diff --git a/src/impl_as_ref.rs b/src/impl_as_ref.rs
index 6eb4051..80adae1 100644
--- a/src/impl_as_ref.rs
+++ b/src/impl_as_ref.rs
@@ -11,42 +11,40 @@ use model::*;
 pub fn build(component: &AutoImpl, ref_ty: Trait) -> Result<Tokens, String> {
     let component_ident = &component.ident;
 
-    let impl_methods = try_iter!(
-        component.methods.iter()
-            .map(|method| {
-                let valid_receiver = match method.arg_self {
-                    Some(ref arg_self) => match *arg_self {
-                        SelfArg::Ref(_, syn::Mutability::Immutable) => true,
-                        _ => false
-                    },
-                    None => false
-                };
-
-                if !valid_receiver {
-                    Err(format!("auto impl for `{}` is only supported for methods with a `&self` reciever", ref_ty))?
-                }
-
-                method.build_impl_item(|method| {
-                    let fn_ident = &method.ident;
-                    let fn_args = &method.arg_pats;
-
-                    quote!({
-                        self.as_ref().#fn_ident( #(#fn_args),* )
-                    })
+    let impl_methods = component.methods.iter()
+        .map(|method| {
+            let valid_receiver = match method.arg_self {
+                Some(ref arg_self) => match *arg_self {
+                    SelfArg::Ref(_, syn::Mutability::Immutable) => true,
+                    _ => false
+                },
+                None => false
+            };
+
+            if !valid_receiver {
+                Err(format!("auto impl for `{}` is only supported for methods with a `&self` reciever", ref_ty))?
+            }
+
+            method.build_impl_item(|method| {
+                let fn_ident = &method.ident;
+                let fn_args = &method.arg_pats;
+
+                quote!({
+                    self.as_ref().#fn_ident( #(#fn_args),* )
                 })
             })
-    );
+        })
+        .collect::<Result<Vec<_>, _>>()?;
 
-    let impl_associated_types = try_iter!(
-        component.associated_types.iter()
-            .map(|associated_type| {
-                associated_type.build_impl_item(|associated_type| {
-                    let ty_ident = &associated_type.ident;
+    let impl_associated_types = component.associated_types.iter()
+        .map(|associated_type| {
+            associated_type.build_impl_item(|associated_type| {
+                let ty_ident = &associated_type.ident;
 
-                    quote!(TAutoImpl :: #ty_ident)
-                })
+                quote!(TAutoImpl :: #ty_ident)
             })
-    );
+        })
+        .collect::<Result<Vec<_>, _>>()?;
 
     let (trait_tys, impl_lifetimes, impl_tys, where_clauses) = component.split_generics();
 
diff --git a/src/lib.rs b/src/lib.rs
index 3f50989..3eb6b6d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -8,25 +8,6 @@ include!("lib.proc_macro.rs");
 extern crate quote;
 extern crate syn;
 
-macro_rules! try_iter {
-    ($vec_expr:expr) => ({
-        let v: Vec<_> = $vec_expr.collect();
-
-        if let Some(err) = v.iter().find(|res| res.is_err()) {
-            match *err {
-                Err(ref err) => Err(err.clone())?,
-                _ => unreachable!()
-            }
-        }
-
-        let v: Vec<_> = v.into_iter()
-            .filter_map(Result::ok)
-            .collect();
-        
-        v
-    })
-}
-
 mod model;
 mod impl_as_ref;
 mod impl_fn;
@@ -80,9 +61,7 @@ fn parse_impl_types(tokens: Tokens) -> Result<Vec<ImplForTrait>, String> {
         _ => Err(IMPL_FOR_TRAIT_ERR)?
     };
 
-    let idents = try_iter!(idents.into_iter());
-
-    Ok(idents)
+    idents.into_iter().collect()
 }
 
 fn auto_impl_expand(impl_for_traits: &[ImplForTrait], tokens: Tokens) -> Result<Tokens, String> {