Remove Send + Sync bounds from callbacks

src/types.rs

@@ -158,8 +158,6 @@ pub type FileFn<T, E> = Box<
             Mime,
             Pin<Box<dyn Stream<Item = Result<Bytes, Error>>>>,
         ) -> Pin<Box<dyn Future<Output = Result<T, E>>>>
-        + Send
-        + Sync,
 >;
 
 /// The field type represents a field in the form-data that is allowed to be parsed.
@@ -218,8 +216,6 @@ impl<T, E> Field<T, E> {
     pub fn file<F, Fut>(f: F) -> Self
     where
         F: Fn(String, Mime, Pin<Box<dyn Stream<Item = Result<Bytes, Error>>>>) -> Fut
-            + Send
-            + Sync
             + Clone
             + 'static,
         Fut: Future<Output = Result<T, E>> + 'static,
@@ -477,7 +473,7 @@ pub struct Form<T, E> {
     pub(crate) max_field_size: usize,
     pub(crate) max_files: u32,
     pub(crate) max_file_size: usize,
-    pub(crate) transform_error: Option<Box<dyn Fn(Error) -> actix_web::Error + Send + Sync>>,
+    pub(crate) transform_error: Option<Box<dyn Fn(Error) -> actix_web::Error + Sync>>,
     inner: Map<T, E>,
 }
 
@@ -511,7 +507,7 @@ impl<T, E> Form<T, E> {
     /// Set the Transform Error method to convert Error types into actix_web::Error by hand
     pub fn transform_error(
         mut self,
-        f: impl Fn(Error) -> actix_web::Error + Send + Sync + 'static,
+        f: impl Fn(Error) -> actix_web::Error + Sync + 'static,
     ) -> Self {
         self.transform_error = Some(Box::new(f));
         self