auto merge of #6223 : alexcrichton/rust/issue-6183, r=pcwalton

Closes #6183.

The first commit changes the compiler's method of treating a `for` loop, and all the remaining commits are just dealing with the fallout.

The biggest fallout was the `IterBytes` trait, although it's really a whole lot nicer now because all of the `iter_bytes_XX` methods are just and-ed together. Sadly there was a huge amount of stuff that's `cfg(stage0)` gated, but whoever lands the next snapshot is going to have a lot of fun deleting all this code!

1 files changed, 8 insertions, 5 deletions

diff --git a/src/libcore/task/spawn.rs b/src/libcore/task/spawn.rs
index 19c417dfdfc..846d4a34950 100644
--- a/src/libcore/task/spawn.rs
+++ b/src/libcore/task/spawn.rs
@@ -110,9 +110,14 @@ fn taskset_remove(tasks: &mut TaskSet, task: *rust_task) {
     let was_present = tasks.remove(&task);
     assert!(was_present);
 }
+#[cfg(stage0)]
 pub fn taskset_each(tasks: &TaskSet, blk: &fn(v: *rust_task) -> bool) {
     tasks.each(|k| blk(*k))
 }
+#[cfg(not(stage0))]
+pub fn taskset_each(tasks: &TaskSet, blk: &fn(v: *rust_task) -> bool) -> bool {
+    tasks.each(|k| blk(*k))
+}
 
 // One of these per group of linked-failure tasks.
 struct TaskGroupData {
@@ -685,13 +690,11 @@ fn spawn_raw_oldsched(mut opts: TaskOpts, f: ~fn()) {
                 };
                 // Attempt to join every ancestor group.
                 result =
-                    for each_ancestor(ancestors, Some(bail)) |ancestor_tg| {
+                    each_ancestor(ancestors, Some(bail), |ancestor_tg| {
                         // Enlist as a descendant, not as an actual member.
                         // Descendants don't kill ancestor groups on failure.
-                        if !enlist_in_taskgroup(ancestor_tg, child, false) {
-                            break;
-                        }
-                    };
+                        enlist_in_taskgroup(ancestor_tg, child, false)
+                    });
                 // If any ancestor group fails, need to exit this group too.
                 if !result {
                     do access_group(child_arc) |child_tg| {