From 293cd3480c10855de68503db36c6cc3ce8988b54 Mon Sep 17 00:00:00 2001
From: Erick Tryzelaar <erick.tryzelaar@gmail.com>
Date: Mon, 14 Jan 2013 21:36:27 -0800
Subject: [PATCH] convert ast::{field_,capture_item_,mt} and middle::ty::mt
 into structs

---
 src/librustc/front/test.rs                    | 37 +++++----
 src/librustc/metadata/tydecode.rs             |  2 +-
 src/librustc/middle/mem_categorization.rs     |  2 +-
 src/librustc/middle/trans/_match.rs           |  2 +-
 src/librustc/middle/trans/base.rs             |  2 +-
 src/librustc/middle/trans/closure.rs          |  2 +-
 src/librustc/middle/trans/common.rs           |  5 +-
 src/librustc/middle/trans/expr.rs             |  3 +-
 src/librustc/middle/trans/machine.rs          |  7 +-
 src/librustc/middle/trans/tvec.rs             |  2 +-
 src/librustc/middle/ty.rs                     | 78 ++++++++++---------
 src/librustc/middle/typeck/astconv.rs         |  4 +-
 src/librustc/middle/typeck/check/_match.rs    |  4 +-
 src/librustc/middle/typeck/check/method.rs    | 16 ++--
 src/librustc/middle/typeck/check/mod.rs       | 22 +++---
 .../middle/typeck/check/regionmanip.rs        |  2 +-
 .../middle/typeck/infer/assignment.rs         |  9 ++-
 src/librustc/middle/typeck/infer/glb.rs       | 10 +--
 src/librustc/middle/typeck/infer/lub.rs       |  6 +-
 src/libsyntax/ast.rs                          | 17 ++--
 src/libsyntax/ext/auto_encode.rs              | 10 ++-
 src/libsyntax/ext/build.rs                    |  6 +-
 src/libsyntax/ext/deriving.rs                 |  5 +-
 src/libsyntax/ext/pipes/ast_builder.rs        | 15 +++-
 src/libsyntax/fold.rs                         | 34 +++++---
 src/libsyntax/parse/parser.rs                 | 22 ++++--
 26 files changed, 195 insertions(+), 129 deletions(-)

diff --git a/src/librustc/front/test.rs b/src/librustc/front/test.rs
index 32faeea464db..e7e3a412a9ea 100644
--- a/src/librustc/front/test.rs
+++ b/src/librustc/front/test.rs
@@ -340,13 +340,13 @@ fn mk_test_desc_vec_ty(cx: test_ctxt) -> @ast::Ty {
          node: ast::ty_path(test_desc_ty_path, cx.sess.next_node_id()),
          span: dummy_sp()};
 
-    let vec_mt: ast::mt = {ty: @test_desc_ty, mutbl: ast::m_imm};
+    let vec_mt = ast::mt {ty: @test_desc_ty, mutbl: ast::m_imm};
 
     let inner_ty = @{id: cx.sess.next_node_id(),
                      node: ast::ty_vec(vec_mt),
                      span: dummy_sp()};
     return @{id: cx.sess.next_node_id(),
-          node: ast::ty_uniq({ty: inner_ty, mutbl: ast::m_imm}),
+          node: ast::ty_uniq(ast::mt {ty: inner_ty, mutbl: ast::m_imm}),
           span: dummy_sp()};
 }
 
@@ -389,9 +389,11 @@ fn mk_test_desc_rec(cx: test_ctxt, test: test) -> @ast::expr {
                      span: dummy_sp()};
 
 
-    let name_field: ast::field =
-        nospan({mutbl: ast::m_imm, ident: cx.sess.ident_of(~"name"),
-                expr: @name_expr});
+    let name_field = nospan(ast::field_ {
+        mutbl: ast::m_imm,
+        ident: cx.sess.ident_of(~"name"),
+        expr: @name_expr,
+    });
 
     let fn_path = path_node_global(path);
 
@@ -403,9 +405,11 @@ fn mk_test_desc_rec(cx: test_ctxt, test: test) -> @ast::expr {
 
     let fn_wrapper_expr = mk_test_wrapper(cx, fn_expr, span);
 
-    let fn_field: ast::field =
-        nospan({mutbl: ast::m_imm, ident: cx.sess.ident_of(~"testfn"),
-                expr: fn_wrapper_expr});
+    let fn_field = nospan(ast::field_ {
+        mutbl: ast::m_imm,
+        ident: cx.sess.ident_of(~"testfn"),
+        expr: fn_wrapper_expr,
+    });
 
     let ignore_lit: ast::lit = nospan(ast::lit_bool(test.ignore));
 
@@ -415,9 +419,11 @@ fn mk_test_desc_rec(cx: test_ctxt, test: test) -> @ast::expr {
          node: ast::expr_lit(@ignore_lit),
          span: span};
 
-    let ignore_field: ast::field =
-        nospan({mutbl: ast::m_imm, ident: cx.sess.ident_of(~"ignore"),
-                expr: @ignore_expr});
+    let ignore_field = nospan(ast::field_ {
+        mutbl: ast::m_imm,
+        ident: cx.sess.ident_of(~"ignore"),
+        expr: @ignore_expr,
+    });
 
     let fail_lit: ast::lit = nospan(ast::lit_bool(test.should_fail));
 
@@ -427,10 +433,11 @@ fn mk_test_desc_rec(cx: test_ctxt, test: test) -> @ast::expr {
          node: ast::expr_lit(@fail_lit),
          span: span};
 
-    let fail_field: ast::field =
-        nospan({mutbl: ast::m_imm,
-                ident: cx.sess.ident_of(~"should_fail"),
-                expr: @fail_expr});
+    let fail_field = nospan(ast::field_ {
+        mutbl: ast::m_imm,
+        ident: cx.sess.ident_of(~"should_fail"),
+        expr: @fail_expr,
+    });
 
     let test_desc_path =
         mk_path(cx, ~[cx.sess.ident_of(~"test"),
diff --git a/src/librustc/metadata/tydecode.rs b/src/librustc/metadata/tydecode.rs
index 2d7904b3bc2e..9f9e00491461 100644
--- a/src/librustc/metadata/tydecode.rs
+++ b/src/librustc/metadata/tydecode.rs
@@ -353,7 +353,7 @@ fn parse_mt(st: @pstate, conv: conv_did) -> ty::mt {
       '?' => { next(st); m = ast::m_const; }
       _ => { m = ast::m_imm; }
     }
-    return {ty: parse_ty(st, conv), mutbl: m};
+    ty::mt { ty: parse_ty(st, conv), mutbl: m }
 }
 
 fn parse_def(st: @pstate, conv: conv_did) -> ast::def_id {
diff --git a/src/librustc/middle/mem_categorization.rs b/src/librustc/middle/mem_categorization.rs
index b72950cbf4b1..13e559e6ce4c 100644
--- a/src/librustc/middle/mem_categorization.rs
+++ b/src/librustc/middle/mem_categorization.rs
@@ -728,7 +728,7 @@ impl &mem_categorization_ctxt {
         // know what type lies at the other end, so we just call it
         // `()` (the empty tuple).
 
-        let mt = {ty: ty::mk_tup(self.tcx, ~[]), mutbl: m_imm};
+        let mt = ty::mt {ty: ty::mk_tup(self.tcx, ~[]), mutbl: m_imm};
         return self.cat_deref_common(node, base_cmt, deref_cnt, mt);
     }
 
diff --git a/src/librustc/middle/trans/_match.rs b/src/librustc/middle/trans/_match.rs
index dcc5e2b83c16..9a5e4cb21768 100644
--- a/src/librustc/middle/trans/_match.rs
+++ b/src/librustc/middle/trans/_match.rs
@@ -857,7 +857,7 @@ fn extract_vec_elems(bcx: block, pat_id: ast::node_id,
         let tail_begin = tvec::pointer_add(bcx, base, tail_offset);
         let tail_len = Sub(bcx, len, tail_offset);
         let tail_ty = ty::mk_evec(bcx.tcx(),
-            {ty: vt.unit_ty, mutbl: ast::m_imm},
+            ty::mt {ty: vt.unit_ty, mutbl: ast::m_imm},
             ty::vstore_slice(ty::re_static)
         );
         let scratch = scratch_datum(bcx, tail_ty, false);
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index 92de2897a735..f66823c80819 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -2184,7 +2184,7 @@ fn create_main_wrapper(ccx: @crate_ctxt, sp: span, main_llfn: ValueRef) {
         let unit_ty = ty::mk_estr(ccx.tcx, ty::vstore_uniq);
         let vecarg_ty: ty::arg =
             {mode: ast::expl(ast::by_val),
-             ty: ty::mk_evec(ccx.tcx, {ty: unit_ty, mutbl: ast::m_imm},
+             ty: ty::mk_evec(ccx.tcx, ty::mt {ty: unit_ty, mutbl: ast::m_imm},
                              ty::vstore_uniq)};
         let nt = ty::mk_nil(ccx.tcx);
         let llfty = type_of_fn(ccx, ~[vecarg_ty], nt);
diff --git a/src/librustc/middle/trans/closure.rs b/src/librustc/middle/trans/closure.rs
index 35917e4911cc..09d188b6cd2c 100644
--- a/src/librustc/middle/trans/closure.rs
+++ b/src/librustc/middle/trans/closure.rs
@@ -224,7 +224,7 @@ fn store_environment(bcx: block,
     // tuple.  This could be a ptr in uniq or a box or on stack,
     // whatever.
     let cbox_ty = tuplify_box_ty(tcx, cdata_ty);
-    let cboxptr_ty = ty::mk_ptr(tcx, {ty:cbox_ty, mutbl:ast::m_imm});
+    let cboxptr_ty = ty::mk_ptr(tcx, ty::mt {ty:cbox_ty, mutbl:ast::m_imm});
 
     let llbox = PointerCast(bcx, llbox, type_of(ccx, cboxptr_ty));
     debug!("tuplify_box_ty = %s", ty_to_str(tcx, cbox_ty));
diff --git a/src/librustc/middle/trans/common.rs b/src/librustc/middle/trans/common.rs
index 4c89495f27a9..4481deec3c74 100644
--- a/src/librustc/middle/trans/common.rs
+++ b/src/librustc/middle/trans/common.rs
@@ -945,7 +945,10 @@ fn T_opaque_vec(targ_cfg: @session::config) -> TypeRef {
 // representation of @T as a tuple (i.e., the ty::t version of what T_box()
 // returns).
 fn tuplify_box_ty(tcx: ty::ctxt, t: ty::t) -> ty::t {
-    let ptr = ty::mk_ptr(tcx, {ty: ty::mk_nil(tcx), mutbl: ast::m_imm});
+    let ptr = ty::mk_ptr(
+        tcx,
+        ty::mt {ty: ty::mk_nil(tcx), mutbl: ast::m_imm}
+    );
     return ty::mk_tup(tcx, ~[ty::mk_uint(tcx), ty::mk_type(tcx),
                          ptr, ptr,
                          t]);
diff --git a/src/librustc/middle/trans/expr.rs b/src/librustc/middle/trans/expr.rs
index c26328d7d9c3..4c8bb91df4c6 100644
--- a/src/librustc/middle/trans/expr.rs
+++ b/src/librustc/middle/trans/expr.rs
@@ -251,7 +251,8 @@ fn trans_to_datum(bcx: block, expr: @ast::expr) -> DatumBlock {
 
         // this type may have a different region/mutability than the
         // real one, but it will have the same runtime representation
-        let slice_ty = ty::mk_evec(tcx, {ty: unit_ty, mutbl: ast::m_imm},
+        let slice_ty = ty::mk_evec(tcx,
+                                   ty::mt { ty: unit_ty, mutbl: ast::m_imm },
                                    ty::vstore_slice(ty::re_static));
 
         let scratch = scratch_datum(bcx, slice_ty, false);
diff --git a/src/librustc/middle/trans/machine.rs b/src/librustc/middle/trans/machine.rs
index bc1cd5ec9112..5c0498d5a147 100644
--- a/src/librustc/middle/trans/machine.rs
+++ b/src/librustc/middle/trans/machine.rs
@@ -26,7 +26,7 @@ use syntax::parse::token::special_idents;
 // nominal type that has pointers to itself in it.
 pub fn simplify_type(tcx: ty::ctxt, typ: ty::t) -> ty::t {
     fn nilptr(tcx: ty::ctxt) -> ty::t {
-        ty::mk_ptr(tcx, {ty: ty::mk_nil(tcx), mutbl: ast::m_imm})
+        ty::mk_ptr(tcx, ty::mt {ty: ty::mk_nil(tcx), mutbl: ast::m_imm})
     }
     fn simplifier(tcx: ty::ctxt, typ: ty::t) -> ty::t {
         match ty::get(typ).sty {
@@ -45,13 +45,12 @@ pub fn simplify_type(tcx: ty::ctxt, typ: ty::t) -> ty::t {
             let simpl_fields = (if ty::ty_dtor(tcx, did).is_present() {
                 // remember the drop flag
                   ~[{ident: special_idents::dtor,
-                     mt: {ty: ty::mk_u8(tcx),
-                          mutbl: ast::m_mutbl}}] }
+                     mt: ty::mt {ty: ty::mk_u8(tcx), mutbl: ast::m_mutbl}}] }
                 else { ~[] }) +
                 do ty::lookup_struct_fields(tcx, did).map |f| {
                  let t = ty::lookup_field_type(tcx, did, f.id, substs);
                  {ident: f.ident,
-                  mt: {ty: simplify_type(tcx, t), mutbl: ast::m_const}}
+                  mt: ty::mt {ty: simplify_type(tcx, t), mutbl: ast::m_const}}
             };
             ty::mk_rec(tcx, simpl_fields)
           }
diff --git a/src/librustc/middle/trans/tvec.rs b/src/librustc/middle/trans/tvec.rs
index 9db607773eb4..eb2fd91e6051 100644
--- a/src/librustc/middle/trans/tvec.rs
+++ b/src/librustc/middle/trans/tvec.rs
@@ -214,7 +214,7 @@ fn trans_slice_vstore(bcx: block,
 
     // Arrange for the backing array to be cleaned up.
     let fixed_ty = ty::mk_evec(bcx.tcx(),
-                               {ty: vt.unit_ty, mutbl: ast::m_mutbl},
+                               ty::mt {ty: vt.unit_ty, mutbl: ast::m_mutbl},
                                ty::vstore_fixed(count));
     let llfixed_ty = T_ptr(type_of::type_of(bcx.ccx(), fixed_ty));
     let llfixed_casted = BitCast(bcx, llfixed, llfixed_ty);
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index 8e24bd0f38e9..b84fbd8a3810 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -258,7 +258,10 @@ type method = {ident: ast::ident,
                vis: ast::visibility,
                def_id: ast::def_id};
 
-type mt = {ty: t, mutbl: ast::mutability};
+struct mt {
+    ty: t,
+    mutbl: ast::mutability,
+}
 
 #[auto_encode]
 #[auto_decode]
@@ -1149,34 +1152,37 @@ fn mk_enum(cx: ctxt, did: ast::def_id, +substs: substs) -> t {
 
 fn mk_box(cx: ctxt, tm: mt) -> t { mk_t(cx, ty_box(tm)) }
 
-fn mk_imm_box(cx: ctxt, ty: t) -> t { mk_box(cx, {ty: ty,
-                                                  mutbl: ast::m_imm}) }
+fn mk_imm_box(cx: ctxt, ty: t) -> t {
+    mk_box(cx, mt {ty: ty, mutbl: ast::m_imm})
+}
 
 fn mk_uniq(cx: ctxt, tm: mt) -> t { mk_t(cx, ty_uniq(tm)) }
 
-fn mk_imm_uniq(cx: ctxt, ty: t) -> t { mk_uniq(cx, {ty: ty,
-                                                    mutbl: ast::m_imm}) }
+fn mk_imm_uniq(cx: ctxt, ty: t) -> t {
+    mk_uniq(cx, mt {ty: ty, mutbl: ast::m_imm})
+}
 
 fn mk_ptr(cx: ctxt, tm: mt) -> t { mk_t(cx, ty_ptr(tm)) }
 
 fn mk_rptr(cx: ctxt, r: Region, tm: mt) -> t { mk_t(cx, ty_rptr(r, tm)) }
 
 fn mk_mut_rptr(cx: ctxt, r: Region, ty: t) -> t {
-    mk_rptr(cx, r, {ty: ty, mutbl: ast::m_mutbl})
+    mk_rptr(cx, r, mt {ty: ty, mutbl: ast::m_mutbl})
 }
 fn mk_imm_rptr(cx: ctxt, r: Region, ty: t) -> t {
-    mk_rptr(cx, r, {ty: ty, mutbl: ast::m_imm})
+    mk_rptr(cx, r, mt {ty: ty, mutbl: ast::m_imm})
 }
 
-fn mk_mut_ptr(cx: ctxt, ty: t) -> t { mk_ptr(cx, {ty: ty,
-                                                  mutbl: ast::m_mutbl}) }
+fn mk_mut_ptr(cx: ctxt, ty: t) -> t {
+    mk_ptr(cx, mt {ty: ty, mutbl: ast::m_mutbl})
+}
 
 fn mk_imm_ptr(cx: ctxt, ty: t) -> t {
-    mk_ptr(cx, {ty: ty, mutbl: ast::m_imm})
+    mk_ptr(cx, mt {ty: ty, mutbl: ast::m_imm})
 }
 
 fn mk_nil_ptr(cx: ctxt) -> t {
-    mk_ptr(cx, {ty: mk_nil(cx), mutbl: ast::m_imm})
+    mk_ptr(cx, mt {ty: mk_nil(cx), mutbl: ast::m_imm})
 }
 
 fn mk_evec(cx: ctxt, tm: mt, t: vstore) -> t {
@@ -1187,7 +1193,7 @@ fn mk_unboxed_vec(cx: ctxt, tm: mt) -> t {
     mk_t(cx, ty_unboxed_vec(tm))
 }
 fn mk_mut_unboxed_vec(cx: ctxt, ty: t) -> t {
-    mk_t(cx, ty_unboxed_vec({ty: ty, mutbl: ast::m_imm}))
+    mk_t(cx, ty_unboxed_vec(mt {ty: ty, mutbl: ast::m_imm}))
 }
 
 fn mk_rec(cx: ctxt, +fs: ~[field]) -> t { mk_t(cx, ty_rec(fs)) }
@@ -1353,19 +1359,19 @@ fn fold_sty(sty: &sty, fldop: fn(t) -> t) -> sty {
 
     match /*bad*/copy *sty {
         ty_box(tm) => {
-            ty_box({ty: fldop(tm.ty), mutbl: tm.mutbl})
+            ty_box(mt {ty: fldop(tm.ty), mutbl: tm.mutbl})
         }
         ty_uniq(tm) => {
-            ty_uniq({ty: fldop(tm.ty), mutbl: tm.mutbl})
+            ty_uniq(mt {ty: fldop(tm.ty), mutbl: tm.mutbl})
         }
         ty_ptr(tm) => {
-            ty_ptr({ty: fldop(tm.ty), mutbl: tm.mutbl})
+            ty_ptr(mt {ty: fldop(tm.ty), mutbl: tm.mutbl})
         }
         ty_unboxed_vec(tm) => {
-            ty_unboxed_vec({ty: fldop(tm.ty), mutbl: tm.mutbl})
+            ty_unboxed_vec(mt {ty: fldop(tm.ty), mutbl: tm.mutbl})
         }
         ty_evec(tm, vst) => {
-            ty_evec({ty: fldop(tm.ty), mutbl: tm.mutbl}, vst)
+            ty_evec(mt {ty: fldop(tm.ty), mutbl: tm.mutbl}, vst)
         }
         ty_enum(tid, ref substs) => {
             ty_enum(tid, fold_substs(substs, fldop))
@@ -1376,7 +1382,7 @@ fn fold_sty(sty: &sty, fldop: fn(t) -> t) -> sty {
         ty_rec(fields) => {
             let new_fields = do vec::map(fields) |fl| {
                 let new_ty = fldop(fl.mt.ty);
-                let new_mt = {ty: new_ty, mutbl: fl.mt.mutbl};
+                let new_mt = mt {ty: new_ty, mutbl: fl.mt.mutbl};
                 {ident: fl.ident, mt: new_mt}
             };
             ty_rec(new_fields)
@@ -1390,7 +1396,7 @@ fn fold_sty(sty: &sty, fldop: fn(t) -> t) -> sty {
             ty_fn(FnTyBase {meta: f.meta, sig: sig})
         }
         ty_rptr(r, tm) => {
-            ty_rptr(r, {ty: fldop(tm.ty), mutbl: tm.mutbl})
+            ty_rptr(r, mt {ty: fldop(tm.ty), mutbl: tm.mutbl})
         }
         ty_struct(did, ref substs) => {
             ty_struct(did, fold_substs(substs, fldop))
@@ -1446,7 +1452,7 @@ fn fold_regions_and_ty(
       ty::ty_rptr(r, mt) => {
         let m_r = fldr(r);
         let m_t = fldt(mt.ty);
-        ty::mk_rptr(cx, m_r, {ty: m_t, mutbl: mt.mutbl})
+        ty::mk_rptr(cx, m_r, mt {ty: m_t, mutbl: mt.mutbl})
       }
       ty_estr(vstore_slice(r)) => {
         let m_r = fldr(r);
@@ -1455,7 +1461,7 @@ fn fold_regions_and_ty(
       ty_evec(mt, vstore_slice(r)) => {
         let m_r = fldr(r);
         let m_t = fldt(mt.ty);
-        ty::mk_evec(cx, {ty: m_t, mutbl: mt.mutbl}, vstore_slice(m_r))
+        ty::mk_evec(cx, mt {ty: m_t, mutbl: mt.mutbl}, vstore_slice(m_r))
       }
       ty_enum(def_id, ref substs) => {
         ty::mk_enum(cx, def_id, fold_substs(substs, fldr, fldt))
@@ -1527,19 +1533,19 @@ fn fold_region(cx: ctxt, t0: t, fldop: fn(Region, bool) -> Region) -> t {
         let tb = get(t0);
         if !tbox_has_flag(tb, has_regions) { return t0; }
         match tb.sty {
-          ty_rptr(r, {ty: t1, mutbl: m}) => {
+          ty_rptr(r, mt {ty: t1, mutbl: m}) => {
             let m_r = fldop(r, under_r);
             let m_t1 = do_fold(cx, t1, true, fldop);
-            ty::mk_rptr(cx, m_r, {ty: m_t1, mutbl: m})
+            ty::mk_rptr(cx, m_r, mt {ty: m_t1, mutbl: m})
           }
           ty_estr(vstore_slice(r)) => {
             let m_r = fldop(r, under_r);
             ty::mk_estr(cx, vstore_slice(m_r))
           }
-          ty_evec({ty: t1, mutbl: m}, vstore_slice(r)) => {
+          ty_evec(mt {ty: t1, mutbl: m}, vstore_slice(r)) => {
             let m_r = fldop(r, under_r);
             let m_t1 = do_fold(cx, t1, true, fldop);
-            ty::mk_evec(cx, {ty: m_t1, mutbl: m}, vstore_slice(m_r))
+            ty::mk_evec(cx, mt {ty: m_t1, mutbl: m}, vstore_slice(m_r))
           }
           ty_fn(_) => {
             // do not recurse into functions, which introduce fresh bindings
@@ -2707,7 +2713,7 @@ fn deref_sty(cx: ctxt, sty: &sty, explicit: bool) -> Option<mt> {
         let variants = enum_variants(cx, did);
         if vec::len(*variants) == 1u && vec::len(variants[0].args) == 1u {
             let v_t = subst(cx, substs, variants[0].args[0]);
-            Some({ty: v_t, mutbl: ast::m_imm})
+            Some(mt {ty: v_t, mutbl: ast::m_imm})
         } else {
             None
         }
@@ -2717,7 +2723,7 @@ fn deref_sty(cx: ctxt, sty: &sty, explicit: bool) -> Option<mt> {
         let fields = struct_fields(cx, did, substs);
         if fields.len() == 1 && fields[0].ident ==
                 syntax::parse::token::special_idents::unnamed_field {
-            Some({ty: fields[0].mt.ty, mutbl: ast::m_imm})
+            Some(mt {ty: fields[0].mt.ty, mutbl: ast::m_imm})
         } else {
             None
         }
@@ -2745,7 +2751,7 @@ fn index(cx: ctxt, t: t) -> Option<mt> {
 fn index_sty(cx: ctxt, sty: &sty) -> Option<mt> {
     match *sty {
       ty_evec(mt, _) => Some(mt),
-      ty_estr(_) => Some({ty: mk_u8(cx), mutbl: ast::m_imm}),
+      ty_estr(_) => Some(mt {ty: mk_u8(cx), mutbl: ast::m_imm}),
       _ => None
     }
 }
@@ -4111,15 +4117,17 @@ fn struct_item_fields(cx:ctxt,
                      substs: &substs,
                      frob_mutability: fn(struct_mutability) -> mutability)
     -> ~[field] {
-    let mut rslt = ~[];
-    for lookup_struct_fields(cx, did).each |f| {
+    do lookup_struct_fields(cx, did).map |f| {
        // consider all instance vars mut, because the
        // constructor may mutate all vars
-       rslt.push({ident: f.ident, mt:
-               {ty: lookup_field_type(cx, did, f.id, substs),
-                    mutbl: frob_mutability(f.mutability)}});
+       {
+           ident: f.ident,
+            mt: mt {
+                ty: lookup_field_type(cx, did, f.id, substs),
+                mutbl: frob_mutability(f.mutability)
+            }
+        }
     }
-    rslt
 }
 
 fn is_binopable(_cx: ctxt, ty: t, op: ast::binop) -> bool {
@@ -4199,7 +4207,7 @@ fn ty_params_to_tys(tcx: ty::ctxt, tps: ~[ast::ty_param]) -> ~[t] {
 /// Returns an equivalent type with all the typedefs and self regions removed.
 fn normalize_ty(cx: ctxt, t: t) -> t {
     fn normalize_mt(cx: ctxt, mt: mt) -> mt {
-        { ty: normalize_ty(cx, mt.ty), mutbl: mt.mutbl }
+        mt { ty: normalize_ty(cx, mt.ty), mutbl: mt.mutbl }
     }
     fn normalize_vstore(vstore: vstore) -> vstore {
         match vstore {
diff --git a/src/librustc/middle/typeck/astconv.rs b/src/librustc/middle/typeck/astconv.rs
index 043ff3fbec48..7e1c5f54134e 100644
--- a/src/librustc/middle/typeck/astconv.rs
+++ b/src/librustc/middle/typeck/astconv.rs
@@ -185,7 +185,7 @@ fn ast_ty_to_ty<AC: ast_conv, RS: region_scope Copy Durable>(
     fn ast_mt_to_mt<AC: ast_conv, RS: region_scope Copy Durable>(
         self: AC, rscope: RS, mt: ast::mt) -> ty::mt {
 
-        return {ty: ast_ty_to_ty(self, rscope, mt.ty), mutbl: mt.mutbl};
+        ty::mt {ty: ast_ty_to_ty(self, rscope, mt.ty), mutbl: mt.mutbl}
     }
 
     // Handle @, ~, and & being able to mean estrs and evecs.
@@ -204,7 +204,7 @@ fn ast_ty_to_ty<AC: ast_conv, RS: region_scope Copy Durable>(
             ast::ty_vec(mt) => {
                 let mut mt = ast_mt_to_mt(self, rscope, mt);
                 if a_seq_ty.mutbl == ast::m_mutbl {
-                    mt = { ty: mt.ty, mutbl: ast::m_mutbl };
+                    mt = ty::mt { ty: mt.ty, mutbl: ast::m_mutbl };
                 }
                 return ty::mk_evec(tcx, mt, vst);
             }
diff --git a/src/librustc/middle/typeck/check/_match.rs b/src/librustc/middle/typeck/check/_match.rs
index 5514d2f04b3b..9861178afb0e 100644
--- a/src/librustc/middle/typeck/check/_match.rs
+++ b/src/librustc/middle/typeck/check/_match.rs
@@ -377,7 +377,7 @@ fn check_pat(pcx: pat_ctxt, pat: @ast::pat, expected: ty::t) {
             let region_var =
                 fcx.infcx().next_region_var_with_lb(
                     pat.span, pcx.block_region);
-            let mt = {ty: expected, mutbl: mutbl};
+            let mt = ty::mt {ty: expected, mutbl: mutbl};
             let region_ty = ty::mk_rptr(tcx, region_var, mt);
             demand::eqtype(fcx, pat.span, region_ty, typ);
           }
@@ -575,7 +575,7 @@ fn check_pat(pcx: pat_ctxt, pat: @ast::pat, expected: ty::t) {
         match tail {
             Some(tail_pat) => {
                 let slice_ty = ty::mk_evec(tcx,
-                    {ty: elt_type.ty, mutbl: elt_type.mutbl},
+                    ty::mt {ty: elt_type.ty, mutbl: elt_type.mutbl},
                     ty::vstore_slice(region_var)
                 );
                 check_pat(pcx, tail_pat, slice_ty);
diff --git a/src/librustc/middle/typeck/check/method.rs b/src/librustc/middle/typeck/check/method.rs
index 05061ccfa13f..a8e834bff435 100644
--- a/src/librustc/middle/typeck/check/method.rs
+++ b/src/librustc/middle/typeck/check/method.rs
@@ -731,7 +731,7 @@ impl LookupContext {
                 let entry = self.search_for_some_kind_of_autorefd_method(
                     AutoBorrowVec, autoderefs, [m_const, m_imm, m_mutbl],
                     |m,r| ty::mk_evec(tcx,
-                                      {ty:mt.ty, mutbl:m},
+                                      ty::mt {ty:mt.ty, mutbl:m},
                                       vstore_slice(r)));
 
                 if entry.is_some() { return entry; }
@@ -741,14 +741,14 @@ impl LookupContext {
                     AutoBorrowVecRef, autoderefs, [m_const, m_imm, m_mutbl],
                     |m,r| {
                         let slice_ty = ty::mk_evec(tcx,
-                                                   {ty:mt.ty, mutbl:m},
+                                                   ty::mt {ty:mt.ty, mutbl:m},
                                                    vstore_slice(r));
                         // NB: we do not try to autoref to a mutable
                         // pointer. That would be creating a pointer
                         // to a temporary pointer (the borrowed
                         // slice), so any update the callee makes to
                         // it can't be observed.
-                        ty::mk_rptr(tcx, r, {ty:slice_ty, mutbl:m_imm})
+                        ty::mk_rptr(tcx, r, ty::mt {ty:slice_ty, mutbl:m_imm})
                     })
             }
 
@@ -765,7 +765,7 @@ impl LookupContext {
                     AutoBorrowVecRef, autoderefs, [m_imm],
                     |m,r| {
                         let slice_ty = ty::mk_estr(tcx, vstore_slice(r));
-                        ty::mk_rptr(tcx, r, {ty:slice_ty, mutbl:m})
+                        ty::mk_rptr(tcx, r, ty::mt {ty:slice_ty, mutbl:m})
                     })
             }
 
@@ -802,7 +802,7 @@ impl LookupContext {
             ty_trait(*) | ty_fn(*) => {
                 self.search_for_some_kind_of_autorefd_method(
                     AutoPtr, autoderefs, [m_const, m_imm, m_mutbl],
-                    |m,r| ty::mk_rptr(tcx, r, {ty:self_ty, mutbl:m}))
+                    |m,r| ty::mk_rptr(tcx, r, ty::mt {ty:self_ty, mutbl:m}))
             }
 
             ty_err => None,
@@ -1183,12 +1183,12 @@ fn transform_self_type_for_method(tcx: ty::ctxt,
       sty_region(mutability) => {
         mk_rptr(tcx,
                 self_region.expect(~"self region missing for &self param"),
-                { ty: impl_ty, mutbl: mutability })
+                ty::mt { ty: impl_ty, mutbl: mutability })
       }
       sty_box(mutability) => {
         match flag {
             TransformTypeNormally => {
-                mk_box(tcx, { ty: impl_ty, mutbl: mutability })
+                mk_box(tcx, ty::mt { ty: impl_ty, mutbl: mutability })
             }
             TransformTypeForObject => impl_ty
         }
@@ -1196,7 +1196,7 @@ fn transform_self_type_for_method(tcx: ty::ctxt,
       sty_uniq(mutability) => {
         match flag {
             TransformTypeNormally => {
-                mk_uniq(tcx, { ty: impl_ty, mutbl: mutability })
+                mk_uniq(tcx, ty::mt { ty: impl_ty, mutbl: mutability })
             }
             TransformTypeForObject => impl_ty
         }
diff --git a/src/librustc/middle/typeck/check/mod.rs b/src/librustc/middle/typeck/check/mod.rs
index 792588a8cd3a..8365c261dece 100644
--- a/src/librustc/middle/typeck/check/mod.rs
+++ b/src/librustc/middle/typeck/check/mod.rs
@@ -1936,7 +1936,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
             }
             let t: ty::t = fcx.infcx().next_ty_var();
             for args.each |e| { bot |= check_expr_with(fcx, *e, t); }
-            ty::mk_evec(tcx, {ty: t, mutbl: mutability}, tt)
+            ty::mk_evec(tcx, ty::mt {ty: t, mutbl: mutability}, tt)
           }
           ast::expr_repeat(element, count_expr, mutbl) => {
             let count = ty::eval_repeat_count(tcx, count_expr, expr.span);
@@ -1944,7 +1944,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
             let tt = ast_expr_vstore_to_vstore(fcx, ev, count, vst);
             let t: ty::t = fcx.infcx().next_ty_var();
             bot |= check_expr_with(fcx, element, t);
-            ty::mk_evec(tcx, {ty: t, mutbl: mutbl}, tt)
+            ty::mk_evec(tcx, ty::mt {ty: t, mutbl: mutbl}, tt)
           }
           _ =>
             tcx.sess.span_bug(expr.span, ~"vstore modifier on non-sequence")
@@ -1986,10 +1986,10 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
         let mut oprnd_t = fcx.expr_ty(oprnd);
         match unop {
           ast::box(mutbl) => {
-            oprnd_t = ty::mk_box(tcx, {ty: oprnd_t, mutbl: mutbl});
+            oprnd_t = ty::mk_box(tcx, ty::mt {ty: oprnd_t, mutbl: mutbl});
           }
           ast::uniq(mutbl) => {
-            oprnd_t = ty::mk_uniq(tcx, {ty: oprnd_t, mutbl: mutbl});
+            oprnd_t = ty::mk_uniq(tcx, ty::mt {ty: oprnd_t, mutbl: mutbl});
           }
           ast::deref => {
             let sty = structure_of(fcx, expr.span, oprnd_t);
@@ -2075,7 +2075,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
         // it needs to live.
         let region = fcx.infcx().next_region_var(expr.span, expr.id);
 
-        let tm = { ty: fcx.expr_ty(oprnd), mutbl: mutbl };
+        let tm = ty::mt { ty: fcx.expr_ty(oprnd), mutbl: mutbl };
         let oprnd_t = ty::mk_rptr(tcx, region, tm);
         fcx.write_ty(id, oprnd_t);
       }
@@ -2339,7 +2339,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
       ast::expr_vec(args, mutbl) => {
         let t: ty::t = fcx.infcx().next_ty_var();
         for args.each |e| { bot |= check_expr_with(fcx, *e, t); }
-        let typ = ty::mk_evec(tcx, {ty: t, mutbl: mutbl},
+        let typ = ty::mk_evec(tcx, ty::mt {ty: t, mutbl: mutbl},
                               ty::vstore_fixed(args.len()));
         fcx.write_ty(id, typ);
       }
@@ -2348,7 +2348,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
         fcx.write_ty(count_expr.id, ty::mk_uint(tcx));
         let t: ty::t = fcx.infcx().next_ty_var();
         bot |= check_expr_with(fcx, element, t);
-        let t = ty::mk_evec(tcx, {ty: t, mutbl: mutbl},
+        let t = ty::mk_evec(tcx, ty::mt {ty: t, mutbl: mutbl},
                             ty::vstore_fixed(count));
         fcx.write_ty(id, t);
       }
@@ -2379,7 +2379,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
                 vec::find(*flds, |tf| tf.ident == f.node.ident)
             ).map(|tf| tf.mt.ty));
             let expr_t = fcx.expr_ty(f.node.expr);
-            let expr_mt = {ty: expr_t, mutbl: f.node.mutbl};
+            let expr_mt = ty::mt {ty: expr_t, mutbl: f.node.mutbl};
             // for the most precise error message,
             // should be f.node.expr.span, not f.span
             respan(f.node.expr.span, {ident: f.node.ident, mt: expr_mt})
@@ -2804,7 +2804,7 @@ fn ty_param_bounds_and_ty_for_def(fcx: @fn_ctxt, sp: span, defn: ast::def) ->
             region_param: None,
             ty: ty::mk_ptr(
                 fcx.ccx.tcx,
-                {
+                ty::mt {
                     ty: ty::mk_mach_uint(fcx.ccx.tcx, ast::ty_u8),
                     mutbl: ast::m_imm
                 })
@@ -3078,8 +3078,8 @@ fn check_intrinsic_type(ccx: @crate_ctxt, it: @ast::foreign_item) {
           assert ccx.tcx.intrinsic_defs.contains_key(ty_visitor_name);
           let (_, tydesc_ty) = tcx.intrinsic_defs.get(tydesc_name);
           let (_, visitor_trait) = tcx.intrinsic_defs.get(ty_visitor_name);
-          let td_ptr = ty::mk_ptr(ccx.tcx, {ty: tydesc_ty,
-                                            mutbl: ast::m_imm});
+          let td_ptr = ty::mk_ptr(ccx.tcx, ty::mt {ty: tydesc_ty,
+                                                   mutbl: ast::m_imm});
           (0u, ~[arg(ast::by_val, td_ptr),
                  arg(ast::by_ref, visitor_trait)], ty::mk_nil(tcx))
       }
diff --git a/src/librustc/middle/typeck/check/regionmanip.rs b/src/librustc/middle/typeck/check/regionmanip.rs
index 8097b0eca840..b22b061883c7 100644
--- a/src/librustc/middle/typeck/check/regionmanip.rs
+++ b/src/librustc/middle/typeck/check/regionmanip.rs
@@ -63,7 +63,7 @@ pub fn replace_bound_regions_in_fn_sig(
                                           _}, _}) => {
         let region = ty::re_bound(ty::br_self);
         let ty = ty::mk_rptr(tcx, region,
-                             { ty: ty::mk_self(tcx), mutbl: m });
+                             ty::mt { ty: ty::mk_self(tcx), mutbl: m });
         all_tys.push(ty);
       }
       _ => {}
diff --git a/src/librustc/middle/typeck/infer/assignment.rs b/src/librustc/middle/typeck/infer/assignment.rs
index 62080f4db358..d25fed274b3e 100644
--- a/src/librustc/middle/typeck/infer/assignment.rs
+++ b/src/librustc/middle/typeck/infer/assignment.rs
@@ -173,14 +173,16 @@ priv impl Assign {
                     // being assigned to a region pointer:
                     (ty::ty_box(_), ty::ty_rptr(r_b, mt_b)) => {
                         let nr_b = ty::mk_box(self.infcx.tcx,
-                                              {ty: mt_b.ty, mutbl: m_const});
+                                              ty::mt {ty: mt_b.ty,
+                                                      mutbl: m_const});
                         self.try_assign(1, ty::AutoPtr,
                                         a, nr_b,
                                         mt_b.mutbl, r_b)
                     }
                     (ty::ty_uniq(_), ty::ty_rptr(r_b, mt_b)) => {
                         let nr_b = ty::mk_uniq(self.infcx.tcx,
-                                               {ty: mt_b.ty, mutbl: m_const});
+                                               ty::mt {ty: mt_b.ty,
+                                                       mutbl: m_const});
                         self.try_assign(1, ty::AutoPtr,
                                         a, nr_b,
                                         mt_b.mutbl, r_b)
@@ -198,7 +200,8 @@ priv impl Assign {
                      ty::ty_evec(mt_b, ty::vstore_slice(r_b)))
                     if is_borrowable(vs_a) => {
                         let nr_b = ty::mk_evec(self.infcx.tcx,
-                                               {ty: mt_b.ty, mutbl: m_const},
+                                               ty::mt {ty: mt_b.ty,
+                                                       mutbl: m_const},
                                                vs_a);
                         self.try_assign(0, ty::AutoBorrowVec,
                                         a, nr_b,
diff --git a/src/librustc/middle/typeck/infer/glb.rs b/src/librustc/middle/typeck/infer/glb.rs
index 4d697ad3433e..aa718cbe36c3 100644
--- a/src/librustc/middle/typeck/infer/glb.rs
+++ b/src/librustc/middle/typeck/infer/glb.rs
@@ -50,17 +50,17 @@ impl Glb: Combine {
           // the precise type from the mut side.
           (m_mutbl, m_const) => {
             Sub(*self).tys(a.ty, b.ty).chain(|_t| {
-                Ok({ty: a.ty, mutbl: m_mutbl})
+                Ok(ty::mt {ty: a.ty, mutbl: m_mutbl})
             })
           }
           (m_const, m_mutbl) => {
             Sub(*self).tys(b.ty, a.ty).chain(|_t| {
-                Ok({ty: b.ty, mutbl: m_mutbl})
+                Ok(ty::mt {ty: b.ty, mutbl: m_mutbl})
             })
           }
           (m_mutbl, m_mutbl) => {
             eq_tys(&self, a.ty, b.ty).then(|| {
-                Ok({ty: a.ty, mutbl: m_mutbl})
+                Ok(ty::mt {ty: a.ty, mutbl: m_mutbl})
             })
           }
 
@@ -70,7 +70,7 @@ impl Glb: Combine {
           (m_const, m_imm) |
           (m_imm, m_imm) => {
             self.tys(a.ty, b.ty).chain(|t| {
-                Ok({ty: t, mutbl: m_imm})
+                Ok(ty::mt {ty: t, mutbl: m_imm})
             })
           }
 
@@ -78,7 +78,7 @@ impl Glb: Combine {
           // sides and mutbl of only `m_const`.
           (m_const, m_const) => {
             self.tys(a.ty, b.ty).chain(|t| {
-                Ok({ty: t, mutbl: m_const})
+                Ok(ty::mt {ty: t, mutbl: m_const})
             })
           }
 
diff --git a/src/librustc/middle/typeck/infer/lub.rs b/src/librustc/middle/typeck/infer/lub.rs
index ac6c4473999c..a6ae3cdb4fdb 100644
--- a/src/librustc/middle/typeck/infer/lub.rs
+++ b/src/librustc/middle/typeck/infer/lub.rs
@@ -59,17 +59,17 @@ impl Lub: Combine {
 
         match m {
           m_imm | m_const => {
-            self.tys(a.ty, b.ty).chain(|t| Ok({ty: t, mutbl: m}) )
+            self.tys(a.ty, b.ty).chain(|t| Ok(ty::mt {ty: t, mutbl: m}) )
           }
 
           m_mutbl => {
             self.infcx.try(|| {
                 eq_tys(&self, a.ty, b.ty).then(|| {
-                    Ok({ty: a.ty, mutbl: m})
+                    Ok(ty::mt {ty: a.ty, mutbl: m})
                 })
             }).chain_err(|_e| {
                 self.tys(a.ty, b.ty).chain(|t| {
-                    Ok({ty: t, mutbl: m_const})
+                    Ok(ty::mt {ty: t, mutbl: m_const})
                 })
             })
           }
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index c3f2eac8a2aa..6f2ffe008497 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -670,7 +670,11 @@ struct arm {
 
 #[auto_encode]
 #[auto_decode]
-type field_ = {mutbl: mutability, ident: ident, expr: @expr};
+struct field_ {
+    mutbl: mutability,
+    ident: ident,
+    expr: @expr,
+}
 
 type field = spanned<field_>;
 
@@ -762,12 +766,12 @@ enum expr_ {
 
 #[auto_encode]
 #[auto_decode]
-type capture_item_ = {
+struct capture_item_ {
     id: int,
     is_move: bool,
     name: ident, // Currently, can only capture a local var.
-    span: span
-};
+    span: span,
+}
 
 type capture_item = @capture_item_;
 
@@ -923,7 +927,10 @@ impl lit_: cmp::Eq {
 // type structure in middle/ty.rs as well.
 #[auto_encode]
 #[auto_decode]
-type mt = {ty: @Ty, mutbl: mutability};
+struct mt {
+    ty: @Ty,
+    mutbl: mutability,
+}
 
 #[auto_encode]
 #[auto_decode]
diff --git a/src/libsyntax/ext/auto_encode.rs b/src/libsyntax/ext/auto_encode.rs
index fcb11f426478..e241f6435d3d 100644
--- a/src/libsyntax/ext/auto_encode.rs
+++ b/src/libsyntax/ext/auto_encode.rs
@@ -571,7 +571,7 @@ fn mk_ser_method(
                 id: cx.next_id(),
                 node: ast::re_anon,
             },
-            {
+            ast::mt {
                 ty: cx.ty_path(span, ~[cx.ident_of(~"__S")], ~[]),
                 mutbl: ast::m_imm
             }
@@ -634,7 +634,7 @@ fn mk_deser_method(
                 id: cx.next_id(),
                 node: ast::re_anon,
             },
-            {
+            ast::mt {
                 ty: cx.ty_path(span, ~[cx.ident_of(~"__D")], ~[]),
                 mutbl: ast::m_imm
             }
@@ -908,7 +908,11 @@ fn mk_deser_fields(
         );
 
         ast::spanned {
-            node: { mutbl: field.mutbl, ident: field.ident, expr: expr },
+            node: ast::field_ {
+                mutbl: field.mutbl,
+                ident: field.ident,
+                expr: expr,
+            },
             span: span,
         }
     }
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index 72c13747bf18..cc4c58f3504c 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -145,8 +145,10 @@ fn mk_uniq_str(cx: ext_ctxt, sp: span, s: ~str) -> @ast::expr {
 }
 fn mk_field(sp: span, f: &{ident: ast::ident, ex: @ast::expr})
     -> ast::field {
-    ast::spanned { node: {mutbl: ast::m_imm, ident: f.ident, expr: f.ex},
-                   span: sp }
+    ast::spanned {
+        node: ast::field_ { mutbl: ast::m_imm, ident: f.ident, expr: f.ex },
+        span: sp,
+    }
 }
 fn mk_fields(sp: span, fields: ~[{ident: ast::ident, ex: @ast::expr}]) ->
     ~[ast::field] {
diff --git a/src/libsyntax/ext/deriving.rs b/src/libsyntax/ext/deriving.rs
index 2148ad0cdb6e..83d968bb2ac2 100644
--- a/src/libsyntax/ext/deriving.rs
+++ b/src/libsyntax/ext/deriving.rs
@@ -136,7 +136,10 @@ fn create_eq_method(cx: ext_ctxt,
                                                      type_ident,
                                                      ty_params);
     let arg_region = @{ id: cx.next_id(), node: re_anon };
-    let arg_type = ty_rptr(arg_region, { ty: arg_path_type, mutbl: m_imm });
+    let arg_type = ty_rptr(
+        arg_region,
+        ast::mt { ty: arg_path_type, mutbl: m_imm }
+    );
     let arg_type = @{ id: cx.next_id(), node: move arg_type, span: span };
 
     // Create the `other` parameter.
diff --git a/src/libsyntax/ext/pipes/ast_builder.rs b/src/libsyntax/ext/pipes/ast_builder.rs
index 29d27e53d689..19cbf833c0fa 100644
--- a/src/libsyntax/ext/pipes/ast_builder.rs
+++ b/src/libsyntax/ext/pipes/ast_builder.rs
@@ -146,8 +146,10 @@ impl ext_ctxt: ext_ctxt_ast_builder {
     }
 
     fn field_imm(name: ident, e: @ast::expr) -> ast::field {
-        spanned { node: { mutbl: ast::m_imm, ident: name, expr: e },
-                  span: dummy_sp()}
+        spanned {
+            node: ast::field_ { mutbl: ast::m_imm, ident: name, expr: e },
+            span: dummy_sp(),
+        }
     }
 
     fn rec(+fields: ~[ast::field]) -> @ast::expr {
@@ -158,8 +160,13 @@ impl ext_ctxt: ext_ctxt_ast_builder {
     }
 
     fn ty_field_imm(name: ident, ty: @ast::Ty) -> ast::ty_field {
-        spanned { node: { ident: name, mt: { ty: ty, mutbl: ast::m_imm } },
-                  span: dummy_sp() }
+        spanned {
+            node: {
+                ident: name,
+                mt: ast::mt { ty: ty, mutbl: ast::m_imm },
+            },
+            span: dummy_sp(),
+        }
     }
 
     fn ty_rec(+fields: ~[ast::ty_field]) -> @ast::Ty {
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index c1d5e6094fcb..23915ea189bb 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -412,10 +412,14 @@ fn wrap<T>(f: fn@(T, ast_fold) -> T)
 
 fn noop_fold_expr(e: expr_, fld: ast_fold) -> expr_ {
     fn fold_field_(field: field, fld: ast_fold) -> field {
-        spanned { node: { mutbl: field.node.mutbl,
-                          ident: fld.fold_ident(field.node.ident),
-                          expr: fld.fold_expr(field.node.expr)},
-                  span: fld.new_span(field.span) }
+        spanned {
+            node: ast::field_ {
+                mutbl: field.node.mutbl,
+                ident: fld.fold_ident(field.node.ident),
+                expr: fld.fold_expr(field.node.expr),
+            },
+            span: fld.new_span(field.span),
+        }
     }
     let fold_field = |x| fold_field_(x, fld);
 
@@ -472,17 +476,25 @@ fn noop_fold_expr(e: expr_, fld: ast_fold) -> expr_ {
                      vec::map((*arms), |x| fld.fold_arm(*x)))
           }
           expr_fn(proto, decl, ref body, captures) => {
+            let captures = do captures.map |cap_item| {
+                @ast::capture_item_ {
+                    id: fld.new_id(cap_item.id),
+                    ..**cap_item
+                }
+            };
             expr_fn(proto, fold_fn_decl(decl, fld),
                     fld.fold_block((*body)),
-                    @((*captures).map(|cap_item| {
-                        @({id: fld.new_id(cap_item.id),
-                           ..**cap_item})})))
+                    @captures)
           }
           expr_fn_block(decl, ref body, captures) => {
+            let captures = do captures.map |cap_item| {
+                @ast::capture_item_ {
+                    id: fld.new_id(cap_item.id),
+                    ..**cap_item
+                }
+            };
             expr_fn_block(fold_fn_decl(decl, fld), fld.fold_block((*body)),
-                          @((*captures).map(|cap_item| {
-                              @({id: fld.new_id(cap_item.id),
-                                 ..**cap_item})})))
+                          @captures)
           }
           expr_block(ref blk) => expr_block(fld.fold_block((*blk))),
           expr_copy(e) => expr_copy(fld.fold_expr(e)),
@@ -526,7 +538,7 @@ fn noop_fold_expr(e: expr_, fld: ast_fold) -> expr_ {
 fn noop_fold_ty(t: ty_, fld: ast_fold) -> ty_ {
     let fold_mac = |x| fold_mac_(x, fld);
     fn fold_mt(mt: mt, fld: ast_fold) -> mt {
-        {ty: fld.fold_ty(mt.ty), mutbl: mt.mutbl}
+        mt { ty: fld.fold_ty(mt.ty), mutbl: mt.mutbl }
     }
     fn fold_field(f: ty_field, fld: ast_fold) -> ty_field {
         spanned { node: { ident: fld.fold_ident(f.node.ident),
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 770c942059ee..6fba59d6a84d 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -455,7 +455,7 @@ impl Parser {
     fn parse_mt() -> mt {
         let mutbl = self.parse_mutability();
         let t = self.parse_ty(false);
-        return {ty: t, mutbl: mutbl};
+        mt { ty: t, mutbl: mutbl }
     }
 
     fn parse_ty_field() -> ty_field {
@@ -464,9 +464,14 @@ impl Parser {
         let id = self.parse_ident();
         self.expect(token::COLON);
         let ty = self.parse_ty(false);
-        return spanned(lo, ty.span.hi, {
-            ident: id, mt: {ty: ty, mutbl: mutbl}
-        });
+        spanned(
+            lo,
+            ty.span.hi,
+            {
+                ident: id,
+                mt: ast::mt { ty: ty, mutbl: mutbl }
+            }
+        )
     }
 
     fn parse_ret_ty() -> (ret_style, @Ty) {
@@ -673,7 +678,12 @@ impl Parser {
         fn parse_capture_item(p:Parser, is_move: bool) -> capture_item {
             let sp = mk_sp(p.span.lo, p.span.hi);
             let ident = p.parse_ident();
-            @{id: p.get_id(), is_move: is_move, name: ident, span: sp}
+            @ast::capture_item_ {
+                id: p.get_id(),
+                is_move: is_move,
+                name: ident,
+                span: sp,
+            }
         }
 
         if self.eat_keyword(~"move") {
@@ -874,7 +884,7 @@ impl Parser {
         let i = self.parse_ident();
         self.expect(sep);
         let e = self.parse_expr();
-        return spanned(lo, e.span.hi, {mutbl: m, ident: i, expr: e});
+        spanned(lo, e.span.hi, ast::field_ { mutbl: m, ident: i, expr: e })
     }
 
     fn mk_expr(+lo: BytePos, +hi: BytePos, +node: expr_) -> @expr {