commit 028d3d23f9c11be9c8d0a791dba36f905698f294
author David Tolnay <dtolnay@gmail.com> Sun Nov 29 18:09:52 2020 -0800
committer David Tolnay <dtolnay@gmail.com> Sun Nov 29 21:50:54 2020 -0800
tree 4e7dc74ac109dea11847cb366a376e0ea62c00d3
parent 76dfe624d0b61b3c4cbfd7a73e702d5d2842665b

Parse negative impls

syntax/parse.rs

diff --git a/syntax/parse.rs b/syntax/parse.rs
index aa86a9f..a3f50ec 100644
--- a/syntax/parse.rs
+++ b/syntax/parse.rs
@@ -673,8 +673,8 @@
         return Err(Error::new_spanned(span, "expected an empty impl block"));
     }
 
-    let self_ty = &imp.self_ty;
     if let Some((bang, path, for_token)) = &imp.trait_ {
+        let self_ty = &imp.self_ty;
         let span = quote!(#bang #path #for_token #self_ty);
         return Err(Error::new_spanned(
             span,
@@ -690,10 +690,27 @@
         ));
     }
 
+    let mut negative_token = None;
+    let mut self_ty = *imp.self_ty;
+    if let RustType::Verbatim(ty) = &self_ty {
+        let mut iter = ty.clone().into_iter();
+        if let Some(TokenTree::Punct(punct)) = iter.next() {
+            if punct.as_char() == '!' {
+                let ty = iter.collect::<TokenStream>();
+                if !ty.is_empty() {
+                    negative_token = Some(Token![!](punct.span()));
+                    self_ty = syn::parse2(ty)?;
+                }
+            }
+        }
+    }
+
     Ok(Api::Impl(Impl {
         impl_token: imp.impl_token,
+        negative: negative_token.is_some(),
         ty: parse_type(&self_ty)?,
         brace_token: imp.brace_token,
+        negative_token,
     }))
 }