Use $crate and macro reexport to reduce duplicated code

Many of libstd's macros are now re-exported from libcore and libcollections.
Their libstd definitions have moved to a macros_stage0 module and can disappear
after the next snapshot.

Where the two crates had already diverged, I took the libstd versions as
they're generally newer and better-tested. See e.g. d3c831b, which was a fix to
libstd's assert_eq!() that didn't make it into libcore's.

Fixes #16806.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/libcore/fmt/mod.rs b/src/libcore/fmt/mod.rs
index 102836f8d30..b7c225c276a 100644
--- a/src/libcore/fmt/mod.rs
+++ b/src/libcore/fmt/mod.rs
@@ -20,12 +20,15 @@ use mem;
 use option::Option;
 use option::Option::{Some, None};
 use ops::{Deref, FnOnce};
-use result::Result::{Ok, Err};
+use result::Result::Ok;
 use result;
 use slice::SliceExt;
 use slice;
 use str::{self, StrExt, Utf8Error};
 
+// NOTE: for old macros; remove after the next snapshot
+#[cfg(stage0)] use result::Result::Err;
+
 pub use self::num::radix;
 pub use self::num::Radix;
 pub use self::num::RadixFmt;