Copy `AsciiExt` methods to `[u8]` directly

This is done in order to deprecate AsciiExt eventually. Note that
this commit contains a bunch of `cfg(stage0)` statements. This is
due to a new compiler feature I am using: the `slice_u8` lang item.
Once this lang item is available in the stage0 compiler, all those
cfg flags (and more) can be removed.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/libstd/ascii.rs b/src/libstd/ascii.rs
index 6524838f8b0..7a474c1f254 100644
--- a/src/libstd/ascii.rs
+++ b/src/libstd/ascii.rs
@@ -389,6 +389,10 @@ impl AsciiExt for str {
     }
 }
 
+// TODO(LukasKalbertodt): this impl block can be removed in the future. This is
+// possible once the stage0 compiler is new enough to contain the inherent
+// ascii methods for `[u8]`. See TODO comment further down.
+#[cfg(stage0)]
 #[stable(feature = "rust1", since = "1.0.0")]
 impl AsciiExt for [u8] {
     type Owned = Vec<u8>;
@@ -542,6 +546,12 @@ macro_rules! impl_by_delegating {
 impl_by_delegating!(u8, u8);
 impl_by_delegating!(char, char);
 
+// TODO(LukasKalbertodt): the macro invocation should replace the impl block
+// for `[u8]` above. But this is not possible until the stage0 compiler is new
+// enough to contain the inherent ascii methods for `[u8]`.
+#[cfg(not(stage0))]
+impl_by_delegating!([u8], Vec<u8>);
+
 /// An iterator over the escaped version of a byte.
 ///
 /// This `struct` is created by the [`escape_default`] function. See its