Allow fail messages to be caught, and introduce the Any trait

Some code cleanup, sorting of import blocks

Removed std::unstable::UnsafeArc's use of Either

Added run-fail tests for the new FailWithCause impls

Changed future_result and try to return Result<(), ~Any>.

- Internally, there is an enum of possible fail messages passend around.
- In case of linked failure or a string message, the ~Any gets
  lazyly allocated in future_results recv method.
- For that, future result now returns a wrapper around a Port.
- Moved and renamed task::TaskResult into rt::task::UnwindResult
  and made it an internal enum.
- Introduced a replacement typedef `type TaskResult = Result<(), ~Any>`.

2 files changed, 4 insertions, 3 deletions

diff --git a/src/libstd/rt/io/option.rs b/src/libstd/rt/io/option.rs
index 52699964b62..234b46458b4 100644
--- a/src/libstd/rt/io/option.rs
+++ b/src/libstd/rt/io/option.rs
@@ -107,7 +107,7 @@ mod test {
     use option::*;
     use super::super::mem::*;
     use rt::test::*;
-    use super::super::{PreviousIoError, io_error, io_error};
+    use super::super::{PreviousIoError, io_error};
 
     #[test]
     fn test_option_writer() {
diff --git a/src/libstd/rt/io/signal.rs b/src/libstd/rt/io/signal.rs
index d2266c8d5d6..4c6c675df03 100644
--- a/src/libstd/rt/io/signal.rs
+++ b/src/libstd/rt/io/signal.rs
@@ -145,10 +145,10 @@ impl Listener {
 
 #[cfg(test)]
 mod test {
+    use super::*;
+
     use libc;
     use rt::io::timer;
-    use rt::io;
-    use super::*;
 
     // kill is only available on Unixes
     #[cfg(unix)]
@@ -206,6 +206,7 @@ mod test {
     #[cfg(windows)]
     #[test]
     fn test_io_signal_invalid_signum() {
+        use rt::io;
         let mut s = Listener::new();
         let mut called = false;
         do io::io_error::cond.trap(|_| {