Move from venial to syn.

.vscode/settings.json

@@ -2,29 +2,32 @@
     "cSpell.diagnosticLevel": "Information",
     "cSpell.words": [
         "castable",
+        "casted",
+        "clippy",
         "downcastable",
+        "downcasting",
         "downcasts",
+        "intertrait",
         "Kokusnuss",
+        "mopa",
+        "onestacked",
         "Peekable",
+        "println",
+        "proc",
         "ptrs",
         "punct",
+        "raldone",
+        "rustc",
+        "rustdoc",
         "selv",
+        "struct",
+        "structs",
         "Traitcast",
         "traitcastable",
         "TraitcastableAny",
         "TraitcastableTo",
-        "ptrs",
         "upcasting",
-        "downcasting",
-        "casted",
-        "structs",
-        "struct",
-        "println",
-        "raldone",
-        "onestacked",
-        "mopa",
-        "intertrait",
-        "rustc",
-        "clippy"
+        "vars",
+        "Zunstable"
     ]
-}
+}

Cargo.toml

@@ -1,2 +1,47 @@
 [workspace]
+resolver = "2"
 members = ["trait_cast_impl_rs", "trait_cast_rs"]
+
+[workspace.lints.clippy]
+pedantic = "warn"
+nursery = "warn"
+doc_markdown = "warn"
+manual_let_else = "warn"
+match_same_arms = "warn"
+redundant_closure_for_method_calls = "warn"
+redundant_else = "warn"
+semicolon_if_nothing_returned = "warn"
+type_complexity = "allow"
+undocumented_unsafe_blocks = "warn"
+unwrap_or_default = "warn"
+needless_lifetimes = "allow"
+option_if_let_else = "allow"
+
+ptr_as_ptr = "warn"
+ptr_cast_constness = "warn"
+ref_as_ptr = "warn"
+
+# see: https://github.com/bevyengine/bevy/pull/15375#issuecomment-2366966219
+too_long_first_doc_paragraph = "allow"
+
+std_instead_of_core = "warn"
+std_instead_of_alloc = "warn"
+alloc_instead_of_core = "warn"
+
+[workspace.lints.rust]
+nonstandard-style = "warn"
+future-incompatible = "warn"
+missing_docs = "warn"
+unused = "warn"
+rust_2018_idioms = "warn"
+rust-2024-compatibility = "warn"
+array-into-iter = "warn"
+bare-trait-objects = "warn"
+ellipsis-inclusive-range-patterns = "warn"
+non-fmt-panics = "warn"
+explicit-outlives-requirements = "warn"
+unused-extern-crates = "warn"
+unexpected_cfgs = { level = "warn", check-cfg = ['cfg(docsrs_dep)'] }
+unsafe_code = "deny"
+unsafe_op_in_unsafe_fn = "warn"
+unused_qualifications = "warn"

clippy.toml

@@ -0,0 +1 @@
+check-private-items = true

rustfmt.toml

@@ -1,2 +1,13 @@
 match_block_trailing_comma = true
 tab_spaces = 2
+condense_wildcard_suffixes = false
+newline_style = "Unix"
+
+# The options below are unstable
+unstable_features = true
+imports_granularity = "Crate"
+normalize_comments = true
+
+# these options seem poorly implemented and cause churn, so, try to avoid them
+# wrap_comments = true
+# comment_width = 100

trait_cast_impl_rs/Cargo.toml

@@ -20,5 +20,17 @@ proc-macro = true
 
 [dependencies]
 proc-macro2 = { version = "1.0", features = ["nightly"] }
-venial = "0.5.0"
-quote = "1.0.21"
+syn = { version = "2.0", default-features = false, features = [
+  "full",
+  "parsing",
+  "printing",
+  "proc-macro",
+] }
+quote = "1.0"
+
+[lints]
+workspace = true
+
+[package.metadata.docs.rs]
+rustdoc-args = ["-Zunstable-options", "--generate-link-to-definition"]
+all-features = true

trait_cast_impl_rs/src/lib.rs

@@ -1,13 +1,37 @@
-#![deny(missing_docs)]
-#![warn(clippy::undocumented_unsafe_blocks, clippy::pedantic, clippy::nursery)]
 //! Proc-macro automating the implementation of `trait_cast_rs::TraitcastableAny`.
 //!
 //! See `make_trait_castable` for more details.
 
 use proc_macro::TokenStream as TokenStream1;
-use proc_macro2::TokenStream;
+use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
-use venial::{parse_declaration, Declaration, Error};
+use syn::{
+  parse::{self, Parse, ParseStream},
+  parse_macro_input,
+  punctuated::Punctuated,
+  Error, ItemEnum, ItemStruct, Token, TypePath,
+};
+
+/// Parses a list of TypePaths separated by commas.
+struct TraitCastTargets {
+  vars: Vec<TypePath>,
+}
+
+impl Parse for TraitCastTargets {
+  fn parse(input: ParseStream<'_>) -> parse::Result<Self> {
+    let vars: Vec<TypePath> = Punctuated::<TypePath, Token![,]>::parse_terminated(input)?
+      .into_iter()
+      .collect();
+    Ok(TraitCastTargets { vars: vars })
+  }
+}
+
+impl quote::ToTokens for TraitCastTargets {
+  fn to_tokens(&self, tokens: &mut TokenStream2) {
+    let vars = &self.vars;
+    tokens.extend(quote!(#(#vars),*));
+  }
+}
 
 /// Attribute macro implementing `TraitcastableAny` for a struct, enum or union.
 ///
@@ -42,26 +66,32 @@ use venial::{parse_declaration, Declaration, Error};
 /// ```
 #[proc_macro_attribute]
 pub fn make_trait_castable(args: TokenStream1, input: TokenStream1) -> TokenStream1 {
-  let args = TokenStream::from(args);
-  let input = match parse_declaration(input.into()) {
-    Ok(Declaration::Function(fun)) => {
-      return Error::new_at_span(
-        fun.name.span(),
-        "Can not implement `Traitcast` for functions, expected a struct, enum or union definition",
-      )
-      .to_compile_error()
-      .into();
-    },
-    Ok(input) => input,
-    Err(error) => {
-      return error.to_compile_error().into();
-    },
-  };
-  let item_name = input.name();
+  // Convert the input to a TokenStream2
+  let input = TokenStream2::from(input);
+
+  let trait_cast_targets = parse_macro_input!(args as TraitCastTargets);
+
+  // First, try to parse the input as a struct
+  let input_struct = syn::parse2::<ItemStruct>(input.clone());
+  let mut source_ident = input_struct.map(|item_struct| item_struct.ident);
+
+  // Maybe it's an enum
+  if source_ident.is_err() {
+    let input_enum = syn::parse2::<ItemEnum>(input.clone());
+    source_ident = input_enum.map(|item_enum| item_enum.ident);
+  }
+
+  if let Err(err) = source_ident {
+    let mut custom_error_message = Error::new(err.span(), "Expected a struct or enum");
+    custom_error_message.combine(err);
+    return custom_error_message.to_compile_error().into();
+  }
+
+  let source_ident = source_ident.unwrap();
 
   TokenStream1::from(quote!(
     #input
     ::trait_cast_rs::make_trait_castable_decl! {
-    #item_name => (#args)
+    #source_ident => (#trait_cast_targets)
   }))
 }

trait_cast_rs/Cargo.toml

@@ -23,5 +23,12 @@ const_sort = ["dep:const_sort_rs"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-trait_cast_impl_rs = { path = "../trait_cast_impl_rs", version = "0.2.2" }
-const_sort_rs = { version = "0.3.3", optional = true }
+trait_cast_impl_rs = { path = "../trait_cast_impl_rs" }
+const_sort_rs = { version = "0.3", optional = true }
+
+[lints]
+workspace = true
+
+[package.metadata.docs.rs]
+rustdoc-args = ["-Zunstable-options", "--generate-link-to-definition"]
+all-features = true

trait_cast_rs/examples/manual.rs

@@ -1,3 +1,7 @@
+#![expect(
+  unsafe_code,
+  reason = "Manual traitcast implementations require unsafe code."
+)]
 #![cfg_attr(feature = "min_specialization", feature(min_specialization))]
 #![feature(trait_upcasting)]
 #![allow(incomplete_features)]

trait_cast_rs/examples/manual_gen_struct.rs

@@ -1,3 +1,7 @@
+#![expect(
+  unsafe_code,
+  reason = "Manual traitcast implementations require unsafe code."
+)]
 #![cfg_attr(feature = "min_specialization", feature(min_specialization))]
 #![feature(ptr_metadata)]