Make the unstable StrExt and SliceExt traits private to libcore in not(stage0)

`Float` still needs to be public for libcore unit tests.

Author: SimonSapin

src/liballoc/lib.rs

@@ -75,7 +75,7 @@
 #![deny(missing_debug_implementations)]
 
 #![cfg_attr(test, allow(deprecated))] // rand
-#![cfg_attr(not(test), feature(core_float))]
+#![cfg_attr(all(not(test), stage0), feature(float_internals))]
 #![cfg_attr(not(test), feature(exact_size_is_empty))]
 #![cfg_attr(not(test), feature(generator_trait))]
 #![cfg_attr(test, feature(rand, test))]

src/libcore/internal_macros.rs

@@ -87,3 +87,16 @@ macro_rules! forward_ref_op_assign {
     }
 }
 
+#[cfg(stage0)]
+macro_rules! public_in_stage0 {
+    ( { $(#[$attr:meta])* } $($Item: tt)*) => {
+        $(#[$attr])* pub $($Item)*
+    }
+}
+
+#[cfg(not(stage0))]
+macro_rules! public_in_stage0 {
+    ( { $(#[$attr:meta])* } $($Item: tt)*) => {
+        $(#[$attr])* pub(crate) $($Item)*
+    }
+}

src/libcore/num/mod.rs

@@ -4009,65 +4009,58 @@ pub enum FpCategory {
     Normal,
 }
 
-/// A built-in floating point number.
+// Technically private and only exposed for coretests:
 #[doc(hidden)]
-#[unstable(feature = "core_float",
-           reason = "stable interface is via `impl f{32,64}` in later crates",
-           issue = "32110")]
+#[unstable(feature = "float_internals",
+           reason = "internal routines only exposed for testing",
+           issue = "0")]
 pub trait Float: Sized {
     /// Type used by `to_bits` and `from_bits`.
-    #[stable(feature = "core_float_bits", since = "1.25.0")]
     type Bits;
 
     /// Returns `true` if this value is NaN and false otherwise.
-    #[stable(feature = "core", since = "1.6.0")]
     fn is_nan(self) -> bool;
+
     /// Returns `true` if this value is positive infinity or negative infinity and
     /// false otherwise.
-    #[stable(feature = "core", since = "1.6.0")]
     fn is_infinite(self) -> bool;
+
     /// Returns `true` if this number is neither infinite nor NaN.
-    #[stable(feature = "core", since = "1.6.0")]
     fn is_finite(self) -> bool;
+
     /// Returns `true` if this number is neither zero, infinite, denormal, or NaN.
-    #[stable(feature = "core", since = "1.6.0")]
     fn is_normal(self) -> bool;
+
     /// Returns the category that this number falls into.
-    #[stable(feature = "core", since = "1.6.0")]
     fn classify(self) -> FpCategory;
 
     /// Returns `true` if `self` is positive, including `+0.0` and
     /// `Float::infinity()`.
-    #[stable(feature = "core", since = "1.6.0")]
     fn is_sign_positive(self) -> bool;
+
     /// Returns `true` if `self` is negative, including `-0.0` and
     /// `Float::neg_infinity()`.
-    #[stable(feature = "core", since = "1.6.0")]
     fn is_sign_negative(self) -> bool;
 
     /// Take the reciprocal (inverse) of a number, `1/x`.
-    #[stable(feature = "core", since = "1.6.0")]
     fn recip(self) -> Self;
 
     /// Convert radians to degrees.
-    #[stable(feature = "deg_rad_conversions", since="1.7.0")]
     fn to_degrees(self) -> Self;
+
     /// Convert degrees to radians.
-    #[stable(feature = "deg_rad_conversions", since="1.7.0")]
     fn to_radians(self) -> Self;
 
     /// Returns the maximum of the two numbers.
-    #[stable(feature = "core_float_min_max", since="1.20.0")]
     fn max(self, other: Self) -> Self;
+
     /// Returns the minimum of the two numbers.
-    #[stable(feature = "core_float_min_max", since="1.20.0")]
     fn min(self, other: Self) -> Self;
 
     /// Raw transmutation to integer.
-    #[stable(feature = "core_float_bits", since="1.25.0")]
     fn to_bits(self) -> Self::Bits;
+
     /// Raw transmutation from integer.
-    #[stable(feature = "core_float_bits", since="1.25.0")]
     fn from_bits(v: Self::Bits) -> Self;
 }
 

src/libcore/slice/mod.rs

@@ -68,12 +68,15 @@ struct Repr<T> {
 // Extension traits
 //
 
+public_in_stage0! {
+{
 /// Extension methods for slices.
 #[unstable(feature = "core_slice_ext",
            reason = "stable interface provided by `impl [T]` in later crates",
            issue = "32110")]
 #[allow(missing_docs)] // documented elsewhere
-pub trait SliceExt {
+}
+trait SliceExt {
     type Item;
 
     #[stable(feature = "core", since = "1.6.0")]
@@ -238,7 +241,7 @@ pub trait SliceExt {
     fn sort_unstable_by_key<B, F>(&mut self, f: F)
         where F: FnMut(&Self::Item) -> B,
               B: Ord;
-}
+}}
 
 // Use macros to be generic over const/mut
 macro_rules! slice_offset {

src/libcore/str/mod.rs

@@ -2117,14 +2117,16 @@ mod traits {
 
 }
 
-
+public_in_stage0! {
+{
 /// Methods for string slices
 #[allow(missing_docs)]
 #[doc(hidden)]
 #[unstable(feature = "core_str_ext",
            reason = "stable interface provided by `impl str` in later crates",
            issue = "32110")]
-pub trait StrExt {
+}
+trait StrExt {
     // NB there are no docs here are they're all located on the StrExt trait in
     // liballoc, not here.
 
@@ -2228,7 +2230,7 @@ pub trait StrExt {
     fn trim_left(&self) -> &str;
     #[stable(feature = "rust1", since = "1.0.0")]
     fn trim_right(&self) -> &str;
-}
+}}
 
 // truncate `&str` to length at most equal to `max`
 // return `true` if it were truncated, and the new str.

src/libcore/tests/lib.rs

@@ -17,6 +17,7 @@
 #![feature(decode_utf8)]
 #![feature(exact_size_is_empty)]
 #![feature(fixed_size_array)]
+#![feature(float_internals)]
 #![feature(flt2dec)]
 #![feature(fmt_internals)]
 #![feature(hashmap_internals)]

src/libstd/lib.rs

@@ -252,14 +252,15 @@
 #![feature(collections_range)]
 #![feature(compiler_builtins_lib)]
 #![feature(const_fn)]
-#![feature(core_float)]
+#![cfg_attr(stage0, feature(core_float))]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
 #![feature(exact_size_is_empty)]
 #![feature(external_doc)]
 #![feature(fs_read_write)]
 #![feature(fixed_size_array)]
 #![feature(float_from_str_radix)]
+#![cfg_attr(stage0, feature(float_internals))]
 #![feature(fn_traits)]
 #![feature(fnbox)]
 #![cfg_attr(stage0, feature(generic_param_attrs))]

src/test/ui/impl-trait/method-suggestion-no-duplication.stderr

@@ -8,10 +8,8 @@ LL |     foo(|s| s.is_empty());
    |               ^^^^^^^^
    |
    = help: items from traits can only be used if the trait is implemented and in scope
-   = note: the following traits define an item `is_empty`, perhaps you need to implement one of them:
+   = note: the following trait defines an item `is_empty`, perhaps you need to implement it:
            candidate #1: `std::iter::ExactSizeIterator`
-           candidate #2: `core::slice::SliceExt`
-           candidate #3: `core::str::StrExt`
 
 error: aborting due to previous error