From 8407ec9fedccdd410dee2bca67651ce245ed5cd3 Mon Sep 17 00:00:00 2001
From: Huon Wilson <dbau.pp+github@gmail.com>
Date: Sun, 28 Jul 2013 01:16:30 +1000
Subject: syntax: make #[deriving(TotalOrd)] lazy.

Previously it would call:

  f(sf1.cmp(&of1), f(sf2.cmp(&of2), ...))

(where s/of1 = 'self/other field 1', and f was
std::cmp::lexical_ordering)

This meant that every .cmp subcall got evaluated when calling a derived
TotalOrd.cmp.

This corrects this to use

   let test = sf1.cmp(&of1);
   if test == Equal {
      let test = sf2.cmp(&of2);
      if test == Equal {
        // ...
      } else {
        test
      }
   } else {
     test
   }

This gives a lexical ordering by short-circuiting on the first comparison
that is not Equal.
---
 src/libstd/cmp.rs | 1 -
 1 file changed, 1 deletion(-)

(limited to 'src/libstd')

diff --git a/src/libstd/cmp.rs b/src/libstd/cmp.rs
index 43a632562b2..b66f89e8341 100644
--- a/src/libstd/cmp.rs
+++ b/src/libstd/cmp.rs
@@ -153,7 +153,6 @@ pub fn cmp2<A:TotalOrd,B:TotalOrd>(
 Return `o1` if it is not `Equal`, otherwise `o2`. Simulates the
 lexical ordering on a type `(int, int)`.
 */
-// used in deriving code in libsyntax
 #[inline]
 pub fn lexical_ordering(o1: Ordering, o2: Ordering) -> Ordering {
     match o1 {
-- 
cgit 1.4.1-3-g733a5


From 88620c25f5a2b5e17f3bff1e70ed2fbee97c2217 Mon Sep 17 00:00:00 2001
From: Huon Wilson <dbau.pp+github@gmail.com>
Date: Sun, 28 Jul 2013 01:25:30 +1000
Subject: std: implement Total{Ord,Eq} for pointers.

---
 src/libstd/borrow.rs  | 12 ++++++++++++
 src/libstd/managed.rs | 25 ++++++++++++++++++++++++-
 src/libstd/owned.rs   | 14 +++++++++++++-
 3 files changed, 49 insertions(+), 2 deletions(-)

(limited to 'src/libstd')

diff --git a/src/libstd/borrow.rs b/src/libstd/borrow.rs
index 9e3a3a28fe8..6c3d4c5f1fb 100644
--- a/src/libstd/borrow.rs
+++ b/src/libstd/borrow.rs
@@ -58,3 +58,15 @@ impl<'self, T: Ord> Ord for &'self T {
         *(*self) > *(*other)
     }
 }
+
+#[cfg(not(test))]
+impl<'self, T: TotalOrd> TotalOrd for &'self T {
+    #[inline]
+    fn cmp(&self, other: & &'self T) -> Ordering { (**self).cmp(*other) }
+}
+
+#[cfg(not(test))]
+impl<'self, T: TotalEq> TotalEq for &'self T {
+    #[inline]
+    fn equals(&self, other: & &'self T) -> bool { (**self).equals(*other) }
+}
diff --git a/src/libstd/managed.rs b/src/libstd/managed.rs
index bd4dc69537c..57230b2fd24 100644
--- a/src/libstd/managed.rs
+++ b/src/libstd/managed.rs
@@ -12,7 +12,7 @@
 
 use ptr::to_unsafe_ptr;
 
-#[cfg(not(test))] use cmp::{Eq, Ord};
+#[cfg(not(test))] use cmp::*;
 
 pub static RC_MANAGED_UNIQUE : uint = (-2) as uint;
 pub static RC_IMMORTAL : uint = 0x77777777;
@@ -71,6 +71,29 @@ impl<T:Ord> Ord for @mut T {
     fn gt(&self, other: &@mut T) -> bool { *(*self) > *(*other) }
 }
 
+#[cfg(not(test))]
+impl<T: TotalOrd> TotalOrd for @T {
+    #[inline]
+    fn cmp(&self, other: &@T) -> Ordering { (**self).cmp(*other) }
+}
+
+#[cfg(not(test))]
+impl<T: TotalOrd> TotalOrd for @mut T {
+    #[inline]
+    fn cmp(&self, other: &@mut T) -> Ordering { (**self).cmp(*other) }
+}
+
+#[cfg(not(test))]
+impl<T: TotalEq> TotalEq for @T {
+    #[inline]
+    fn equals(&self, other: &@T) -> bool { (**self).equals(*other) }
+}
+
+#[cfg(not(test))]
+impl<T: TotalEq> TotalEq for @mut T {
+    #[inline]
+    fn equals(&self, other: &@mut T) -> bool { (**self).equals(*other) }
+}
 #[test]
 fn test() {
     let x = @3;
diff --git a/src/libstd/owned.rs b/src/libstd/owned.rs
index e7a6e38fdb0..424c4fd6b2f 100644
--- a/src/libstd/owned.rs
+++ b/src/libstd/owned.rs
@@ -10,7 +10,7 @@
 
 //! Operations on unique pointer types
 
-#[cfg(not(test))] use cmp::{Eq, Ord};
+#[cfg(not(test))] use cmp::*;
 
 #[cfg(not(test))]
 impl<T:Eq> Eq for ~T {
@@ -31,3 +31,15 @@ impl<T:Ord> Ord for ~T {
     #[inline]
     fn gt(&self, other: &~T) -> bool { *(*self) > *(*other) }
 }
+
+#[cfg(not(test))]
+impl<T: TotalOrd> TotalOrd for ~T {
+    #[inline]
+    fn cmp(&self, other: &~T) -> Ordering { (**self).cmp(*other) }
+}
+
+#[cfg(not(test))]
+impl<T: TotalEq> TotalEq for ~T {
+    #[inline]
+    fn equals(&self, other: &~T) -> bool { (**self).equals(*other) }
+}
-- 
cgit 1.4.1-3-g733a5