilationTarget::Module(module_name) => {
                retraction_info.push_record(RetractionRecord::ReplacedModuleOp(
                    *module_name,
                    *op_decl,
@@ -110,7 +110,7 @@ pub(super) fn add_op_decl(
            CompilationTarget::User => {
                retraction_info.push_record(RetractionRecord::AddedUserOp(*op_decl));
            }
-            CompilationTarget::Module(ref module_name) => {
+            CompilationTarget::Module(module_name) => {
                retraction_info
                    .push_record(RetractionRecord::AddedModuleOp(*module_name, *op_decl));
            }
@@ -167,7 +167,7 @@ pub(super) fn import_module_exports<'a, LS: LoadState<'a>>(
                    ));
                }
            }
-            ModuleExport::OpDecl(ref op_decl) => {
+            ModuleExport::OpDecl(op_decl) => {
                add_op_decl(
                    &mut payload.retraction_info,
                    compilation_target,
@@ -221,7 +221,7 @@ fn import_module_exports_into_module<'a, LS: LoadState<'a>>(
                    ));
                }
            }
-            ModuleExport::OpDecl(ref op_decl) => {
+            ModuleExport::OpDecl(op_decl) => {
                add_op_decl_as_module_export::<LS>(payload, op_dir, wam_op_dir, op_decl);
            }
        }
@@ -276,7 +276,7 @@ fn import_qualified_module_exports<'a, LS: LoadState<'a>>(
                    ));
                }
            }
-            ModuleExport::OpDecl(ref op_decl) => {
+            ModuleExport::OpDecl(op_decl) => {
                add_op_decl(
                    &mut payload.retraction_info,
                    compilation_target,
@@ -336,7 +336,7 @@ fn import_qualified_module_exports_into_module<'a, LS: LoadState<'a>>(
                    ));
                }
            }
-            ModuleExport::OpDecl(ref op_decl) => {
+            ModuleExport::OpDecl(op_decl) => {
                add_op_decl_as_module_export::<LS>(payload, op_dir, wam_op_dir, op_decl);
            }
        }
@@ -545,7 +545,7 @@ impl<'a, LS: LoadState<'a>> Loader<'a, LS> {
        ) {
            for export in removed_module.module_decl.exports.iter() {
                match export {
-                    ModuleExport::PredicateKey(ref key) => {
+                    ModuleExport::PredicateKey(key) => {
                        if let (Some(module_code_idx), Some(target_code_idx)) = (
                            removed_module.code_dir.get(key).cloned(),
                            code_dir.get_mut(key).cloned(),
@@ -1050,7 +1050,7 @@ impl<'a, LS: LoadState<'a>> Loader<'a, LS> {
        );
        for export in &module.module_decl.exports {
-            if let ModuleExport::OpDecl(ref op_decl) = export {
+            if let ModuleExport::OpDecl(op_decl) = export {
                add_op_decl_as_module_export::<LS>(
                    &mut self.payload,
                    &mut module.op_dir,
@@ -1084,7 +1084,7 @@ impl<'a, LS: LoadState<'a>> Loader<'a, LS> {
                        &mut self.wam_prelude.indices.meta_predicates,
                    )?;
                }
-                CompilationTarget::Module(ref defining_module_name) => {
+                CompilationTarget::Module(defining_module_name) => {
                    match self
                        .wam_prelude
                        .indices
@@ -1137,7 +1137,7 @@ impl<'a, LS: LoadState<'a>> Loader<'a, LS> {
                    &exports,
                    &mut self.wam_prelude,
                ),
-                CompilationTarget::Module(ref defining_module_name) => {
+                CompilationTarget::Module(defining_module_name) => {
                    match self
                        .wam_prelude
                        .indices
--- a/src/machine/loader.rs
+++ b/src/machine/loader.rs
@@ -160,7 +160,7 @@ impl fmt::Display for CompilationTarget {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            CompilationTarget::User => write!(f, "user"),
-            CompilationTarget::Module(ref module_name) => write!(f, "{}", module_name.as_str()),
+            CompilationTarget::Module(module_name) => write!(f, "{}", module_name.as_str()),
        }
    }
 }
@@ -821,7 +821,7 @@ impl<'a, LS: LoadState<'a>> Loader<'a, LS> {
                    {
                        if let IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(
                            _,
-                            ref mut v,
+                            v,
                            ..,
                        )) = &mut indexing_code[0]
                        {
@@ -1110,7 +1110,7 @@ impl<'a, LS: LoadState<'a>> Loader<'a, LS> {
                    }
                }
            }
-            CompilationTarget::Module(ref module_name) => {
+            CompilationTarget::Module(module_name) => {
                match self.wam_prelude.indices.modules.get_mut(module_name) {
                    Some(ref mut module) => match module.extensible_predicates.get_mut(&key) {
                        Some(ref mut skeleton) => {
@@ -1364,7 +1364,7 @@ impl<'a> MachinePreludeView<'a> {
    ) -> CompositeOpDir<'_, '_> {
        match compilation_target {
            CompilationTarget::User => CompositeOpDir::new(&self.indices.op_dir, None),
-            CompilationTarget::Module(ref module_name) => {
+            CompilationTarget::Module(module_name) => {
                match self.indices.modules.get(module_name) {
                    Some(module) => CompositeOpDir::new(&self.indices.op_dir, Some(&module.op_dir)),
                    None => {
@@ -2374,7 +2374,7 @@ impl Machine {
                            MetaSpec::Plus => atom_as_cell!(atom!("-")),
                            MetaSpec::Either => atom_as_cell!(atom!("?")),
                            MetaSpec::Colon => atom_as_cell!(atom!(":")),
-                            MetaSpec::RequiresExpansionWithArgument(ref arg_num) => {
+                            MetaSpec::RequiresExpansionWithArgument(arg_num) => {
                                fixnum_as_cell!(/* FIXME this is not safe */ unsafe {
                                    Fixnum::build_with_unchecked(*arg_num as i64)
                                })
--- a/src/machine/machine_errors.rs
+++ b/src/machine/machine_errors.rs
@@ -900,7 +900,7 @@ impl CompilationError {
            CompilationError::InvalidUseModuleDecl => {
                functor!(atom!("invalid_use_module_declaration"))
            }
-            CompilationError::ParserError(ref err) => {
+            CompilationError::ParserError(err) => {
                functor!(err.as_atom())
            }
            CompilationError::FiniteMemoryInHeap(_) => {
--- a/src/machine/machine_indices.rs
+++ b/src/machine/machine_indices.rs
@@ -292,7 +292,7 @@ impl IndexStore {
    ) -> Option<&mut PredicateSkeleton> {
        match compilation_target {
            CompilationTarget::User => self.extensible_predicates.get_mut(key),
-            CompilationTarget::Module(ref module_name) => {
+            CompilationTarget::Module(module_name) => {
                if let Some(module) = self.modules.get_mut(module_name) {
                    module.extensible_predicates.get_mut(key)
                } else {
@@ -309,7 +309,7 @@ impl IndexStore {
    ) -> Option<&PredicateSkeleton> {
        match compilation_target {
            CompilationTarget::User => self.extensible_predicates.get(key),
-            CompilationTarget::Module(ref module_name) => {
+            CompilationTarget::Module(module_name) => {
                if let Some(module) = self.modules.get(module_name) {
                    module.extensible_predicates.get(key)
                } else {
@@ -380,7 +380,7 @@ impl IndexStore {
    ) -> Option<PredicateSkeleton> {
        match compilation_target {
            CompilationTarget::User => self.extensible_predicates.swap_remove(key),
-            CompilationTarget::Module(ref module_name) => {
+            CompilationTarget::Module(module_name) => {
                if let Some(module) = self.modules.get_mut(module_name) {
                    module.extensible_predicates.swap_remove(key)
                } else {
@@ -413,7 +413,7 @@ impl IndexStore {
    ) -> Option<&Vec<MetaSpec>> {
        match compilation_target {
            CompilationTarget::User => self.meta_predicates.get(&(name, arity)),
-            CompilationTarget::Module(ref module_name) => match self.modules.get(module_name) {
+            CompilationTarget::Module(module_name) => match self.modules.get(module_name) {
                Some(module) => module
                    .meta_predicates
                    .get(&(name, arity))
--- a/src/machine/machine_state.rs
+++ b/src/machine/machine_state.rs
@@ -1133,7 +1133,7 @@ impl CWIL {
        limit = limit.strict_add(self.local_count);
        match self.limits.last() {
-            Some((ref inner_limit, _)) if *inner_limit <= limit => {}
+            Some((inner_limit, _)) if *inner_limit <= limit => {}
            _ => self.limits.push((limit, block)),
        }
--- a/src/machine/mod.rs
+++ b/src/machine/mod.rs
@@ -1224,7 +1224,7 @@ impl Machine {
                    let key = Atom::from(h as u64);
                    match self.indices.global_variables.get_mut(&key) {
-                        Some((_, ref mut loc)) => *loc = None,
+                        Some((_, loc)) => *loc = None,
                        None => unreachable!(),
                    }
                }
@@ -1233,7 +1233,7 @@ impl Machine {
                    let value_cell = HeapCellValue::from(u64::from(self.machine_st.trail[i + 1]));
                    match self.indices.global_variables.get_mut(&key) {
-                        Some((_, ref mut loc)) => *loc = Some(value_cell),
+                        Some((_, loc)) => *loc = Some(value_cell),
                        None => unreachable!(),
                    }
                }
--- a/src/machine/preprocessor.rs
+++ b/src/machine/preprocessor.rs
@@ -82,7 +82,7 @@ fn setup_op_decl(mut terms: Vec<Term>) -> Result<OpDecl, CompilationError> {
 fn setup_predicate_indicator(term: &mut Term) -> Result<PredicateKey, CompilationError> {
    match term {
-        Term::Clause(_, slash, ref mut terms)
+        Term::Clause(_, slash, terms)
            if (*slash == atom!("/") || *slash == atom!("//")) && terms.len() == 2 =>
        {
            let arity = terms.pop().unwrap();
--- a/src/machine/stack.rs
+++ b/src/machine/stack.rs
@@ -175,7 +175,7 @@ impl Stack {
    }
    #[inline(always)]
-    unsafe fn alloc(&mut self, frame_size: usize) -> Result<NonNull<u8>, AllocError> {
+    unsafe fn alloc(&mut self, frame_size: usize) -> Result<NonNull<u8>, AllocError> { unsafe {
        loop {
            let ptr = self.buf.alloc(frame_size);
            if let Some(ptr) = NonNull::new(ptr) {
@@ -183,7 +183,7 @@ impl Stack {
            }
            self.buf.grow()?;
        }
-    }
+    }}
    pub(crate) fn allocate_and_frame(&mut self, num_cells: usize) -> Result<usize, AllocError> {
        let frame_size = AndFrame::size_of(num_cells);
--- a/src/machine/streams.rs
+++ b/src/machine/streams.rs
@@ -750,49 +750,49 @@ impl Stream {
    pub fn options(&self) -> &StreamOptions {
        match self {
-            Stream::Byte(ref ptr) => &ptr.options,
+            Stream::Byte(ptr) => &ptr.options,
-            Stream::InputFile(ref ptr) => &ptr.options,
+            Stream::InputFile(ptr) => &ptr.options,
-            Stream::OutputFile(ref ptr) => &ptr.options,
+            Stream::OutputFile(ptr) => &ptr.options,
-            Stream::StaticString(ref ptr) => &ptr.options,
+            Stream::StaticString(ptr) => &ptr.options,
-            Stream::NamedTcp(ref ptr) => &ptr.options,
+            Stream::NamedTcp(ptr) => &ptr.options,
            #[cfg(feature = "tls")]
-            Stream::NamedTls(ref ptr) => &ptr.options,
+            Stream::NamedTls(ptr) => &ptr.options,
            #[cfg(feature = "http")]
-            Stream::HttpRead(ref ptr) => &ptr.options,
+            Stream::HttpRead(ptr) => &ptr.options,
            #[cfg(feature = "http")]
-            Stream::HttpWrite(ref ptr) => &ptr.options,
+            Stream::HttpWrite(ptr) => &ptr.options,
-            Stream::Null(ref options) => options,
+            Stream::Null(options) => options,
-            Stream::Readline(ref ptr) => &ptr.options,
+            Stream::Readline(ptr) => &ptr.options,
-            Stream::StandardOutput(ref ptr) => &ptr.options,
+            Stream::StandardOutput(ptr) => &ptr.options,
-            Stream::StandardError(ref ptr) => &ptr.options,
+            Stream::StandardError(ptr) => &ptr.options,
-            Stream::Callback(ref ptr) => &ptr.options,
+            Stream::Callback(ptr) => &ptr.options,
-            Stream::InputChannel(ref ptr) => &ptr.options,
+            Stream::InputChannel(ptr) => &ptr.options,
-            Stream::PipeReader(ref ptr) => &ptr.options,
+            Stream::PipeReader(ptr) => &ptr.options,
-            Stream::PipeWriter(ref ptr) => &ptr.options,
+            Stream::PipeWriter(ptr) => &ptr.options,
        }
    }
    pub(super) fn options_mut(&mut self) -> &mut StreamOptions {
        match self {
-            Stream::Byte(ref mut ptr) => &mut ptr.options,
+            Stream::Byte(ptr) => &mut ptr.options,
-            Stream::InputFile(ref mut ptr) => &mut ptr.options,
+            Stream::InputFile(ptr) => &mut ptr.options,
-            Stream::OutputFile(ref mut ptr) => &mut ptr.options,
+            Stream::OutputFile(ptr) => &mut ptr.options,
-            Stream::StaticString(ref mut ptr) => &mut ptr.options,
+            Stream::StaticString(ptr) => &mut ptr.options,
-            Stream::NamedTcp(ref mut ptr) => &mut ptr.options,
+            Stream::NamedTcp(ptr) => &mut ptr.options,
            #[cfg(feature = "tls")]
-            Stream::NamedTls(ref mut ptr) => &mut ptr.options,
+            Stream::NamedTls(ptr) => &mut ptr.options,
            #[cfg(feature = "http")]
-            Stream::HttpRead(ref mut ptr) => &mut ptr.options,
+            Stream::HttpRead(ptr) => &mut ptr.options,
            #[cfg(feature = "http")]
-            Stream::HttpWrite(ref mut ptr) => &mut ptr.options,
+            Stream::HttpWrite(ptr) => &mut ptr.options,
-            Stream::Null(ref mut options) => options,
+            Stream::Null(options) => options,
-            Stream::Readline(ref mut ptr) => &mut ptr.options,
+            Stream::Readline(ptr) => &mut ptr.options,
-            Stream::StandardOutput(ref mut ptr) => &mut ptr.options,
+            Stream::StandardOutput(ptr) => &mut ptr.options,
-            Stream::StandardError(ref mut ptr) => &mut ptr.options,
+            Stream::StandardError(ptr) => &mut ptr.options,
-            Stream::Callback(ref mut ptr) => &mut ptr.options,
+            Stream::Callback(ptr) => &mut ptr.options,
-            Stream::InputChannel(ref mut ptr) => &mut ptr.options,
+            Stream::InputChannel(ptr) => &mut ptr.options,
-            Stream::PipeReader(ref mut ptr) => &mut ptr.options,
+            Stream::PipeReader(ptr) => &mut ptr.options,
-            Stream::PipeWriter(ref mut ptr) => &mut ptr.options,
+            Stream::PipeWriter(ptr) => &mut ptr.options,
        }
    }
@@ -960,17 +960,17 @@ impl CharRead for Stream {
    fn consume(&mut self, nread: usize) {
        match self {
-            Stream::InputFile(ref mut file) => file.consume(nread),
+            Stream::InputFile(file) => file.consume(nread),
-            Stream::NamedTcp(ref mut tcp_stream) => tcp_stream.consume(nread),
+            Stream::NamedTcp(tcp_stream) => tcp_stream.consume(nread),
            #[cfg(feature = "tls")]
-            Stream::NamedTls(ref mut tls_stream) => tls_stream.consume(nread),
+            Stream::NamedTls(tls_stream) => tls_stream.consume(nread),
            #[cfg(feature = "http")]
-            Stream::HttpRead(ref mut http_stream) => http_stream.consume(nread),
+            Stream::HttpRead(http_stream) => http_stream.consume(nread),
-            Stream::Readline(ref mut rl_stream) => rl_stream.consume(nread),
+            Stream::Readline(rl_stream) => rl_stream.consume(nread),
-            Stream::StaticString(ref mut src) => src.consume(nread),
+            Stream::StaticString(src) => src.consume(nread),
-            Stream::Byte(ref mut cursor) => cursor.consume(nread),
+            Stream::Byte(cursor) => cursor.consume(nread),
-            Stream::InputChannel(ref mut cursor) => cursor.consume(nread),
+            Stream::InputChannel(cursor) => cursor.consume(nread),
-            Stream::PipeReader(ref mut cursor) => cursor.consume(nread),
+            Stream::PipeReader(cursor) => cursor.consume(nread),
            #[cfg(feature = "http")]
            Stream::HttpWrite(_) => {}
            Stream::OutputFile(_)
@@ -1019,17 +1019,17 @@ impl Read for Stream {
 impl Write for Stream {
    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
        match self {
-            Stream::OutputFile(ref mut file) => file.write(buf),
+            Stream::OutputFile(file) => file.write(buf),
-            Stream::NamedTcp(ref mut tcp_stream) => tcp_stream.get_mut().write(buf),
+            Stream::NamedTcp(tcp_stream) => tcp_stream.get_mut().write(buf),
            #[cfg(feature = "tls")]
-            Stream::NamedTls(ref mut tls_stream) => tls_stream.get_mut().write(buf),
+            Stream::NamedTls(tls_stream) => tls_stream.get_mut().write(buf),
-            Stream::Byte(ref mut cursor) => cursor.get_mut().write(buf),
+            Stream::Byte(cursor) => cursor.get_mut().write(buf),
-            Stream::Callback(ref mut callback_stream) => callback_stream.get_mut().write(buf),
+            Stream::Callback(callback_stream) => callback_stream.get_mut().write(buf),
            Stream::StandardOutput(stream) => stream.write(buf),
            Stream::StandardError(stream) => stream.write(buf),
            #[cfg(feature = "http")]
-            Stream::HttpWrite(ref mut stream) => stream.get_mut().write(buf),
+            Stream::HttpWrite(stream) => stream.get_mut().write(buf),
-            Stream::PipeWriter(ref mut stream) => stream.get_mut().write(buf),
+            Stream::PipeWriter(stream) => stream.get_mut().write(buf),
            #[cfg(feature = "http")]
            Stream::HttpRead(_) => Err(std::io::Error::new(
                ErrorKind::PermissionDenied,
@@ -1049,17 +1049,17 @@ impl Write for Stream {
    fn flush(&mut self) -> std::io::Result<()> {
        match self {
-            Stream::OutputFile(ref mut file) => file.stream.flush(),
+            Stream::OutputFile(file) => file.stream.flush(),
-            Stream::NamedTcp(ref mut tcp_stream) => tcp_stream.stream.get_mut().flush(),
+            Stream::NamedTcp(tcp_stream) => tcp_stream.stream.get_mut().flush(),
            #[cfg(feature = "tls")]
-            Stream::NamedTls(ref mut tls_stream) => tls_stream.stream.get_mut().flush(),
+            Stream::NamedTls(tls_stream) => tls_stream.stream.get_mut().flush(),
-            Stream::Byte(ref mut cursor) => cursor.stream.get_mut().flush(),
+            Stream::Byte(cursor) => cursor.stream.get_mut().flush(),
-            Stream::Callback(ref mut callback_stream) => callback_stream.stream.get_mut().flush(),
+            Stream::Callback(callback_stream) => callback_stream.stream.get_mut().flush(),
            Stream::StandardError(stream) => stream.stream.flush(),
            Stream::StandardOutput(stream) => stream.stream.flush(),
-            Stream::PipeWriter(ref mut stream) => stream.stream.get_mut().flush(),
+            Stream::PipeWriter(stream) => stream.stream.get_mut().flush(),
            #[cfg(feature = "http")]
-            Stream::HttpWrite(ref mut stream) => stream.stream.get_mut().flush(),
+            Stream::HttpWrite(stream) => stream.stream.get_mut().flush(),
            #[cfg(feature = "http")]
            Stream::HttpRead(_) => Err(std::io::Error::new(
                ErrorKind::PermissionDenied,
@@ -1530,58 +1530,58 @@ impl Stream {
    #[inline]
    pub(crate) fn close(&mut self) -> Result<(), std::io::Error> {
        match self {
-            Stream::NamedTcp(ref mut tcp_stream) => {
+            Stream::NamedTcp(tcp_stream) => {
                tcp_stream.inner_mut().tcp_stream.shutdown(Shutdown::Both)
            }
            #[cfg(feature = "tls")]
-            Stream::NamedTls(ref mut tls_stream) => tls_stream.inner_mut().tls_stream.shutdown(),
+            Stream::NamedTls(tls_stream) => tls_stream.inner_mut().tls_stream.shutdown(),
            #[cfg(feature = "http")]
-            Stream::HttpRead(ref mut http_stream) => {
+            Stream::HttpRead(http_stream) => {
                http_stream.drop_payload();
                Ok(())
            }
            #[cfg(feature = "http")]
-            Stream::HttpWrite(mut http_stream) => {
+            &mut Stream::HttpWrite(mut http_stream) => {
                http_stream.drop_payload();
                Ok(())
            }
-            Stream::InputFile(mut file_stream) => {
+            &mut Stream::InputFile(mut file_stream) => {
                // close the stream by dropping the inner File.
                file_stream.drop_payload();
                Ok(())
            }
-            Stream::OutputFile(mut file_stream) => {
+            &mut Stream::OutputFile(mut file_stream) => {
                // close the stream by dropping the inner File.
                file_stream.drop_payload();
                Ok(())
            }
-            Stream::Byte(mut stream) => {
+            &mut Stream::Byte(mut stream) => {
                stream.drop_payload();
                Ok(())
            }
-            Stream::Callback(mut stream) => {
+            &mut Stream::Callback(mut stream) => {
                stream.drop_payload();
                Ok(())
            }
-            Stream::InputChannel(mut stream) => {
+            &mut Stream::InputChannel(mut stream) => {
                stream.drop_payload();
                Ok(())
            }
-            Stream::StaticString(mut stream) => {
+            &mut Stream::StaticString(mut stream) => {
                stream.drop_payload();
                Ok(())
            }
-            Stream::PipeReader(mut stream) => {
+            &mut Stream::PipeReader(mut stream) => {
                stream.drop_payload();
                Ok(())
            }
-            Stream::PipeWriter(mut stream) => {
+            &mut Stream::PipeWriter(mut stream) => {
                stream.drop_payload();
                Ok(())
            }
@@ -1644,11 +1644,11 @@ impl Stream {
        self.set_past_end_of_stream(false);
        match self {
-            Stream::Byte(ref mut cursor) => {
+            Stream::Byte(cursor) => {
                cursor.stream.get_mut().0.set_position(0);
                true
            }
-            Stream::InputFile(ref mut file_stream) => {
+            Stream::InputFile(file_stream) => {
                file_stream
                    .stream
                    .get_mut()
@@ -1657,11 +1657,11 @@ impl Stream {
                    .unwrap();
                true
            }
-            Stream::Readline(ref mut readline_stream) => {
+            Stream::Readline(readline_stream) => {
                readline_stream.reset();
                true
            }
-            Stream::InputChannel(ref mut input_channel_stream) => {
+            Stream::InputChannel(input_channel_stream) => {
                input_channel_stream.stream.get_mut().inner.set_position(0);
                true
            }
@@ -1672,7 +1672,7 @@ impl Stream {
    #[inline]
    pub(crate) fn peek_byte(&mut self) -> std::io::Result<u8> {
        match self {
-            Stream::Byte(ref mut cursor) => {
+            Stream::Byte(cursor) => {
                let mut b = [0u8; 1];
                let pos = cursor.stream.get_mut().0.position();
@@ -1684,15 +1684,15 @@ impl Stream {
                    _ => Err(std::io::Error::new(ErrorKind::UnexpectedEof, "end of file")),
                }
            }
-            Stream::InputFile(ref mut file) => match file.peek_byte() {
+            Stream::InputFile(file) => match file.peek_byte() {
                Some(result) => Ok(result?),
                _ => Err(std::io::Error::new(
                    ErrorKind::UnexpectedEof,
                    StreamError::PeekByteFailed,
                )),
            },
-            Stream::Readline(ref mut stream) => stream.stream.peek_byte(),
+            Stream::Readline(stream) => stream.stream.peek_byte(),
-            Stream::NamedTcp(ref mut stream) => {
+            Stream::NamedTcp(stream) => {
                let mut b = [0u8; 1];
                stream.stream.get_mut().tcp_stream.peek(&mut b)?;
                Ok(b[0])
--- a/src/machine/system_calls.rs
+++ b/src/machine/system_calls.rs
@@ -1252,7 +1252,7 @@ impl Machine {
        loop {
            match &self.code[bp] {
-                Instruction::IndexingCode(ref indexing_code) => {
+                Instruction::IndexingCode(indexing_code) => {
                    let indexing_code_ptr = match &indexing_code[0] {
                        &IndexingLine::Indexing(IndexingInstruction::SwitchOnTerm(
                            _,
@@ -1275,10 +1275,10 @@ impl Machine {
                    let boip = extract_ptr!(indexing_code_ptr);
                    let boip = match &indexing_code[boip] {
-                        IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(ref hm)) => {
+                        IndexingLine::Indexing(IndexingInstruction::SwitchOnStructure(hm)) => {
                            boip + extract_ptr!(hm.get(&key).cloned().unwrap())
                        }
-                        IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(ref hm)) => {
+                        IndexingLine::Indexing(IndexingInstruction::SwitchOnConstant(hm)) => {
                            boip + extract_ptr!(hm.get(&atom_as_cell!(key.0)).cloned().unwrap())
                        }
                        _ => boip,
@@ -3138,7 +3138,7 @@ impl Machine {
        let addr = self.machine_st.registers[2];
        match self.indices.global_variables.get_mut(&key) {
-            Some((ref ball, ref mut loc)) => match loc {
+            Some(&mut (ref ball, ref mut loc)) => match loc {
                Some(value_loc) => {
                    unify_fn!(self.machine_st, addr, *value_loc);
                }
@@ -4319,7 +4319,7 @@ impl Machine {
    #[inline(always)]
    pub(crate) fn maybe(&mut self) {
-        self.machine_st.fail = self.rng.gen();
+        self.machine_st.fail = self.rng.r#gen();
    }
    #[cfg(not(target_arch = "wasm32"))]
@@ -7522,8 +7522,8 @@ impl Machine {
        let new_value = self.deref_register(2);
        match self.indices.global_variables.get_mut(&key) {
-            Some((_, ref mut loc)) => match loc {
+            Some((_, loc)) => match loc {
-                Some(ref mut value) => {
+                Some(value) => {
                    self.machine_st
                        .trail(TrailRef::BlackboardOffset(key, *value));
                    *value = new_value;
@@ -8667,7 +8667,8 @@ impl Machine {
            .value_to_str_like(self.machine_st.registers[2])
            .unwrap();
-        env::set_var(&*key.as_str(), &*value.as_str());
+        // TODO: Audit that the environment access only happens in single-threaded code.
        unsafe { env::set_var(&*key.as_str(), &*value.as_str()) };
    }
    #[inline(always)]
@@ -8676,7 +8677,8 @@ impl Machine {
            .machine_st
            .value_to_str_like(self.machine_st.registers[1])
            .unwrap();
-        env::remove_var(&*key.as_str());
+        // TODO: Audit that the environment access only happens in single-threaded code.
        unsafe { env::remove_var(&*key.as_str()) };
    }
    #[inline(always)]
--- a/src/offset_table.rs
+++ b/src/offset_table.rs
@@ -211,7 +211,7 @@ impl<T: RawBlockTraits> SerialOffsetTable<T> {
        })
    }
-    unsafe fn build_with(&mut self, value: T) -> usize {
+    unsafe fn build_with(&mut self, value: T) -> usize { unsafe {
        let mut ptr;
        loop {
@@ -228,17 +228,17 @@ impl<T: RawBlockTraits> SerialOffsetTable<T> {
        ptr::write(ptr as *mut T, value);
        // SAFETY: `ptr` was obtained from `self.block.alloc()`
        self.block.get_offset(ptr)
-    }
+    }}
    #[inline]
-    unsafe fn lookup(&self, offset: usize) -> &T {
+    unsafe fn lookup(&self, offset: usize) -> &T { unsafe {
        &*self.block.get_unchecked(offset).cast::<T>()
-    }
+    }}
    #[inline]
-    unsafe fn lookup_mut(&mut self, offset: usize) -> &mut T {
+    unsafe fn lookup_mut(&mut self, offset: usize) -> &mut T { unsafe {
        &mut *self.block.get_unchecked(offset).cast::<T>().cast_mut()
-    }
+    }}
    #[allow(clippy::wrong_self_convention)]
    fn to_concurrent(&mut self) -> ConcurrentOffsetTable<T>
--- a/src/parser/ast.rs
+++ b/src/parser/ast.rs
@@ -877,7 +877,7 @@ pub enum Term {
 impl Term {
    pub fn first_arg(&self) -> Option<&Term> {
        match self {
-            Term::Clause(_, _, ref terms) => terms.first(),
+            Term::Clause(_, _, terms) => terms.first(),
            _ => None,
        }
    }
@@ -892,14 +892,14 @@ impl Term {
    pub fn arity(&self) -> usize {
        match self {
-            Term::Clause(_, _, ref child_terms, ..) => child_terms.len(),
+            Term::Clause(_, _, child_terms, ..) => child_terms.len(),
            _ => 0,
        }
    }
 }
 pub(crate) fn unfold_by_str_once(term: &mut Term, s: Atom) -> Option<(Term, Term)> {
-    if let Term::Clause(_, ref name, ref mut subterms) = term {
+    if let &mut Term::Clause(_, ref name, ref mut subterms) = term {
        if let Some(Term::Literal(_, Literal::CodeIndexOffset(_))) = subterms.last() {
            subterms.pop();
        }
--- a/src/types.rs
+++ b/src/types.rs
@@ -761,9 +761,9 @@ impl UntypedArenaPtr {
    pub unsafe fn as_typed_ptr<T: ?Sized + ArenaAllocated>(self) -> TypedArenaPtr<T>
    where
        T::Payload: Sized,
-    {
+    { unsafe {
        T::typed_ptr(self)
-    }
+    }}
    #[inline]
    pub fn get_mark_bit(self) -> bool {
--- a/src/variable_records.rs
+++ b/src/variable_records.rs
@@ -105,9 +105,9 @@ impl VarAlloc {
    #[inline]
    pub(crate) fn set_register(&mut self, reg_num: usize) {
        match self {
-            VarAlloc::Perm(ref mut p, _) => *p = reg_num,
+            VarAlloc::Perm(p, _) => *p = reg_num,
            VarAlloc::Temp {
-                ref mut temp_reg, ..
+                temp_reg, ..
            } => *temp_reg = reg_num,
        };
    }