1 files changed, 49 insertions, 0 deletions
diff --git a/vendor/maybe-async/src/parse.rs b/vendor/maybe-async/src/parse.rs
new file mode 100644
index 000000000..b5a8cf903
--- /dev/null
+++ b/vendor/maybe-async/src/parse.rs
@@ -0,0 +1,49 @@
+use proc_macro2::Span;
+use syn::{
+    parse::{discouraged::Speculative, Parse, ParseStream, Result},
+    Attribute, Error, ItemFn, ItemImpl, ItemStatic, ItemTrait,
+};
+
+pub enum Item {
+    Trait(ItemTrait),
+    Impl(ItemImpl),
+    Fn(ItemFn),
+    Static(ItemStatic),
+}
+
+macro_rules! fork {
+    ($fork:ident = $input:ident) => {{
+        $fork = $input.fork();
+        &$fork
+    }};
+}
+
+impl Parse for Item {
+    fn parse(input: ParseStream) -> Result<Self> {
+        let attrs = input.call(Attribute::parse_outer)?;
+        let mut fork;
+        let item = if let Some(mut item) = fork!(fork = input).parse::<ItemImpl>().ok() {
+            if item.trait_.is_none() {
+                return Err(Error::new(Span::call_site(), "expected a trait impl"));
+            }
+            item.attrs = attrs;
+            Item::Impl(item)
+        } else if let Some(mut item) = fork!(fork = input).parse::<ItemTrait>().ok() {
+            item.attrs = attrs;
+            Item::Trait(item)
+        } else if let Some(mut item) = fork!(fork = input).parse::<ItemFn>().ok() {
+            item.attrs = attrs;
+            Item::Fn(item)
+        } else if let Some(mut item) = fork!(fork = input).parse::<ItemStatic>().ok() {
+            item.attrs = attrs;
+            Item::Static(item)
+        } else {
+            return Err(Error::new(
+                Span::call_site(),
+                "expected trait impl, trait or fn",
+            ));
+        };
+        input.advance_to(&fork);
+        Ok(item)
+    }
+}