diff --git a/src/compiletest/header.rs b/src/compiletest/header.rs
index 64d1aae5ff5ef..daa3036687c44 100644
--- a/src/compiletest/header.rs
+++ b/src/compiletest/header.rs
@@ -59,11 +59,11 @@ pub fn load_props(testfile: &Path) -> TestProps {
             pp_exact = parse_pp_exact(ln, testfile);
         }
 
-        do parse_aux_build(ln).iter |ab| {
+        for parse_aux_build(ln).each |ab| {
             aux_builds.push(*ab);
         }
 
-        do parse_exec_env(ln).iter |ee| {
+        for parse_exec_env(ln).each |ee| {
             exec_env.push(*ee);
         }
 
diff --git a/src/libcore/core.rc b/src/libcore/core.rc
index 190421955734a..c112e53dedda2 100644
--- a/src/libcore/core.rc
+++ b/src/libcore/core.rc
@@ -132,8 +132,6 @@ pub mod container;
 /* Common data structures */
 
 pub mod option;
-#[path="iter-trait.rs"] #[merge = "iter-trait/option.rs"]
-pub mod option_iter;
 pub mod result;
 pub mod either;
 pub mod dvec;
diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index 53944c4c2c825..db97c17ad694c 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -48,6 +48,7 @@ use ptr;
 use str;
 use util;
 use num::Zero;
+use iter::BaseIter;
 
 /// The option type
 #[deriving_eq]
@@ -228,12 +229,6 @@ pub pure fn map_default<T, U>(opt: &r/Option<T>, def: U,
     match *opt { None => def, Some(ref t) => f(t) }
 }
 
-#[inline(always)]
-pub pure fn iter<T>(opt: &r/Option<T>, f: fn(x: &r/T)) {
-    //! Performs an operation on the contained value by reference
-    match *opt { None => (), Some(ref t) => f(t) }
-}
-
 #[inline(always)]
 pub pure fn unwrap<T>(opt: Option<T>) -> T {
     /*!
@@ -281,6 +276,19 @@ pub pure fn expect<T>(opt: Option<T>, reason: &str) -> T {
     }
 }
 
+impl<T> BaseIter<T> for Option<T> {
+    /// Performs an operation on the contained value by reference
+    #[inline(always)]
+    pure fn each(&self, f: fn(x: &self/T) -> bool) {
+        match *self { None => (), Some(ref t) => { f(t); } }
+    }
+
+    #[inline(always)]
+    pure fn size_hint(&self) -> Option<uint> {
+        if self.is_some() { Some(1) } else { Some(0) }
+    }
+}
+
 pub impl<T> Option<T> {
     /// Returns true if the option equals `none`
     #[inline(always)]
@@ -339,10 +347,6 @@ pub impl<T> Option<T> {
         }
     }
 
-    /// Performs an operation on the contained value by reference
-    #[inline(always)]
-    pure fn iter(&self, f: fn(x: &self/T)) { iter(self, f) }
-
     /**
     Gets an immutable reference to the value inside an option.
 
@@ -476,7 +480,7 @@ fn test_option_dance() {
     let x = Some(());
     let mut y = Some(5);
     let mut y2 = 0;
-    do x.iter |_x| {
+    for x.each |_x| {
         y2 = swap_unwrap(&mut y);
     }
     assert y2 == 5;
diff --git a/src/libcore/os.rs b/src/libcore/os.rs
index cf74ec6d77a22..c03f8dbafed2f 100644
--- a/src/libcore/os.rs
+++ b/src/libcore/os.rs
@@ -1237,7 +1237,7 @@ mod tests {
         setenv(~"HOME", ~"");
         assert os::homedir().is_none();
 
-        oldhome.iter(|s| setenv(~"HOME", *s));
+        for oldhome.each |s| { setenv(~"HOME", *s) }
     }
 
     #[test]
diff --git a/src/libcore/task/spawn.rs b/src/libcore/task/spawn.rs
index 152e602eeee07..5a74e341116c5 100644
--- a/src/libcore/task/spawn.rs
+++ b/src/libcore/task/spawn.rs
@@ -268,7 +268,7 @@ fn each_ancestor(list:        &mut AncestorList,
                  * Step 3: Maybe unwind; compute return info for our caller.
                  *##########################################################*/
                 if need_unwind && !nobe_is_dead {
-                    do bail_opt.iter |bail_blk| {
+                    for bail_opt.each |bail_blk| {
                         do with_parent_tg(&mut nobe.parent_group) |tg_opt| {
                             (*bail_blk)(tg_opt)
                         }
@@ -317,7 +317,7 @@ impl Drop for TCB {
         unsafe {
             // If we are failing, the whole taskgroup needs to die.
             if rt::rust_task_is_unwinding(self.me) {
-                self.notifier.iter(|x| { x.failed = true; });
+                for self.notifier.each |x| { x.failed = true; }
                 // Take everybody down with us.
                 do access_group(&self.tasks) |tg| {
                     kill_taskgroup(tg, self.me, self.is_main);
@@ -341,9 +341,7 @@ impl Drop for TCB {
 
 fn TCB(me: *rust_task, tasks: TaskGroupArc, ancestors: AncestorList,
        is_main: bool, notifier: Option<AutoNotify>) -> TCB {
-
-    let notifier = notifier;
-    notifier.iter(|x| { x.failed = false; });
+    for notifier.each |x| { x.failed = false; }
 
     TCB {
         me: me,
diff --git a/src/librustc/metadata/encoder.rs b/src/librustc/metadata/encoder.rs
index 403cc1cf97845..a0f697c9680c5 100644
--- a/src/librustc/metadata/encoder.rs
+++ b/src/librustc/metadata/encoder.rs
@@ -715,7 +715,7 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
         let idx = encode_info_for_struct(ecx, ebml_w, path,
                                          struct_def.fields, index);
         /* Encode the dtor */
-        do struct_def.dtor.iter |dtor| {
+        for struct_def.dtor.each |dtor| {
             index.push(entry {val: dtor.node.id, pos: ebml_w.writer.tell()});
           encode_info_for_ctor(ecx,
                                ebml_w,
@@ -767,7 +767,7 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
         encode_region_param(ecx, ebml_w, item);
         /* Encode the dtor */
         /* Encode id for dtor */
-        do struct_def.dtor.iter |dtor| {
+        for struct_def.dtor.each |dtor| {
             do ebml_w.wr_tag(tag_item_dtor) {
                 encode_def_id(ebml_w, local_def(dtor.node.id));
             }
@@ -821,7 +821,7 @@ fn encode_info_for_item(ecx: @EncodeContext, ebml_w: writer::Encoder,
             ebml_w.writer.write(str::to_bytes(def_to_str(method_def_id)));
             ebml_w.end_tag();
         }
-        do opt_trait.iter() |associated_trait| {
+        for opt_trait.each |associated_trait| {
            encode_trait_ref(ebml_w, ecx, *associated_trait);
         }
         encode_path(ecx, ebml_w, path, ast_map::path_name(item.ident));
diff --git a/src/librustc/middle/astencode.rs b/src/librustc/middle/astencode.rs
index b52a2d0bb093c..f08f7b343e267 100644
--- a/src/librustc/middle/astencode.rs
+++ b/src/librustc/middle/astencode.rs
@@ -860,7 +860,7 @@ fn encode_side_tables_for_id(ecx: @e::EncodeContext,
 
     debug!("Encoding side tables for id %d", id);
 
-    do option::iter(&tcx.def_map.find(&id)) |def| {
+    for tcx.def_map.find(&id).each |def| {
         do ebml_w.tag(c::tag_table_def) {
             ebml_w.id(id);
             do ebml_w.tag(c::tag_table_val) {
@@ -868,7 +868,8 @@ fn encode_side_tables_for_id(ecx: @e::EncodeContext,
             }
         }
     }
-    do option::iter(&tcx.node_types.find(&(id as uint))) |&ty| {
+
+    for tcx.node_types.find(&(id as uint)).each |&ty| {
         do ebml_w.tag(c::tag_table_node_type) {
             ebml_w.id(id);
             do ebml_w.tag(c::tag_table_val) {
@@ -877,7 +878,7 @@ fn encode_side_tables_for_id(ecx: @e::EncodeContext,
         }
     }
 
-    do option::iter(&tcx.node_type_substs.find(&id)) |tys| {
+    for tcx.node_type_substs.find(&id).each |tys| {
         do ebml_w.tag(c::tag_table_node_type_subst) {
             ebml_w.id(id);
             do ebml_w.tag(c::tag_table_val) {
@@ -886,7 +887,7 @@ fn encode_side_tables_for_id(ecx: @e::EncodeContext,
         }
     }
 
-    do option::iter(&tcx.freevars.find(&id)) |fv| {
+    for tcx.freevars.find(&id).each |fv| {
         do ebml_w.tag(c::tag_table_freevars) {
             ebml_w.id(id);
             do ebml_w.tag(c::tag_table_val) {
@@ -898,7 +899,7 @@ fn encode_side_tables_for_id(ecx: @e::EncodeContext,
     }
 
     let lid = ast::def_id { crate: ast::local_crate, node: id };
-    do option::iter(&tcx.tcache.find(&lid)) |tpbt| {
+    for tcx.tcache.find(&lid).each |tpbt| {
         do ebml_w.tag(c::tag_table_tcache) {
             ebml_w.id(id);
             do ebml_w.tag(c::tag_table_val) {
@@ -907,7 +908,7 @@ fn encode_side_tables_for_id(ecx: @e::EncodeContext,
         }
     }
 
-    do option::iter(&tcx.ty_param_bounds.find(&id)) |pbs| {
+    for tcx.ty_param_bounds.find(&id).each |pbs| {
         do ebml_w.tag(c::tag_table_param_bounds) {
             ebml_w.id(id);
             do ebml_w.tag(c::tag_table_val) {
@@ -921,7 +922,7 @@ fn encode_side_tables_for_id(ecx: @e::EncodeContext,
     // is what we actually use in trans, all modes will have been
     // resolved.
     //
-    //option::iter(tcx.inferred_modes.find(&id)) {|m|
+    //for tcx.inferred_modes.find(&id).each |m| {
     //    ebml_w.tag(c::tag_table_inferred_modes) {||
     //        ebml_w.id(id);
     //        ebml_w.tag(c::tag_table_val) {||
@@ -930,13 +931,13 @@ fn encode_side_tables_for_id(ecx: @e::EncodeContext,
     //    }
     //}
 
-    do option::iter(&maps.mutbl_map.find(&id)) |_m| {
+    if maps.mutbl_map.contains_key(&id) {
         do ebml_w.tag(c::tag_table_mutbl) {
             ebml_w.id(id);
         }
     }
 
-    do option::iter(&maps.last_use_map.find(&id)) |m| {
+    for maps.last_use_map.find(&id).each |m| {
         do ebml_w.tag(c::tag_table_last_use) {
             ebml_w.id(id);
             do ebml_w.tag(c::tag_table_val) {
@@ -947,7 +948,7 @@ fn encode_side_tables_for_id(ecx: @e::EncodeContext,
         }
     }
 
-    do option::iter(&maps.method_map.find(&id)) |mme| {
+    for maps.method_map.find(&id).each |mme| {
         do ebml_w.tag(c::tag_table_method_map) {
             ebml_w.id(id);
             do ebml_w.tag(c::tag_table_val) {
@@ -956,7 +957,7 @@ fn encode_side_tables_for_id(ecx: @e::EncodeContext,
         }
     }
 
-    do option::iter(&maps.vtable_map.find(&id)) |dr| {
+    for maps.vtable_map.find(&id).each |dr| {
         do ebml_w.tag(c::tag_table_vtable_map) {
             ebml_w.id(id);
             do ebml_w.tag(c::tag_table_val) {
@@ -965,7 +966,7 @@ fn encode_side_tables_for_id(ecx: @e::EncodeContext,
         }
     }
 
-    do option::iter(&tcx.adjustments.find(&id)) |adj| {
+    for tcx.adjustments.find(&id).each |adj| {
         do ebml_w.tag(c::tag_table_adjustments) {
             ebml_w.id(id);
             do ebml_w.tag(c::tag_table_val) {
diff --git a/src/librustc/middle/check_const.rs b/src/librustc/middle/check_const.rs
index c86f7ea5a922f..fbb26f85b3a04 100644
--- a/src/librustc/middle/check_const.rs
+++ b/src/librustc/middle/check_const.rs
@@ -51,7 +51,7 @@ pub fn check_item(sess: Session,
       }
       item_enum(ref enum_definition, _) => {
         for (*enum_definition).variants.each |var| {
-            do option::iter(&var.node.disr_expr) |ex| {
+            for var.node.disr_expr.each |ex| {
                 (v.visit_expr)(*ex, true, v);
             }
         }
diff --git a/src/librustc/middle/check_match.rs b/src/librustc/middle/check_match.rs
index f736c403cfccd..2aeec29fa6c0a 100644
--- a/src/librustc/middle/check_match.rs
+++ b/src/librustc/middle/check_match.rs
@@ -365,7 +365,7 @@ pub fn missing_ctor(cx: @MatchCheckCtxt,
       ty::ty_enum(eid, _) => {
         let mut found = ~[];
         for m.each |r| {
-            do option::iter(&pat_ctor_id(cx, r[0])) |id| {
+            for pat_ctor_id(cx, r[0]).each |id| {
                 if !vec::contains(found, id) {
                     found.push(/*bad*/copy *id);
                 }
diff --git a/src/librustc/middle/kind.rs b/src/librustc/middle/kind.rs
index aca5675aa151d..575f9d743ebd5 100644
--- a/src/librustc/middle/kind.rs
+++ b/src/librustc/middle/kind.rs
@@ -194,7 +194,7 @@ pub fn check_expr(e: @expr, cx: Context, v: visit::vt<Context>) {
         expr_unary(*)|expr_binary(*)|expr_method_call(*) => e.callee_id,
         _ => e.id
     };
-    do option::iter(&cx.tcx.node_type_substs.find(&type_parameter_id)) |ts| {
+    for cx.tcx.node_type_substs.find(&type_parameter_id).each |ts| {
         let bounds = match e.node {
           expr_path(_) => {
             let did = ast_util::def_id_of_def(cx.tcx.def_map.get(&e.id));
@@ -255,7 +255,7 @@ pub fn check_expr(e: @expr, cx: Context, v: visit::vt<Context>) {
 fn check_ty(aty: @Ty, cx: Context, v: visit::vt<Context>) {
     match aty.node {
       ty_path(_, id) => {
-        do option::iter(&cx.tcx.node_type_substs.find(&id)) |ts| {
+        for cx.tcx.node_type_substs.find(&id).each |ts| {
             let did = ast_util::def_id_of_def(cx.tcx.def_map.get(&id));
             let bounds = ty::lookup_item_type(cx.tcx, did).bounds;
             for vec::each2(*ts, *bounds) |ty, bound| {
diff --git a/src/librustc/middle/liveness.rs b/src/librustc/middle/liveness.rs
index 95f28578fec66..563864bddd37e 100644
--- a/src/librustc/middle/liveness.rs
+++ b/src/librustc/middle/liveness.rs
@@ -1101,7 +1101,7 @@ pub impl Liveness {
 
     fn propagate_through_opt_expr(&self, opt_expr: Option<@expr>,
                                   succ: LiveNode) -> LiveNode {
-        do opt_expr.foldl(succ) |succ, expr| {
+        do iter::foldl(&opt_expr, succ) |succ, expr| {
             self.propagate_through_expr(*expr, *succ)
         }
     }
diff --git a/src/librustc/middle/resolve.rs b/src/librustc/middle/resolve.rs
index 5298f6c632d64..c7b0dfd4f27e3 100644
--- a/src/librustc/middle/resolve.rs
+++ b/src/librustc/middle/resolve.rs
@@ -1022,7 +1022,7 @@ pub impl Resolver {
                         fmt!("duplicate definition of %s %s",
                              namespace_to_str(ns),
                              *self.session.str_of(name)));
-                    do child.span_for_namespace(ns).iter() |sp| {
+                    for child.span_for_namespace(ns).each |sp| {
                         self.session.span_note(*sp,
                              fmt!("first definition of %s %s here:",
                                   namespace_to_str(ns),
@@ -3463,7 +3463,7 @@ pub impl Resolver {
             // then resolve the ty params
             item_enum(ref enum_def, ref generics) => {
                 for (*enum_def).variants.each() |variant| {
-                    do variant.node.disr_expr.iter() |dis_expr| {
+                    for variant.node.disr_expr.each |dis_expr| {
                         // resolve the discriminator expr
                         // as a constant
                         self.with_constant_rib(|| {
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index a714446235aef..011ebfc8c03d8 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -1221,10 +1221,10 @@ pub fn new_block(cx: fn_ctxt, parent: Option<block>, +kind: block_kind,
                            is_lpad,
                            opt_node_info,
                            cx);
-        do option::iter(&parent) |cx| {
+        for parent.each |cx| {
             if cx.unreachable { Unreachable(bcx); }
         };
-        return bcx;
+        bcx
     }
 }
 
@@ -1452,7 +1452,7 @@ pub fn alloc_local(cx: block, local: @ast::local) -> block {
     };
     let val = alloc_ty(cx, t);
     if cx.sess().opts.debuginfo {
-        do option::iter(&simple_name) |name| {
+        for simple_name.each |name| {
             str::as_c_str(*cx.ccx().sess.str_of(*name), |buf| {
                 unsafe {
                     llvm::LLVMSetValueName(val, buf)
@@ -1461,7 +1461,7 @@ pub fn alloc_local(cx: block, local: @ast::local) -> block {
         }
     }
     cx.fcx.lllocals.insert(local.node.id, local_mem(val));
-    return cx;
+    cx
 }
 
 
@@ -2017,7 +2017,7 @@ pub fn trans_struct_dtor(ccx: @CrateContext,
   /* Look up the parent class's def_id */
   let mut class_ty = ty::lookup_item_type(tcx, parent_id).ty;
   /* Substitute in the class type if necessary */
-    do option::iter(&psubsts) |ss| {
+  for psubsts.each |ss| {
     class_ty = ty::subst_tps(tcx, ss.tys, ss.self_ty, class_ty);
   }
 
@@ -2034,7 +2034,7 @@ pub fn trans_struct_dtor(ccx: @CrateContext,
 
   /* If we're monomorphizing, register the monomorphized decl
      for the dtor */
-    do option::iter(&hash_id) |h_id| {
+  for hash_id.each |h_id| {
     ccx.monomorphized.insert(*h_id, lldecl);
   }
   /* Translate the dtor body */
@@ -2148,7 +2148,7 @@ pub fn trans_struct_def(ccx: @CrateContext, struct_def: @ast::struct_def,
                         path: @ast_map::path,
                         id: ast::node_id) {
     // Translate the destructor.
-    do option::iter(&struct_def.dtor) |dtor| {
+    for struct_def.dtor.each |dtor| {
         trans_struct_dtor(ccx, /*bad*/copy *path, &dtor.node.body,
                          dtor.node.id, None, None, local_def(id));
     };
diff --git a/src/librustc/middle/trans/callee.rs b/src/librustc/middle/trans/callee.rs
index 12864f12abd99..a5b453465f355 100644
--- a/src/librustc/middle/trans/callee.rs
+++ b/src/librustc/middle/trans/callee.rs
@@ -537,7 +537,7 @@ pub fn trans_call_inner(
         } else if ret_in_loop {
             let ret_flag_result = bool_to_i1(bcx, Load(bcx, ret_flag.get()));
             bcx = do with_cond(bcx, ret_flag_result) |bcx| {
-                do option::iter(&copy bcx.fcx.loop_ret) |&(flagptr, _)| {
+                for (copy bcx.fcx.loop_ret).each |&(flagptr, _)| {
                     Store(bcx, C_bool(true), flagptr);
                     Store(bcx, C_bool(false), bcx.fcx.llretptr);
                 }
diff --git a/src/librustc/middle/trans/closure.rs b/src/librustc/middle/trans/closure.rs
index fd149aa71e576..77906247909fd 100644
--- a/src/librustc/middle/trans/closure.rs
+++ b/src/librustc/middle/trans/closure.rs
@@ -293,7 +293,7 @@ pub fn build_closure(bcx0: block,
 
     // If this is a `for` loop body, add two special environment
     // variables:
-    do option::iter(&include_ret_handle) |flagptr| {
+    for include_ret_handle.each |flagptr| {
         // Flag indicating we have returned (a by-ref bool):
         let flag_datum = Datum {val: *flagptr, ty: ty::mk_bool(tcx),
                                 mode: ByRef, source: ZeroMem};
diff --git a/src/librustc/middle/trans/reachable.rs b/src/librustc/middle/trans/reachable.rs
index 17abebad600dc..51898d8385dbf 100644
--- a/src/librustc/middle/trans/reachable.rs
+++ b/src/librustc/middle/trans/reachable.rs
@@ -129,7 +129,7 @@ fn traverse_public_item(cx: ctx, item: @item) {
         for struct_def.ctor_id.each |&ctor_id| {
             cx.rmap.insert(ctor_id, ());
         }
-        do struct_def.dtor.iter |dtor| {
+        for struct_def.dtor.each |dtor| {
             cx.rmap.insert(dtor.node.id, ());
             if generics.ty_params.len() > 0u ||
                 attr::find_inline_attr(dtor.node.attrs) != attr::ia_none
diff --git a/src/librustc/middle/trans/type_use.rs b/src/librustc/middle/trans/type_use.rs
index 7b7a6eee92e7c..51e71650bcf67 100644
--- a/src/librustc/middle/trans/type_use.rs
+++ b/src/librustc/middle/trans/type_use.rs
@@ -241,10 +241,10 @@ pub fn node_type_needs(cx: Context, use_: uint, id: node_id) {
 }
 
 pub fn mark_for_method_call(cx: Context, e_id: node_id, callee_id: node_id) {
-    do option::iter(&cx.ccx.maps.method_map.find(&e_id)) |mth| {
+    for cx.ccx.maps.method_map.find(&e_id).each |mth| {
         match mth.origin {
           typeck::method_static(did) => {
-            do cx.ccx.tcx.node_type_substs.find(&callee_id).iter |ts| {
+            for cx.ccx.tcx.node_type_substs.find(&callee_id).each |ts| {
                 let type_uses = type_uses_for(cx.ccx, did, ts.len());
                 for vec::each2(type_uses, *ts) |uses, subst| {
                     type_needs(cx, *uses, *subst)
@@ -293,7 +293,7 @@ pub fn mark_for_expr(cx: Context, e: @expr) {
         }
       }
       expr_path(_) => {
-        do cx.ccx.tcx.node_type_substs.find(&e.id).iter |ts| {
+        for cx.ccx.tcx.node_type_substs.find(&e.id).each |ts| {
             let id = ast_util::def_id_of_def(cx.ccx.tcx.def_map.get(&e.id));
             let uses_for_ts = type_uses_for(cx.ccx, id, ts.len());
             for vec::each2(uses_for_ts, *ts) |uses, subst| {
@@ -379,7 +379,7 @@ pub fn handle_body(cx: Context, body: &blk) {
         },
         visit_block: |b, cx, v| {
             visit::visit_block(b, cx, v);
-            do option::iter(&b.node.expr) |e| {
+            for b.node.expr.each |e| {
                 node_type_needs(cx, use_repr, e.id);
             }
         },
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index 0b0715dd9ca35..13b456f6ddccf 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -871,7 +871,7 @@ fn mk_t_with_id(cx: ctxt, +st: sty, o_def_id: Option<ast::def_id>) -> t {
     fn sflags(substs: &substs) -> uint {
         let mut f = 0u;
         for substs.tps.each |tt| { f |= get(*tt).flags; }
-        substs.self_r.iter(|r| f |= rflags(*r));
+        for substs.self_r.each |r| { f |= rflags(*r) }
         return f;
     }
     match &st {
diff --git a/src/librustc/middle/typeck/check/_match.rs b/src/librustc/middle/typeck/check/_match.rs
index 39b2a2efdd817..cc218e6b71609 100644
--- a/src/librustc/middle/typeck/check/_match.rs
+++ b/src/librustc/middle/typeck/check/_match.rs
@@ -183,11 +183,11 @@ pub fn check_pat_variant(pcx: pat_ctxt, pat: @ast::pat, path: @ast::path,
             tcx.sess.span_fatal(pat.span, s);
         }
 
-        do subpats.iter() |pats| {
+        for subpats.each |pats| {
             for vec::each2(*pats, arg_types) |subpat, arg_ty| {
               check_pat(pcx, *subpat, *arg_ty);
             }
-        };
+        }
     } else if subpats_len > 0u {
         tcx.sess.span_fatal
             (pat.span, fmt!("this pattern has %u field%s, but the \
diff --git a/src/librustc/middle/typeck/check/mod.rs b/src/librustc/middle/typeck/check/mod.rs
index f724a442902f2..768c748f2bb02 100644
--- a/src/librustc/middle/typeck/check/mod.rs
+++ b/src/librustc/middle/typeck/check/mod.rs
@@ -538,7 +538,7 @@ pub fn check_struct(ccx: @mut CrateCtxt,
     let tcx = ccx.tcx;
     let self_ty = ty::node_id_to_type(tcx, id);
 
-    do struct_def.dtor.iter() |dtor| {
+    for struct_def.dtor.each |dtor| {
         let class_t = SelfInfo {
             self_ty: self_ty,
             self_id: dtor.node.self_id,
@@ -2820,7 +2820,7 @@ pub fn check_enum_variants(ccx: @mut CrateCtxt,
                 variants: &mut ~[ty::VariantInfo]) {
         let rty = ty::node_id_to_type(ccx.tcx, id);
         for vs.each |v| {
-            do v.node.disr_expr.iter |e_ref| {
+            for v.node.disr_expr.each |e_ref| {
                 let e = *e_ref;
                 debug!("disr expr, checking %s",
                        pprust::expr_to_str(e, ccx.tcx.sess.intr()));
diff --git a/src/librustc/middle/typeck/coherence.rs b/src/librustc/middle/typeck/coherence.rs
index f8fcef7580b1d..9c335c918e91f 100644
--- a/src/librustc/middle/typeck/coherence.rs
+++ b/src/librustc/middle/typeck/coherence.rs
@@ -209,7 +209,8 @@ pub impl CoherenceChecker {
 
                 match item.node {
                     item_impl(_, opt_trait, _, _) => {
-                        self.check_implementation(item, opt_trait.to_vec());
+                        self.check_implementation(item,
+                                                  iter::to_vec(&opt_trait));
                     }
                     _ => {
                         // Nothing to do.
@@ -676,7 +677,7 @@ pub impl CoherenceChecker {
                                 _ => ()
                           }
 
-                          do opt_trait.iter() |trait_ref| {
+                          for opt_trait.each |trait_ref| {
                                 // This is OK if and only if the trait was
                                 // defined in this crate.
 
diff --git a/src/librustc/middle/typeck/collect.rs b/src/librustc/middle/typeck/collect.rs
index 67dca7ea81196..0b4bdc049616e 100644
--- a/src/librustc/middle/typeck/collect.rs
+++ b/src/librustc/middle/typeck/collect.rs
@@ -690,7 +690,7 @@ pub fn convert_struct(ccx: @mut CrateCtxt,
                       id: ast::node_id) {
     let tcx = ccx.tcx;
 
-    do option::iter(&struct_def.dtor) |dtor| {
+    for struct_def.dtor.each |dtor| {
         // Write the dtor type
         let t_dtor = ty::mk_bare_fn(
             tcx,
diff --git a/src/librustc/middle/typeck/infer/mod.rs b/src/librustc/middle/typeck/infer/mod.rs
index aff2d599a0ef1..c5b3c71de9071 100644
--- a/src/librustc/middle/typeck/infer/mod.rs
+++ b/src/librustc/middle/typeck/infer/mod.rs
@@ -729,8 +729,9 @@ pub impl @mut InferCtxt {
         self.tcx.sess.span_err(sp,
            fmt!("%s%s", mk_msg(self.ty_to_str(actual_ty)),
                 error_str));
-        err.iter(|err|
-             ty::note_and_explain_type_err(self.tcx, *err));
+        for err.each |err| {
+            ty::note_and_explain_type_err(self.tcx, *err)
+        }
     }
 
     fn report_mismatched_types(&self, sp: span, e: ty::t, a: ty::t,
diff --git a/src/libstd/treemap.rs b/src/libstd/treemap.rs
index a093351c4a763..a8d343f80987e 100644
--- a/src/libstd/treemap.rs
+++ b/src/libstd/treemap.rs
@@ -528,7 +528,7 @@ pub impl<K: TotalOrd, V> TreeNode<K, V> {
 
 pure fn each<K: TotalOrd, V>(node: &r/Option<~TreeNode<K, V>>,
                         f: fn(&(&r/K, &r/V)) -> bool) {
-    do node.iter |x| {
+    for node.each |x| {
         each(&x.left, f);
         if f(&(&x.key, &x.value)) { each(&x.right, f) }
     }
@@ -536,7 +536,7 @@ pure fn each<K: TotalOrd, V>(node: &r/Option<~TreeNode<K, V>>,
 
 pure fn each_reverse<K: TotalOrd, V>(node: &r/Option<~TreeNode<K, V>>,
                                 f: fn(&(&r/K, &r/V)) -> bool) {
-    do node.iter |x| {
+    for node.each |x| {
         each_reverse(&x.right, f);
         if f(&(&x.key, &x.value)) { each_reverse(&x.left, f) }
     }
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index 96f4dadb3dbe9..80b02b83c58a1 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -538,7 +538,7 @@ pub fn walk_pat(pat: @pat, it: fn(@pat)) {
             for elts.each |p| {
                 walk_pat(*p, it)
             }
-            do tail.iter |tail| {
+            for tail.each |tail| {
                 walk_pat(*tail, it)
             }
         }
diff --git a/src/libsyntax/diagnostic.rs b/src/libsyntax/diagnostic.rs
index ba4ec7fb6db27..41931a790f5a0 100644
--- a/src/libsyntax/diagnostic.rs
+++ b/src/libsyntax/diagnostic.rs
@@ -295,7 +295,7 @@ fn highlight_lines(cm: @codemap::CodeMap,
 }
 
 fn print_macro_backtrace(cm: @codemap::CodeMap, sp: span) {
-    do option::iter(&sp.expn_info) |ei| {
+    for sp.expn_info.each |ei| {
         let ss = option::map_default(&ei.callee.span, @~"",
                                      |span| @cm.span_to_str(*span));
         print_diagnostic(*ss, note,
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index f808a3be6bbeb..59c250397c92e 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -736,7 +736,7 @@ pub fn print_struct(s: @ps,
         nbsp(s);
         bopen(s);
         hardbreak_if_not_bol(s);
-        do struct_def.dtor.iter |dtor| {
+        for struct_def.dtor.each |dtor| {
           hardbreak_if_not_bol(s);
           maybe_print_comment(s, dtor.span.lo);
           print_outer_attributes(s, dtor.node.attrs);
@@ -1275,10 +1275,10 @@ pub fn print_expr(s: @ps, &&expr: @ast::expr) {
       ast::expr_loop(ref blk, opt_ident) => {
         head(s, ~"loop");
         space(s.s);
-        opt_ident.iter(|ident| {
+        for opt_ident.each |ident| {
             print_ident(s, *ident);
             word_space(s, ~":");
-        });
+        }
         print_block(s, blk);
       }
       ast::expr_match(expr, ref arms) => {
@@ -1426,12 +1426,12 @@ pub fn print_expr(s: @ps, &&expr: @ast::expr) {
       ast::expr_break(opt_ident) => {
         word(s.s, ~"break");
         space(s.s);
-        opt_ident.iter(|ident| {print_ident(s, *ident); space(s.s)});
+        for opt_ident.each |ident| { print_ident(s, *ident); space(s.s) }
       }
       ast::expr_again(opt_ident) => {
         word(s.s, ~"loop");
         space(s.s);
-        opt_ident.iter(|ident| {print_ident(s, *ident); space(s.s)});
+        for opt_ident.each |ident| { print_ident(s, *ident); space(s.s) }
       }
       ast::expr_ret(result) => {
         word(s.s, ~"return");
@@ -1671,7 +1671,7 @@ pub fn print_pat(s: @ps, &&pat: @ast::pat, refutable: bool) {
       ast::pat_vec(elts, tail) => {
         word(s.s, ~"[");
         commasep(s, inconsistent, elts, |s, p| print_pat(s, p, refutable));
-        do option::iter(&tail) |tail| {
+        for tail.each |tail| {
             if vec::len(elts) != 0u { word_space(s, ~","); }
             word(s.s, ~"..");
             print_pat(s, *tail, refutable);
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 262754624cba5..a2f7392fe0cae 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -223,7 +223,7 @@ pub fn visit_enum_def<E>(enum_definition: ast::enum_def,
             }
         }
         // Visit the disr expr if it exists
-        vr.node.disr_expr.iter(|ex| (v.visit_expr)(*ex, e, v));
+        for vr.node.disr_expr.each |ex| { (v.visit_expr)(*ex, e, v) }
     }
 }
 
@@ -267,7 +267,7 @@ pub fn visit_pat<E>(p: @pat, e: E, v: vt<E>) {
     match p.node {
         pat_enum(path, ref children) => {
             visit_path(path, e, v);
-            do children.iter |children| {
+            for children.each |children| {
                 for children.each |child| { (v.visit_pat)(*child, e, v); }
             }
         }
@@ -292,7 +292,7 @@ pub fn visit_pat<E>(p: @pat, e: E, v: vt<E>) {
         },
         pat_ident(_, path, ref inner) => {
             visit_path(path, e, v);
-            do inner.iter |subpat| { (v.visit_pat)(*subpat, e, v) }
+            for inner.each |subpat| { (v.visit_pat)(*subpat, e, v) }
         }
         pat_lit(ex) => (v.visit_expr)(ex, e, v),
         pat_range(e1, e2) => {
@@ -304,7 +304,7 @@ pub fn visit_pat<E>(p: @pat, e: E, v: vt<E>) {
             for elts.each |elt| {
                 (v.visit_pat)(*elt, e, v);
             }
-            do tail.iter |tail| {
+            for tail.each |tail| {
                 (v.visit_pat)(*tail, e, v);
             }
         }
@@ -418,7 +418,7 @@ pub fn visit_struct_def<E>(
     for sd.fields.each |f| {
         (v.visit_struct_field)(*f, e, v);
     }
-    do sd.dtor.iter |dtor| {
+    for sd.dtor.each |dtor| {
         visit_struct_dtor_helper(
             *dtor,
             generics,
@@ -426,7 +426,7 @@ pub fn visit_struct_def<E>(
             e,
             v
         )
-    };
+    }
 }
 
 pub fn visit_struct_field<E>(sf: @struct_field, e: E, v: vt<E>) {
diff --git a/src/test/run-pass/iter-all.rs b/src/test/run-pass/iter-all.rs
index 3da5c01d19716..d5801a743cb5c 100644
--- a/src/test/run-pass/iter-all.rs
+++ b/src/test/run-pass/iter-all.rs
@@ -15,7 +15,7 @@ pub fn main() {
     assert [2u, 4u].all(is_even);
     assert [].all(is_even);
 
-    assert !Some(1u).all(is_even);
-    assert Some(2u).all(is_even);
-    assert None.all(is_even);
+    assert !iter::all(&Some(1u), is_even);
+    assert iter::all(&Some(2u), is_even);
+    assert iter::all(&None::<uint>, is_even);
 }
diff --git a/src/test/run-pass/iter-any.rs b/src/test/run-pass/iter-any.rs
index eb0b09327bb8f..3a98a28dc244e 100644
--- a/src/test/run-pass/iter-any.rs
+++ b/src/test/run-pass/iter-any.rs
@@ -15,7 +15,7 @@ pub fn main() {
     assert [1u, 2u].any(is_even);
     assert ![].any(is_even);
 
-    assert !Some(1).any(is_even);
-    assert Some(2).any(is_even);
-    assert !None.any(is_even);
+    assert !iter::any(&Some(1u), is_even);
+    assert iter::any(&Some(2u), is_even);
+    assert !iter::any(&None::<uint>, is_even);
 }
diff --git a/src/test/run-pass/iter-contains.rs b/src/test/run-pass/iter-contains.rs
index 6e1fd49811907..bac85c8751759 100644
--- a/src/test/run-pass/iter-contains.rs
+++ b/src/test/run-pass/iter-contains.rs
@@ -14,7 +14,7 @@ pub fn main() {
     assert [22u, 1u, 3u].contains(&22u) == true;
     assert [1u, 22u, 3u].contains(&22u) == true;
     assert [1u, 3u, 22u].contains(&22u) == true;
-    assert None.contains(&22u) == false;
-    assert Some(1u).contains(&22u) == false;
-    assert Some(22u).contains(&22u) == true;
+    assert iter::contains(&None::<uint>, &22u) == false;
+    assert iter::contains(&Some(1u), &22u) == false;
+    assert iter::contains(&Some(22u), &22u) == true;
 }
diff --git a/src/test/run-pass/iter-count.rs b/src/test/run-pass/iter-count.rs
index 1bc6155dce3b1..f2977655518f4 100644
--- a/src/test/run-pass/iter-count.rs
+++ b/src/test/run-pass/iter-count.rs
@@ -13,7 +13,7 @@ pub fn main() {
     assert [1u, 3u].count(&22u) == 0u;
     assert [22u, 1u, 3u].count(&22u) == 1u;
     assert [22u, 1u, 22u].count(&22u) == 2u;
-    assert None.count(&22u) == 0u;
-    assert Some(1u).count(&22u) == 0u;
-    assert Some(22u).count(&22u) == 1u;
+    assert iter::count(&None::<uint>, &22u) == 0u;
+    assert iter::count(&Some(1u), &22u) == 0u;
+    assert iter::count(&Some(22u), &22u) == 1u;
 }
diff --git a/src/test/run-pass/iter-eachi.rs b/src/test/run-pass/iter-eachi.rs
index f0ae9af1d2094..9746fab2eb818 100644
--- a/src/test/run-pass/iter-eachi.rs
+++ b/src/test/run-pass/iter-eachi.rs
@@ -16,13 +16,12 @@ pub fn main() {
     }
     assert c == 5u;
 
-    for None::<uint>.eachi |i, v| { fail!(); }
+    for iter::eachi(&None::<uint>) |i, v| { fail!(); }
 
     let mut c = 0u;
-    for Some(1u).eachi |i, v| {
+    for iter::eachi(&Some(1u)) |i, v| {
         assert (i + 1u) == *v;
         c += 1u;
     }
     assert c == 1u;
-
 }
diff --git a/src/test/run-pass/iter-filter-to-vec.rs b/src/test/run-pass/iter-filter-to-vec.rs
index 8f286ae90490c..b654151079b9c 100644
--- a/src/test/run-pass/iter-filter-to-vec.rs
+++ b/src/test/run-pass/iter-filter-to-vec.rs
@@ -13,7 +13,7 @@ fn is_even(x: &uint) -> bool { (*x % 2) == 0 }
 pub fn main() {
     assert [1, 3].filter_to_vec(is_even) == ~[];
     assert [1, 2, 3].filter_to_vec(is_even) == ~[2];
-    assert None.filter_to_vec(is_even) == ~[];
-    assert Some(1).filter_to_vec(is_even) == ~[];
-    assert Some(2).filter_to_vec(is_even) == ~[2];
+    assert iter::filter_to_vec(&None::<uint>, is_even) == ~[];
+    assert iter::filter_to_vec(&Some(1u), is_even) == ~[];
+    assert iter::filter_to_vec(&Some(2u), is_even) == ~[2];
 }
diff --git a/src/test/run-pass/iter-flat-map-to-vec.rs b/src/test/run-pass/iter-flat-map-to-vec.rs
index c8df707ce97eb..cf54ebf2fe9a6 100644
--- a/src/test/run-pass/iter-flat-map-to-vec.rs
+++ b/src/test/run-pass/iter-flat-map-to-vec.rs
@@ -17,13 +17,13 @@ fn incd_if_even(x: &uint) -> Option<uint> {
 pub fn main() {
     assert (~[1u, 3u]).flat_map_to_vec(repeat) == ~[1u, 1u, 3u, 3u];
     assert (~[]).flat_map_to_vec(repeat) == ~[];
-    assert None.flat_map_to_vec(repeat) == ~[];
-    assert Some(1u).flat_map_to_vec(repeat) == ~[1u, 1u];
-    assert Some(2u).flat_map_to_vec(repeat) == ~[2u, 2u];
+    assert iter::flat_map_to_vec(&None::<uint>, repeat) == ~[];
+    assert iter::flat_map_to_vec(&Some(1u), repeat) == ~[1u, 1u];
+    assert iter::flat_map_to_vec(&Some(2u), repeat) == ~[2u, 2u];
 
     assert (~[1u, 2u, 5u]).flat_map_to_vec(incd_if_even) == ~[3u];
     assert (~[]).flat_map_to_vec(incd_if_even) == ~[];
-    assert None.flat_map_to_vec(incd_if_even) == ~[];
-    assert Some(1u).flat_map_to_vec(incd_if_even) == ~[];
-    assert Some(2u).flat_map_to_vec(incd_if_even) == ~[3u];
+    assert iter::flat_map_to_vec(&None::<uint>, incd_if_even) == ~[];
+    assert iter::flat_map_to_vec(&Some(1u), incd_if_even) == ~[];
+    assert iter::flat_map_to_vec(&Some(2u), incd_if_even) == ~[3u];
 }
diff --git a/src/test/run-pass/iter-foldl.rs b/src/test/run-pass/iter-foldl.rs
index ef1e83235a539..41ac8282347da 100644
--- a/src/test/run-pass/iter-foldl.rs
+++ b/src/test/run-pass/iter-foldl.rs
@@ -13,7 +13,7 @@ fn add(x: &float, y: &uint) -> float { *x + ((*y) as float) }
 pub fn main() {
     assert [1u, 3u].foldl(20f, add) == 24f;
     assert [].foldl(20f, add) == 20f;
-    assert None.foldl(20f, add) == 20f;
-    assert Some(1u).foldl(20f, add) == 21f;
-    assert Some(2u).foldl(20f, add) == 22f;
+    assert iter::foldl(&None::<uint>, 20f, add) == 20f;
+    assert iter::foldl(&Some(1u), 20f, add) == 21f;
+    assert iter::foldl(&Some(2u), 20f, add) == 22f;
 }
diff --git a/src/test/run-pass/iter-map-to-vec.rs b/src/test/run-pass/iter-map-to-vec.rs
index 4277ce777620e..edbd372ad846f 100644
--- a/src/test/run-pass/iter-map-to-vec.rs
+++ b/src/test/run-pass/iter-map-to-vec.rs
@@ -13,7 +13,7 @@ fn inc(x: &uint) -> uint { *x + 1 }
 pub fn main() {
     assert [1, 3].map_to_vec(inc) == ~[2, 4];
     assert [1, 2, 3].map_to_vec(inc) == ~[2, 3, 4];
-    assert None.map_to_vec(inc) == ~[];
-    assert Some(1).map_to_vec(inc) == ~[2];
-    assert Some(2).map_to_vec(inc) == ~[3];
+    assert iter::map_to_vec(&None::<uint>, inc) == ~[];
+    assert iter::map_to_vec(&Some(1u), inc) == ~[2];
+    assert iter::map_to_vec(&Some(2u), inc) == ~[3];
 }
diff --git a/src/test/run-pass/iter-min-max.rs b/src/test/run-pass/iter-min-max.rs
index 7c75d80bd0fd3..1c95432b2b92c 100644
--- a/src/test/run-pass/iter-min-max.rs
+++ b/src/test/run-pass/iter-min-max.rs
@@ -13,9 +13,9 @@ fn is_even(&&x: uint) -> bool { (x % 2u) == 0u }
 pub fn main() {
     assert [1u, 3u].min() == 1u;
     assert [3u, 1u].min() == 1u;
-    assert Some(1u).min() == 1u;
+    assert iter::min(&Some(1u)) == 1u;
 
     assert [1u, 3u].max() == 3u;
     assert [3u, 1u].max() == 3u;
-    assert Some(3u).max() == 3u;
+    assert iter::max(&Some(3u)) == 3u;
 }
diff --git a/src/test/run-pass/iter-to-vec.rs b/src/test/run-pass/iter-to-vec.rs
index c613c688c9d3d..ab102944b1e15 100644
--- a/src/test/run-pass/iter-to-vec.rs
+++ b/src/test/run-pass/iter-to-vec.rs
@@ -12,7 +12,7 @@ pub fn main() {
     assert [1u, 3u].to_vec() == ~[1u, 3u];
     let e: ~[uint] = ~[];
     assert e.to_vec() == ~[];
-    assert None::<uint>.to_vec() == ~[];
-    assert Some(1u).to_vec() == ~[1u];
-    assert Some(2u).to_vec() == ~[2u];
+    assert iter::to_vec(&None::<uint>) == ~[];
+    assert iter::to_vec(&Some(1u)) == ~[1u];
+    assert iter::to_vec(&Some(2u)) == ~[2u];
 }