Bump syn from 1.0 to 2.0

Cargo.toml

@@ -27,7 +27,7 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1.0"
 quote = "1.0"
-syn = { version = "1.0", features = ["full", "visit", "visit-mut"] }
+syn = { version = "2.0", features = ["full", "visit", "visit-mut"] }
 proc-macro-error = "1.0.0"
 
 [dev-dependencies]

README.md

@@ -5,7 +5,7 @@ some common smart pointers and closures.
 
 # Usage
 
-This library requires Rust 1.37.0 or newer. This library doesn't leave any public API in your code.
+This library requires Rust 1.56.0 or newer. This library doesn't leave any public API in your code.
 
 Add `auto_impl` to your `Cargo.toml` and just use it in your crate:
 

src/attr.rs

@@ -6,7 +6,7 @@ use proc_macro_error::{abort, emit_error};
 use syn::{
     spanned::Spanned,
     visit_mut::{visit_item_trait_mut, VisitMut},
-    Attribute, TraitItem,
+    Attribute, Meta, TraitItem,
 };
 
 use crate::proxy::{parse_types, ProxyType};
@@ -19,7 +19,7 @@ pub(crate) fn remove_our_attrs(trait_def: &mut syn::ItemTrait) {
         fn visit_trait_item_mut(&mut self, item: &mut TraitItem) {
             let item_span = item.span();
             let (attrs, is_method) = match item {
-                TraitItem::Method(m) => (&mut m.attrs, true),
+                TraitItem::Fn(m) => (&mut m.attrs, true),
                 TraitItem::Const(c) => (&mut c.attrs, false),
                 TraitItem::Type(t) => (&mut t.attrs, false),
                 TraitItem::Macro(m) => (&mut m.attrs, false),
@@ -48,7 +48,7 @@ pub(crate) fn remove_our_attrs(trait_def: &mut syn::ItemTrait) {
 /// Checks if the given attribute is "our" attribute. That means that it's path
 /// is `auto_impl`.
 pub(crate) fn is_our_attr(attr: &Attribute) -> bool {
-    attr.path.is_ident("auto_impl")
+    attr.path().is_ident("auto_impl")
 }
 
 /// Tries to parse the given attribute as one of our own `auto_impl`
@@ -61,15 +61,10 @@ pub(crate) fn parse_our_attr(attr: &Attribute) -> Result<OurAttr, ()> {
     // Get the body of the attribute (which has to be a ground, because we
     // required the syntax `auto_impl(...)` and forbid stuff like
     // `auto_impl = ...`).
-    let tokens = attr.tokens.clone().into_iter().collect::<Vec<_>>();
-    let body = match &*tokens {
-        [TokenTree::Group(g)] => g.stream(),
+    let body = match &attr.meta {
+        Meta::List(list) => list.tokens.clone(),
         _ => {
-            emit_error!(
-                attr.tokens.span(),
-                "expected single group delimited by `()`, found '{:?}'",
-                tokens,
-            );
+            emit_error!(attr.span(), "expected single group delimited by `()`");
             return Err(());
         }
     };
@@ -84,7 +79,7 @@ pub(crate) fn parse_our_attr(attr: &Attribute) -> Result<OurAttr, ()> {
             return Err(());
         }
         None => {
-            emit_error!(attr.tokens.span(), "expected ident, found nothing");
+            emit_error!(attr.span(), "expected ident, found nothing");
             return Err(());
         }
     };

src/gen.rs

@@ -4,8 +4,7 @@ use quote::{ToTokens, TokenStreamExt};
 use syn::{
     punctuated::Punctuated, spanned::Spanned, Attribute, FnArg, GenericParam, Ident, ItemTrait,
     Lifetime, Pat, PatIdent, PatType, ReturnType, Signature, Token, TraitBound, TraitBoundModifier,
-    TraitItem, TraitItemConst, TraitItemMethod, TraitItemType, Type, TypeParamBound,
-    WherePredicate,
+    TraitItem, TraitItemConst, TraitItemFn, TraitItemType, Type, TypeParamBound, WherePredicate,
 };
 
 use crate::{
@@ -78,7 +77,7 @@ fn gen_header(
             .iter()
             // Only interested in methods
             .filter_map(|item| {
-                if let TraitItem::Method(m) = item {
+                if let TraitItem::Fn(m) = item {
                     Some(m)
                 } else {
                     None
@@ -163,7 +162,7 @@ fn gen_header(
             .iter()
             // Only interested in methods
             .filter_map(|item| {
-                if let TraitItem::Method(m) = item {
+                if let TraitItem::Fn(m) = item {
                     Some(m)
                 } else {
                     None
@@ -204,7 +203,7 @@ fn gen_header(
                         // `self.field` is always `: 'a` if `Self: 'a`.
                         match b {
                             TypeParamBound::Trait(t) => Some(t),
-                            TypeParamBound::Lifetime(_) => None,
+                            _ => None,
                         }
                     })
             });
@@ -296,7 +295,7 @@ fn gen_fn_type_for_trait(proxy_type: &ProxyType, trait_def: &ItemTrait) -> Token
     // Only traits with exactly one method can be implemented for Fn-traits.
     // Associated types and consts are also not allowed.
     let method = trait_def.items.get(0).and_then(|item| {
-        if let TraitItem::Method(m) = item {
+        if let TraitItem::Fn(m) = item {
             Some(m)
         } else {
             None
@@ -475,7 +474,7 @@ fn gen_items(
                 TraitItem::Const(c) => {
                     gen_const_item(proxy_type, c, trait_def, proxy_ty_param).ok()
                 }
-                TraitItem::Method(method) => {
+                TraitItem::Fn(method) => {
                     gen_method_item(proxy_type, method, trait_def, proxy_ty_param).ok()
                 }
                 TraitItem::Type(ty) => {
@@ -591,7 +590,7 @@ fn gen_type_item(
 /// immediately emitted and `Err(())` is returned.
 fn gen_method_item(
     proxy_type: &ProxyType,
-    item: &TraitItemMethod,
+    item: &TraitItemFn,
     trait_def: &ItemTrait,
     proxy_ty_param: &Ident,
 ) -> Result<TokenStream2, ()> {
@@ -874,7 +873,7 @@ fn get_arg_list<'a>(
 
 /// Checks if the given method has the attribute `#[auto_impl(keep_default_for(...))]`
 /// and if it contains the given proxy type.
-fn should_keep_default_for(m: &TraitItemMethod, proxy_type: &ProxyType) -> bool {
+fn should_keep_default_for(m: &TraitItemFn, proxy_type: &ProxyType) -> bool {
     // Get an iterator of just the attribute we are interested in.
     let mut it = m
         .attrs
@@ -908,7 +907,7 @@ fn should_keep_default_for(m: &TraitItemMethod, proxy_type: &ProxyType) -> bool
 fn filter_attrs(attrs: &[Attribute]) -> Vec<Attribute> {
     attrs
         .iter()
-        .filter(|attr| attr.path.is_ident("cfg"))
+        .filter(|attr| attr.path().is_ident("cfg"))
         .cloned()
         .collect()
 }