Added unty dependency and added type checks

Cargo.toml

@@ -1,69 +1,70 @@
-[workspace]
-members = ["derive", "compatibility"]
-
-[package]
-name = "bincode"
-version = "2.0.0-rc.3" # remember to update html_root_url and bincode_derive
-authors = [
-    "Ty Overby <[email protected]>",
-    "Zoey Riordan <[email protected]>",
-    "Victor Koenders <[email protected]>",
-]
-exclude = ["logo.svg", "examples/*", ".gitignore", ".github/"]
-
-publish = true
-
-repository = "https://github.com/bincode-org/bincode"
-documentation = "https://docs.rs/bincode"
-readme = "./readme.md"
-categories = ["encoding", "network-programming"]
-keywords = ["binary", "encode", "decode", "serialize", "deserialize"]
-
-license = "MIT"
-description = "A binary serialization / deserialization strategy for transforming structs into bytes and vice versa!"
-
-edition = "2021"
-
-[features]
-default = ["std", "derive"]
-std = ["alloc", "serde?/std"]
-alloc = ["serde?/alloc"]
-derive = ["bincode_derive"]
-
-[dependencies]
-bincode_derive = { path = "derive", version = "2.0.0-rc.3", optional = true }
-serde = { version = "1.0", default-features = false, optional = true }
-
-# Used for tests
-[dev-dependencies]
-serde_derive = "1.0"
-serde_json = { version = "1.0", default-features = false }
-tempfile = "3.2"
-criterion = "0.5"
-rand = "0.8"
-uuid = { version = "1.1", features = ["serde"] }
-chrono = { version = "0.4", features = ["serde"] }
-glam = { version = "0.24", features = ["serde"] }
-bincode_1 = { version = "1.3", package = "bincode" }
-serde = { version = "1.0", features = ["derive"] }
-
-[[bench]]
-name = "varint"
-harness = false
-
-[[bench]]
-name = "inline"
-harness = false
-
-[[bench]]
-name = "string"
-harness = false
-
-[profile.bench]
-codegen-units = 1
-debug = 1
-lto = true
-
-[package.metadata.docs.rs]
-all-features = true
-rustdoc-args = ["--cfg", "docsrs"]
+[workspace]
+members = ["derive", "compatibility"]
+
+[package]
+name = "bincode"
+version = "2.0.0-rc.3" # remember to update html_root_url and bincode_derive
+authors = [
+    "Ty Overby <[email protected]>",
+    "Zoey Riordan <[email protected]>",
+    "Victor Koenders <[email protected]>",
+]
+exclude = ["logo.svg", "examples/*", ".gitignore", ".github/"]
+
+publish = true
+
+repository = "https://github.com/bincode-org/bincode"
+documentation = "https://docs.rs/bincode"
+readme = "./readme.md"
+categories = ["encoding", "network-programming"]
+keywords = ["binary", "encode", "decode", "serialize", "deserialize"]
+
+license = "MIT"
+description = "A binary serialization / deserialization strategy for transforming structs into bytes and vice versa!"
+
+edition = "2021"
+
+[features]
+default = ["std", "derive"]
+std = ["alloc", "serde?/std"]
+alloc = ["serde?/alloc"]
+derive = ["bincode_derive"]
+
+[dependencies]
+bincode_derive = { path = "derive", version = "2.0.0-rc.3", optional = true }
+serde = { version = "1.0", default-features = false, optional = true }
+unty = "0.0.3"
+
+# Used for tests
+[dev-dependencies]
+serde_derive = "1.0"
+serde_json = { version = "1.0", default-features = false }
+tempfile = "3.2"
+criterion = "0.5"
+rand = "0.8"
+uuid = { version = "1.1", features = ["serde"] }
+chrono = { version = "0.4", features = ["serde"] }
+glam = { version = "0.24", features = ["serde"] }
+bincode_1 = { version = "1.3", package = "bincode" }
+serde = { version = "1.0", features = ["derive"] }
+
+[[bench]]
+name = "varint"
+harness = false
+
+[[bench]]
+name = "inline"
+harness = false
+
+[[bench]]
+name = "string"
+harness = false
+
+[profile.bench]
+codegen-units = 1
+debug = 1
+lto = true
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]

src/de/impls.rs

@@ -441,65 +441,61 @@ impl<'a, 'de: 'a> BorrowDecode<'de> for &'a str {
 
 impl<T, const N: usize> Decode for [T; N]
 where
-    T: Decode + Sized,
+    T: Decode,
 {
     fn decode<D: Decoder>(decoder: &mut D) -> Result<Self, DecodeError> {
         decoder.claim_bytes_read(core::mem::size_of::<[T; N]>())?;
 
-        // TODO: we can't limit `T: 'static` because that would break other things
-        // but we want to have this optimization
-        // This will be another contendor for specialization implementation
-        // if TypeId::of::<u8>() == TypeId::of::<T>() {
-        //     let mut buf = [0u8; N];
-        //     decoder.reader().read(&mut buf)?;
-        //     let ptr = &mut buf as *mut _ as *mut [T; N];
-
-        //     // Safety: we know that T is a u8, so it is perfectly safe to
-        //     // translate an array of u8 into an array of T
-        //     let res = unsafe { ptr.read() };
-        //     Ok(res)
-        // }
-        let result = super::impl_core::collect_into_array(&mut (0..N).map(|_| {
-            // See the documentation on `unclaim_bytes_read` as to why we're doing this here
-            decoder.unclaim_bytes_read(core::mem::size_of::<T>());
-            T::decode(decoder)
-        }));
+        if unty::type_equal::<T, u8>() {
+            let mut buf = [0u8; N];
+            decoder.reader().read(&mut buf)?;
+            let ptr = &mut buf as *mut _ as *mut [T; N];
 
-        // result is only None if N does not match the values of `(0..N)`, which it always should
-        // So this unwrap should never occur
-        result.unwrap()
+            // Safety: we know that T is a u8, so it is perfectly safe to
+            // translate an array of u8 into an array of T
+            let res = unsafe { ptr.read() };
+            Ok(res)
+        } else {
+            let result = super::impl_core::collect_into_array(&mut (0..N).map(|_| {
+                // See the documentation on `unclaim_bytes_read` as to why we're doing this here
+                decoder.unclaim_bytes_read(core::mem::size_of::<T>());
+                T::decode(decoder)
+            }));
+
+            // result is only None if N does not match the values of `(0..N)`, which it always should
+            // So this unwrap should never occur
+            result.unwrap()
+        }
     }
 }
 
 impl<'de, T, const N: usize> BorrowDecode<'de> for [T; N]
 where
-    T: BorrowDecode<'de> + Sized,
+    T: BorrowDecode<'de>,
 {
     fn borrow_decode<D: BorrowDecoder<'de>>(decoder: &mut D) -> Result<Self, DecodeError> {
         decoder.claim_bytes_read(core::mem::size_of::<[T; N]>())?;
 
-        // TODO: we can't limit `T: 'static` because that would break other things
-        // but we want to have this optimization
-        // This will be another contendor for specialization implementation
-        // if TypeId::of::<u8>() == TypeId::of::<T>() {
-        //     let mut buf = [0u8; N];
-        //     decoder.reader().read(&mut buf)?;
-        //     let ptr = &mut buf as *mut _ as *mut [T; N];
+        if unty::type_equal::<T, u8>() {
+            let mut buf = [0u8; N];
+            decoder.reader().read(&mut buf)?;
+            let ptr = &mut buf as *mut _ as *mut [T; N];
 
-        //     // Safety: we know that T is a u8, so it is perfectly safe to
-        //     // translate an array of u8 into an array of T
-        //     let res = unsafe { ptr.read() };
-        //     Ok(res)
-        // }
-        let result = super::impl_core::collect_into_array(&mut (0..N).map(|_| {
-            // See the documentation on `unclaim_bytes_read` as to why we're doing this here
-            decoder.unclaim_bytes_read(core::mem::size_of::<T>());
-            T::borrow_decode(decoder)
-        }));
-
-        // result is only None if N does not match the values of `(0..N)`, which it always should
-        // So this unwrap should never occur
-        result.unwrap()
+            // Safety: we know that T is a u8, so it is perfectly safe to
+            // translate an array of u8 into an array of T
+            let res = unsafe { ptr.read() };
+            Ok(res)
+        } else {
+            let result = super::impl_core::collect_into_array(&mut (0..N).map(|_| {
+                // See the documentation on `unclaim_bytes_read` as to why we're doing this here
+                decoder.unclaim_bytes_read(core::mem::size_of::<T>());
+                T::borrow_decode(decoder)
+            }));
+
+            // result is only None if N does not match the values of `(0..N)`, which it always should
+            // So this unwrap should never occur
+            result.unwrap()
+        }
     }
 }
 
@@ -547,22 +543,6 @@ where
     }
 }
 
-// BlockedTODO: https://github.com/rust-lang/rust/issues/37653
-//
-// We'll want to implement BorrowDecode for both Option<&[u8]> and Option<&[T: Encode]>,
-// but those implementations overlap because &'a [u8] also implements BorrowDecode
-// impl<'a, 'de: 'a> BorrowDecode<'de> for Option<&'a [u8]> {
-//     fn borrow_decode<D: BorrowDecoder<'de>>(decoder: &mut D) -> Result<Self, DecodeError> {
-//         match super::decode_option_variant(decoder, core::any::type_name::<Option<&[u8]>>())? {
-//             Some(_) => {
-//                 let val = BorrowDecode::borrow_decode(decoder)?;
-//                 Ok(Some(val))
-//             }
-//             None => Ok(None),
-//         }
-//     }
-// }
-
 impl<T, U> Decode for Result<T, U>
 where
     T: Decode,

src/enc/impls.rs

@@ -280,24 +280,15 @@ impl Encode for char {
     }
 }
 
-// BlockedTODO: https://github.com/rust-lang/rust/issues/37653
-//
-// We'll want to implement encoding for both &[u8] and &[T: Encode],
-// but those implementations overlap because u8 also implements Encode
-// impl Encode for &'_ [u8] {
-//     fn encode<E: Encoder>(&self, encoder: &mut E) -> Result<(), EncodeError> {
-//         encoder.writer().write(*self)
-//     }
-// }
-
 impl<T> Encode for [T]
 where
-    T: Encode + 'static,
+    T: Encode,
 {
     fn encode<E: Encoder>(&self, encoder: &mut E) -> Result<(), EncodeError> {
         super::encode_slice_len(encoder, self.len())?;
 
-        if core::any::TypeId::of::<T>() == core::any::TypeId::of::<u8>() {
+        if unty::type_equal::<T, u8>() {
+            // Safety: T = u8
             let t: &[u8] = unsafe { core::mem::transmute(self) };
             encoder.writer().write(t)?;
             return Ok(());
@@ -355,10 +346,17 @@ where
     T: Encode,
 {
     fn encode<E: Encoder>(&self, encoder: &mut E) -> Result<(), EncodeError> {
-        for item in self.iter() {
-            item.encode(encoder)?;
+        if unty::type_equal::<T, u8>() {
+            // Safety: this is &[u8; N]
+            let array_slice: &[u8] =
+                unsafe { core::slice::from_raw_parts(self.as_ptr().cast(), N) };
+            encoder.writer().write(array_slice)
+        } else {
+            for item in self.iter() {
+                item.encode(encoder)?;
+            }
+            Ok(())
         }
-        Ok(())
     }
 }