diff --git a/src/libcore/to_bytes.rs b/src/libcore/to_bytes.rs
index 8fad77ff812de..0d409e704959f 100644
--- a/src/libcore/to_bytes.rs
+++ b/src/libcore/to_bytes.rs
@@ -19,7 +19,6 @@ pub type Cb = fn(buf: &[const u8]) -> bool;
  * modified when default methods and trait inheritence are
  * completed.
  */
-#[cfg(stage0)]
 pub trait IterBytes {
     /**
      * Call the provided callback `f` one or more times with
@@ -35,27 +34,9 @@ pub trait IterBytes {
      * left-to-right in declaration order, regardless of
      * underlying memory endianness.
      */
-    pure fn iter_bytes(lsb0: bool, f: Cb);
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
-pub trait IterBytes {
     pure fn iter_bytes(&self, lsb0: bool, f: Cb);
 }
 
-#[cfg(stage0)]
-impl bool: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(_lsb0: bool, f: Cb) {
-        f([
-            self as u8
-        ]);
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl bool: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, _lsb0: bool, f: Cb) {
@@ -65,18 +46,6 @@ impl bool: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl u8: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(_lsb0: bool, f: Cb) {
-        f([
-            self
-        ]);
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl u8: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, _lsb0: bool, f: Cb) {
@@ -86,26 +55,6 @@ impl u8: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl u16: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        if lsb0 {
-            f([
-                self as u8,
-                (self >> 8) as u8
-            ]);
-        } else {
-            f([
-                (self >> 8) as u8,
-                self as u8
-            ]);
-        }
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl u16: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -123,30 +72,6 @@ impl u16: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl u32: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        if lsb0 {
-            f([
-                self as u8,
-                (self >> 8) as u8,
-                (self >> 16) as u8,
-                (self >> 24) as u8,
-            ]);
-        } else {
-            f([
-                (self >> 24) as u8,
-                (self >> 16) as u8,
-                (self >> 8) as u8,
-                self as u8
-            ]);
-        }
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl u32: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -168,38 +93,6 @@ impl u32: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl u64: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        if lsb0 {
-            f([
-                self as u8,
-                (self >> 8) as u8,
-                (self >> 16) as u8,
-                (self >> 24) as u8,
-                (self >> 32) as u8,
-                (self >> 40) as u8,
-                (self >> 48) as u8,
-                (self >> 56) as u8
-            ]);
-        } else {
-            f([
-                (self >> 56) as u8,
-                (self >> 48) as u8,
-                (self >> 40) as u8,
-                (self >> 32) as u8,
-                (self >> 24) as u8,
-                (self >> 16) as u8,
-                (self >> 8) as u8,
-                self as u8
-            ]);
-        }
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl u64: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -229,16 +122,6 @@ impl u64: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl i8: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        (self as u8).iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl i8: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -246,16 +129,6 @@ impl i8: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl i16: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        (self as u16).iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl i16: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -263,16 +136,6 @@ impl i16: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl i32: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        (self as u32).iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl i32: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -280,16 +143,6 @@ impl i32: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl i64: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        (self as u64).iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl i64: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -297,16 +150,6 @@ impl i64: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl char: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        (self as u32).iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl char: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -316,16 +159,6 @@ impl char: IterBytes {
 
 #[cfg(target_word_size = "32")]
 pub mod x32 {
-    #[cfg(stage0)]
-    pub impl uint: IterBytes {
-        #[inline(always)]
-        pure fn iter_bytes(lsb0: bool, f: Cb) {
-            (self as u32).iter_bytes(lsb0, f)
-        }
-    }
-
-    #[cfg(stage1)]
-    #[cfg(stage2)]
     pub impl uint: IterBytes {
         #[inline(always)]
         pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -336,16 +169,6 @@ pub mod x32 {
 
 #[cfg(target_word_size = "64")]
 pub mod x64 {
-    #[cfg(stage0)]
-    pub impl uint: IterBytes {
-        #[inline(always)]
-        pure fn iter_bytes(lsb0: bool, f: Cb) {
-            (self as u64).iter_bytes(lsb0, f)
-        }
-    }
-
-    #[cfg(stage1)]
-    #[cfg(stage2)]
     pub impl uint: IterBytes {
         #[inline(always)]
         pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -354,16 +177,6 @@ pub mod x64 {
     }
 }
 
-#[cfg(stage0)]
-impl int: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        (self as uint).iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl int: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -371,20 +184,6 @@ impl int: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl<A: IterBytes> &[A]: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        for self.each |elt| {
-            do elt.iter_bytes(lsb0) |bytes| {
-                f(bytes)
-            }
-        }
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl<A: IterBytes> &[A]: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -396,18 +195,6 @@ impl<A: IterBytes> &[A]: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl<A: IterBytes, B: IterBytes> (A,B): IterBytes {
-  #[inline(always)]
-  pure fn iter_bytes(lsb0: bool, f: Cb) {
-    let &(ref a, ref b) = &self;
-    a.iter_bytes(lsb0, f);
-    b.iter_bytes(lsb0, f);
-  }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl<A: IterBytes, B: IterBytes> (A,B): IterBytes {
   #[inline(always)]
   pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -417,19 +204,6 @@ impl<A: IterBytes, B: IterBytes> (A,B): IterBytes {
   }
 }
 
-#[cfg(stage0)]
-impl<A: IterBytes, B: IterBytes, C: IterBytes> (A,B,C): IterBytes {
-  #[inline(always)]
-  pure fn iter_bytes(lsb0: bool, f: Cb) {
-    let &(ref a, ref b, ref c) = &self;
-    a.iter_bytes(lsb0, f);
-    b.iter_bytes(lsb0, f);
-    c.iter_bytes(lsb0, f);
-  }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl<A: IterBytes, B: IterBytes, C: IterBytes> (A,B,C): IterBytes {
   #[inline(always)]
   pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -445,16 +219,6 @@ pure fn borrow<A>(a: &x/[A]) -> &x/[A] {
     a
 }
 
-#[cfg(stage0)]
-impl<A: IterBytes> ~[A]: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        borrow(self).iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl<A: IterBytes> ~[A]: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -462,16 +226,6 @@ impl<A: IterBytes> ~[A]: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl<A: IterBytes> @[A]: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        borrow(self).iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl<A: IterBytes> @[A]: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -582,18 +336,6 @@ pub pure fn iter_bytes_7<A: IterBytes,
     g.iter_bytes(lsb0, |bytes| {flag = z(bytes); flag});
 }
 
-#[cfg(stage0)]
-impl &str: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(_lsb0: bool, f: Cb) {
-        do str::byte_slice(self) |bytes| {
-            f(bytes);
-        }
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl &str: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, _lsb0: bool, f: Cb) {
@@ -603,18 +345,6 @@ impl &str: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl ~str: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(_lsb0: bool, f: Cb) {
-        do str::byte_slice(self) |bytes| {
-            f(bytes);
-        }
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl ~str: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, _lsb0: bool, f: Cb) {
@@ -624,18 +354,6 @@ impl ~str: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl @str: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(_lsb0: bool, f: Cb) {
-        do str::byte_slice(self) |bytes| {
-            f(bytes);
-        }
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl @str: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, _lsb0: bool, f: Cb) {
@@ -645,19 +363,6 @@ impl @str: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl<A: IterBytes> Option<A>: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        match self {
-          Some(ref a) => iter_bytes_2(&0u8, a, lsb0, f),
-          None => 1u8.iter_bytes(lsb0, f)
-        }
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl<A: IterBytes> Option<A>: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -668,16 +373,6 @@ impl<A: IterBytes> Option<A>: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl<A: IterBytes> &A: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        (*self).iter_bytes(lsb0, f);
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl<A: IterBytes> &A: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -685,16 +380,6 @@ impl<A: IterBytes> &A: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl<A: IterBytes> @A: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        (*self).iter_bytes(lsb0, f);
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl<A: IterBytes> @A: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -702,16 +387,6 @@ impl<A: IterBytes> @A: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl<A: IterBytes> ~A: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        (*self).iter_bytes(lsb0, f);
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl<A: IterBytes> ~A: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
@@ -719,18 +394,8 @@ impl<A: IterBytes> ~A: IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl<A> *const A: IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(lsb0: bool, f: Cb) {
-        (self as uint).iter_bytes(lsb0, f);
-    }
-}
-
 // NB: raw-pointer IterBytes does _not_ dereference
 // to the target; it just gives you the pointer-bytes.
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl<A> *const A: IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
diff --git a/src/librustc/middle/borrowck/mod.rs b/src/librustc/middle/borrowck/mod.rs
index 6ef80321ec223..880e8f40483b3 100644
--- a/src/librustc/middle/borrowck/mod.rs
+++ b/src/librustc/middle/borrowck/mod.rs
@@ -424,14 +424,6 @@ impl root_map_key : cmp::Eq {
     }
 }
 
-#[cfg(stage0)]
-impl root_map_key : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        to_bytes::iter_bytes_2(&self.id, &self.derefs, lsb0, f);
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 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);
diff --git a/src/librustc/middle/trans/common.rs b/src/librustc/middle/trans/common.rs
index 5f0f3bc9593d1..99241efe9d10d 100644
--- a/src/librustc/middle/trans/common.rs
+++ b/src/librustc/middle/trans/common.rs
@@ -1170,22 +1170,6 @@ impl mono_id_ : cmp::Eq {
     pure fn ne(&self, other: &mono_id_) -> bool { !(*self).eq(other) }
 }
 
-#[cfg(stage0)]
-impl mono_param_id : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        match self {
-          mono_precise(t, mids) =>
-          to_bytes::iter_bytes_3(&0u8, &ty::type_id(t), &mids, lsb0, f),
-
-          mono_any => 1u8.iter_bytes(lsb0, f),
-
-          mono_repr(ref a, ref b, ref c, ref d) =>
-          to_bytes::iter_bytes_5(&2u8, a, b, c, d, lsb0, f)
-        }
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl mono_param_id : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         match *self {
@@ -1200,14 +1184,6 @@ impl mono_param_id : to_bytes::IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl mono_id_ : core::to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        to_bytes::iter_bytes_2(&self.def, &self.params, lsb0, f);
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl mono_id_ : core::to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         to_bytes::iter_bytes_2(&self.def, &self.params, lsb0, f);
diff --git a/src/librustc/middle/trans/datum.rs b/src/librustc/middle/trans/datum.rs
index d1813289df478..e18b5e03446e8 100644
--- a/src/librustc/middle/trans/datum.rs
+++ b/src/librustc/middle/trans/datum.rs
@@ -145,14 +145,6 @@ impl DatumMode: cmp::Eq {
     pure fn ne(&self, other: &DatumMode) -> bool { !(*self).eq(other) }
 }
 
-#[cfg(stage0)]
-impl DatumMode: to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (self as uint).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl DatumMode: to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (*self as uint).iter_bytes(lsb0, f)
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index d52f507e53e9e..8660f1a5165b2 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -258,14 +258,6 @@ impl creader_cache_key : cmp::Eq {
     }
 }
 
-#[cfg(stage0)]
-impl creader_cache_key : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        to_bytes::iter_bytes_3(&self.cnum, &self.pos, &self.len, lsb0, f);
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 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);
@@ -281,14 +273,6 @@ impl intern_key : cmp::Eq {
     pure fn ne(&self, other: &intern_key) -> bool { !(*self).eq(other) }
 }
 
-#[cfg(stage0)]
-impl intern_key : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        to_bytes::iter_bytes_2(&self.sty, &self.o_def_id, lsb0, f);
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl intern_key : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         to_bytes::iter_bytes_2(&self.sty, &self.o_def_id, lsb0, f);
@@ -531,14 +515,6 @@ impl param_ty : cmp::Eq {
     pure fn ne(&self, other: &param_ty) -> bool { !(*self).eq(other) }
 }
 
-#[cfg(stage0)]
-impl param_ty : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        to_bytes::iter_bytes_2(&self.idx, &self.def_id, lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl param_ty : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         to_bytes::iter_bytes_2(&self.idx, &self.def_id, lsb0, f)
@@ -725,18 +701,6 @@ enum InferTy {
     FloatVar(FloatVid)
 }
 
-#[cfg(stage0)]
-impl InferTy : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        match self {
-          TyVar(ref tv) => to_bytes::iter_bytes_2(&0u8, tv, lsb0, f),
-          IntVar(ref iv) => to_bytes::iter_bytes_2(&1u8, iv, lsb0, f),
-          FloatVar(ref fv) => to_bytes::iter_bytes_2(&2u8, fv, lsb0, f)
-        }
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl InferTy : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         match *self {
@@ -754,17 +718,6 @@ enum InferRegion {
     ReSkolemized(uint, bound_region)
 }
 
-#[cfg(stage0)]
-impl InferRegion : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        match self {
-            ReVar(ref rv) => to_bytes::iter_bytes_2(&0u8, rv, lsb0, f),
-            ReSkolemized(ref v, _) => to_bytes::iter_bytes_2(&1u8, v, lsb0, f)
-        }
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl InferRegion : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         match *self {
@@ -791,21 +744,6 @@ impl InferRegion : cmp::Eq {
     }
 }
 
-#[cfg(stage0)]
-impl param_bound : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        match self {
-          bound_copy => 0u8.iter_bytes(lsb0, f),
-          bound_owned => 1u8.iter_bytes(lsb0, f),
-          bound_send => 2u8.iter_bytes(lsb0, f),
-          bound_const => 3u8.iter_bytes(lsb0, f),
-          bound_trait(ref t) =>
-          to_bytes::iter_bytes_2(&4u8, t, lsb0, f)
-        }
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl param_bound : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         match *self {
@@ -877,70 +815,30 @@ impl purity: purity_to_str {
     }
 }
 
-#[cfg(stage0)]
-impl RegionVid : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (*self).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl RegionVid : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (**self).iter_bytes(lsb0, f)
     }
 }
 
-#[cfg(stage0)]
-impl TyVid : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (*self).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl TyVid : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (**self).iter_bytes(lsb0, f)
     }
 }
 
-#[cfg(stage0)]
-impl IntVid : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (*self).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl IntVid : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (**self).iter_bytes(lsb0, f)
     }
 }
 
-#[cfg(stage0)]
-impl FloatVid : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (*self).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl FloatVid : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (**self).iter_bytes(lsb0, f)
     }
 }
 
-#[cfg(stage0)]
-impl FnVid : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (*self).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl FnVid : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (**self).iter_bytes(lsb0, f)
@@ -2756,25 +2654,6 @@ fn index_sty(cx: ctxt, sty: &sty) -> Option<mt> {
     }
 }
 
-#[cfg(stage0)]
-impl bound_region : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        match self {
-          ty::br_self => 0u8.iter_bytes(lsb0, f),
-
-          ty::br_anon(ref idx) =>
-          to_bytes::iter_bytes_2(&1u8, idx, lsb0, f),
-
-          ty::br_named(ref ident) =>
-          to_bytes::iter_bytes_2(&2u8, ident, lsb0, f),
-
-          ty::br_cap_avoid(ref id, ref br) =>
-          to_bytes::iter_bytes_3(&3u8, id, br, lsb0, f)
-        }
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl bound_region : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         match *self {
@@ -2792,28 +2671,6 @@ impl bound_region : to_bytes::IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl Region : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        match self {
-          re_bound(ref br) =>
-          to_bytes::iter_bytes_2(&0u8, br, lsb0, f),
-
-          re_free(ref id, ref br) =>
-          to_bytes::iter_bytes_3(&1u8, id, br, lsb0, f),
-
-          re_scope(ref id) =>
-          to_bytes::iter_bytes_2(&2u8, id, lsb0, f),
-
-          re_infer(ref id) =>
-          to_bytes::iter_bytes_2(&3u8, id, lsb0, f),
-
-          re_static => 4u8.iter_bytes(lsb0, f)
-        }
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl Region : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         match *self {
@@ -2834,23 +2691,6 @@ impl Region : to_bytes::IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl vstore : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        match self {
-          vstore_fixed(ref u) =>
-          to_bytes::iter_bytes_2(&0u8, u, lsb0, f),
-
-          vstore_uniq => 1u8.iter_bytes(lsb0, f),
-          vstore_box => 2u8.iter_bytes(lsb0, f),
-
-          vstore_slice(ref r) =>
-          to_bytes::iter_bytes_2(&3u8, r, lsb0, f),
-        }
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl vstore : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         match *self {
@@ -2866,16 +2706,6 @@ impl vstore : to_bytes::IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl substs : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-          to_bytes::iter_bytes_3(&self.self_r,
-                                 &self.self_ty,
-                                 &self.tps, lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl substs : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
           to_bytes::iter_bytes_3(&self.self_r,
@@ -2884,15 +2714,6 @@ impl substs : to_bytes::IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl mt : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-          to_bytes::iter_bytes_2(&self.ty,
-                                 &self.mutbl, lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl mt : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
           to_bytes::iter_bytes_2(&self.ty,
@@ -2900,15 +2721,6 @@ impl mt : to_bytes::IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl field : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-          to_bytes::iter_bytes_2(&self.ident,
-                                 &self.mt, lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl field : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
           to_bytes::iter_bytes_2(&self.ident,
@@ -2916,15 +2728,6 @@ impl field : to_bytes::IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl arg : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        to_bytes::iter_bytes_2(&self.mode,
-                               &self.ty, lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl arg : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         to_bytes::iter_bytes_2(&self.mode,
@@ -2932,19 +2735,6 @@ impl arg : to_bytes::IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl FnMeta : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        to_bytes::iter_bytes_5(&self.purity,
-                               &self.proto,
-                               &self.region,
-                               &self.bounds,
-                               &self.ret_style,
-                               lsb0, f);
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl FnMeta : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         to_bytes::iter_bytes_5(&self.purity,
@@ -2956,16 +2746,6 @@ impl FnMeta : to_bytes::IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl FnSig : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        to_bytes::iter_bytes_2(&self.inputs,
-                               &self.output,
-                               lsb0, f);
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl FnSig : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         to_bytes::iter_bytes_2(&self.inputs,
@@ -2974,86 +2754,6 @@ impl FnSig : to_bytes::IterBytes {
     }
 }
 
-#[cfg(stage0)]
-impl sty : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        match self {
-          ty_nil => 0u8.iter_bytes(lsb0, f),
-          ty_bool => 1u8.iter_bytes(lsb0, f),
-
-          ty_int(ref t) =>
-          to_bytes::iter_bytes_2(&2u8, t, lsb0, f),
-
-          ty_uint(ref t) =>
-          to_bytes::iter_bytes_2(&3u8, t, lsb0, f),
-
-          ty_float(ref t) =>
-          to_bytes::iter_bytes_2(&4u8, t, lsb0, f),
-
-          ty_estr(ref v) =>
-          to_bytes::iter_bytes_2(&5u8, v, lsb0, f),
-
-          ty_enum(ref did, ref substs) =>
-          to_bytes::iter_bytes_3(&6u8, did, substs, lsb0, f),
-
-          ty_box(ref mt) =>
-          to_bytes::iter_bytes_2(&7u8, mt, lsb0, f),
-
-          ty_evec(ref mt, ref v) =>
-          to_bytes::iter_bytes_3(&8u8, mt, v, lsb0, f),
-
-          ty_unboxed_vec(ref mt) =>
-          to_bytes::iter_bytes_2(&9u8, mt, lsb0, f),
-
-          ty_tup(ref ts) =>
-          to_bytes::iter_bytes_2(&10u8, ts, lsb0, f),
-
-          ty_rec(ref fs) =>
-          to_bytes::iter_bytes_2(&11u8, fs, lsb0, f),
-
-          ty_fn(ref ft) =>
-          to_bytes::iter_bytes_3(&12u8,
-                                 &ft.meta,
-                                 &ft.sig,
-                                 lsb0, f),
-
-          ty_self => 13u8.iter_bytes(lsb0, f),
-
-          ty_infer(ref v) =>
-          to_bytes::iter_bytes_2(&14u8, v, lsb0, f),
-
-          ty_param(ref p) =>
-          to_bytes::iter_bytes_2(&15u8, p, lsb0, f),
-
-          ty_type => 16u8.iter_bytes(lsb0, f),
-          ty_bot => 17u8.iter_bytes(lsb0, f),
-
-          ty_ptr(ref mt) =>
-          to_bytes::iter_bytes_2(&18u8, mt, lsb0, f),
-
-          ty_uniq(ref mt) =>
-          to_bytes::iter_bytes_2(&19u8, mt, lsb0, f),
-
-          ty_trait(ref did, ref substs, ref v) =>
-          to_bytes::iter_bytes_4(&20u8, did, substs, v, lsb0, f),
-
-          ty_opaque_closure_ptr(ref ck) =>
-          to_bytes::iter_bytes_2(&21u8, ck, lsb0, f),
-
-          ty_opaque_box => 22u8.iter_bytes(lsb0, f),
-
-          ty_class(ref did, ref substs) =>
-          to_bytes::iter_bytes_3(&23u8, did, substs, lsb0, f),
-
-          ty_rptr(ref r, ref mt) =>
-          to_bytes::iter_bytes_3(&24u8, r, mt, lsb0, f),
-
-          ty_err => 25u8.iter_bytes(lsb0, f)
-        }
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl sty : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         match *self {
diff --git a/src/librustc/middle/typeck/infer/region_inference.rs b/src/librustc/middle/typeck/infer/region_inference.rs
index f36112d77cbbf..a334977819b2b 100644
--- a/src/librustc/middle/typeck/infer/region_inference.rs
+++ b/src/librustc/middle/typeck/infer/region_inference.rs
@@ -488,23 +488,6 @@ impl Constraint : cmp::Eq {
     pure fn ne(&self, other: &Constraint) -> bool { !(*self).eq(other) }
 }
 
-#[cfg(stage0)]
-impl Constraint : to_bytes::IterBytes {
-   pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        match self {
-          ConstrainVarSubVar(ref v0, ref v1) =>
-          to_bytes::iter_bytes_3(&0u8, v0, v1, lsb0, f),
-
-          ConstrainRegSubVar(ref ra, ref va) =>
-          to_bytes::iter_bytes_3(&1u8, ra, va, lsb0, f),
-
-          ConstrainVarSubReg(ref va, ref ra) =>
-          to_bytes::iter_bytes_3(&2u8, va, ra, lsb0, f)
-        }
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl Constraint : to_bytes::IterBytes {
    pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         match *self {
@@ -532,14 +515,6 @@ impl TwoRegions : cmp::Eq {
     pure fn ne(&self, other: &TwoRegions) -> bool { !(*self).eq(other) }
 }
 
-#[cfg(stage0)]
-impl TwoRegions : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        to_bytes::iter_bytes_2(&self.a, &self.b, lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl TwoRegions : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         to_bytes::iter_bytes_2(&self.a, &self.b, lsb0, f)
diff --git a/src/libstd/net_url.rs b/src/libstd/net_url.rs
index 500d37604bc0f..136df3a4193fd 100644
--- a/src/libstd/net_url.rs
+++ b/src/libstd/net_url.rs
@@ -737,15 +737,6 @@ impl Url : Eq {
     }
 }
 
-#[cfg(stage0)]
-impl Url: IterBytes {
-    pure fn iter_bytes(lsb0: bool, f: to_bytes::Cb) {
-        unsafe { self.to_str() }.iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl Url: IterBytes {
     pure fn iter_bytes(&self, lsb0: bool, f: to_bytes::Cb) {
         unsafe { self.to_str() }.iter_bytes(lsb0, f)
diff --git a/src/libstd/std.rc b/src/libstd/std.rc
index a22bbe1cd6f4b..af2977634e95f 100644
--- a/src/libstd/std.rc
+++ b/src/libstd/std.rc
@@ -85,7 +85,7 @@ pub mod par;
 pub mod cmp;
 pub mod base64;
 pub mod rl;
-// pub mod workcache;
+pub mod workcache;
 
 #[cfg(unicode)]
 mod unicode;
diff --git a/src/libstd/workcache.rs b/src/libstd/workcache.rs
index 5bf90ef29c817..08f3d21be47ad 100644
--- a/src/libstd/workcache.rs
+++ b/src/libstd/workcache.rs
@@ -74,19 +74,6 @@ struct WorkKey {
     name: ~str
 }
 
-#[cfg(stage0)]
-impl WorkKey: to_bytes::IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(&self, lsb0: bool, f: to_bytes::Cb) {
-        let mut flag = true;
-        self.kind.iter_bytes(lsb0, |bytes| {flag = f(bytes); flag});
-        if !flag { return; }
-        self.name.iter_bytes(lsb0, f);
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl WorkKey: to_bytes::IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, lsb0: bool, f: to_bytes::Cb) {
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 252ccdc3e1bbf..1ffe741d255fd 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -54,15 +54,6 @@ impl ident: cmp::Eq {
     pure fn ne(&self, other: &ident) -> bool { !(*self).eq(other) }
 }
 
-#[cfg(stage0)]
-impl ident: to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        self.repr.iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl ident: to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         self.repr.iter_bytes(lsb0, f)
@@ -311,25 +302,6 @@ enum binding_mode {
     bind_by_implicit_ref
 }
 
-#[cfg(stage0)]
-impl binding_mode : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        match self {
-          bind_by_value => 0u8.iter_bytes(lsb0, f),
-
-          bind_by_move => 1u8.iter_bytes(lsb0, f),
-
-          bind_by_ref(ref m) =>
-          to_bytes::iter_bytes_2(&2u8, m, lsb0, f),
-
-          bind_by_implicit_ref =>
-          3u8.iter_bytes(lsb0, f),
-        }
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl binding_mode : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         match *self {
@@ -406,15 +378,6 @@ enum pat_ {
 #[auto_deserialize]
 enum mutability { m_mutbl, m_imm, m_const, }
 
-#[cfg(stage0)]
-impl mutability : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (self as u8).iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl mutability : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (*self as u8).iter_bytes(lsb0, f)
@@ -444,15 +407,6 @@ impl Proto : cmp::Eq {
     pure fn ne(&self, other: &Proto) -> bool { !(*self).eq(other) }
 }
 
-#[cfg(stage0)]
-impl Proto : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (self as uint).iter_bytes(lsb0, f);
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl Proto : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (*self as uint).iter_bytes(lsb0, f);
@@ -576,21 +530,6 @@ enum inferable<T> {
     infer(node_id)
 }
 
-#[cfg(stage0)]
-impl<T: to_bytes::IterBytes> inferable<T> : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        match self {
-          expl(ref t) =>
-          to_bytes::iter_bytes_2(&0u8, t, lsb0, f),
-
-          infer(ref n) =>
-          to_bytes::iter_bytes_2(&1u8, n, lsb0, f),
-        }
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl<T: to_bytes::IterBytes> inferable<T> : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         match *self {
@@ -628,14 +567,6 @@ impl<T:cmp::Eq> inferable<T> : cmp::Eq {
 #[auto_deserialize]
 enum rmode { by_ref, by_val, by_move, by_copy }
 
-#[cfg(stage0)]
-impl rmode : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (self as u8).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl rmode : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (*self as u8).iter_bytes(lsb0, f)
@@ -985,14 +916,6 @@ enum trait_method {
 #[auto_deserialize]
 enum int_ty { ty_i, ty_char, ty_i8, ty_i16, ty_i32, ty_i64, }
 
-#[cfg(stage0)]
-impl int_ty : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (self as u8).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl int_ty : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (*self as u8).iter_bytes(lsb0, f)
@@ -1023,14 +946,6 @@ impl int_ty : cmp::Eq {
 #[auto_deserialize]
 enum uint_ty { ty_u, ty_u8, ty_u16, ty_u32, ty_u64, }
 
-#[cfg(stage0)]
-impl uint_ty : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (self as u8).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl uint_ty : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (*self as u8).iter_bytes(lsb0, f)
@@ -1059,14 +974,6 @@ impl uint_ty : cmp::Eq {
 #[auto_deserialize]
 enum float_ty { ty_f, ty_f32, ty_f64, }
 
-#[cfg(stage0)]
-impl float_ty : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (self as u8).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl float_ty : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (*self as u8).iter_bytes(lsb0, f)
@@ -1212,15 +1119,6 @@ impl Ty : cmp::Eq {
     }
 }
 
-#[cfg(stage0)]
-impl Ty : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        to_bytes::iter_bytes_2(&self.span.lo, &self.span.hi, lsb0, f);
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl Ty : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         to_bytes::iter_bytes_2(&self.span.lo, &self.span.hi, lsb0, f);
@@ -1248,15 +1146,6 @@ enum purity {
     extern_fn, // declared with "extern fn"
 }
 
-#[cfg(stage0)]
-impl purity : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (self as u8).iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl purity : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (*self as u8).iter_bytes(lsb0, f)
@@ -1278,14 +1167,6 @@ enum ret_style {
     return_val, // everything else
 }
 
-#[cfg(stage0)]
-impl ret_style : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (self as u8).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl ret_style : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (*self as u8).iter_bytes(lsb0, f)
@@ -1635,14 +1516,6 @@ enum item_ {
 #[auto_deserialize]
 enum class_mutability { class_mutable, class_immutable }
 
-#[cfg(stage0)]
-impl class_mutability : to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (self as u8).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl class_mutability : to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (*self as u8).iter_bytes(lsb0, f)
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index d0cd6ad54d1c7..0b066b5716815 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -252,15 +252,6 @@ pure fn is_call_expr(e: @expr) -> bool {
 }
 
 // This makes def_id hashable
-#[cfg(stage0)]
-impl def_id : core::to_bytes::IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(+lsb0: bool, f: core::to_bytes::Cb) {
-        core::to_bytes::iter_bytes_2(&self.crate, &self.node, lsb0, f);
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl def_id : core::to_bytes::IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, +lsb0: bool, f: core::to_bytes::Cb) {
diff --git a/src/libsyntax/codemap.rs b/src/libsyntax/codemap.rs
index 8126f1d720074..693597eb8405e 100644
--- a/src/libsyntax/codemap.rs
+++ b/src/libsyntax/codemap.rs
@@ -72,15 +72,6 @@ impl BytePos: Num {
     static pure fn from_int(+n: int) -> BytePos { BytePos(n as uint) }
 }
 
-#[cfg(stage0)]
-impl BytePos: to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (*self).iter_bytes(lsb0, f)
-    }
-}
-
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl BytePos: to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (**self).iter_bytes(lsb0, f)
@@ -127,14 +118,6 @@ impl CharPos: Num {
     static pure fn from_int(+n: int) -> CharPos { CharPos(n as uint) }
 }
 
-#[cfg(stage0)]
-impl CharPos: to_bytes::IterBytes {
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (*self).iter_bytes(lsb0, f)
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl CharPos: to_bytes::IterBytes {
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {
         (**self).iter_bytes(lsb0, f)
diff --git a/src/libsyntax/parse/obsolete.rs b/src/libsyntax/parse/obsolete.rs
index 1407b56336c38..afa87c261f1bb 100644
--- a/src/libsyntax/parse/obsolete.rs
+++ b/src/libsyntax/parse/obsolete.rs
@@ -36,15 +36,6 @@ impl ObsoleteSyntax : cmp::Eq {
     }
 }
 
-#[cfg(stage0)]
-impl ObsoleteSyntax: to_bytes::IterBytes {
-    #[inline(always)]
-    pure fn iter_bytes(+lsb0: bool, f: to_bytes::Cb) {
-        (self as uint).iter_bytes(lsb0, f);
-    }
-}
-#[cfg(stage1)]
-#[cfg(stage2)]
 impl ObsoleteSyntax: to_bytes::IterBytes {
     #[inline(always)]
     pure fn iter_bytes(&self, +lsb0: bool, f: to_bytes::Cb) {