libstd: Remove "dual impls" from the language and enforce coherence rules. r=brson

"Dual impls" are impls that are both type implementations and trait
implementations. They can lead to ambiguity and so this patch removes them
from the language.

This also enforces coherence rules. Without this patch, records can implement
traits not defined in the current crate. This patch fixes this, and updates
all of rustc to adhere to the new enforcement. Most of this patch is fixing
rustc to obey the coherence rules, which involves converting a bunch of records
to structs.

77 files changed, 704 insertions, 837 deletions

diff --git a/src/libcore/gc.rs b/src/libcore/gc.rs
index bb2e7d788fd..4e69947ac67 100644
--- a/src/libcore/gc.rs
+++ b/src/libcore/gc.rs
@@ -42,6 +42,7 @@ with destructors.
 #[allow(structural_records)];
 
 use cast;
+use container::{Container, Mutable, Map, Set};
 use io;
 use libc::{size_t, uintptr_t};
 use option::{None, Option, Some};
diff --git a/src/libcore/hashmap.rs b/src/libcore/hashmap.rs
index 27b5ddadff9..df98e469bbc 100644
--- a/src/libcore/hashmap.rs
+++ b/src/libcore/hashmap.rs
@@ -16,7 +16,6 @@
 
 use cmp::Eq;
 use hash::Hash;
-use prelude::*;
 use to_bytes::IterBytes;
 
 /// Open addressing with linear probing.
@@ -464,6 +463,7 @@ pub mod linear {
 
 #[test]
 pub mod test {
+    use container::{Container, Mutable, Map, Set};
     use option::{None, Some};
     use hashmap::linear::LinearMap;
     use hashmap::linear;
diff --git a/src/libcore/num.rs b/src/libcore/num.rs
index 4c2daa458a4..6eb22e53a24 100644
--- a/src/libcore/num.rs
+++ b/src/libcore/num.rs
@@ -23,6 +23,11 @@ pub trait Num {
     static pure fn from_int(n: int) -> self;
 }
 
+pub trait IntConvertible {
+    pure fn to_int(&self) -> int;
+    static pure fn from_int(n: int) -> self;
+}
+
 pub trait Zero {
     static pure fn zero() -> self;
 }
diff --git a/src/libcore/pipes.rs b/src/libcore/pipes.rs
index 5029fc89b34..33826d10c3c 100644
--- a/src/libcore/pipes.rs
+++ b/src/libcore/pipes.rs
@@ -96,10 +96,9 @@ use either::{Either, Left, Right};
 use kinds::Owned;
 use libc;
 use option;
-use option::unwrap;
+use option::{None, Option, Some, unwrap};
 use pipes;
 use ptr;
-use prelude::*;
 use private;
 use task;
 use vec;
diff --git a/src/libcore/prelude.rs b/src/libcore/prelude.rs
index 72aa828ff12..d3813d1ae85 100644
--- a/src/libcore/prelude.rs
+++ b/src/libcore/prelude.rs
@@ -35,6 +35,8 @@ pub use vec::{ImmutableEqVector, ImmutableCopyableVector};
 pub use vec::{OwnedVector, OwnedCopyableVector};
 pub use iter::{BaseIter, ExtendedIter, EqIter, CopyableIter};
 pub use iter::{CopyableOrderedIter, CopyableNonstrictIter, Times};
+pub use container::{Container, Mutable, Map, Set};
+pub use pipes::{GenericChan, GenericPort};
 
 pub use num::Num;
 pub use ptr::Ptr;
diff --git a/src/libcore/private/weak_task.rs b/src/libcore/private/weak_task.rs
index 25a03ff960f..573a3e54b44 100644
--- a/src/libcore/private/weak_task.rs
+++ b/src/libcore/private/weak_task.rs
@@ -22,7 +22,7 @@ use option::{Some, None, swap_unwrap};
 use private::at_exit::at_exit;
 use private::global::global_data_clone_create;
 use private::finally::Finally;
-use pipes::{Port, Chan, SharedChan, stream};
+use pipes::{Port, Chan, SharedChan, GenericSmartChan, stream};
 use task::{Task, task, spawn};
 use task::rt::{task_id, get_task_id};
 use hashmap::linear::LinearMap;
diff --git a/src/libcore/task/mod.rs b/src/libcore/task/mod.rs
index aa82309c78a..9ddafee6938 100644
--- a/src/libcore/task/mod.rs
+++ b/src/libcore/task/mod.rs
@@ -45,7 +45,7 @@ use iter;
 use libc;
 use option;
 use result::Result;
-use pipes::{stream, Chan, Port, SharedChan};
+use pipes::{stream, Chan, GenericChan, GenericPort, Port, SharedChan};
 use pipes;
 use prelude::*;
 use ptr;
diff --git a/src/libcore/task/spawn.rs b/src/libcore/task/spawn.rs
index a5ab4af40be..0a2f6634214 100644
--- a/src/libcore/task/spawn.rs
+++ b/src/libcore/task/spawn.rs
@@ -74,8 +74,10 @@
 #[warn(deprecated_mode)];
 
 use cast;
+use container::Map;
+use oldcomm;
 use option;
-use pipes::{stream, Chan, Port};
+use pipes::{Chan, GenericChan, GenericPort, Port};
 use pipes;
 use prelude::*;
 use private;
diff --git a/src/librustc/metadata/encoder.rs b/src/librustc/metadata/encoder.rs
index 79ce755137e..399184ea8a5 100644
--- a/src/librustc/metadata/encoder.rs
+++ b/src/librustc/metadata/encoder.rs
@@ -37,6 +37,7 @@ use core::to_bytes::IterBytes;
 use core::uint;
 use core::vec;
 use std::map::HashMap;
+use std::serialize::Encodable;
 use std::{ebml, map};
 use std;
 use syntax::ast::*;
diff --git a/src/librustc/metadata/tydecode.rs b/src/librustc/metadata/tydecode.rs
index 590dd9f7ea7..787a1d3c906 100644
--- a/src/librustc/metadata/tydecode.rs
+++ b/src/librustc/metadata/tydecode.rs
@@ -17,7 +17,8 @@
 use core::prelude::*;
 
 use middle::ty;
-use middle::ty::{FnTyBase, FnMeta, FnSig};
+use middle::ty::{FnTyBase, FnMeta, FnSig, arg, creader_cache_key, field};
+use middle::ty::{substs};
 
 use core::io;
 use core::str;
@@ -174,9 +175,11 @@ fn parse_substs(st: @pstate, conv: conv_did) -> ty::substs {
     while peek(st) != ']' { params.push(parse_ty(st, conv)); }
     st.pos = st.pos + 1u;
 
-    return {self_r: self_r,
-         self_ty: self_ty,
-         tps: params};
+    return substs {
+        self_r: self_r,
+        self_ty: self_ty,
+        tps: params
+    };
 }
 
 fn parse_bound_region(st: @pstate) -> ty::bound_region {
@@ -308,7 +311,7 @@ fn parse_ty(st: @pstate, conv: conv_did) -> ty::t {
         let mut fields: ~[ty::field] = ~[];
         while peek(st) != ']' {
             let name = st.tcx.sess.ident_of(parse_str(st, '='));
-            fields.push({ident: name, mt: parse_mt(st, conv)});
+            fields.push(ty::field { ident: name, mt: parse_mt(st, conv) });
         }
         st.pos = st.pos + 1u;
         return ty::mk_rec(st.tcx, fields);
@@ -333,12 +336,13 @@ fn parse_ty(st: @pstate, conv: conv_did) -> ty::t {
         assert (next(st) == ':');
         let len = parse_hex(st);
         assert (next(st) == '#');
-        match st.tcx.rcache.find({cnum: st.crate, pos: pos, len: len}) {
+        let key = creader_cache_key { cnum: st.crate, pos: pos, len: len };
+        match st.tcx.rcache.find(key) {
           Some(tt) => return tt,
           None => {
             let ps = @{pos: pos ,.. copy *st};
             let tt = parse_ty(ps, conv);
-            st.tcx.rcache.insert({cnum: st.crate, pos: pos, len: len}, tt);
+            st.tcx.rcache.insert(key, tt);
             return tt;
           }
         }
@@ -421,8 +425,7 @@ fn parse_onceness(c: char) -> ast::Onceness {
 }
 
 fn parse_arg(st: @pstate, conv: conv_did) -> ty::arg {
-    {mode: parse_mode(st),
-     ty: parse_ty(st, conv)}
+    ty::arg { mode: parse_mode(st), ty: parse_ty(st, conv) }
 }
 
 fn parse_mode(st: @pstate) -> ast::mode {
@@ -446,7 +449,7 @@ fn parse_ty_fn(st: @pstate, conv: conv_did) -> ty::FnTy {
     let mut inputs: ~[ty::arg] = ~[];
     while peek(st) != ']' {
         let mode = parse_mode(st);
-        inputs.push({mode: mode, ty: parse_ty(st, conv)});
+        inputs.push(ty::arg { mode: mode, ty: parse_ty(st, conv) });
     }
     st.pos += 1u; // eat the ']'
     let ret_ty = parse_ty(st, conv);
diff --git a/src/librustc/metadata/tyencode.rs b/src/librustc/metadata/tyencode.rs
index d318f00ad67..04e833d812b 100644
--- a/src/librustc/metadata/tyencode.rs
+++ b/src/librustc/metadata/tyencode.rs
@@ -13,8 +13,8 @@
 
 use core::prelude::*;
 
+use middle::ty::{Vid, param_ty};
 use middle::ty;
-use middle::ty::Vid;
 
 use core::io::WriterUtil;
 use core::io;
@@ -301,7 +301,7 @@ fn enc_sty(w: io::Writer, cx: @ctxt, +st: ty::sty) {
       ty::ty_infer(_) => {
         cx.diag.handler().bug(~"Cannot encode inference variable types");
       }
-      ty::ty_param({idx: id, def_id: did}) => {
+      ty::ty_param(param_ty {idx: id, def_id: did}) => {
         w.write_char('p');
         w.write_str((cx.ds)(did));
         w.write_char('|');
diff --git a/src/librustc/middle/borrowck/check_loans.rs b/src/librustc/middle/borrowck/check_loans.rs
index ff5854322f4..bdb889b68f1 100644
--- a/src/librustc/middle/borrowck/check_loans.rs
+++ b/src/librustc/middle/borrowck/check_loans.rs
@@ -20,7 +20,7 @@
 use core::prelude::*;
 
 use middle::borrowck::{Loan, bckerr, borrowck_ctxt, cmt, inherent_mutability};
-use middle::borrowck::{req_maps, save_and_restore};
+use middle::borrowck::{req_maps, root_map_key, save_and_restore};
 use middle::mem_categorization::{cat_arg, cat_binding, cat_comp, cat_deref};
 use middle::mem_categorization::{cat_local, cat_rvalue, cat_self};
 use middle::mem_categorization::{cat_special, gc_ptr, loan_path, lp_arg};
@@ -396,7 +396,10 @@ impl check_loan_ctxt {
 
                 match ptr_kind {
                     gc_ptr(ast::m_mutbl) => {
-                        let key = { id: base.id, derefs: deref_count };
+                        let key = root_map_key {
+                            id: base.id,
+                            derefs: deref_count
+                        };
                         self.bccx.write_guard_map.insert(key, ());
                     }
                     _ => {}
diff --git a/src/librustc/middle/borrowck/gather_loans.rs b/src/librustc/middle/borrowck/gather_loans.rs
index 0fff0c66a38..6f913f99e11 100644
--- a/src/librustc/middle/borrowck/gather_loans.rs
+++ b/src/librustc/middle/borrowck/gather_loans.rs
@@ -19,7 +19,8 @@
 use core::prelude::*;
 
 use middle::borrowck::preserve::{preserve_condition, pc_ok, pc_if_pure};
-use middle::borrowck::{Loan, bckres, borrowck_ctxt, err_mutbl, req_maps};
+use middle::borrowck::{Loan, bckerr, bckres, borrowck_ctxt, err_mutbl};
+use middle::borrowck::{req_maps};
 use middle::mem_categorization::{cat_binding, cat_discr, cmt, comp_variant};
 use middle::mem_categorization::{mem_categorization_ctxt};
 use middle::mem_categorization::{opt_deref_kind};
@@ -452,8 +453,7 @@ impl gather_loan_ctxt {
             debug!("required is const or they are the same");
             Ok(pc_ok)
         } else {
-            let e = {cmt: cmt,
-                     code: err_mutbl(req_mutbl)};
+            let e = bckerr { cmt: cmt, code: err_mutbl(req_mutbl) };
             if req_mutbl == m_imm {
                 // if this is an @mut box, then it's generally OK to borrow as
                 // &imm; this will result in a write guard
diff --git a/src/librustc/middle/borrowck/loan.rs b/src/librustc/middle/borrowck/loan.rs
index d3dc75aad7f..48cc0502f6c 100644
--- a/src/librustc/middle/borrowck/loan.rs
+++ b/src/librustc/middle/borrowck/loan.rs
@@ -43,7 +43,7 @@ XXX --- much more needed, don't have time to write this all up now
 
 use core::prelude::*;
 
-use middle::borrowck::{Loan, bckres, borrowck_ctxt, cmt, err_mutbl};
+use middle::borrowck::{Loan, bckerr, bckres, borrowck_ctxt, cmt, err_mutbl};
 use middle::borrowck::{err_out_of_scope};
 use middle::mem_categorization::{cat_arg, cat_binding, cat_discr, cat_comp};
 use middle::mem_categorization::{cat_deref, cat_discr, cat_local, cat_self};
@@ -309,8 +309,10 @@ impl LoanContext {
                     // We do not allow non-mutable data to be loaned
                     // out as mutable under any circumstances.
                     if cmt.mutbl != m_mutbl {
-                        return Err({cmt:cmt,
-                                    code:err_mutbl(req_mutbl)});
+                        return Err(bckerr {
+                            cmt:cmt,
+                            code:err_mutbl(req_mutbl)
+                        });
                     }
                 }
                 m_const | m_imm => {
@@ -332,9 +334,10 @@ impl LoanContext {
         } else {
             // The loan being requested lives longer than the data
             // being loaned out!
-            return Err({cmt:cmt,
-                        code:err_out_of_scope(scope_ub,
-                                              self.scope_region)});
+            return Err(bckerr {
+                cmt:cmt,
+                code:err_out_of_scope(scope_ub, self.scope_region)
+            });
         }
     }
 }
diff --git a/src/librustc/middle/borrowck/mod.rs b/src/librustc/middle/borrowck/mod.rs
index a01c04a8abf..2afdcc9d47d 100644
--- a/src/librustc/middle/borrowck/mod.rs
+++ b/src/librustc/middle/borrowck/mod.rs
@@ -344,7 +344,11 @@ type root_map = HashMap<root_map_key, RootInfo>;
 // if you have an expression `x.f` and x has type ~@T, we could add an
 // entry {id:x, derefs:0} to refer to `x` itself, `{id:x, derefs:1}`
 // to refer to the deref of the unique pointer, and so on.
-type root_map_key = {id: ast::node_id, derefs: uint};
+#[deriving_eq]
+struct root_map_key {
+    id: ast::node_id,
+    derefs: uint
+}
 
 // set of ids of local vars / formal arguments that are modified / moved.
 // this is used in trans for optimization purposes.
@@ -411,13 +415,10 @@ impl bckerr_code : cmp::Eq {
 
 // Combination of an error code and the categorization of the expression
 // that caused it
-type bckerr = {cmt: cmt, code: bckerr_code};
-
-impl bckerr : cmp::Eq {
-    pure fn eq(&self, other: &bckerr) -> bool {
-        (*self).cmt == (*other).cmt && (*self).code == (*other).code
-    }
-    pure fn ne(&self, other: &bckerr) -> bool { !(*self).eq(other) }
+#[deriving_eq]
+struct bckerr {
+    cmt: cmt,
+    code: bckerr_code
 }
 
 // shorthand for something that fails with `bckerr` or succeeds with `T`
@@ -446,15 +447,6 @@ fn save_and_restore<T:Copy,U>(save_and_restore_t: &mut T, f: fn() -> U) -> U {
 
 /// Creates and returns a new root_map
 
-impl root_map_key : cmp::Eq {
-    pure fn eq(&self, other: &root_map_key) -> bool {
-        (*self).id == (*other).id && (*self).derefs == (*other).derefs
-    }
-    pure fn ne(&self, other: &root_map_key) -> bool {
-        ! ((*self) == (*other))
-    }
-}
-
 impl root_map_key : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         to_bytes::iter_bytes_2(&self.id, &self.derefs, lsb0, f);
@@ -501,7 +493,7 @@ impl borrowck_ctxt {
     }
 
     fn cat_discr(cmt: cmt, match_id: ast::node_id) -> cmt {
-        return @{cat:cat_discr(cmt, match_id),.. *cmt};
+        return @cmt_ { cat: cat_discr(cmt, match_id),.. *cmt };
     }
 
     fn mc_ctxt() -> mem_categorization_ctxt {
diff --git a/src/librustc/middle/borrowck/preserve.rs b/src/librustc/middle/borrowck/preserve.rs
index 5916588a9a2..5edfd294d84 100644
--- a/src/librustc/middle/borrowck/preserve.rs
+++ b/src/librustc/middle/borrowck/preserve.rs
@@ -18,7 +18,7 @@ use core::prelude::*;
 use middle::borrowck::{RootInfo, bckerr, bckerr_code, bckres, borrowck_ctxt};
 use middle::borrowck::{cmt, err_mut_uniq, err_mut_variant};
 use middle::borrowck::{err_out_of_root_scope, err_out_of_scope};
-use middle::borrowck::{err_root_not_permitted};
+use middle::borrowck::{err_root_not_permitted, root_map_key};
 use middle::mem_categorization::{cat_arg, cat_binding, cat_comp, cat_deref};
 use middle::mem_categorization::{cat_discr, cat_local, cat_self, cat_special};
 use middle::mem_categorization::{cat_stack_upvar, comp_field, comp_index};
@@ -291,7 +291,7 @@ priv impl &preserve_ctxt {
           Ok(pc_ok) => {
             match cmt_base.mutbl {
               m_mutbl | m_const => {
-                Ok(pc_if_pure({cmt:cmt, code:code}))
+                Ok(pc_if_pure(bckerr { cmt: cmt, code: code }))
               }
               m_imm => {
                 Ok(pc_ok)
@@ -318,8 +318,10 @@ priv impl &preserve_ctxt {
         if self.bccx.is_subregion_of(self.scope_region, scope_ub) {
             Ok(pc_ok)
         } else {
-            Err({cmt:cmt, code:err_out_of_scope(scope_ub,
-                                                self.scope_region)})
+            Err(bckerr {
+                cmt:cmt,
+                code:err_out_of_scope(scope_ub, self.scope_region)
+            })
         }
     }
 
@@ -345,7 +347,7 @@ priv impl &preserve_ctxt {
             // would be sort of pointless to avoid rooting the inner
             // box by rooting an outer box, as it would just keep more
             // memory live than necessary, so we set root_ub to none.
-            return Err({cmt:cmt, code:err_root_not_permitted});
+            return Err(bckerr { cmt: cmt, code: err_root_not_permitted });
         }
 
         let root_region = ty::re_scope(self.root_ub);
@@ -359,7 +361,7 @@ priv impl &preserve_ctxt {
                    derefs, scope_id, self.root_ub);
             if self.bccx.is_subregion_of(self.scope_region, root_region) {
                 debug!("Elected to root");
-                let rk = {id: base.id, derefs: derefs};
+                let rk = root_map_key { id: base.id, derefs: derefs };
                 // This code could potentially lead cause boxes to be frozen
                 // for longer than necessarily at runtime. It prevents an
                 // ICE in trans; the fundamental problem is that it's hard
@@ -389,17 +391,20 @@ priv impl &preserve_ctxt {
                 return Ok(pc_ok);
             } else {
                 debug!("Unable to root");
-                return Err({cmt:cmt,
-                            code:err_out_of_root_scope(root_region,
-                                                       self.scope_region)});
+                return Err(bckerr {
+                    cmt: cmt,
+                    code: err_out_of_root_scope(root_region,
+                                                self.scope_region)
+                });
             }
           }
 
           // we won't be able to root long enough
           _ => {
-              return Err({cmt:cmt,
-                          code:err_out_of_root_scope(root_region,
-                                                     self.scope_region)});
+              return Err(bckerr {
+                cmt:cmt,
+                code:err_out_of_root_scope(root_region, self.scope_region)
+              });
           }
 
         }
diff --git a/src/librustc/middle/mem_categorization.rs b/src/librustc/middle/mem_categorization.rs
index 7c1e96e5c0e..9ea03440ad6 100644
--- a/src/librustc/middle/mem_categorization.rs
+++ b/src/librustc/middle/mem_categorization.rs
@@ -113,27 +113,18 @@ enum special_kind {
 // which the value is stored.
 //
 // note: cmt stands for "categorized mutable type".
-type cmt_ = {id: ast::node_id,        // id of expr/pat producing this value
-             span: span,              // span of same expr/pat
-             cat: categorization,     // categorization of expr
-             lp: Option<@loan_path>,  // loan path for expr, if any
-             mutbl: ast::mutability,  // mutability of expr as lvalue
-             ty: ty::t};              // type of the expr
+#[deriving_eq]
+struct cmt_ {
+    id: ast::node_id,        // id of expr/pat producing this value
+    span: span,              // span of same expr/pat
+    cat: categorization,     // categorization of expr
+    lp: Option<@loan_path>,  // loan path for expr, if any
+    mutbl: ast::mutability,  // mutability of expr as lvalue
+    ty: ty::t                // type of the expr
+}
 
 type cmt = @cmt_;
 
-impl cmt_ : cmp::Eq {
-    pure fn eq(&self, other: &cmt_) -> bool {
-        (*self).id == (*other).id &&
-        (*self).span == (*other).span &&
-        (*self).cat == (*other).cat &&
-        (*self).lp == (*other).lp &&
-        (*self).mutbl == (*other).mutbl &&
-        (*self).ty == (*other).ty
-    }
-    pure fn ne(&self, other: &cmt_) -> bool { !(*self).eq(other) }
-}
-
 // a loan path is like a category, but it exists only when the data is
 // interior to the stack frame.  loan paths are used as the key to a
 // map indicating what is borrowed at any point in time.
@@ -423,9 +414,14 @@ impl &mem_categorization_ctxt {
           ast::def_ty_param(*) | ast::def_struct(*) |
           ast::def_typaram_binder(*) | ast::def_region(_) |
           ast::def_label(_) | ast::def_self_ty(*) => {
-            @{id:id, span:span,
-              cat:cat_special(sk_static_item), lp:None,
-              mutbl:m_imm, ty:expr_ty}
+            @cmt_ {
+                id:id,
+                span:span,
+                cat:cat_special(sk_static_item),
+                lp:None,
+                mutbl:m_imm,
+                ty:expr_ty
+            }
           }
 
           ast::def_arg(vid, mode, mutbl) => {
@@ -451,9 +447,14 @@ impl &mem_categorization_ctxt {
                 None
               }
             };
-            @{id:id, span:span,
-              cat:cat_arg(vid), lp:lp,
-              mutbl:m, ty:expr_ty}
+            @cmt_ {
+                id:id,
+                span:span,
+                cat:cat_arg(vid),
+                lp:lp,
+                mutbl:m,
+                ty:expr_ty
+            }
           }
 
           ast::def_self(self_id, is_implicit) => {
@@ -466,9 +467,14 @@ impl &mem_categorization_ctxt {
                 loan_path = Some(@lp_self);
             };
 
-            @{id:id, span:span,
-              cat:cat, lp:loan_path,
-              mutbl:m_imm, ty:expr_ty}
+            @cmt_ {
+                id:id,
+                span:span,
+                cat:cat,
+                lp:loan_path,
+                mutbl:m_imm,
+                ty:expr_ty
+            }
           }
 
           ast::def_upvar(_, inner, fn_node_id, _) => {
@@ -477,15 +483,25 @@ impl &mem_categorization_ctxt {
             match proto {
                 ast::ProtoBorrowed => {
                     let upcmt = self.cat_def(id, span, expr_ty, *inner);
-                    @{id:id, span:span,
-                      cat:cat_stack_upvar(upcmt), lp:upcmt.lp,
-                      mutbl:upcmt.mutbl, ty:upcmt.ty}
+                    @cmt_ {
+                        id:id,
+                        span:span,
+                        cat:cat_stack_upvar(upcmt),
+                        lp:upcmt.lp,
+                        mutbl:upcmt.mutbl,
+                        ty:upcmt.ty
+                    }
                 }
                 ast::ProtoUniq | ast::ProtoBox => {
                     // FIXME #2152 allow mutation of moved upvars
-                    @{id:id, span:span,
-                      cat:cat_special(sk_heap_upvar), lp:None,
-                      mutbl:m_imm, ty:expr_ty}
+                    @cmt_ {
+                        id:id,
+                        span:span,
+                        cat:cat_special(sk_heap_upvar),
+                        lp:None,
+                        mutbl:m_imm,
+                        ty:expr_ty
+                    }
                 }
                 ast::ProtoBare => {
                     self.tcx.sess.span_bug(
@@ -497,16 +513,26 @@ impl &mem_categorization_ctxt {
 
           ast::def_local(vid, mutbl) => {
             let m = if mutbl {m_mutbl} else {m_imm};
-            @{id:id, span:span,
-              cat:cat_local(vid), lp:Some(@lp_local(vid)),
-              mutbl:m, ty:expr_ty}
+            @cmt_ {
+                id:id,
+                span:span,
+                cat:cat_local(vid),
+                lp:Some(@lp_local(vid)),
+                mutbl:m,
+                ty:expr_ty
+            }
           }
 
           ast::def_binding(vid, _) => {
             // by-value/by-ref bindings are local variables
-            @{id:id, span:span,
-              cat:cat_local(vid), lp:Some(@lp_local(vid)),
-              mutbl:m_imm, ty:expr_ty}
+            @cmt_ {
+                id:id,
+                span:span,
+                cat:cat_local(vid),
+                lp:Some(@lp_local(vid)),
+                mutbl:m_imm,
+                ty:expr_ty
+            }
           }
         }
     }
@@ -514,17 +540,25 @@ impl &mem_categorization_ctxt {
     fn cat_variant<N: ast_node>(arg: N,
                                 enum_did: ast::def_id,
                                 cmt: cmt) -> cmt {
-        @{id: arg.id(), span: arg.span(),
-          cat: cat_comp(cmt, comp_variant(enum_did)),
-          lp: cmt.lp.map(|l| @lp_comp(*l, comp_variant(enum_did)) ),
-          mutbl: cmt.mutbl, // imm iff in an immutable context
-          ty: self.tcx.ty(arg)}
+        @cmt_ {
+            id: arg.id(),
+            span: arg.span(),
+            cat: cat_comp(cmt, comp_variant(enum_did)),
+            lp: cmt.lp.map(|l| @lp_comp(*l, comp_variant(enum_did)) ),
+            mutbl: cmt.mutbl, // imm iff in an immutable context
+            ty: self.tcx.ty(arg)
+        }
     }
 
     fn cat_rvalue<N: ast_node>(elt: N, expr_ty: ty::t) -> cmt {
-        @{id:elt.id(), span:elt.span(),
-          cat:cat_rvalue, lp:None,
-          mutbl:m_imm, ty:expr_ty}
+        @cmt_ {
+            id:elt.id(),
+            span:elt.span(),
+            cat:cat_rvalue,
+            lp:None,
+            mutbl:m_imm,
+            ty:expr_ty
+        }
     }
 
     /// inherited mutability: used in cases where the mutability of a
@@ -559,9 +593,14 @@ impl &mem_categorization_ctxt {
         let m = self.inherited_mutability(base_cmt.mutbl, f_mutbl);
         let f_comp = comp_field(f_name, f_mutbl);
         let lp = base_cmt.lp.map(|lp| @lp_comp(*lp, f_comp) );
-        @{id: node.id(), span: node.span(),
-          cat: cat_comp(base_cmt, f_comp), lp:lp,
-          mutbl: m, ty: self.tcx.ty(node)}
+        @cmt_ {
+            id: node.id(),
+            span: node.span(),
+            cat: cat_comp(base_cmt, f_comp),
+            lp:lp,
+            mutbl: m,
+            ty: self.tcx.ty(node)
+        }
     }
 
     fn cat_deref_fn<N:ast_node>(node: N,
@@ -628,17 +667,27 @@ impl &mem_categorization_ctxt {
                     }
                 };
 
-                @{id:node.id(), span:node.span(),
-                  cat:cat_deref(base_cmt, deref_cnt, ptr), lp:lp,
-                  mutbl:m, ty:mt.ty}
+                @cmt_ {
+                    id:node.id(),
+                    span:node.span(),
+                    cat:cat_deref(base_cmt, deref_cnt, ptr),
+                    lp:lp,
+                    mutbl:m,
+                    ty:mt.ty
+                }
             }
 
             deref_comp(comp) => {
                 let lp = base_cmt.lp.map(|l| @lp_comp(*l, comp) );
                 let m = self.inherited_mutability(base_cmt.mutbl, mt.mutbl);
-                @{id:node.id(), span:node.span(),
-                  cat:cat_comp(base_cmt, comp), lp:lp,
-                  mutbl:m, ty:mt.ty}
+                @cmt_ {
+                    id:node.id(),
+                    span:node.span(),
+                    cat:cat_comp(base_cmt, comp),
+                    lp:lp,
+                    mutbl:m,
+                    ty:mt.ty
+                }
             }
         }
     }
@@ -675,9 +724,14 @@ impl &mem_categorization_ctxt {
             };
 
             // (c) the deref is explicit in the resulting cmt
-            let deref_cmt = @{id:elt.id(), span:elt.span(),
-              cat:cat_deref(base_cmt, 0u, ptr), lp:deref_lp,
-              mutbl:m, ty:mt.ty};
+            let deref_cmt = @cmt_ {
+                id:elt.id(),
+                span:elt.span(),
+                cat:cat_deref(base_cmt, 0u, ptr),
+                lp:deref_lp,
+                mutbl:m,
+                ty:mt.ty
+            };
 
             comp(elt, deref_cmt, base_cmt.ty, m, mt.ty)
           }
@@ -695,32 +749,48 @@ impl &mem_categorization_ctxt {
         {
             let comp = comp_index(vect, mutbl);
             let index_lp = of_cmt.lp.map(|lp| @lp_comp(*lp, comp) );
-            @{id:elt.id(), span:elt.span(),
-              cat:cat_comp(of_cmt, comp), lp:index_lp,
-              mutbl:mutbl, ty:ty}
+            @cmt_ {
+                id:elt.id(),
+                span:elt.span(),
+                cat:cat_comp(of_cmt, comp),
+                lp:index_lp,
+                mutbl:mutbl,
+                ty:ty
+            }
         }
     }
 
     fn cat_tuple_elt<N: ast_node>(elt: N, cmt: cmt) -> cmt {
-        @{id: elt.id(), span: elt.span(),
-          cat: cat_comp(cmt, comp_tuple),
-          lp: cmt.lp.map(|l| @lp_comp(*l, comp_tuple) ),
-          mutbl: cmt.mutbl, // imm iff in an immutable context
-          ty: self.tcx.ty(elt)}
+        @cmt_ {
+            id: elt.id(),
+            span: elt.span(),
+            cat: cat_comp(cmt, comp_tuple),
+            lp: cmt.lp.map(|l| @lp_comp(*l, comp_tuple) ),
+            mutbl: cmt.mutbl, // imm iff in an immutable context
+            ty: self.tcx.ty(elt)
+        }
     }
 
     fn cat_anon_struct_field<N: ast_node>(elt: N, cmt: cmt) -> cmt {
-        @{id: elt.id(), span: elt.span(),
-          cat: cat_comp(cmt, comp_anon_field),
-          lp: cmt.lp.map(|l| @lp_comp(*l, comp_anon_field)),
-          mutbl: cmt.mutbl, // imm iff in an immutable context
-          ty: self.tcx.ty(elt)}
+        @cmt_ {
+            id: elt.id(),
+            span: elt.span(),
+            cat: cat_comp(cmt, comp_anon_field),
+            lp: cmt.lp.map(|l| @lp_comp(*l, comp_anon_field)),
+            mutbl: cmt.mutbl, // imm iff in an immutable context
+            ty: self.tcx.ty(elt)
+        }
     }
 
     fn cat_method_ref(expr: @ast::expr, expr_ty: ty::t) -> cmt {
-        @{id:expr.id, span:expr.span,
-          cat:cat_special(sk_method), lp:None,
-          mutbl:m_imm, ty:expr_ty}
+        @cmt_ {
+            id:expr.id,
+            span:expr.span,
+            cat:cat_special(sk_method),
+            lp:None,
+            mutbl:m_imm,
+            ty:expr_ty
+        }
     }
 
     fn cat_pattern(cmt: cmt, pat: @ast::pat, op: fn(cmt, @ast::pat)) {
diff --git a/src/librustc/middle/region.rs b/src/librustc/middle/region.rs
index dd355f6df70..ac3a16b07a0 100644
--- a/src/librustc/middle/region.rs
+++ b/src/librustc/middle/region.rs
@@ -397,17 +397,15 @@ fn resolve_crate(sess: Session, def_map: resolve::DefMap,
 // dependencies until a fixed point is reached.
 
 type region_paramd_items = HashMap<ast::node_id, region_variance>;
-type region_dep = {ambient_variance: region_variance, id: ast::node_id};
-type dep_map = HashMap<ast::node_id, @DVec<region_dep>>;
 
-impl region_dep : cmp::Eq {
-    pure fn eq(&self, other: &region_dep) -> bool {
-        (*self).ambient_variance == (*other).ambient_variance &&
-        (*self).id == (*other).id
-    }
-    pure fn ne(&self, other: &region_dep) -> bool { !(*self).eq(other) }
+#[deriving_eq]
+struct region_dep {
+    ambient_variance: region_variance,
+    id: ast::node_id
 }
 
+type dep_map = HashMap<ast::node_id, @DVec<region_dep>>;
+
 type determine_rp_ctxt_ = {
     sess: Session,
     ast_map: ast_map::map,
@@ -511,7 +509,10 @@ impl determine_rp_ctxt {
                 vec
             }
         };
-        let dep = {ambient_variance: self.ambient_variance, id: self.item_id};
+        let dep = region_dep {
+            ambient_variance: self.ambient_variance,
+            id: self.item_id
+        };
         if !vec.contains(&dep) { vec.push(dep); }
     }
 
diff --git a/src/librustc/middle/trans/_match.rs b/src/librustc/middle/trans/_match.rs
index db266464860..084f0ba421e 100644
--- a/src/librustc/middle/trans/_match.rs
+++ b/src/librustc/middle/trans/_match.rs
@@ -910,7 +910,8 @@ fn root_pats_as_necessary(bcx: block,
     for vec::each(m) |br| {
         let pat_id = br.pats[col].id;
 
-        match bcx.ccx().maps.root_map.find({id:pat_id, derefs:0u}) {
+        let key = root_map_key {id: pat_id, derefs: 0u };
+        match bcx.ccx().maps.root_map.find(key) {
             None => (),
             Some(root_info) => {
                 // Note: the scope_id will always be the id of the match.  See
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index 3bf1547a7d9..f4814b4657b 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -61,6 +61,7 @@ use middle::trans::reachable;
 use middle::trans::shape::*;
 use middle::trans::tvec;
 use middle::trans::type_of::*;
+use middle::ty::arg;
 use util::common::indenter;
 use util::ppaux::{ty_to_str, ty_to_short_str};
 use util::ppaux;
@@ -2198,9 +2199,12 @@ fn create_main_wrapper(ccx: @crate_ctxt, _sp: span, main_llfn: ValueRef) {
     fn create_main(ccx: @crate_ctxt, main_llfn: ValueRef) -> 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::mt {ty: unit_ty, mutbl: ast::m_imm},
-                             ty::vstore_uniq)};
+            arg {
+                mode: ast::expl(ast::by_val),
+                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);
         let llfdecl = decl_fn(ccx.llmod, ~"_rust_main",
diff --git a/src/librustc/middle/trans/common.rs b/src/librustc/middle/trans/common.rs
index 0128876a898..3babfbd8285 100644
--- a/src/librustc/middle/trans/common.rs
+++ b/src/librustc/middle/trans/common.rs
@@ -39,6 +39,7 @@ use middle::trans::reachable;
 use middle::trans::shape;
 use middle::trans::type_of;
 use middle::trans::type_use;
+use middle::ty::substs;
 use middle::ty;
 use middle::typeck;
 use util::ppaux::{expr_repr, ty_to_str};
@@ -1459,9 +1460,11 @@ fn find_vtable(tcx: ty::ctxt, ps: &param_substs,
 }
 
 fn dummy_substs(+tps: ~[ty::t]) -> ty::substs {
-    {self_r: Some(ty::re_bound(ty::br_self)),
-     self_ty: None,
-     tps: tps}
+    substs {
+        self_r: Some(ty::re_bound(ty::br_self)),
+        self_ty: None,
+        tps: tps
+    }
 }
 
 fn struct_field(index: uint) -> [uint * 3] {
diff --git a/src/librustc/middle/trans/datum.rs b/src/librustc/middle/trans/datum.rs
index 8c024b364c3..94145be2a1e 100644
--- a/src/librustc/middle/trans/datum.rs
+++ b/src/librustc/middle/trans/datum.rs
@@ -98,7 +98,7 @@
 use core::prelude::*;
 
 use lib::llvm::ValueRef;
-use middle::borrowck::RootInfo;
+use middle::borrowck::{RootInfo, root_map_key};
 use middle::trans::base::*;
 use middle::trans::build::*;
 use middle::trans::common::*;
@@ -652,7 +652,7 @@ impl Datum {
         // root the autoderef'd value, if necessary:
         //
         // (Note: root'd values are always boxes)
-        let key = {id:expr_id, derefs:derefs};
+        let key = root_map_key { id: expr_id, derefs: derefs };
         let bcx = match ccx.maps.root_map.find(key) {
             None => bcx,
             Some(root_info) => self.root(bcx, root_info)
diff --git a/src/librustc/middle/trans/expr.rs b/src/librustc/middle/trans/expr.rs
index ea9ddc2e5d0..24d8e94abbd 100644
--- a/src/librustc/middle/trans/expr.rs
+++ b/src/librustc/middle/trans/expr.rs
@@ -114,6 +114,7 @@ lvalues are *never* stored by value.
 use core::prelude::*;
 
 use lib::llvm::ValueRef;
+use middle::borrowck::root_map_key;
 use middle::resolve;
 use middle::trans::base::*;
 use middle::trans::callee::{AutorefArg, DoAutorefArg, DontAutorefArg};
@@ -757,7 +758,7 @@ fn trans_lvalue_unadjusted(bcx: block, expr: @ast::expr) -> DatumBlock {
     // If the lvalue must remain rooted, create a scratch datum, copy
     // the lvalue in there, and then arrange for it to be cleaned up
     // at the end of the scope with id `scope_id`:
-    let root_key = {id:expr.id, derefs:0u};
+    let root_key = root_map_key { id: expr.id, derefs: 0u };
     for bcx.ccx().maps.root_map.find(root_key).each |&root_info| {
         bcx = unrooted_datum.root(bcx, root_info);
     }
diff --git a/src/librustc/middle/trans/foreign.rs b/src/librustc/middle/trans/foreign.rs
index ac641222b3c..317a64ea528 100644
--- a/src/librustc/middle/trans/foreign.rs
+++ b/src/librustc/middle/trans/foreign.rs
@@ -31,7 +31,7 @@ use middle::trans::machine;
 use middle::trans::shape;
 use middle::trans::type_of::*;
 use middle::trans::type_of;
-use middle::ty::{FnTyBase, FnMeta, FnSig};
+use middle::ty::{FnTyBase, FnMeta, FnSig, arg};
 use util::ppaux::ty_to_str;
 
 use core::libc::c_uint;
@@ -546,8 +546,8 @@ fn trans_intrinsic(ccx: @crate_ctxt, decl: ValueRef, item: @ast::foreign_item,
                               onceness: ast::Many,
                               region: ty::re_bound(ty::br_anon(0)),
                               bounds: @~[]},
-                sig: FnSig {inputs: ~[{mode: ast::expl(ast::by_val),
-                                       ty: star_u8}],
+                sig: FnSig {inputs: ~[arg {mode: ast::expl(ast::by_val),
+                                           ty: star_u8}],
                             output: ty::mk_nil(bcx.tcx())}
             });
             let datum = Datum {val: get_param(decl, first_real_arg),
diff --git a/src/librustc/middle/trans/machine.rs b/src/librustc/middle/trans/machine.rs
index 5c0498d5a14..7af3b7a0683 100644
--- a/src/librustc/middle/trans/machine.rs
+++ b/src/librustc/middle/trans/machine.rs
@@ -13,6 +13,7 @@
 
 use middle::trans::common::*;
 use middle::trans::type_of;
+use middle::ty::field;
 use middle::ty;
 
 use syntax::parse::token::special_idents;
@@ -44,13 +45,17 @@ pub fn simplify_type(tcx: ty::ctxt, typ: ty::t) -> ty::t {
           ty::ty_struct(did, ref substs) => {
             let simpl_fields = (if ty::ty_dtor(tcx, did).is_present() {
                 // remember the drop flag
-                  ~[{ident: special_idents::dtor,
-                     mt: ty::mt {ty: ty::mk_u8(tcx), mutbl: ast::m_mutbl}}] }
+                  ~[field {
+                    ident: special_idents::dtor,
+                    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::mt {ty: simplify_type(tcx, t), mutbl: ast::m_const}}
+                 field {
+                    ident: f.ident,
+                    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/meth.rs b/src/librustc/middle/trans/meth.rs
index 7eccf97f76c..a90c25abf3d 100644
--- a/src/librustc/middle/trans/meth.rs
+++ b/src/librustc/middle/trans/meth.rs
@@ -28,6 +28,7 @@ use middle::trans::glue;
 use middle::trans::inline;
 use middle::trans::monomorphize;
 use middle::trans::type_of::*;
+use middle::ty::arg;
 use middle::typeck;
 use util::ppaux::{ty_to_str, tys_to_str};
 
@@ -154,8 +155,10 @@ fn trans_self_arg(bcx: block,
     let mut temp_cleanups = ~[];
 
     // Compute the mode and type of self.
-    let self_arg = {mode: mentry.self_arg.mode,
-                    ty: monomorphize_type(bcx, mentry.self_arg.ty)};
+    let self_arg = arg {
+        mode: mentry.self_arg.mode,
+        ty: monomorphize_type(bcx, mentry.self_arg.ty)
+    };
 
     let result = trans_arg_expr(bcx, self_arg, base,
                                 &mut temp_cleanups, None, DontAutorefArg);
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index a839de967ca..002e04ca475 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -242,14 +242,23 @@ export AutoRefKind, AutoPtr, AutoBorrowVec, AutoBorrowVecRef, AutoBorrowFn;
 export iter_bound_traits_and_supertraits;
 export count_traits_and_supertraits;
 export IntVarValue, IntType, UintType;
+export creader_cache_key;
 
 // Data types
 
 // Note: after typeck, you should use resolved_mode() to convert this mode
 // into an rmode, which will take into account the results of mode inference.
-type arg = {mode: ast::mode, ty: t};
+#[deriving_eq]
+struct arg {
+    mode: ast::mode,
+    ty: t
+}
 
-type field = {ident: ast::ident, mt: mt};
+#[deriving_eq]
+struct field {
+    ident: ast::ident,
+    mt: mt
+}
 
 type param_bounds = @~[param_bound];
 
@@ -292,35 +301,38 @@ pub enum ValueMode {
 
 // Contains information needed to resolve types and (in the future) look up
 // the types of AST nodes.
-type creader_cache_key = {cnum: int, pos: uint, len: uint};
-type creader_cache = HashMap<creader_cache_key, t>;
-
-impl creader_cache_key : cmp::Eq {
-    pure fn eq(&self, other: &creader_cache_key) -> bool {
-        (*self).cnum == (*other).cnum &&
-            (*self).pos == (*other).pos &&
-            (*self).len == (*other).len
-    }
-    pure fn ne(&self, other: &creader_cache_key) -> bool {
-        !((*self) == (*other))
-    }
+#[deriving_eq]
+struct creader_cache_key {
+    cnum: int,
+    pos: uint,
+    len: uint
 }
 
+type creader_cache = HashMap<creader_cache_key, t>;
+
 impl creader_cache_key : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         to_bytes::iter_bytes_3(&self.cnum, &self.pos, &self.len, lsb0, f);
     }
 }
 
-type intern_key = {sty: *sty, o_def_id: Option<ast::def_id>};
+struct intern_key {
+    sty: *sty,
+    o_def_id: Option<ast::def_id>
+}
 
+// NB: Do not replace this with #[deriving_eq]. The automatically-derived
+// implementation will not recurse through sty and you will get stack
+// exhaustion.
 impl intern_key : cmp::Eq {
     pure fn eq(&self, other: &intern_key) -> bool {
         unsafe {
             *self.sty == *other.sty && self.o_def_id == other.o_def_id
         }
     }
-    pure fn ne(&self, other: &intern_key) -> bool { !(*self).eq(other) }
+    pure fn ne(&self, other: &intern_key) -> bool {
+        !self.eq(other)
+    }
 }
 
 impl intern_key : to_bytes::IterBytes {
@@ -570,13 +582,10 @@ impl<M: to_bytes::IterBytes> FnTyBase<M> : to_bytes::IterBytes {
 
 type FnTy = FnTyBase<FnMeta>;
 
-type param_ty = {idx: uint, def_id: def_id};
-
-impl param_ty : cmp::Eq {
-    pure fn eq(&self, other: &param_ty) -> bool {
-        (*self).idx == (*other).idx && (*self).def_id == (*other).def_id
-    }
-    pure fn ne(&self, other: &param_ty) -> bool { !(*self).eq(other) }
+#[deriving_eq]
+struct param_ty {
+    idx: uint,
+    def_id: def_id
 }
 
 impl param_ty : to_bytes::IterBytes {
@@ -662,11 +671,12 @@ type opt_region = Option<Region>;
  * - `self_ty` is the type to which `self` should be remapped, if any.  The
  *   `self` type is rather funny in that it can only appear on traits and is
  *   always substituted away to the implementing type for a trait. */
-type substs = {
+#[deriving_eq]
+struct substs {
     self_r: opt_region,
     self_ty: Option<ty::t>,
     tps: ~[t]
-};
+}
 
 // NB: If you change this, you'll probably want to change the corresponding
 // AST structure in libsyntax/ast.rs as well.
@@ -1051,7 +1061,7 @@ fn mk_t(cx: ctxt, +st: sty) -> t { mk_t_with_id(cx, st, None) }
 // Interns a type/name combination, stores the resulting box in cx.interner,
 // and returns the box as cast to an unsafe ptr (see comments for t above).
 fn mk_t_with_id(cx: ctxt, +st: sty, o_def_id: Option<ast::def_id>) -> t {
-    let key = {sty: to_unsafe_ptr(&st), o_def_id: o_def_id};
+    let key = intern_key { sty: to_unsafe_ptr(&st), o_def_id: o_def_id };
     match cx.interner.find(key) {
       Some(t) => unsafe { return cast::reinterpret_cast(&t); },
       _ => ()
@@ -1110,7 +1120,7 @@ fn mk_t_with_id(cx: ctxt, +st: sty, o_def_id: Option<ast::def_id>) -> t {
 
     let t = @{sty: move st, id: cx.next_id, flags: flags, o_def_id: o_def_id};
 
-    let key = {sty: to_unsafe_ptr(&t.sty), o_def_id: o_def_id};
+    let key = intern_key {sty: to_unsafe_ptr(&t.sty), o_def_id: o_def_id};
     cx.interner.insert(move key, t);
 
     cx.next_id += 1u;
@@ -1243,7 +1253,7 @@ fn mk_infer(cx: ctxt, +it: InferTy) -> t { mk_t(cx, ty_infer(it)) }
 fn mk_self(cx: ctxt) -> t { mk_t(cx, ty_self) }
 
 fn mk_param(cx: ctxt, n: uint, k: def_id) -> t {
-    mk_t(cx, ty_param({idx: n, def_id: k}))
+    mk_t(cx, ty_param(param_ty { idx: n, def_id: k }))
 }
 
 fn mk_type(cx: ctxt) -> t { mk_t(cx, ty_type) }
@@ -1359,7 +1369,7 @@ fn fold_sty_to_ty(tcx: ty::ctxt, sty: &sty, foldop: fn(t) -> t) -> t {
 
 fn fold_sig(sig: &FnSig, fldop: fn(t) -> t) -> FnSig {
     let args = do sig.inputs.map |arg| {
-        { mode: arg.mode, ty: fldop(arg.ty) }
+        arg { mode: arg.mode, ty: fldop(arg.ty) }
     };
 
     FnSig {
@@ -1370,9 +1380,9 @@ fn fold_sig(sig: &FnSig, fldop: fn(t) -> t) -> FnSig {
 
 fn fold_sty(sty: &sty, fldop: fn(t) -> t) -> sty {
     fn fold_substs(substs: &substs, fldop: fn(t) -> t) -> substs {
-        {self_r: substs.self_r,
-         self_ty: substs.self_ty.map(|t| fldop(*t)),
-         tps: substs.tps.map(|t| fldop(*t))}
+        substs {self_r: substs.self_r,
+                self_ty: substs.self_ty.map(|t| fldop(*t)),
+                tps: substs.tps.map(|t| fldop(*t))}
     }
 
     match /*bad*/copy *sty {
@@ -1400,8 +1410,8 @@ 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 = mt {ty: new_ty, mutbl: fl.mt.mutbl};
-                {ident: fl.ident, mt: new_mt}
+                let new_mt = mt { ty: new_ty, mutbl: fl.mt.mutbl };
+                field { ident: fl.ident, mt: new_mt }
             };
             ty_rec(new_fields)
         }
@@ -1458,11 +1468,13 @@ fn fold_regions_and_ty(
     fn fold_substs(
         substs: &substs,
         fldr: fn(r: Region) -> Region,
-        fldt: fn(t: t) -> t) -> substs
-    {
-        {self_r: substs.self_r.map(|r| fldr(*r)),
-         self_ty: substs.self_ty.map(|t| fldt(*t)),
-         tps: substs.tps.map(|t| fldt(*t))}
+        fldt: fn(t: t) -> t)
+     -> substs {
+        substs {
+            self_r: substs.self_r.map(|r| fldr(*r)),
+            self_ty: substs.self_ty.map(|t| fldt(*t)),
+            tps: substs.tps.map(|t| fldt(*t))
+        }
     }
 
     let tb = ty::get(ty);
@@ -1678,7 +1690,7 @@ fn subst(cx: ctxt,
 // Performs substitutions on a set of substitutions (result = sup(sub)) to
 // yield a new set of substitutions. This is used in trait inheritance.
 fn subst_substs(cx: ctxt, sup: &substs, sub: &substs) -> substs {
-    {
+    substs {
         self_r: sup.self_r,
         self_ty: sup.self_ty.map(|typ| subst(cx, sub, *typ)),
         tps: sup.tps.map(|typ| subst(cx, sub, *typ))
@@ -4159,7 +4171,7 @@ fn struct_item_fields(cx:ctxt,
     do lookup_struct_fields(cx, did).map |f| {
        // consider all instance vars mut, because the
        // constructor may mutate all vars
-       {
+       field {
            ident: f.ident,
             mt: mt {
                 ty: lookup_field_type(cx, did, f.id, substs),
@@ -4288,9 +4300,11 @@ fn normalize_ty(cx: ctxt, t: t) -> t {
                 Some(_) =>
                     // Use re_static since trans doesn't care about regions
                     mk_enum(cx, did,
-                     {self_r: Some(ty::re_static),
-                      self_ty: None,
-                      tps: /*bad*/copy (*r).tps}),
+                     substs {
+                        self_r: Some(ty::re_static),
+                        self_ty: None,
+                        tps: /*bad*/copy (*r).tps
+                     }),
                 None =>
                     t
             },
@@ -4299,9 +4313,9 @@ fn normalize_ty(cx: ctxt, t: t) -> t {
             match (*r).self_r {
               Some(_) =>
                 // Ditto.
-                mk_struct(cx, did, {self_r: Some(ty::re_static),
-                                    self_ty: None,
-                                    tps: /*bad*/copy (*r).tps}),
+                mk_struct(cx, did, substs {self_r: Some(ty::re_static),
+                                           self_ty: None,
+                                           tps: /*bad*/copy (*r).tps}),
               None =>
                 t
             },
@@ -4421,20 +4435,6 @@ impl mt : cmp::Eq {
     pure fn ne(&self, other: &mt) -> bool { !(*self).eq(other) }
 }
 
-impl arg : cmp::Eq {
-    pure fn eq(&self, other: &arg) -> bool {
-        (*self).mode == (*other).mode && (*self).ty == (*other).ty
-    }
-    pure fn ne(&self, other: &arg) -> bool { !(*self).eq(other) }
-}
-
-impl field : cmp::Eq {
-    pure fn eq(&self, other: &field) -> bool {
-        (*self).ident == (*other).ident && (*self).mt == (*other).mt
-    }
-    pure fn ne(&self, other: &field) -> bool { !(*self).eq(other) }
-}
-
 impl vstore : cmp::Eq {
     pure fn eq(&self, other: &vstore) -> bool {
         match (*self) {
@@ -4543,15 +4543,6 @@ impl bound_region : cmp::Eq {
     pure fn ne(&self, other: &bound_region) -> bool { !(*self).eq(other) }
 }
 
-impl substs : cmp::Eq {
-    pure fn eq(&self, other: &substs) -> bool {
-        (*self).self_r == (*other).self_r &&
-        (*self).self_ty == (*other).self_ty &&
-        (*self).tps == (*other).tps
-    }
-    pure fn ne(&self, other: &substs) -> bool { !(*self).eq(other) }
-}
-
 impl sty : cmp::Eq {
     pure fn eq(&self, other: &sty) -> bool {
         match (/*bad*/copy *self) {
diff --git a/src/librustc/middle/typeck/astconv.rs b/src/librustc/middle/typeck/astconv.rs
index 7e1c5f54134..e845904956d 100644
--- a/src/librustc/middle/typeck/astconv.rs
+++ b/src/librustc/middle/typeck/astconv.rs
@@ -55,7 +55,8 @@
 use core::prelude::*;
 
 use middle::pat_util::pat_id_map;
-use middle::ty::{FnTyBase, FnMeta, FnSig, ty_param_substs_and_ty};
+use middle::ty::{FnTyBase, FnMeta, FnSig, arg, field, substs};
+use middle::ty::{ty_param_substs_and_ty};
 use middle::ty;
 use middle::typeck::check::fn_ctxt;
 use middle::typeck::collect;
@@ -151,7 +152,7 @@ fn ast_path_to_substs_and_ty<AC: ast_conv, RS: region_scope Copy Durable>(
     }
     let tps = path.types.map(|a_t| ast_ty_to_ty(self, rscope, *a_t));
 
-    let substs = {self_r:self_r, self_ty:None, tps:tps};
+    let substs = substs {self_r:self_r, self_ty:None, tps:tps};
     let ty = ty::subst(tcx, &substs, decl_ty);
     {substs: substs, ty: ty}
 }
@@ -315,7 +316,7 @@ fn ast_ty_to_ty<AC: ast_conv, RS: region_scope Copy Durable>(
       ast::ty_rec(ref fields) => {
         let flds = do (*fields).map |f| {
             let tm = ast_mt_to_mt(self, rscope, f.node.mt);
-            {ident: f.node.ident, mt: tm}
+            field {ident: f.node.ident, mt: tm}
         };
         ty::mk_rec(tcx, flds)
       }
@@ -447,7 +448,7 @@ fn ty_of_arg<AC: ast_conv, RS: region_scope Copy Durable>(
         }
     };
 
-    {mode: mode, ty: ty}
+    arg {mode: mode, ty: ty}
 }
 
 type expected_tys = Option<{inputs: ~[ty::arg],
diff --git a/src/librustc/middle/typeck/check/method.rs b/src/librustc/middle/typeck/check/method.rs
index 86f58edd6c8..543adbd53aa 100644
--- a/src/librustc/middle/typeck/check/method.rs
+++ b/src/librustc/middle/typeck/check/method.rs
@@ -295,7 +295,11 @@ impl LookupContext {
                     let self_did = self.fcx.self_info.expect(
                         ~"self_impl_def_id is undefined (`self` may not \
                           be in scope here").def_id;
-                    let substs = {self_r: None, self_ty: None, tps: ~[]};
+                    let substs = substs {
+                        self_r: None,
+                        self_ty: None,
+                        tps: ~[]
+                    };
                     self.push_inherent_candidates_from_self(
                         self_ty, self_did, &substs);
                 }
@@ -392,7 +396,10 @@ impl LookupContext {
             // impl or class (where the self type is not permitted),
             // or from a trait type (in which case methods that refer
             // to self are not permitted).
-            let init_substs = {self_ty: Some(rcvr_ty), ..init_substs};
+            let init_substs = substs {
+                self_ty: Some(rcvr_ty),
+                ..init_substs
+            };
 
             worklist.push((init_trait_ty, init_substs));
 
@@ -416,7 +423,10 @@ impl LookupContext {
                         &init_substs);
 
                     // Again replacing the self type
-                    let new_substs = {self_ty: Some(rcvr_ty), ..new_substs};
+                    let new_substs = substs {
+                        self_ty: Some(rcvr_ty),
+                        ..new_substs
+                    };
 
                     worklist.push((supertrait.tpt.ty, new_substs));
                 }
@@ -506,7 +516,10 @@ impl LookupContext {
         // `trait_ty` for `self` here, because it allows the compiler
         // to soldier on.  An error will be reported should this
         // candidate be selected if the method refers to `self`.
-        let rcvr_substs = {self_ty: Some(self_ty), ../*bad*/copy *substs};
+        let rcvr_substs = substs {
+            self_ty: Some(self_ty),
+            ../*bad*/copy *substs
+        };
 
         let (rcvr_ty, rcvr_substs) =
             self.create_rcvr_ty_and_substs_for_method(method.self_ty,
@@ -537,7 +550,10 @@ impl LookupContext {
         }
         let method = &methods[index];
 
-        let rcvr_substs = { self_ty: Some(self_ty), ../*bad*/copy *substs };
+        let rcvr_substs = substs {
+            self_ty: Some(self_ty),
+            ../*bad*/copy *substs
+        };
         let (rcvr_ty, rcvr_substs) =
             self.create_rcvr_ty_and_substs_for_method(
                 method.self_ty,
@@ -628,7 +644,11 @@ impl LookupContext {
                     candidate");
 
             // XXX: Needs to support generics.
-            let dummy_substs = { self_r: None, self_ty: None, tps: ~[] };
+            let dummy_substs = substs {
+                self_r: None,
+                self_ty: None,
+                tps: ~[]
+            };
             let (impl_ty, impl_substs) =
                 self.create_rcvr_ty_and_substs_for_method(
                     provided_method_info.method_info.self_type,
@@ -673,11 +693,13 @@ impl LookupContext {
                     move self_substs
                 }
                 sty_region(_) => {
-                    {self_r:
-                         Some(self.infcx().next_region_var(
-                             self.expr.span,
-                             self.expr.id)),
-                     ..self_substs}
+                    substs {
+                        self_r:
+                             Some(self.infcx().next_region_var(
+                                 self.expr.span,
+                                 self.expr.id)),
+                        ..self_substs
+                    }
                 }
             }
         };
@@ -1058,7 +1080,7 @@ impl LookupContext {
 
         // Construct the full set of type parameters for the method,
         // which is equal to the class tps + the method tps.
-        let all_substs = {
+        let all_substs = substs {
             tps: vec::append(/*bad*/copy candidate.rcvr_substs.tps,
                              m_substs),
             ../*bad*/copy candidate.rcvr_substs
@@ -1066,7 +1088,7 @@ impl LookupContext {
 
         self.fcx.write_ty_substs(self.callee_id, fty, all_substs);
         method_map_entry {
-            self_arg: {
+            self_arg: arg {
                 mode: ast::expl(candidate.self_mode),
                 ty: candidate.rcvr_ty,
             },
diff --git a/src/librustc/middle/typeck/check/mod.rs b/src/librustc/middle/typeck/check/mod.rs
index cf13fcb86e8..3d5f6e9d303 100644
--- a/src/librustc/middle/typeck/check/mod.rs
+++ b/src/librustc/middle/typeck/check/mod.rs
@@ -84,7 +84,7 @@ use middle::pat_util::pat_id_map;
 use middle::pat_util;
 use middle::ty::{TyVid, Vid, FnTyBase, FnMeta, FnSig, VariantInfo_, field};
 use middle::ty::{ty_param_bounds_and_ty, ty_param_substs_and_ty};
-use middle::ty::{re_bound, br_cap_avoid};
+use middle::ty::{re_bound, br_cap_avoid, substs, arg, param_ty};
 use middle::ty;
 use middle::typeck::astconv::{ast_conv, ast_path_to_ty};
 use middle::typeck::astconv::{ast_region_to_region, ast_ty_to_ty};
@@ -1059,9 +1059,11 @@ pub fn impl_self_ty(vcx: &VtableContext,
               {n_tps: ts.len(),
                region_param: region_param,
                raw_ty: ty::mk_struct(tcx, local_def(class_id),
-                      {self_r: rscope::bound_self_region(region_param),
-                       self_ty: None,
-                       tps: ty::ty_params_to_tys(tcx, /*bad*/copy *ts)})}
+                      substs {
+                        self_r: rscope::bound_self_region(region_param),
+                        self_ty: None,
+                        tps: ty::ty_params_to_tys(tcx, /*bad*/copy *ts)
+                      })}
           }
           _ => { tcx.sess.bug(~"impl_self_ty: unbound item or item that \
                doesn't have a self_ty"); }
@@ -1081,7 +1083,7 @@ pub fn impl_self_ty(vcx: &VtableContext,
     };
     let tps = vcx.infcx.next_ty_vars(n_tps);
 
-    let substs = {self_r: self_r, self_ty: None, tps: tps};
+    let substs = substs { self_r: self_r, self_ty: None, tps: tps };
     let substd_ty = ty::subst(tcx, &substs, raw_ty);
     {substs: substs, ty: substd_ty}
 }
@@ -1814,7 +1816,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
                     let self_region =
                         bound_self_region(region_parameterized);
 
-                    raw_type = ty::mk_struct(tcx, class_id, {
+                    raw_type = ty::mk_struct(tcx, class_id, substs {
                         self_r: self_region,
                         self_ty: None,
                         tps: ty::ty_params_to_tys(
@@ -1840,7 +1842,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
                                             span,
                                             ty::re_scope(id));
         let type_parameters = fcx.infcx().next_ty_vars(type_parameter_count);
-        let substitutions = {
+        let substitutions = substs {
             self_r: self_region,
             self_ty: None,
             tps: type_parameters
@@ -1897,7 +1899,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
                     let self_region =
                         bound_self_region(region_parameterized);
 
-                    raw_type = ty::mk_enum(tcx, enum_id, {
+                    raw_type = ty::mk_enum(tcx, enum_id, substs {
                         self_r: self_region,
                         self_ty: None,
                         tps: ty::ty_params_to_tys(
@@ -1923,7 +1925,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
                                             span,
                                             ty::re_scope(id));
         let type_parameters = fcx.infcx().next_ty_vars(type_parameter_count);
-        let substitutions = {
+        let substitutions = substs {
             self_r: self_region,
             self_ty: None,
             tps: type_parameters
@@ -2434,7 +2436,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt,
             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})
+            respan(f.node.expr.span, field {ident: f.node.ident, mt: expr_mt})
         });
         match base {
           None => {
@@ -2951,7 +2953,7 @@ fn instantiate_path(fcx: @fn_ctxt,
         pth.types.map(|aty| fcx.to_ty(*aty))
     };
 
-    let substs = {self_r: self_r, self_ty: None, tps: tps};
+    let substs = substs { self_r: self_r, self_ty: None, tps: tps };
     fcx.write_ty_substs(node_id, tpt.ty, substs);
 
     debug!("<<<");
@@ -3050,7 +3052,7 @@ fn check_bounds_are_used(ccx: @crate_ctxt,
         |_r| {},
         |t| {
             match ty::get(t).sty {
-              ty::ty_param({idx, _}) => {
+              ty::ty_param(param_ty {idx, _}) => {
                   debug!("Found use of ty param #%u", idx);
                   tps_used[idx] = true;
               }
@@ -3073,7 +3075,7 @@ fn check_intrinsic_type(ccx: @crate_ctxt, it: @ast::foreign_item) {
         ty::mk_param(ccx.tcx, n, local_def(0))
     }
     fn arg(m: ast::rmode, ty: ty::t) -> ty::arg {
-        {mode: ast::expl(m), ty: ty}
+        arg {mode: ast::expl(m), ty: ty}
     }
     let tcx = ccx.tcx;
     let (n_tps, inputs, output) = match ccx.tcx.sess.str_of(it.ident) {
@@ -3136,12 +3138,14 @@ fn check_intrinsic_type(ccx: @crate_ctxt, it: @ast::foreign_item) {
                           onceness: ast::Once,
                           region: ty::re_bound(ty::br_anon(0)),
                           bounds: @~[]},
-            sig: FnSig {inputs: ~[{mode: ast::expl(ast::by_val),
-                                   ty: ty::mk_imm_ptr(
-                                       ccx.tcx,
-                                       ty::mk_mach_uint(ccx.tcx, ast::ty_u8))
-                                  }],
-                        output: ty::mk_nil(ccx.tcx)}
+            sig: FnSig {
+                inputs: ~[arg {
+                    mode: ast::expl(ast::by_val),
+                    ty: ty::mk_imm_ptr(
+                        ccx.tcx,
+                        ty::mk_mach_uint(ccx.tcx, ast::ty_u8))
+                }],
+                output: ty::mk_nil(ccx.tcx)}
         });
         (0u, ~[arg(ast::by_ref, fty)], ty::mk_nil(tcx))
       }
diff --git a/src/librustc/middle/typeck/check/vtable.rs b/src/librustc/middle/typeck/check/vtable.rs
index 9d309d4996b..9f6cc6835b7 100644
--- a/src/librustc/middle/typeck/check/vtable.rs
+++ b/src/librustc/middle/typeck/check/vtable.rs
@@ -11,6 +11,7 @@
 use core::prelude::*;
 
 use middle::resolve;
+use middle::ty::{param_ty, substs};
 use middle::ty;
 use middle::typeck::check::{fn_ctxt, impl_self_ty};
 use middle::typeck::check::{structurally_resolved_type};
@@ -103,7 +104,10 @@ fn lookup_vtables(vcx: &VtableContext,
                    ppaux::ty_to_str(tcx, trait_ty),
                    ty::substs_to_str(tcx, substs));
 
-            let new_substs = {self_ty: Some(*ty), ../*bad*/copy *substs};
+            let new_substs = substs {
+                self_ty: Some(*ty),
+                ../*bad*/copy *substs
+            };
             let trait_ty = ty::subst(tcx, &new_substs, trait_ty);
 
             debug!("after subst: %?",
@@ -189,7 +193,7 @@ fn lookup_vtable(vcx: &VtableContext,
     };
 
     match ty::get(ty).sty {
-        ty::ty_param({idx: n, def_id: did}) => {
+        ty::ty_param(param_ty {idx: n, def_id: did}) => {
             let mut n_bound = 0;
             let bounds = tcx.ty_param_bounds.get(did.node);
             for ty::iter_bound_traits_and_supertraits(
diff --git a/src/librustc/middle/typeck/check/writeback.rs b/src/librustc/middle/typeck/check/writeback.rs
index e5dc91b7f17..c5374af2dd0 100644
--- a/src/librustc/middle/typeck/check/writeback.rs
+++ b/src/librustc/middle/typeck/check/writeback.rs
@@ -15,6 +15,7 @@
 use core::prelude::*;
 
 use middle::pat_util;
+use middle::ty::arg;
 use middle::ty;
 use middle::typeck::check::{fn_ctxt, self_info};
 use middle::typeck::infer::{force_all, resolve_all, resolve_region};
@@ -65,7 +66,7 @@ fn resolve_method_map_entry(fcx: @fn_ctxt, sp: span, id: ast::node_id)
                 fcx.ccx.method_map.insert(
                     id,
                     method_map_entry {
-                        self_arg: {mode: mme.self_arg.mode, ty: *t},
+                        self_arg: arg {mode: mme.self_arg.mode, ty: *t},
                         .. *mme
                     }
                 );
diff --git a/src/librustc/middle/typeck/coherence.rs b/src/librustc/middle/typeck/coherence.rs
index b0c98cfa2b1..4cd2eaaf003 100644
--- a/src/librustc/middle/typeck/coherence.rs
+++ b/src/librustc/middle/typeck/coherence.rs
@@ -25,8 +25,8 @@ use metadata::decoder::{dl_def, dl_field, dl_impl};
 use middle::resolve::{Impl, MethodInfo};
 use middle::ty::{ProvidedMethodSource, ProvidedMethodInfo, bound_copy, get};
 use middle::ty::{kind_can_be_copied, lookup_item_type, param_bounds, subst};
-use middle::ty::{t, ty_bool, ty_bot, ty_box, ty_enum, ty_err, ty_estr};
-use middle::ty::{ty_evec, ty_float, ty_fn, ty_infer, ty_int, ty_nil};
+use middle::ty::{substs, t, ty_bool, ty_bot, ty_box, ty_enum, ty_err};
+use middle::ty::{ty_estr, ty_evec, ty_float, ty_fn, ty_infer, ty_int, ty_nil};
 use middle::ty::{ty_opaque_box, ty_param, ty_param_bounds_and_ty, ty_ptr};
 use middle::ty::{ty_rec, ty_rptr, ty_self, ty_struct, ty_trait, ty_tup};
 use middle::ty::{ty_type, ty_uint, ty_uniq};
@@ -34,6 +34,7 @@ use middle::ty::{ty_opaque_closure_ptr, ty_unboxed_vec, type_kind_ext};
 use middle::ty::{type_is_ty_var};
 use middle::ty;
 use middle::typeck::crate_ctxt;
+use middle::typeck::infer::combine::Combine;
 use middle::typeck::infer::{InferCtxt, can_mk_subty};
 use middle::typeck::infer::{new_infer_ctxt, resolve_ivar};
 use middle::typeck::infer::{resolve_nested_tvar, resolve_type};
@@ -286,8 +287,8 @@ impl CoherenceChecker {
         }
 
         // Add the implementation to the mapping from implementation to base
-        // type def ID, if there is a base type for this implementation.
-
+        // type def ID, if there is a base type for this implementation and
+        // the implementation does not have any associated traits.
         match get_base_type_def_id(self.inference_context,
                                    item.span,
                                    self_type.ty) {
@@ -296,16 +297,19 @@ impl CoherenceChecker {
             }
             Some(base_type_def_id) => {
                 // XXX: Gather up default methods?
-                let implementation;
-                match implementation_opt {
-                    None => {
-                        implementation = self.create_impl_from_item(item);
-                    }
-                    Some(copy existing_implementation) => {
-                        implementation = existing_implementation;
+                if associated_traits.len() == 0 {
+                    let implementation;
+                    match implementation_opt {
+                        None => {
+                            implementation = self.create_impl_from_item(item);
+                        }
+                        Some(copy existing_implementation) => {
+                            implementation = existing_implementation;
+                        }
                     }
+                    self.add_inherent_method(base_type_def_id,
+                                             implementation);
                 }
-                self.add_inherent_method(base_type_def_id, implementation);
 
                 self.base_type_def_ids.insert(local_def(item.id),
                                               base_type_def_id);
@@ -510,7 +514,7 @@ impl CoherenceChecker {
         let type_parameters =
             self.inference_context.next_ty_vars(bounds_count);
 
-        let substitutions = {
+        let substitutions = substs {
             self_r: self_region,
             self_ty: None,
             tps: type_parameters
@@ -520,7 +524,8 @@ impl CoherenceChecker {
                              polytype.ty);
 
         // Get our type parameters back.
-        let { self_r: _, self_ty: _, tps: type_parameters } = substitutions;
+        let substs { self_r: _, self_ty: _, tps: type_parameters } =
+            substitutions;
 
         UniversalQuantificationResult {
             monotype: monotype,
@@ -597,6 +602,7 @@ impl CoherenceChecker {
                         visit_mod(module_, item.span, item.id, (), visitor);
                     }
                     item_impl(_, opt_trait, _, _) => {
+                        let mut ok = false;
                         match self.base_type_def_ids.find(
                             local_def(item.id)) {
 
@@ -611,57 +617,50 @@ impl CoherenceChecker {
                                     // Record that this implementation is OK.
                                     self.privileged_implementations.insert
                                         (item.id, ());
-                                } else {
-                                    // This implementation is not in scope of
-                                    // its base type. This still might be OK
-                                    // if the traits are defined in the same
-                                    // crate.
-
-                                  match opt_trait {
-                                    None => {
-                                        // There is no trait to implement, so
-                                        // this is an error.
-
-                                        let session =
-                                            self.crate_context.tcx.sess;
-                                        session.span_err(item.span,
-                                                         ~"cannot implement \
-                                                          inherent methods \
-                                                          for a type outside \
-                                                          the crate the type \
-                                                          was defined in; \
-                                                          define and \
-                                                          implement a trait \
-                                                          or new type \
-                                                          instead");
-                                    }
-                                    _ => ()
-                                  }
-
-                                  do opt_trait.iter() |trait_ref| {
-                                        // This is OK if and only if the
-                                        // trait was defined in this
-                                        // crate.
-
-                                        let trait_def_id =
-                                            self.trait_ref_to_trait_def_id(
-                                                *trait_ref);
-
-                                        if trait_def_id.crate != local_crate {
-                                            let session =
-                                                self.crate_context.tcx.sess;
-                                            session.span_err(item.span,
-                                                             ~"cannot \
-                                                               provide an \
-                                                               extension \
-                                                               implementa\
-                                                                  tion \
-                                                               for a trait \
-                                                               not defined \
-                                                               in this \
-                                                               crate");
-                                        }
-                                    }
+                                    ok = true;
+                                }
+                            }
+                        }
+
+                        if !ok {
+                            // This implementation is not in scope of its base
+                            // type. This still might be OK if the trait is
+                            // defined in the same crate.
+
+                            match opt_trait {
+                                None => {
+                                    // There is no trait to implement, so
+                                    // this is an error.
+
+                                    let session = self.crate_context.tcx.sess;
+                                    session.span_err(item.span,
+                                                     ~"cannot implement \
+                                                      inherent methods for a \
+                                                      type outside the crate \
+                                                      the type was defined \
+                                                      in; define and \
+                                                      implement a trait or \
+                                                      new type instead");
+                                }
+                                _ => ()
+                          }
+
+                          do opt_trait.iter() |trait_ref| {
+                                // This is OK if and only if the trait was
+                                // defined in this crate.
+
+                                let trait_def_id =
+                                    self.trait_ref_to_trait_def_id(
+                                        *trait_ref);
+
+                                if trait_def_id.crate != local_crate {
+                                    let session = self.crate_context.tcx.sess;
+                                    session.span_err(item.span,
+                                                     ~"cannot provide an \
+                                                       extension \
+                                                       implementation for a \
+                                                       trait not defined in \
+                                                       this crate");
                                 }
                             }
                         }
diff --git a/src/librustc/middle/typeck/collect.rs b/src/librustc/middle/typeck/collect.rs
index ba34846ca97..ce0c7a94c7c 100644
--- a/src/librustc/middle/typeck/collect.rs
+++ b/src/librustc/middle/typeck/collect.rs
@@ -33,8 +33,8 @@ are represented as `ty_param()` instances.
 use core::prelude::*;
 
 use metadata::csearch;
-use middle::ty::{FnMeta, FnSig, FnTyBase, InstantiatedTraitRef};
-use middle::ty::{ty_param_substs_and_ty};
+use middle::ty::{FnMeta, FnSig, FnTyBase, InstantiatedTraitRef, arg};
+use middle::ty::{substs, ty_param_substs_and_ty};
 use middle::ty;
 use middle::typeck::astconv::{ast_conv, ty_of_fn_decl, ty_of_arg};
 use middle::typeck::astconv::{ast_ty_to_ty};
@@ -75,7 +75,11 @@ fn collect_item_types(ccx: @crate_ctxt, crate: @ast::crate) {
                 for m.items.each |intrinsic_item| {
                     let def_id = ast::def_id { crate: ast::local_crate,
                                                node: intrinsic_item.id };
-                    let substs = {self_r: None, self_ty: None, tps: ~[]};
+                    let substs = substs {
+                        self_r: None,
+                        self_ty: None,
+                        tps: ~[]
+                    };
 
                     match intrinsic_item.node {
                       ast::item_trait(*) => {
@@ -164,7 +168,7 @@ fn get_enum_variant_types(ccx: @crate_ctxt,
                 let rs = type_rscope(rp);
                 let args = args.map(|va| {
                     let arg_ty = ccx.to_ty(rs, va.ty);
-                    {mode: ast::expl(ast::by_copy), ty: arg_ty}
+                    arg { mode: ast::expl(ast::by_copy), ty: arg_ty }
                 });
                 result_ty = Some(ty::mk_fn(tcx, FnTyBase {
                     meta: FnMeta {purity: ast::pure_fn,
@@ -195,8 +199,9 @@ fn get_enum_variant_types(ccx: @crate_ctxt,
                     variant.node.id);
                 // Compute the ctor arg types from the struct fields
                 let struct_fields = do struct_def.fields.map |struct_field| {
-                    {mode: ast::expl(ast::by_val),
-                     ty: ty::node_id_to_type(ccx.tcx, (*struct_field).node.id)
+                    arg {
+                        mode: ast::expl(ast::by_val),
+                        ty: ty::node_id_to_type(ccx.tcx, struct_field.node.id)
                     }
                 };
                 result_ty = Some(ty::mk_fn(tcx, FnTyBase {
@@ -265,8 +270,11 @@ fn ensure_trait_methods(ccx: @crate_ctxt, id: ast::node_id, trait_ty: ty::t) {
             ty::mk_param(ccx.tcx, i + 1, dummy_defid)
         };
 
-        let substs = { self_r: None, self_ty: Some(self_param),
-                       tps: non_shifted_trait_tps + shifted_method_tps };
+        let substs = substs {
+            self_r: None,
+            self_ty: Some(self_param),
+            tps: non_shifted_trait_tps + shifted_method_tps
+        };
         let ty = ty::subst(ccx.tcx,
                            &substs,
                            ty::mk_fn(ccx.tcx, /*bad*/copy m.fty));
@@ -462,7 +470,7 @@ fn compare_impl_method(tcx: ty::ctxt,
         };
         let trait_tps = trait_substs.tps.map(
             |t| replace_bound_self(tcx, *t, dummy_self_r));
-        let substs = {
+        let substs = substs {
             self_r: Some(dummy_self_r),
             self_ty: Some(self_ty),
             tps: vec::append(trait_tps, dummy_tps)
@@ -705,7 +713,7 @@ fn convert_struct(ccx: @crate_ctxt,
                     },
                     sig: FnSig {
                         inputs: do struct_def.fields.map |field| {
-                            {
+                            arg {
                                 mode: ast::expl(ast::by_copy),
                                 ty: ccx.tcx.tcache.get
                                         (local_def(field.node.id)).ty
@@ -1002,5 +1010,8 @@ fn mk_substs(ccx: @crate_ctxt,
           -> {bounds: @~[ty::param_bounds], substs: ty::substs} {
     let {bounds, params} = mk_ty_params(ccx, atps);
     let self_r = rscope::bound_self_region(rp);
-    {bounds: bounds, substs: {self_r: self_r, self_ty: None, tps: params}}
+    {
+        bounds: bounds,
+        substs: substs { self_r: self_r, self_ty: None, tps: params }
+    }
 }
diff --git a/src/librustc/middle/typeck/infer/combine.rs b/src/librustc/middle/typeck/infer/combine.rs
index e9946ae7c13..d1c57a21a3b 100644
--- a/src/librustc/middle/typeck/infer/combine.rs
+++ b/src/librustc/middle/typeck/infer/combine.rs
@@ -57,7 +57,7 @@
 use core::prelude::*;
 
 use middle::ty::{FloatVar, FnTyBase, FnMeta, FnSig, IntVar, TyVar};
-use middle::ty::{IntType, UintType};
+use middle::ty::{IntType, UintType, arg, substs};
 use middle::ty;
 use middle::typeck::infer::glb::Glb;
 use middle::typeck::infer::lub::Lub;
@@ -233,7 +233,11 @@ fn super_substs<C:Combine>(
             do relate_region_param(self, did,
                                    a.self_r, b.self_r).chain |self_r|
             {
-                Ok({self_r: self_r, self_ty: self_ty, tps: /*bad*/copy tps})
+                Ok(substs {
+                    self_r: self_r,
+                    self_ty: self_ty,
+                    tps: /*bad*/copy tps
+                })
             }
         }
     }
@@ -295,7 +299,7 @@ fn super_flds<C:Combine>(
 
     if a.ident == b.ident {
         self.mts(a.mt, b.mt)
-            .chain(|mt| Ok({ident: a.ident, mt: mt}) )
+            .chain(|mt| Ok(ty::field {ident: a.ident, mt: mt}) )
             .chain_err(|e| Err(ty::terr_in_field(@e, a.ident)) )
     } else {
         Err(ty::terr_record_fields(
@@ -317,7 +321,7 @@ fn super_args<C:Combine>(
 
     do self.modes(a.mode, b.mode).chain |m| {
         do self.contratys(a.ty, b.ty).chain |t| {
-            Ok({mode: m, ty: t})
+            Ok(arg {mode: m, ty: t})
         }
     }
 }
@@ -587,4 +591,4 @@ fn super_tys<C:Combine>(
         if_ok!(self.infcx().simple_var_t(vid_is_expected, vid, val));
         Ok(ty::mk_mach_float(tcx, val))
     }
-}
\ No newline at end of file
+}
diff --git a/src/librustc/middle/typeck/infer/mod.rs b/src/librustc/middle/typeck/infer/mod.rs
index cac5fa5feb1..cab40ce21b1 100644
--- a/src/librustc/middle/typeck/infer/mod.rs
+++ b/src/librustc/middle/typeck/infer/mod.rs
@@ -255,7 +255,7 @@ use middle::ty::IntVarValue;
 use middle::ty;
 use middle::typeck::check::regionmanip::{replace_bound_regions_in_fn_sig};
 use middle::typeck::infer::coercion::Coerce;
-use middle::typeck::infer::combine::{CombineFields, eq_tys};
+use middle::typeck::infer::combine::{Combine, CombineFields, eq_tys};
 use middle::typeck::infer::glb::Glb;
 use middle::typeck::infer::lub::Lub;
 use middle::typeck::infer::region_inference::{RegionVarBindings};
diff --git a/src/librustc/util/ppaux.rs b/src/librustc/util/ppaux.rs
index ac079f8f044..fb9e0f36c2f 100644
--- a/src/librustc/util/ppaux.rs
+++ b/src/librustc/util/ppaux.rs
@@ -17,7 +17,7 @@ use middle::ty::{bound_copy, bound_const, bound_durable, bound_owned,
 use middle::ty::{bound_region, br_anon, br_named, br_self, br_cap_avoid,
                  br_fresh};
 use middle::ty::{ctxt, field, method};
-use middle::ty::{mt, t, param_bound};
+use middle::ty::{mt, t, param_bound, param_ty};
 use middle::ty::{re_bound, re_free, re_scope, re_infer, re_static, Region};
 use middle::ty::{ReSkolemized, ReVar};
 use middle::ty::{ty_bool, ty_bot, ty_box, ty_struct, ty_enum};
@@ -292,9 +292,8 @@ fn fn_sig_to_str(cx: ctxt, typ: &ty::FnSig) -> ~str {
 }
 
 fn ty_to_str(cx: ctxt, typ: t) -> ~str {
-    fn fn_input_to_str(cx: ctxt, input: {mode: ast::mode, ty: t}) ->
-       ~str {
-        let {mode, ty} = input;
+    fn fn_input_to_str(cx: ctxt, input: ty::arg) -> ~str {
+        let ty::arg {mode: mode, ty: ty} = input;
         let modestr = match canon_mode(cx, mode) {
           ast::infer(_) => ~"",
           ast::expl(m) => {
@@ -423,7 +422,7 @@ fn ty_to_str(cx: ctxt, typ: t) -> ~str {
       }
       ty_infer(infer_ty) => infer_ty.to_str(),
       ty_err => ~"[type error]",
-      ty_param({idx: id, _}) => {
+      ty_param(param_ty {idx: id, _}) => {
         ~"'" + str::from_bytes(~[('a' as u8) + (id as u8)])
       }
       ty_self => ~"self",
diff --git a/src/librustdoc/astsrv.rs b/src/librustdoc/astsrv.rs
index 99cf301f182..bc332615eaa 100644
--- a/src/librustdoc/astsrv.rs
+++ b/src/librustdoc/astsrv.rs
@@ -155,9 +155,9 @@ fn build_error_handlers(
     codemap: @codemap::CodeMap
 ) -> ErrorHandlers {
 
-    type DiagnosticHandler = {
+    struct DiagnosticHandler {
         inner: diagnostic::handler,
-    };
+    }
 
     impl DiagnosticHandler: diagnostic::handler {
         fn fatal(msg: &str) -> ! { self.inner.fatal(msg) }
@@ -182,7 +182,7 @@ fn build_error_handlers(
         diagnostic::emit(cmsp, msg, lvl);
     };
     let inner_handler = diagnostic::mk_handler(Some(emitter));
-    let handler = {
+    let handler = DiagnosticHandler {
         inner: inner_handler,
     };
     let span_handler = diagnostic::mk_span_handler(
diff --git a/src/librustdoc/attr_pass.rs b/src/librustdoc/attr_pass.rs
index 1ab3ce2d6f3..39a893a4076 100644
--- a/src/librustdoc/attr_pass.rs
+++ b/src/librustdoc/attr_pass.rs
@@ -69,9 +69,9 @@ fn fold_crate(
         attr_parser::parse_crate(attrs)
     };
 
-    {
-        topmod: doc::ModDoc_({
-            item: {
+    doc::CrateDoc {
+        topmod: doc::ModDoc_(doc::ModDoc_ {
+            item: doc::ItemDoc {
                 name: option::get_or_default(attrs.name, doc.topmod.name()),
                 .. doc.topmod.item
             },
@@ -103,7 +103,7 @@ fn fold_item(
         parse_item_attrs(srv, doc.id, attr_parser::parse_desc)
     };
 
-    {
+    doc::ItemDoc {
         desc: desc,
         .. doc
     }
@@ -162,7 +162,7 @@ fn fold_enum(
     let doc_id = doc.id();
     let doc = fold::default_seq_fold_enum(fold, doc);
 
-    {
+    doc::EnumDoc {
         variants: do par::map(doc.variants) |variant| {
             let variant = *variant;
             let desc = do astsrv::exec(srv) |ctxt| {
@@ -182,7 +182,7 @@ fn fold_enum(
                 }
             };
 
-            {
+            doc::VariantDoc {
                 desc: desc,
                 .. variant
             }
@@ -211,7 +211,7 @@ fn fold_trait(
     let srv = fold.ctxt;
     let doc = fold::default_seq_fold_trait(fold, doc);
 
-    {
+    doc::TraitDoc {
         methods: merge_method_attrs(srv, doc.id(), doc.methods),
         .. doc
     }
@@ -256,7 +256,7 @@ fn merge_method_attrs(
         assert doc.name == attrs.first();
         let desc = attrs.second();
 
-        {
+        doc::MethodDoc {
             desc: desc,
             ..*doc
         }
@@ -287,7 +287,7 @@ fn fold_impl(
     let srv = fold.ctxt;
     let doc = fold::default_seq_fold_impl(fold, doc);
 
-    {
+    doc::ImplDoc {
         methods: merge_method_attrs(srv, doc.id(), doc.methods),
         .. doc
     }
diff --git a/src/librustdoc/config.rs b/src/librustdoc/config.rs
index ebd5c047df3..0ad048d49bb 100644
--- a/src/librustdoc/config.rs
+++ b/src/librustdoc/config.rs
@@ -50,13 +50,13 @@ impl OutputStyle : cmp::Eq {
 }
 
 /// The configuration for a rustdoc session
-pub type Config = {
+pub struct Config {
     input_crate: Path,
     output_dir: Path,
     output_format: OutputFormat,
     output_style: OutputStyle,
     pandoc_cmd: Option<~str>
-};
+}
 
 pub impl Config: Clone {
     fn clone(&self) -> Config { copy *self }
@@ -95,7 +95,7 @@ pub fn usage() {
 }
 
 pub fn default_config(input_crate: &Path) -> Config {
-    {
+    Config {
         input_crate: *input_crate,
         output_dir: Path("."),
         output_format: PandocHtml,
@@ -155,7 +155,7 @@ fn config_from_opts(
     let result = do result::chain(result) |config| {
         let output_dir = getopts::opt_maybe_str(matches, opt_output_dir());
         let output_dir = output_dir.map(|s| Path(*s));
-        result::Ok({
+        result::Ok(Config {
             output_dir: output_dir.get_or_default(config.output_dir),
             .. config
         })
@@ -168,7 +168,7 @@ fn config_from_opts(
             do result::chain(parse_output_format(*output_format))
                 |output_format| {
 
-                result::Ok({
+                result::Ok(Config {
                     output_format: output_format,
                     .. config
                 })
@@ -182,7 +182,7 @@ fn config_from_opts(
             |output_style| {
             do result::chain(parse_output_style(*output_style))
                 |output_style| {
-                result::Ok({
+                result::Ok(Config {
                     output_style: output_style,
                     .. config
                 })
@@ -195,7 +195,7 @@ fn config_from_opts(
         let pandoc_cmd = maybe_find_pandoc(
             &config, pandoc_cmd, move program_output.take());
         do result::chain(pandoc_cmd) |pandoc_cmd| {
-            result::Ok({
+            result::Ok(Config {
                 pandoc_cmd: pandoc_cmd,
                 .. config
             })
diff --git a/src/librustdoc/desc_to_brief_pass.rs b/src/librustdoc/desc_to_brief_pass.rs
index f53e0058b63..93f4be10a5c 100644
--- a/src/librustdoc/desc_to_brief_pass.rs
+++ b/src/librustdoc/desc_to_brief_pass.rs
@@ -51,7 +51,7 @@ pub fn run(
 fn fold_item(fold: &fold::Fold<()>, +doc: doc::ItemDoc) -> doc::ItemDoc {
     let doc = fold::default_seq_fold_item(fold, doc);
 
-    {
+    doc::ItemDoc {
         brief: extract(doc.desc),
         .. doc
     }
@@ -60,8 +60,8 @@ fn fold_item(fold: &fold::Fold<()>, +doc: doc::ItemDoc) -> doc::ItemDoc {
 fn fold_trait(fold: &fold::Fold<()>, +doc: doc::TraitDoc) -> doc::TraitDoc {
     let doc =fold::default_seq_fold_trait(fold, doc);
 
-    {
-        methods: par::map(doc.methods, |doc| {
+    doc::TraitDoc {
+        methods: par::map(doc.methods, |doc| doc::MethodDoc {
             brief: extract(doc.desc),
             .. *doc
         }),
@@ -72,8 +72,8 @@ fn fold_trait(fold: &fold::Fold<()>, +doc: doc::TraitDoc) -> doc::TraitDoc {
 fn fold_impl(fold: &fold::Fold<()>, +doc: doc::ImplDoc) -> doc::ImplDoc {
     let doc =fold::default_seq_fold_impl(fold, doc);
 
-    {
-        methods: par::map(doc.methods, |doc| {
+    doc::ImplDoc {
+        methods: par::map(doc.methods, |doc| doc::MethodDoc {
             brief: extract(doc.desc),
             .. *doc
         }),
diff --git a/src/librustdoc/doc.rs b/src/librustdoc/doc.rs
index 18742720b90..247694fb26a 100644
--- a/src/librustdoc/doc.rs
+++ b/src/librustdoc/doc.rs
@@ -21,94 +21,47 @@ use core::vec;
 
 pub type AstId = int;
 
-pub type Doc_ = {
+#[deriving_eq]
+pub struct Doc_ {
     pages: ~[Page]
-};
-
-impl Doc_ : cmp::Eq {
-    pure fn eq(&self, other: &Doc_) -> bool {
-        (*self).pages == (*other).pages
-    }
-    pure fn ne(&self, other: &Doc_) -> bool { !(*self).eq(other) }
 }
 
+#[deriving_eq]
 pub enum Doc {
     Doc_(Doc_)
 }
 
-impl Doc : cmp::Eq {
-    pure fn eq(&self, other: &Doc) -> bool { *(*self) == *(*other) }
-    pure fn ne(&self, other: &Doc) -> bool { *(*self) != *(*other) }
-}
-
+#[deriving_eq]
 pub enum Page {
     CratePage(CrateDoc),
     ItemPage(ItemTag)
 }
 
-impl Page : cmp::Eq {
-    pure fn eq(&self, other: &Page) -> bool {
-        match (*self) {
-            CratePage(e0a) => {
-                match (*other) {
-                    CratePage(e0b) => e0a == e0b,
-                    _ => false
-                }
-            }
-            ItemPage(e0a) => {
-                match (*other) {
-                    ItemPage(e0b) => e0a == e0b,
-                    _ => false
-                }
-            }
-        }
-    }
-    pure fn ne(&self, other: &Page) -> bool { !(*self).eq(other) }
-}
-
+#[deriving_eq]
 pub enum Implementation {
     Required,
     Provided,
 }
 
-impl Implementation : cmp::Eq {
-    pure fn eq(&self, other: &Implementation) -> bool {
-        ((*self) as uint) == ((*other) as uint)
-    }
-    pure fn ne(&self, other: &Implementation) -> bool { !(*self).eq(other) }
-}
-
-
 /**
  * Most rustdocs can be parsed into 'sections' according to their markdown
  * headers
  */
-pub type Section = {
+#[deriving_eq]
+pub struct Section {
     header: ~str,
     body: ~str
-};
-
-impl Section : cmp::Eq {
-    pure fn eq(&self, other: &Section) -> bool {
-        (*self).header == (*other).header && (*self).body == (*other).body
-    }
-    pure fn ne(&self, other: &Section) -> bool { !(*self).eq(other) }
 }
 
 // FIXME (#2596): We currently give topmod the name of the crate.  There
 // would probably be fewer special cases if the crate had its own name
 // and topmod's name was the empty string.
-pub type CrateDoc = {
-    topmod: ModDoc,
-};
-
-impl CrateDoc : cmp::Eq {
-    pure fn eq(&self, other: &CrateDoc) -> bool {
-        (*self).topmod == (*other).topmod
-    }
-    pure fn ne(&self, other: &CrateDoc) -> bool { !(*self).eq(other) }
+#[deriving_eq]
+pub struct CrateDoc {
+    topmod: ModDoc
 }
 
+#[deriving_eq]
 pub enum ItemTag {
     ModTag(ModDoc),
     NmodTag(NmodDoc),
@@ -121,69 +74,8 @@ pub enum ItemTag {
     StructTag(StructDoc)
 }
 
-impl ItemTag : cmp::Eq {
-    pure fn eq(&self, other: &ItemTag) -> bool {
-        match (*self) {
-            ModTag(e0a) => {
-                match (*other) {
-                    ModTag(e0b) => e0a == e0b,
-                    _ => false
-                }
-            }
-            NmodTag(e0a) => {
-                match (*other) {
-                    NmodTag(e0b) => e0a == e0b,
-                    _ => false
-                }
-            }
-            ConstTag(e0a) => {
-                match (*other) {
-                    ConstTag(e0b) => e0a == e0b,
-                    _ => false
-                }
-            }
-            FnTag(e0a) => {
-                match (*other) {
-                    FnTag(e0b) => e0a == e0b,
-                    _ => false
-                }
-            }
-            EnumTag(e0a) => {
-                match (*other) {
-                    EnumTag(e0b) => e0a == e0b,
-                    _ => false
-                }
-            }
-            TraitTag(e0a) => {
-                match (*other) {
-                    TraitTag(e0b) => e0a == e0b,
-                    _ => false
-                }
-            }
-            ImplTag(e0a) => {
-                match (*other) {
-                    ImplTag(e0b) => e0a == e0b,
-                    _ => false
-                }
-            }
-            TyTag(e0a) => {
-                match (*other) {
-                    TyTag(e0b) => e0a == e0b,
-                    _ => false
-                }
-            }
-            StructTag(e0a) => {
-                match (*other) {
-                    StructTag(e0b) => e0a == e0b,
-                    _ => false
-                }
-            }
-        }
-    }
-    pure fn ne(&self, other: &ItemTag) -> bool { !(*self).eq(other) }
-}
-
-pub type ItemDoc = {
+#[deriving_eq]
+pub struct ItemDoc {
     id: AstId,
     name: ~str,
     path: ~[~str],
@@ -192,179 +84,86 @@ pub type ItemDoc = {
     sections: ~[Section],
     // Indicates that this node is a reexport of a different item
     reexport: bool
-};
-
-impl ItemDoc : cmp::Eq {
-    pure fn eq(&self, other: &ItemDoc) -> bool {
-        (*self).id == (*other).id &&
-        (*self).name == (*other).name &&
-        (*self).path == (*other).path &&
-        (*self).brief == (*other).brief &&
-        (*self).desc == (*other).desc &&
-        (*self).sections == (*other).sections &&
-        (*self).reexport == (*other).reexport
-    }
-    pure fn ne(&self, other: &ItemDoc) -> bool { !(*self).eq(other) }
 }
 
-pub type SimpleItemDoc = {
+#[deriving_eq]
+pub struct SimpleItemDoc {
     item: ItemDoc,
     sig: Option<~str>
-};
-
-impl SimpleItemDoc : cmp::Eq {
-    pure fn eq(&self, other: &SimpleItemDoc) -> bool {
-        (*self).item == (*other).item && (*self).sig == (*other).sig
-    }
-    pure fn ne(&self, other: &SimpleItemDoc) -> bool { !(*self).eq(other) }
 }
 
-pub type ModDoc_ = {
+#[deriving_eq]
+pub struct ModDoc_ {
     item: ItemDoc,
     items: ~[ItemTag],
     index: Option<Index>
-};
-
-impl ModDoc_ : cmp::Eq {
-    pure fn eq(&self, other: &ModDoc_) -> bool {
-        (*self).item == (*other).item &&
-        (*self).items == (*other).items &&
-        (*self).index == (*other).index
-    }
-    pure fn ne(&self, other: &ModDoc_) -> bool { !(*self).eq(other) }
 }
 
+#[deriving_eq]
 pub enum ModDoc {
     ModDoc_(ModDoc_)
 }
 
-impl ModDoc : cmp::Eq {
-    pure fn eq(&self, other: &ModDoc) -> bool { *(*self) == *(*other) }
-    pure fn ne(&self, other: &ModDoc) -> bool { *(*self) != *(*other) }
-}
-
-pub type NmodDoc = {
+#[deriving_eq]
+pub struct NmodDoc {
     item: ItemDoc,
     fns: ~[FnDoc],
     index: Option<Index>
-};
-
-impl NmodDoc : cmp::Eq {
-    pure fn eq(&self, other: &NmodDoc) -> bool {
-        (*self).item == (*other).item &&
-        (*self).fns == (*other).fns &&
-        (*self).index == (*other).index
-    }
-    pure fn ne(&self, other: &NmodDoc) -> bool { !(*self).eq(other) }
 }
 
 pub type ConstDoc = SimpleItemDoc;
 
 pub type FnDoc = SimpleItemDoc;
 
-pub type EnumDoc = {
+#[deriving_eq]
+pub struct EnumDoc {
     item: ItemDoc,
     variants: ~[VariantDoc]
-};
-
-impl EnumDoc : cmp::Eq {
-    pure fn eq(&self, other: &EnumDoc) -> bool {
-        (*self).item == (*other).item && (*self).variants == (*other).variants
-    }
-    pure fn ne(&self, other: &EnumDoc) -> bool { !(*self).eq(other) }
 }
 
-pub type VariantDoc = {
+#[deriving_eq]
+pub struct VariantDoc {
     name: ~str,
     desc: Option<~str>,
     sig: Option<~str>
-};
-
-impl VariantDoc : cmp::Eq {
-    pure fn eq(&self, other: &VariantDoc) -> bool {
-        (*self).name == (*other).name &&
-        (*self).desc == (*other).desc &&
-        (*self).sig == (*other).sig
-    }
-    pure fn ne(&self, other: &VariantDoc) -> bool { !(*self).eq(other) }
 }
 
-pub type TraitDoc = {
+#[deriving_eq]
+pub struct TraitDoc {
     item: ItemDoc,
     methods: ~[MethodDoc]
-};
-
-impl TraitDoc : cmp::Eq {
-    pure fn eq(&self, other: &TraitDoc) -> bool {
-        (*self).item == (*other).item && (*self).methods == (*other).methods
-    }
-    pure fn ne(&self, other: &TraitDoc) -> bool { !(*self).eq(other) }
 }
 
-pub type MethodDoc = {
+#[deriving_eq]
+pub struct MethodDoc {
     name: ~str,
     brief: Option<~str>,
     desc: Option<~str>,
     sections: ~[Section],
     sig: Option<~str>,
     implementation: Implementation,
-};
-
-impl MethodDoc : cmp::Eq {
-    pure fn eq(&self, other: &MethodDoc) -> bool {
-        (*self).name == (*other).name &&
-        (*self).brief == (*other).brief &&
-        (*self).desc == (*other).desc &&
-        (*self).sections == (*other).sections &&
-        (*self).sig == (*other).sig &&
-        (*self).implementation == (*other).implementation
-    }
-    pure fn ne(&self, other: &MethodDoc) -> bool { !(*self).eq(other) }
 }
 
-pub type ImplDoc = {
+#[deriving_eq]
+pub struct ImplDoc {
     item: ItemDoc,
     trait_types: ~[~str],
     self_ty: Option<~str>,
     methods: ~[MethodDoc]
-};
-
-impl ImplDoc : cmp::Eq {
-    pure fn eq(&self, other: &ImplDoc) -> bool {
-        (*self).item == (*other).item &&
-        (*self).trait_types == (*other).trait_types &&
-        (*self).self_ty == (*other).self_ty &&
-        (*self).methods == (*other).methods
-    }
-    pure fn ne(&self, other: &ImplDoc) -> bool { !(*self).eq(other) }
 }
 
 pub type TyDoc = SimpleItemDoc;
 
-pub type StructDoc = {
+#[deriving_eq]
+pub struct StructDoc {
     item: ItemDoc,
     fields: ~[~str],
     sig: Option<~str>
-};
-
-impl StructDoc : cmp::Eq {
-    pure fn eq(&self, other: &StructDoc) -> bool {
-        return (*self).item == other.item
-            && (*self).fields == other.fields
-            && (*self).sig == other.sig;
-    }
-    pure fn ne(&self, other: &StructDoc) -> bool { !(*self).eq(other) }
 }
 
-pub type Index = {
+#[deriving_eq]
+pub struct Index {
     entries: ~[IndexEntry]
-};
-
-impl Index : cmp::Eq {
-    pure fn eq(&self, other: &Index) -> bool {
-        (*self).entries == (*other).entries
-    }
-    pure fn ne(&self, other: &Index) -> bool { !(*self).eq(other) }
 }
 
 /**
@@ -377,21 +176,12 @@ impl Index : cmp::Eq {
  * * brief - The brief description
  * * link - A format-specific string representing the link target
  */
-pub type IndexEntry = {
+#[deriving_eq]
+pub struct IndexEntry {
     kind: ~str,
     name: ~str,
     brief: Option<~str>,
     link: ~str
-};
-
-impl IndexEntry : cmp::Eq {
-    pure fn eq(&self, other: &IndexEntry) -> bool {
-        (*self).kind == (*other).kind &&
-        (*self).name == (*other).name &&
-        (*self).brief == (*other).brief &&
-        (*self).link == (*other).link
-    }
-    pure fn ne(&self, other: &IndexEntry) -> bool { !(*self).eq(other) }
 }
 
 impl Doc {
@@ -411,7 +201,6 @@ impl Doc {
 
 /// Some helper methods on ModDoc, mostly for testing
 impl ModDoc {
-
     fn mods() -> ~[ModDoc] {
         do vec::filter_map(self.items) |itemtag| {
             match *itemtag {
diff --git a/src/librustdoc/extract.rs b/src/librustdoc/extract.rs
index 444949cfb7f..93226cb5ed8 100644
--- a/src/librustdoc/extract.rs
+++ b/src/librustdoc/extract.rs
@@ -57,9 +57,9 @@ pub fn extract(
     crate: @ast::crate,
     +default_name: ~str
 ) -> doc::Doc {
-    doc::Doc_({
+    doc::Doc_(doc::Doc_ {
         pages: ~[
-            doc::CratePage({
+            doc::CratePage(doc::CrateDoc {
                 topmod: top_moddoc_from_crate(crate, default_name),
             })
         ]
@@ -75,7 +75,7 @@ fn top_moddoc_from_crate(
 }
 
 fn mk_itemdoc(id: ast::node_id, +name: ~str) -> doc::ItemDoc {
-    {
+    doc::ItemDoc {
         id: id,
         name: name,
         path: ~[],
@@ -90,7 +90,7 @@ fn moddoc_from_mod(
     +itemdoc: doc::ItemDoc,
     module_: ast::_mod
 ) -> doc::ModDoc {
-    doc::ModDoc_({
+    doc::ModDoc_(doc::ModDoc_ {
         item: itemdoc,
         items: do vec::filter_map(module_.items) |item| {
             let ItemDoc = mk_itemdoc(item.id, to_str(item.ident));
@@ -161,7 +161,7 @@ fn nmoddoc_from_mod(
           ast::foreign_item_const(*) => {} // XXX: Not implemented.
         }
     }
-    {
+    doc:: NmodDoc {
         item: itemdoc,
         fns: fns,
         index: None
@@ -169,14 +169,14 @@ fn nmoddoc_from_mod(
 }
 
 fn fndoc_from_fn(+itemdoc: doc::ItemDoc) -> doc::FnDoc {
-    {
+    doc::SimpleItemDoc {
         item: itemdoc,
         sig: None
     }
 }
 
 fn constdoc_from_const(+itemdoc: doc::ItemDoc) -> doc::ConstDoc {
-    {
+    doc::SimpleItemDoc {
         item: itemdoc,
         sig: None
     }
@@ -193,7 +193,7 @@ fn enumdoc_from_enum(
     +itemdoc: doc::ItemDoc,
     +variants: ~[ast::variant]
 ) -> doc::EnumDoc {
-    {
+    doc::EnumDoc {
         item: itemdoc,
         variants: variantdocs_from_variants(variants)
     }
@@ -206,8 +206,7 @@ fn variantdocs_from_variants(
 }
 
 fn variantdoc_from_variant(variant: &ast::variant) -> doc::VariantDoc {
-
-    {
+    doc::VariantDoc {
         name: to_str(variant.node.name),
         desc: None,
         sig: None
@@ -231,12 +230,12 @@ fn traitdoc_from_trait(
     +itemdoc: doc::ItemDoc,
     +methods: ~[ast::trait_method]
 ) -> doc::TraitDoc {
-    {
+    doc::TraitDoc {
         item: itemdoc,
         methods: do vec::map(methods) |method| {
             match *method {
               ast::required(ty_m) => {
-                {
+                doc::MethodDoc {
                     name: to_str(ty_m.ident),
                     brief: None,
                     desc: None,
@@ -246,7 +245,7 @@ fn traitdoc_from_trait(
                 }
               }
               ast::provided(m) => {
-                {
+                doc::MethodDoc {
                     name: to_str(m.ident),
                     brief: None,
                     desc: None,
@@ -276,12 +275,12 @@ fn impldoc_from_impl(
     +itemdoc: doc::ItemDoc,
     methods: ~[@ast::method]
 ) -> doc::ImplDoc {
-    {
+    doc::ImplDoc {
         item: itemdoc,
         trait_types: ~[],
         self_ty: None,
         methods: do vec::map(methods) |method| {
-            {
+            doc::MethodDoc {
                 name: to_str(method.ident),
                 brief: None,
                 desc: None,
@@ -302,7 +301,7 @@ fn should_extract_impl_methods() {
 fn tydoc_from_ty(
     +itemdoc: doc::ItemDoc
 ) -> doc::TyDoc {
-    {
+    doc::SimpleItemDoc {
         item: itemdoc,
         sig: None
     }
@@ -318,7 +317,7 @@ fn structdoc_from_struct(
     +itemdoc: doc::ItemDoc,
     struct_def: @ast::struct_def
 ) -> doc::StructDoc {
-    {
+    doc::StructDoc {
         item: itemdoc,
         fields: do struct_def.fields.map |field| {
             match field.node.kind {
diff --git a/src/librustdoc/fold.rs b/src/librustdoc/fold.rs
index 29c53e0af25..f352ed7f7e7 100644
--- a/src/librustdoc/fold.rs
+++ b/src/librustdoc/fold.rs
@@ -158,7 +158,7 @@ pub fn default_par_fold<T:Owned Clone>(+ctxt: T) -> Fold<T> {
 }
 
 pub fn default_seq_fold_doc<T>(fold: &Fold<T>, +doc: doc::Doc) -> doc::Doc {
-    doc::Doc_({
+    doc::Doc_(doc::Doc_ {
         pages: do vec::map(doc.pages) |page| {
             match *page {
               doc::CratePage(doc) => {
@@ -177,7 +177,7 @@ pub fn default_seq_fold_crate<T>(
     fold: &Fold<T>,
     +doc: doc::CrateDoc
 ) -> doc::CrateDoc {
-    {
+    doc::CrateDoc {
         topmod: (fold.fold_mod)(fold, doc.topmod)
     }
 }
@@ -194,7 +194,7 @@ pub fn default_any_fold_mod<T:Owned Clone>(
     +doc: doc::ModDoc
 ) -> doc::ModDoc {
     let fold_copy = fold.clone();
-    doc::ModDoc_({
+    doc::ModDoc_(doc::ModDoc_ {
         item: (fold.fold_item)(fold, doc.item),
         items: par::map(doc.items, |ItemTag, move fold_copy| {
             fold_ItemTag(&fold_copy, *ItemTag)
@@ -207,7 +207,7 @@ pub fn default_seq_fold_mod<T>(
     fold: &Fold<T>,
     +doc: doc::ModDoc
 ) -> doc::ModDoc {
-    doc::ModDoc_({
+    doc::ModDoc_(doc::ModDoc_ {
         item: (fold.fold_item)(fold, doc.item),
         items: vec::map(doc.items, |ItemTag| {
             fold_ItemTag(fold, *ItemTag)
@@ -221,7 +221,7 @@ pub fn default_par_fold_mod<T:Owned Clone>(
     +doc: doc::ModDoc
 ) -> doc::ModDoc {
     let fold_copy = fold.clone();
-    doc::ModDoc_({
+    doc::ModDoc_(doc::ModDoc_ {
         item: (fold.fold_item)(fold, doc.item),
         items: par::map(doc.items, |ItemTag, move fold_copy| {
             fold_ItemTag(&fold_copy, *ItemTag)
@@ -235,7 +235,7 @@ pub fn default_any_fold_nmod<T:Owned Clone>(
     +doc: doc::NmodDoc
 ) -> doc::NmodDoc {
     let fold_copy = fold.clone();
-    {
+    doc::NmodDoc {
         item: (fold.fold_item)(fold, doc.item),
         fns: par::map(doc.fns, |FnDoc, move fold_copy| {
             (fold_copy.fold_fn)(&fold_copy, *FnDoc)
@@ -248,7 +248,7 @@ pub fn default_seq_fold_nmod<T>(
     fold: &Fold<T>,
     +doc: doc::NmodDoc
 ) -> doc::NmodDoc {
-    {
+    doc::NmodDoc {
         item: (fold.fold_item)(fold, doc.item),
         fns: vec::map(doc.fns, |FnDoc| {
             (fold.fold_fn)(fold, *FnDoc)
@@ -262,7 +262,7 @@ pub fn default_par_fold_nmod<T:Owned Clone>(
     +doc: doc::NmodDoc
 ) -> doc::NmodDoc {
     let fold_copy = fold.clone();
-    {
+    doc::NmodDoc {
         item: (fold.fold_item)(fold, doc.item),
         fns: par::map(doc.fns, |FnDoc, move fold_copy| {
             (fold_copy.fold_fn)(&fold_copy, *FnDoc)
@@ -307,7 +307,7 @@ pub fn default_seq_fold_fn<T>(
     fold: &Fold<T>,
     +doc: doc::FnDoc
 ) -> doc::FnDoc {
-    {
+    doc::SimpleItemDoc {
         item: (fold.fold_item)(fold, doc.item),
         .. doc
     }
@@ -317,7 +317,7 @@ pub fn default_seq_fold_const<T>(
     fold: &Fold<T>,
     +doc: doc::ConstDoc
 ) -> doc::ConstDoc {
-    {
+    doc::SimpleItemDoc {
         item: (fold.fold_item)(fold, doc.item),
         .. doc
     }
@@ -327,7 +327,7 @@ pub fn default_seq_fold_enum<T>(
     fold: &Fold<T>,
     +doc: doc::EnumDoc
 ) -> doc::EnumDoc {
-    {
+    doc::EnumDoc {
         item: (fold.fold_item)(fold, doc.item),
         .. doc
     }
@@ -337,7 +337,7 @@ pub fn default_seq_fold_trait<T>(
     fold: &Fold<T>,
     +doc: doc::TraitDoc
 ) -> doc::TraitDoc {
-    {
+    doc::TraitDoc {
         item: (fold.fold_item)(fold, doc.item),
         .. doc
     }
@@ -347,7 +347,7 @@ pub fn default_seq_fold_impl<T>(
     fold: &Fold<T>,
     +doc: doc::ImplDoc
 ) -> doc::ImplDoc {
-    {
+    doc::ImplDoc {
         item: (fold.fold_item)(fold, doc.item),
         .. doc
     }
@@ -357,7 +357,7 @@ pub fn default_seq_fold_type<T>(
     fold: &Fold<T>,
     +doc: doc::TyDoc
 ) -> doc::TyDoc {
-    {
+    doc::SimpleItemDoc {
         item: (fold.fold_item)(fold, doc.item),
         .. doc
     }
@@ -367,7 +367,7 @@ pub fn default_seq_fold_struct<T>(
     fold: &Fold<T>,
     +doc: doc::StructDoc
 ) -> doc::StructDoc {
-    {
+    doc::StructDoc {
         item: (fold.fold_item)(fold, doc.item),
         .. doc
     }
diff --git a/src/librustdoc/markdown_index_pass.rs b/src/librustdoc/markdown_index_pass.rs
index 1f4e1be62fc..b0b4278a91e 100644
--- a/src/librustdoc/markdown_index_pass.rs
+++ b/src/librustdoc/markdown_index_pass.rs
@@ -54,7 +54,7 @@ fn fold_mod(
 
     let doc = fold::default_any_fold_mod(fold, doc);
 
-    doc::ModDoc_({
+    doc::ModDoc_(doc::ModDoc_ {
         index: Some(build_mod_index(doc, fold.ctxt)),
         .. *doc
     })
@@ -67,7 +67,7 @@ fn fold_nmod(
 
     let doc = fold::default_any_fold_nmod(fold, doc);
 
-    {
+    doc::NmodDoc {
         index: Some(build_nmod_index(doc, fold.ctxt)),
         .. doc
     }
@@ -77,7 +77,7 @@ fn build_mod_index(
     +doc: doc::ModDoc,
     +config: config::Config
 ) -> doc::Index {
-    {
+    doc::Index {
         entries: par::map(doc.items, |doc| {
             item_to_entry(*doc, config)
         })
@@ -88,7 +88,7 @@ fn build_nmod_index(
     +doc: doc::NmodDoc,
     +config: config::Config
 ) -> doc::Index {
-    {
+    doc::Index {
         entries: par::map(doc.fns, |doc| {
             item_to_entry(doc::FnTag(*doc), config)
         })
@@ -109,7 +109,7 @@ fn item_to_entry(
       }
     };
 
-    {
+    doc::IndexEntry {
         kind: markdown_pass::header_kind(doc),
         name: markdown_pass::header_name(doc),
         brief: doc.brief(),
diff --git a/src/librustdoc/page_pass.rs b/src/librustdoc/page_pass.rs
index 2629d45635e..d121d7e8478 100644
--- a/src/librustdoc/page_pass.rs
+++ b/src/librustdoc/page_pass.rs
@@ -76,7 +76,7 @@ fn make_doc_from_pages(page_port: PagePort) -> doc::Doc {
             break;
         }
     }
-    doc::Doc_({
+    doc::Doc_(doc::Doc_ {
         pages: pages
     })
 }
@@ -100,7 +100,7 @@ fn fold_crate(
 
     let doc = fold::default_seq_fold_crate(fold, doc);
 
-    let page = doc::CratePage({
+    let page = doc::CratePage(doc::CrateDoc {
         topmod: strip_mod(doc.topmod),
         .. doc
     });
@@ -128,7 +128,7 @@ fn fold_mod(
 }
 
 fn strip_mod(doc: doc::ModDoc) -> doc::ModDoc {
-    doc::ModDoc_({
+    doc::ModDoc_(doc::ModDoc_ {
         items: do doc.items.filtered |item| {
             match *item {
               doc::ModTag(_) => false,
diff --git a/src/librustdoc/path_pass.rs b/src/librustdoc/path_pass.rs
index 48ed1878771..bc69ea7ed5a 100644
--- a/src/librustdoc/path_pass.rs
+++ b/src/librustdoc/path_pass.rs
@@ -54,7 +54,7 @@ fn run(srv: astsrv::Srv, +doc: doc::Doc) -> doc::Doc {
 }
 
 fn fold_item(fold: &fold::Fold<Ctxt>, +doc: doc::ItemDoc) -> doc::ItemDoc {
-    {
+    doc::ItemDoc {
         path: fold.ctxt.path,
         .. doc
     }
@@ -68,7 +68,7 @@ fn fold_mod(fold: &fold::Fold<Ctxt>, +doc: doc::ModDoc) -> doc::ModDoc {
     let doc = fold::default_any_fold_mod(fold, doc);
     if !is_topmod { fold.ctxt.path.pop(); }
 
-    doc::ModDoc_({
+    doc::ModDoc_(doc::ModDoc_ {
         item: (fold.fold_item)(fold, doc.item),
         .. *doc
     })
@@ -79,7 +79,7 @@ fn fold_nmod(fold: &fold::Fold<Ctxt>, +doc: doc::NmodDoc) -> doc::NmodDoc {
     let doc = fold::default_seq_fold_nmod(fold, doc);
     fold.ctxt.path.pop();
 
-    {
+    doc::NmodDoc {
         item: (fold.fold_item)(fold, doc.item),
         .. doc
     }
diff --git a/src/librustdoc/prune_hidden_pass.rs b/src/librustdoc/prune_hidden_pass.rs
index 3a924e3bddf..c3d31d4a5b0 100644
--- a/src/librustdoc/prune_hidden_pass.rs
+++ b/src/librustdoc/prune_hidden_pass.rs
@@ -42,7 +42,7 @@ fn fold_mod(
 ) -> doc::ModDoc {
     let doc = fold::default_any_fold_mod(fold, doc);
 
-    doc::ModDoc_({
+    doc::ModDoc_(doc::ModDoc_ {
         items: do doc.items.filtered |ItemTag| {
             !is_hidden(fold.ctxt, ItemTag.item())
         },
diff --git a/src/librustdoc/prune_private_pass.rs b/src/librustdoc/prune_private_pass.rs
index 3b11437aceb..a18530a7460 100644
--- a/src/librustdoc/prune_private_pass.rs
+++ b/src/librustdoc/prune_private_pass.rs
@@ -48,7 +48,7 @@ fn fold_mod(
 ) -> doc::ModDoc {
     let doc = fold::default_any_fold_mod(fold, doc);
 
-    doc::ModDoc_({
+    doc::ModDoc_(doc::ModDoc_ {
         items: doc.items.filtered(|ItemTag| {
             is_visible(fold.ctxt, ItemTag.item())
         }),
diff --git a/src/librustdoc/sectionalize_pass.rs b/src/librustdoc/sectionalize_pass.rs
index eeadd82371f..706aecf49b9 100644
--- a/src/librustdoc/sectionalize_pass.rs
+++ b/src/librustdoc/sectionalize_pass.rs
@@ -46,7 +46,7 @@ fn fold_item(fold: &fold::Fold<()>, +doc: doc::ItemDoc) -> doc::ItemDoc {
     let doc = fold::default_seq_fold_item(fold, doc);
     let (desc, sections) = sectionalize(doc.desc);
 
-    {
+    doc::ItemDoc {
         desc: desc,
         sections: sections,
         .. doc
@@ -56,11 +56,11 @@ fn fold_item(fold: &fold::Fold<()>, +doc: doc::ItemDoc) -> doc::ItemDoc {
 fn fold_trait(fold: &fold::Fold<()>, +doc: doc::TraitDoc) -> doc::TraitDoc {
     let doc = fold::default_seq_fold_trait(fold, doc);
 
-    {
+    doc::TraitDoc {
         methods: do par::map(doc.methods) |method| {
             let (desc, sections) = sectionalize(method.desc);
 
-            {
+            doc::MethodDoc {
                 desc: desc,
                 sections: sections,
                 .. *method
@@ -73,11 +73,11 @@ fn fold_trait(fold: &fold::Fold<()>, +doc: doc::TraitDoc) -> doc::TraitDoc {
 fn fold_impl(fold: &fold::Fold<()>, +doc: doc::ImplDoc) -> doc::ImplDoc {
     let doc = fold::default_seq_fold_impl(fold, doc);
 
-    {
+    doc::ImplDoc {
         methods: do par::map(doc.methods) |method| {
             let (desc, sections) = sectionalize(method.desc);
 
-            {
+            doc::MethodDoc {
                 desc: desc,
                 sections: sections,
                 .. *method
@@ -121,7 +121,7 @@ fn sectionalize(desc: Option<~str>) -> (Option<~str>, ~[doc::Section]) {
             if current_section.is_some() {
                 sections += ~[current_section.get()];
             }
-            current_section = Some({
+            current_section = Some(doc::Section {
                 header: header,
                 body: ~""
             });
@@ -129,7 +129,7 @@ fn sectionalize(desc: Option<~str>) -> (Option<~str>, ~[doc::Section]) {
           None => {
             match copy current_section {
               Some(section) => {
-                current_section = Some({
+                current_section = Some(doc::Section {
                     body: section.body + ~"\n" + *line,
                     .. section
                 });
diff --git a/src/librustdoc/sort_pass.rs b/src/librustdoc/sort_pass.rs
index b3ecb8173fe..42759be68ad 100644
--- a/src/librustdoc/sort_pass.rs
+++ b/src/librustdoc/sort_pass.rs
@@ -55,7 +55,7 @@ fn fold_mod(
     +doc: doc::ModDoc
 ) -> doc::ModDoc {
     let doc = fold::default_any_fold_mod(fold, doc);
-    doc::ModDoc_({
+    doc::ModDoc_(doc::ModDoc_ {
         items: sort::merge_sort(doc.items, fold.ctxt.op),
         .. *doc
     })
diff --git a/src/librustdoc/text_pass.rs b/src/librustdoc/text_pass.rs
index 5627bfead9f..fb55641b764 100644
--- a/src/librustdoc/text_pass.rs
+++ b/src/librustdoc/text_pass.rs
@@ -62,7 +62,7 @@ fn fold_item(
 ) -> doc::ItemDoc {
     let doc = fold::default_seq_fold_item(fold, doc);
 
-    {
+    doc::ItemDoc {
         brief: maybe_apply_op(fold.ctxt, doc.brief),
         desc: maybe_apply_op(fold.ctxt, doc.desc),
         sections: apply_to_sections(fold.ctxt, doc.sections),
@@ -74,7 +74,7 @@ fn apply_to_sections(
     op: NominalOp<Op>,
     sections: ~[doc::Section]
 ) -> ~[doc::Section] {
-    par::map(sections, |section, copy op| {
+    par::map(sections, |section, copy op| doc::Section {
         header: (op.op)(section.header),
         body: (op.op)(section.body)
     })
@@ -86,9 +86,9 @@ fn fold_enum(
     let doc = fold::default_seq_fold_enum(fold, doc);
     let fold_copy = copy *fold;
 
-    {
+    doc::EnumDoc {
         variants: do par::map(doc.variants) |variant, copy fold_copy| {
-            {
+            doc::VariantDoc {
                 desc: maybe_apply_op(fold_copy.ctxt, variant.desc),
                 .. *variant
             }
@@ -103,7 +103,7 @@ fn fold_trait(
 ) -> doc::TraitDoc {
     let doc = fold::default_seq_fold_trait(fold, doc);
 
-    {
+    doc::TraitDoc {
         methods: apply_to_methods(fold.ctxt, doc.methods),
         .. doc
     }
@@ -114,7 +114,7 @@ fn apply_to_methods(
     docs: ~[doc::MethodDoc]
 ) -> ~[doc::MethodDoc] {
     do par::map(docs) |doc, copy op| {
-        {
+        doc::MethodDoc {
             brief: maybe_apply_op(op, doc.brief),
             desc: maybe_apply_op(op, doc.desc),
             sections: apply_to_sections(op, doc.sections),
@@ -129,7 +129,7 @@ fn fold_impl(
 ) -> doc::ImplDoc {
     let doc = fold::default_seq_fold_impl(fold, doc);
 
-    {
+    doc::ImplDoc {
         methods: apply_to_methods(fold.ctxt, doc.methods),
         .. doc
     }
diff --git a/src/librustdoc/tystr_pass.rs b/src/librustdoc/tystr_pass.rs
index 5d92ed14c18..3b9991d1827 100644
--- a/src/librustdoc/tystr_pass.rs
+++ b/src/librustdoc/tystr_pass.rs
@@ -59,7 +59,7 @@ fn fold_fn(
 
     let srv = fold.ctxt;
 
-    {
+    doc::SimpleItemDoc {
         sig: get_fn_sig(srv, doc.id()),
         .. doc
     }
@@ -101,7 +101,7 @@ fn fold_const(
 ) -> doc::ConstDoc {
     let srv = fold.ctxt;
 
-    {
+    doc::SimpleItemDoc {
         sig: Some(do astsrv::exec(srv) |ctxt| {
             match ctxt.ast_map.get(doc.id()) {
               ast_map::node_item(@ast::item {
@@ -129,7 +129,7 @@ fn fold_enum(
     let doc_id = doc.id();
     let srv = fold.ctxt;
 
-    {
+    doc::EnumDoc {
         variants: do par::map(doc.variants) |variant| {
             let variant = *variant;
             let sig = do astsrv::exec(srv) |ctxt| {
@@ -148,7 +148,7 @@ fn fold_enum(
                 }
             };
 
-            {
+            doc::VariantDoc {
                 sig: Some(sig),
                 .. variant
             }
@@ -167,7 +167,7 @@ fn fold_trait(
     fold: &fold::Fold<astsrv::Srv>,
     +doc: doc::TraitDoc
 ) -> doc::TraitDoc {
-    {
+    doc::TraitDoc {
         methods: merge_methods(fold.ctxt, doc.id(), doc.methods),
         .. doc
     }
@@ -179,7 +179,7 @@ fn merge_methods(
     docs: ~[doc::MethodDoc]
 ) -> ~[doc::MethodDoc] {
     do par::map(docs) |doc| {
-        {
+        doc::MethodDoc {
             sig: get_method_sig(srv, item_id, doc.name),
             .. *doc
         }
@@ -276,7 +276,7 @@ fn fold_impl(
         }
     };
 
-    {
+    doc::ImplDoc {
         trait_types: trait_types,
         self_ty: self_ty,
         methods: merge_methods(fold.ctxt, doc.id(), doc.methods),
@@ -316,7 +316,7 @@ fn fold_type(
 
     let srv = fold.ctxt;
 
-    {
+    doc::SimpleItemDoc {
         sig: do astsrv::exec(srv) |ctxt| {
             match ctxt.ast_map.get(doc.id()) {
               ast_map::node_item(@ast::item {
@@ -349,7 +349,7 @@ fn fold_struct(
 ) -> doc::StructDoc {
     let srv = fold.ctxt;
 
-    {
+    doc::StructDoc {
         sig: do astsrv::exec(srv) |ctxt| {
             match ctxt.ast_map.get(doc.id()) {
                 ast_map::node_item(item, _) => {
diff --git a/src/libstd/bigint.rs b/src/libstd/bigint.rs
index fc783429126..4283a7e402b 100644
--- a/src/libstd/bigint.rs
+++ b/src/libstd/bigint.rs
@@ -17,7 +17,7 @@ A BigInt is a combination of BigUint and Sign.
 */
 
 use core::cmp::{Eq, Ord};
-use core::num::{Num, Zero, One};
+use core::num::{IntConvertible, Zero, One};
 use core::*;
 
 /**
@@ -121,7 +121,7 @@ impl BigUint : One {
     static pub pure fn one() -> BigUint { BigUint::new(~[1]) }
 }
 
-impl BigUint : Num {
+impl BigUint : Add<BigUint, BigUint> {
     pure fn add(&self, other: &BigUint) -> BigUint {
         let new_len = uint::max(self.data.len(), other.data.len());
 
@@ -138,7 +138,9 @@ impl BigUint : Num {
         if carry == 0 { return BigUint::new(sum) };
         return BigUint::new(sum + [carry]);
     }
+}
 
+impl BigUint : Sub<BigUint, BigUint> {
     pure fn sub(&self, other: &BigUint) -> BigUint {
         let new_len = uint::max(self.data.len(), other.data.len());
 
@@ -161,7 +163,9 @@ impl BigUint : Num {
         assert borrow == 0;     // <=> assert (self >= other);
         return BigUint::new(diff);
     }
+}
 
+impl BigUint : Mul<BigUint, BigUint> {
     pure fn mul(&self, other: &BigUint) -> BigUint {
         if self.is_zero() || other.is_zero() { return Zero::zero(); }
 
@@ -224,18 +228,27 @@ impl BigUint : Num {
             }
         }
     }
+}
 
+impl BigUint : Div<BigUint, BigUint> {
     pure fn div(&self, other: &BigUint) -> BigUint {
         let (d, _) = self.divmod(other);
         return d;
     }
+}
+
+impl BigUint : Modulo<BigUint, BigUint> {
     pure fn modulo(&self, other: &BigUint) -> BigUint {
         let (_, m) = self.divmod(other);
         return m;
     }
+}
 
+impl BigUint : Neg<BigUint> {
     pure fn neg(&self) -> BigUint { fail }
+}
 
+impl BigUint : IntConvertible {
     pure fn to_int(&self) -> int {
         uint::min(self.to_uint(), int::max_value as uint) as int
     }
@@ -625,7 +638,7 @@ impl BigInt : One {
     }
 }
 
-impl BigInt : Num {
+impl BigInt : Add<BigInt, BigInt> {
     pure fn add(&self, other: &BigInt) -> BigInt {
         match (self.sign, other.sign) {
             (Zero, _)      => copy *other,
@@ -637,6 +650,9 @@ impl BigInt : Num {
             (Minus, Minus) => -((-self) + (-*other))
         }
     }
+}
+
+impl BigInt : Sub<BigInt, BigInt> {
     pure fn sub(&self, other: &BigInt) -> BigInt {
         match (self.sign, other.sign) {
             (Zero, _)    => -other,
@@ -654,6 +670,9 @@ impl BigInt : Num {
             (Minus, Minus) => (-other) - (-*self)
         }
     }
+}
+
+impl BigInt : Mul<BigInt, BigInt> {
     pure fn mul(&self, other: &BigInt) -> BigInt {
         match (self.sign, other.sign) {
             (Zero, _)     | (_,     Zero)  => Zero::zero(),
@@ -665,18 +684,29 @@ impl BigInt : Num {
             }
         }
     }
+}
+
+impl BigInt : Div<BigInt, BigInt> {
     pure fn div(&self, other: &BigInt) -> BigInt {
         let (d, _) = self.divmod(other);
         return d;
     }
+}
+
+impl BigInt : Modulo<BigInt, BigInt> {
     pure fn modulo(&self, other: &BigInt) -> BigInt {
         let (_, m) = self.divmod(other);
         return m;
     }
+}
+
+impl BigInt : Neg<BigInt> {
     pure fn neg(&self) -> BigInt {
         BigInt::from_biguint(self.sign.neg(), copy self.data)
     }
+}
 
+impl BigInt : IntConvertible {
     pure fn to_int(&self) -> int {
         match self.sign {
             Plus  => uint::min(self.to_uint(), int::max_value as uint) as int,
@@ -834,7 +864,7 @@ pub impl BigInt {
 mod biguint_tests {
 
     use core::*;
-    use core::num::{Num, Zero, One};
+    use num::{IntConvertible, Zero, One};
     use super::{BigInt, BigUint, BigDigit};
 
     #[test]
@@ -974,7 +1004,7 @@ mod biguint_tests {
     fn test_convert_int() {
         fn check(v: ~[BigDigit], i: int) {
             let b = BigUint::new(v);
-            assert b == Num::from_int(i);
+            assert b == IntConvertible::from_int(i);
             assert b.to_int() == i;
         }
 
@@ -1244,7 +1274,7 @@ mod bigint_tests {
     use super::{BigInt, BigUint, BigDigit, Sign, Minus, Zero, Plus};
 
     use core::*;
-    use core::num::{Num, Zero, One};
+    use core::num::{IntConvertible, Zero, One};
 
     #[test]
     fn test_from_biguint() {
@@ -1303,7 +1333,7 @@ mod bigint_tests {
     #[test]
     fn test_convert_int() {
         fn check(b: BigInt, i: int) {
-            assert b == Num::from_int(i);
+            assert b == IntConvertible::from_int(i);
             assert b.to_int() == i;
         }
 
@@ -1563,7 +1593,8 @@ mod bigint_tests {
     #[test]
     fn test_to_str_radix() {
         fn check(n: int, ans: &str) {
-            assert ans == Num::from_int::<BigInt>(n).to_str_radix(10);
+            assert ans == IntConvertible::from_int::<BigInt>(
+                n).to_str_radix(10);
         }
         check(10, "10");
         check(1, "1");
@@ -1576,7 +1607,7 @@ mod bigint_tests {
     #[test]
     fn test_from_str_radix() {
         fn check(s: &str, ans: Option<int>) {
-            let ans = ans.map(|&n| Num::from_int(n));
+            let ans = ans.map(|&n| IntConvertible::from_int(n));
             assert BigInt::from_str_radix(s, 10) == ans;
         }
         check("10", Some(10));
diff --git a/src/libstd/deque.rs b/src/libstd/deque.rs
index b4217dfb39d..2abd59523a1 100644
--- a/src/libstd/deque.rs
+++ b/src/libstd/deque.rs
@@ -249,69 +249,19 @@ mod tests {
         assert deq.get(3) == d;
     }
 
+    #[deriving_eq]
     enum Taggy { One(int), Two(int, int), Three(int, int, int), }
 
+    #[deriving_eq]
     enum Taggypar<T> {
         Onepar(int), Twopar(int, int), Threepar(int, int, int),
     }
 
+    #[deriving_eq]
     struct RecCy {
         x: int,
         y: int,
-        t: Taggy,
-    }
-
-    impl Taggy : Eq {
-        pure fn eq(&self, other: &Taggy) -> bool {
-            match (*self) {
-              One(a1) => match (*other) {
-                One(b1) => return a1 == b1,
-                _ => return false
-              },
-              Two(a1, a2) => match (*other) {
-                Two(b1, b2) => return a1 == b1 && a2 == b2,
-                _ => return false
-              },
-              Three(a1, a2, a3) => match (*other) {
-                Three(b1, b2, b3) => return a1 == b1 && a2 == b2 && a3 == b3,
-                _ => return false
-              }
-            }
-        }
-        pure fn ne(&self, other: &Taggy) -> bool { !(*self).eq(other) }
-    }
-
-    impl Taggypar<int> : Eq {
-        //let eq4: EqFn<Taggypar<int>> = |x,y| taggypareq::<int>(x, y);
-        pure fn eq(&self, other: &Taggypar<int>) -> bool {
-                  match (*self) {
-                    Onepar::<int>(a1) => match (*other) {
-                      Onepar::<int>(b1) => return a1 == b1,
-                      _ => return false
-                    },
-                    Twopar::<int>(a1, a2) => match (*other) {
-                      Twopar::<int>(b1, b2) => return a1 == b1 && a2 == b2,
-                      _ => return false
-                    },
-                    Threepar::<int>(a1, a2, a3) => match (*other) {
-                      Threepar::<int>(b1, b2, b3) => {
-                          return a1 == b1 && a2 == b2 && a3 == b3
-                      }
-                      _ => return false
-                    }
-                  }
-        }
-        pure fn ne(&self, other: &Taggypar<int>) -> bool {
-            !(*self).eq(other)
-        }
-    }
-
-    impl RecCy : Eq {
-        pure fn eq(&self, other: &RecCy) -> bool {
-          return (*self).x == (*other).x && (*self).y == (*other).y &&
-                 (*self).t == (*other).t;
-        }
-        pure fn ne(&self, other: &RecCy) -> bool { !(*self).eq(other) }
+        t: Taggy
     }
 
     #[test]
diff --git a/src/libstd/ebml.rs b/src/libstd/ebml.rs
index dc379cec21b..f93705c0c62 100644
--- a/src/libstd/ebml.rs
+++ b/src/libstd/ebml.rs
@@ -676,6 +676,7 @@ pub mod writer {
 mod tests {
     use ebml::reader;
     use ebml::writer;
+    use serialize::Encodable;
     use serialize;
 
     use core::io;
diff --git a/src/libstd/json.rs b/src/libstd/json.rs
index 45d467095fb..1361d8647b5 100644
--- a/src/libstd/json.rs
+++ b/src/libstd/json.rs
@@ -15,6 +15,7 @@
 
 //! json serialization
 
+use serialize::Encodable;
 use serialize;
 use sort::Sort;
 
diff --git a/src/libstd/map.rs b/src/libstd/map.rs
index 3c890ef0654..f3016e9df21 100644
--- a/src/libstd/map.rs
+++ b/src/libstd/map.rs
@@ -28,7 +28,7 @@ pub type Set<K:Eq IterBytes Hash> = HashMap<K, ()>;
 
 pub type HashMap<K:Eq IterBytes Hash, V> = chained::T<K, V>;
 
-pub trait Map<K:Eq IterBytes Hash Copy, V: Copy> {
+pub trait StdMap<K:Eq IterBytes Hash Copy, V: Copy> {
     /// Return the number of elements in the map
     pure fn size() -> uint;
 
@@ -124,7 +124,7 @@ pub mod util {
 // FIXME (#2344): package this up and export it as a datatype usable for
 // external code that doesn't want to pay the cost of a box.
 pub mod chained {
-    use map::{Map, util};
+    use map::{StdMap, util};
 
     use core::io;
     use core::ops;
@@ -239,7 +239,7 @@ pub mod chained {
         }
     }
 
-    impl<K:Eq IterBytes Hash Copy, V: Copy> T<K, V>: Map<K, V> {
+    impl<K:Eq IterBytes Hash Copy, V: Copy> T<K, V>: StdMap<K, V> {
         pure fn size() -> uint { self.count }
 
         pure fn contains_key(k: K) -> bool {
diff --git a/src/libstd/smallintmap.rs b/src/libstd/smallintmap.rs
index 5f16f7155b6..f17fce28ea9 100644
--- a/src/libstd/smallintmap.rs
+++ b/src/libstd/smallintmap.rs
@@ -15,7 +15,7 @@
 #[forbid(deprecated_mode)];
 
 use map;
-use map::Map;
+use map::StdMap;
 
 use core::dvec::DVec;
 use core::ops;
@@ -81,7 +81,7 @@ pub pure fn contains_key<T: Copy>(self: SmallIntMap<T>, key: uint) -> bool {
 }
 
 /// Implements the map::map interface for smallintmap
-impl<V: Copy> SmallIntMap<V>: map::Map<uint, V> {
+impl<V: Copy> SmallIntMap<V>: map::StdMap<uint, V> {
     pure fn size() -> uint {
         let mut sz = 0u;
         for self.v.each |item| {
@@ -165,8 +165,8 @@ impl<V: Copy> SmallIntMap<V>: ops::Index<uint, V> {
 }
 
 /// Cast the given smallintmap to a map::map
-pub fn as_map<V: Copy>(s: SmallIntMap<V>) -> map::Map<uint, V> {
-    s as map::Map::<uint, V>
+pub fn as_map<V: Copy>(s: SmallIntMap<V>) -> map::StdMap<uint, V> {
+    s as map::StdMap::<uint, V>
 }
 
 #[cfg(test)]
diff --git a/src/libsyntax/ast_map.rs b/src/libsyntax/ast_map.rs
index ddd0f846f9d..201d53c0c3f 100644
--- a/src/libsyntax/ast_map.rs
+++ b/src/libsyntax/ast_map.rs
@@ -12,7 +12,7 @@ use core::prelude::*;
 
 use ast::*;
 use ast;
-use ast_util::{path_to_ident, stmt_id};
+use ast_util::{inlined_item_utils, path_to_ident, stmt_id};
 use ast_util;
 use attr;
 use codemap;
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index 23ea27e7c5c..7b134a8db24 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -376,7 +376,7 @@ pure fn struct_field_visibility(field: ast::struct_field) -> visibility {
     }
 }
 
-trait inlined_item_utils {
+pub trait inlined_item_utils {
     fn ident() -> ident;
     fn id() -> ast::node_id;
     fn accept<E>(e: E, v: visit::vt<E>);
diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs
index 7a7c2312f56..7e3cbd18f52 100644
--- a/src/libsyntax/codemap.rs
+++ b/src/libsyntax/codemap.rs
@@ -33,7 +33,7 @@ use core::uint;
 use core::vec;
 use std::serialize::{Encodable, Decodable, Encoder, Decoder};
 
-trait Pos {
+pub trait Pos {
     static pure fn from_uint(n: uint) -> self;
     pure fn to_uint(&self) -> uint;
 }
diff --git a/src/libsyntax/diagnostic.rs b/src/libsyntax/diagnostic.rs
index 6112313cf48..4c0cc161fdd 100644
--- a/src/libsyntax/diagnostic.rs
+++ b/src/libsyntax/diagnostic.rs
@@ -10,7 +10,7 @@
 
 use core::prelude::*;
 
-use codemap::span;
+use codemap::{Pos, span};
 use codemap;
 
 use core::cmp;
diff --git a/src/libsyntax/ext/pipes/ast_builder.rs b/src/libsyntax/ext/pipes/ast_builder.rs
index 343ce4b039b..8a5b8a127d0 100644
--- a/src/libsyntax/ext/pipes/ast_builder.rs
+++ b/src/libsyntax/ext/pipes/ast_builder.rs
@@ -66,7 +66,7 @@ impl @ast::path: append_types {
     }
 }
 
-trait ext_ctxt_ast_builder {
+pub trait ext_ctxt_ast_builder {
     fn ty_param(id: ast::ident, +bounds: ~[ast::ty_param_bound])
         -> ast::ty_param;
     fn arg(name: ident, ty: @ast::Ty) -> ast::arg;
diff --git a/src/libsyntax/ext/pipes/mod.rs b/src/libsyntax/ext/pipes/mod.rs
index 8eef065395e..f91ec1ea48f 100644
--- a/src/libsyntax/ext/pipes/mod.rs
+++ b/src/libsyntax/ext/pipes/mod.rs
@@ -49,6 +49,7 @@ use codemap::span;
 use ext::base;
 use ext::base::ext_ctxt;
 use ext::pipes::parse_proto::proto_parser;
+use ext::pipes::pipec::gen_init;
 use ext::pipes::proto::{visit, protocol};
 use parse::lexer::{new_tt_reader, reader};
 use parse::parser::Parser;
diff --git a/src/libsyntax/ext/pipes/pipec.rs b/src/libsyntax/ext/pipes/pipec.rs
index e53057cb312..774a5596258 100644
--- a/src/libsyntax/ext/pipes/pipec.rs
+++ b/src/libsyntax/ext/pipes/pipec.rs
@@ -13,7 +13,8 @@
 use ast::ident;
 use ast_util::dummy_sp;
 use ext::base::ext_ctxt;
-use ext::pipes::ast_builder::{append_types, path, path_global};
+use ext::pipes::ast_builder::{append_types, ext_ctxt_ast_builder, path};
+use ext::pipes::ast_builder::{path_global};
 use ext::pipes::proto::*;
 use ext::quote::rt::*;
 use parse::*;
@@ -35,7 +36,7 @@ trait to_type_decls {
     fn to_endpoint_decls(cx: ext_ctxt, dir: direction) -> ~[@ast::item];
 }
 
-trait gen_init {
+pub trait gen_init {
     fn gen_init(cx: ext_ctxt) -> @ast::item;
     fn compile(cx: ext_ctxt) -> @ast::item;
     fn buffer_ty_path(cx: ext_ctxt) -> @ast::Ty;
diff --git a/src/libsyntax/ext/pipes/proto.rs b/src/libsyntax/ext/pipes/proto.rs
index 26638cd8cd6..9d24b3db724 100644
--- a/src/libsyntax/ext/pipes/proto.rs
+++ b/src/libsyntax/ext/pipes/proto.rs
@@ -13,7 +13,7 @@ use core::prelude::*;
 use ast;
 use codemap::span;
 use ext::base::ext_ctxt;
-use ext::pipes::ast_builder::{path, append_types};
+use ext::pipes::ast_builder::{append_types, ext_ctxt_ast_builder, path};
 
 use core::cmp;
 use core::dvec::DVec;
diff --git a/src/libsyntax/ext/quote.rs b/src/libsyntax/ext/quote.rs
index 3354d015476..7605e01fbf0 100644
--- a/src/libsyntax/ext/quote.rs
+++ b/src/libsyntax/ext/quote.rs
@@ -10,7 +10,7 @@
 
 use ast;
 use attr;
-use codemap::{span, BytePos};
+use codemap::{BytePos, Pos, span};
 use ext::base::ext_ctxt;
 use ext::base;
 use ext::build;
diff --git a/src/libsyntax/ext/source_util.rs b/src/libsyntax/ext/source_util.rs
index 3ade0bf86b1..4ecbbdc9760 100644
--- a/src/libsyntax/ext/source_util.rs
+++ b/src/libsyntax/ext/source_util.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 use codemap;
-use codemap::{span, Loc, FileMap};
+use codemap::{FileMap, Loc, Pos, span};
 use ext::base::*;
 use ext::base;
 use ext::build::{mk_base_vec_e, mk_uint, mk_u8, mk_base_str};
diff --git a/src/libsyntax/parse/comments.rs b/src/libsyntax/parse/comments.rs
index 66c3111b309..fbe258852e2 100644
--- a/src/libsyntax/parse/comments.rs
+++ b/src/libsyntax/parse/comments.rs
@@ -11,7 +11,7 @@
 use core::prelude::*;
 
 use ast;
-use codemap::{BytePos, CharPos, CodeMap, FileMap};
+use codemap::{BytePos, CharPos, CodeMap, FileMap, Pos};
 use diagnostic;
 use parse::lexer::{is_whitespace, get_str_from, reader};
 use parse::lexer::{string_reader, bump, is_eof, nextch};
diff --git a/src/libsyntax/parse/lexer.rs b/src/libsyntax/parse/lexer.rs
index 1574a037a46..5a0f40f3c12 100644
--- a/src/libsyntax/parse/lexer.rs
+++ b/src/libsyntax/parse/lexer.rs
@@ -12,7 +12,7 @@ use core::prelude::*;
 
 use ast;
 use ast_util;
-use codemap::{span, CodeMap, CharPos, BytePos};
+use codemap::{BytePos, CharPos, CodeMap, Pos, span};
 use codemap;
 use diagnostic::span_handler;
 use ext::tt::transcribe::{tt_next_token};
diff --git a/src/test/auxiliary/issue_2242_b.rs b/src/test/auxiliary/issue_2242_b.rs
deleted file mode 100644
index 73ec1f47230..00000000000
--- a/src/test/auxiliary/issue_2242_b.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[link(name = "b", vers = "0.1")];
-#[crate_type = "lib"];
-
-extern mod a;
-use a::to_strz;
-
-impl int: to_strz {
-    fn to_strz() -> ~str { fmt!("%?", self) }
-}
diff --git a/src/test/compile-fail/drop-on-non-struct.rs b/src/test/compile-fail/drop-on-non-struct.rs
index 95512a2da60..69880272350 100644
--- a/src/test/compile-fail/drop-on-non-struct.rs
+++ b/src/test/compile-fail/drop-on-non-struct.rs
@@ -11,6 +11,7 @@
 type Foo = @[u8];
 
 impl Foo : Drop {   //~ ERROR the Drop trait may only be implemented
+//~^ ERROR cannot provide an extension implementation
     fn finalize(&self) {
         io::println("kaboom");
     }
diff --git a/src/test/compile-fail/map-types.rs b/src/test/compile-fail/map-types.rs
index 89377eb3d15..7161e854447 100644
--- a/src/test/compile-fail/map-types.rs
+++ b/src/test/compile-fail/map-types.rs
@@ -11,12 +11,13 @@
 extern mod std;
 use std::map;
 use std::map::HashMap;
-use std::map::Map;
+use std::map::StdMap;
 
 // Test that trait types printed in error msgs include the type arguments.
 
 fn main() {
-    let x: Map<~str,~str> = map::HashMap::<~str,~str>() as Map::<~str,~str>;
-    let y: Map<uint,~str> = x;
-    //~^ ERROR mismatched types: expected `@std::map::Map<uint,~str>`
+    let x: StdMap<~str,~str> = map::HashMap::<~str,~str>() as
+        StdMap::<~str,~str>;
+    let y: StdMap<uint,~str> = x;
+    //~^ ERROR mismatched types: expected `@std::map::StdMap<uint,~str>`
 }
diff --git a/src/test/run-pass/auto-encode.rs b/src/test/run-pass/auto-encode.rs
index 6ea08d200e7..ec73704ca27 100644
--- a/src/test/run-pass/auto-encode.rs
+++ b/src/test/run-pass/auto-encode.rs
@@ -128,19 +128,16 @@ impl CLike : cmp::Eq {
 
 #[auto_encode]
 #[auto_decode]
+#[deriving_eq]
 struct Spanned<T> {
     lo: uint,
     hi: uint,
     node: T,
 }
 
-impl<T:cmp::Eq> Spanned<T> : cmp::Eq {
-    pure fn eq(&self, other: &Spanned<T>) -> bool {
-        self.lo == other.lo &&
-        self.hi == other.hi &&
-        self.node == other.node
-    }
-    pure fn ne(&self, other: &Spanned<T>) -> bool { !self.eq(other) }
+enum AnEnum {
+    AVariant,
+    AnotherVariant
 }
 
 #[auto_encode]
diff --git a/src/test/run-pass/class-impl-very-parameterized-trait.rs b/src/test/run-pass/class-impl-very-parameterized-trait.rs
index b802b970892..6bc88188452 100644
--- a/src/test/run-pass/class-impl-very-parameterized-trait.rs
+++ b/src/test/run-pass/class-impl-very-parameterized-trait.rs
@@ -51,7 +51,7 @@ impl<T: Copy> cat<T> {
   }
 }
 
-impl<T: Copy> cat<T> : Map<int, T> {
+impl<T: Copy> cat<T> : StdMap<int, T> {
   pure fn size() -> uint { self.meows as uint }
   fn insert(+k: int, +_v: T) -> bool {
     self.meows += k;
diff --git a/src/test/run-pass/issue-2242-d.rs b/src/test/run-pass/issue-2242-d.rs
deleted file mode 100644
index 006a33ebb65..00000000000
--- a/src/test/run-pass/issue-2242-d.rs
+++ /dev/null
@@ -1,26 +0,0 @@
-// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-// xfail-fast (aux-build)
-// aux-build:issue_2242_a.rs
-// aux-build:issue_2242_b.rs
-// aux-build:issue_2242_c.rs
-
-extern mod a;
-extern mod b;
-extern mod c;
-
-use a::to_strz;
-
-fn main() {
-    io::println((~"foo").to_strz());
-    io::println(1.to_strz());
-    io::println(true.to_strz());
-}