3 files changed, 5 insertions, 21 deletions
diff --git a/src/liballoc/boxed.rs b/src/liballoc/boxed.rs
index 0343787d0c0..6f125cdba81 100644
--- a/src/liballoc/boxed.rs
+++ b/src/liballoc/boxed.rs
@@ -300,10 +300,7 @@ impl<T: ?Sized> Box<T> {
                issue = "27730")]
     #[inline]
     pub unsafe fn from_unique(u: Unique<T>) -> Self {
-        #[cfg(stage0)]
-        return mem::transmute(u);
-        #[cfg(not(stage0))]
-        return Box(u);
+        Box(u)
     }
 
     /// Consumes the `Box`, returning the wrapped raw pointer.
@@ -365,14 +362,9 @@ impl<T: ?Sized> Box<T> {
                issue = "27730")]
     #[inline]
     pub fn into_unique(b: Box<T>) -> Unique<T> {
-        #[cfg(stage0)]
-        return unsafe { mem::transmute(b) };
-        #[cfg(not(stage0))]
-        return {
-            let unique = b.0;
-            mem::forget(b);
-            unique
-        };
+        let unique = b.0;
+        mem::forget(b);
+        unique
     }
 
     /// Consumes and leaks the `Box`, returning a mutable reference,
diff --git a/src/liballoc/slice.rs b/src/liballoc/slice.rs
index 0eee7fb722e..ac815629dcf 100644
--- a/src/liballoc/slice.rs
+++ b/src/liballoc/slice.rs
@@ -1626,11 +1626,8 @@ impl<T> [T] {
     }
 }
 
-// FIXME(LukasKalbertodt): the `not(stage0)` constraint can be removed in the
-// future once the stage0 compiler is new enough to know about the `slice_u8`
-// lang item.
 #[lang = "slice_u8"]
-#[cfg(all(not(stage0), not(test)))]
+#[cfg(not(test))]
 impl [u8] {
     /// Checks if all bytes in this slice are within the ASCII range.
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.21.0")]
diff --git a/src/liballoc/str.rs b/src/liballoc/str.rs
index 9755c5d54f2..975ea4e1a3e 100644
--- a/src/liballoc/str.rs
+++ b/src/liballoc/str.rs
@@ -2110,7 +2110,6 @@ impl str {
     /// [`to_uppercase`]: #method.to_uppercase
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.21.0")]
     #[inline]
-    #[cfg(not(stage0))]
     pub fn to_ascii_uppercase(&self) -> String {
         let mut bytes = self.as_bytes().to_vec();
         bytes.make_ascii_uppercase();
@@ -2141,7 +2140,6 @@ impl str {
     /// [`to_lowercase`]: #method.to_lowercase
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.21.0")]
     #[inline]
-    #[cfg(not(stage0))]
     pub fn to_ascii_lowercase(&self) -> String {
         let mut bytes = self.as_bytes().to_vec();
         bytes.make_ascii_lowercase();
@@ -2163,7 +2161,6 @@ impl str {
     /// ```
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.21.0")]
     #[inline]
-    #[cfg(not(stage0))]
     pub fn eq_ignore_ascii_case(&self, other: &str) -> bool {
         self.as_bytes().eq_ignore_ascii_case(other.as_bytes())
     }
@@ -2178,7 +2175,6 @@ impl str {
     ///
     /// [`to_ascii_uppercase`]: #method.to_ascii_uppercase
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.21.0")]
-    #[cfg(not(stage0))]
     pub fn make_ascii_uppercase(&mut self) {
         let me = unsafe { self.as_bytes_mut() };
         me.make_ascii_uppercase()
@@ -2194,7 +2190,6 @@ impl str {
     ///
     /// [`to_ascii_lowercase`]: #method.to_ascii_lowercase
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.21.0")]
-    #[cfg(not(stage0))]
     pub fn make_ascii_lowercase(&mut self) {
         let me = unsafe { self.as_bytes_mut() };
         me.make_ascii_lowercase()