impl<T> *const T, impl<T> *mut T

14 files changed, 135 insertions, 0 deletions

diff --git a/src/liballoc/heap.rs b/src/liballoc/heap.rs
index f9936b7a16a..d1c8ab348d4 100644
--- a/src/liballoc/heap.rs
+++ b/src/liballoc/heap.rs
@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[cfg(stage0)]
 #[cfg(not(test))]
 use core::ptr::PtrExt;
 
diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index 115acd4a0ef..3692149db44 100644
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -159,7 +159,10 @@ use core::nonzero::NonZero;
 use core::ops::{Deref, Drop};
 use core::option::Option;
 use core::option::Option::{Some, None};
+#[cfg(stage0)]
 use core::ptr::{self, PtrExt};
+#[cfg(not(stage0))]
+use core::ptr;
 use core::result::Result;
 use core::result::Result::{Ok, Err};
 use core::intrinsics::assume;
diff --git a/src/libcollections/slice.rs b/src/libcollections/slice.rs
index c98d0cb35e1..0fe513d3118 100644
--- a/src/libcollections/slice.rs
+++ b/src/libcollections/slice.rs
@@ -99,6 +99,7 @@ use core::mem;
 use core::num::wrapping::WrappingOps;
 use core::ops::FnMut;
 use core::option::Option::{self, Some, None};
+#[cfg(stage0)]
 use core::ptr::PtrExt;
 use core::ptr;
 use core::result::Result;
diff --git a/src/libcore/prelude.rs b/src/libcore/prelude.rs
index 6c79233da68..fb793a62390 100644
--- a/src/libcore/prelude.rs
+++ b/src/libcore/prelude.rs
@@ -42,6 +42,7 @@ pub use iter::{Extend, IteratorExt};
 pub use iter::{Iterator, DoubleEndedIterator};
 pub use iter::{ExactSizeIterator};
 pub use option::Option::{self, Some, None};
+#[cfg(stage0)]
 pub use ptr::{PtrExt, MutPtrExt};
 pub use result::Result::{self, Ok, Err};
 pub use slice::{AsSlice, SliceExt};
diff --git a/src/libcore/ptr.rs b/src/libcore/ptr.rs
index 32123a8271c..f28c26d1798 100644
--- a/src/libcore/ptr.rs
+++ b/src/libcore/ptr.rs
@@ -262,6 +262,7 @@ pub unsafe fn write<T>(dst: *mut T, src: T) {
     intrinsics::move_val_init(&mut *dst, src)
 }
 
+#[cfg(stage0)]
 /// Methods on raw pointers
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait PtrExt {
@@ -298,6 +299,7 @@ pub trait PtrExt {
     unsafe fn offset(self, count: isize) -> Self where Self::Target: Sized;
 }
 
+#[cfg(stage0)]
 /// Methods on mutable raw pointers
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait MutPtrExt {
@@ -317,6 +319,7 @@ pub trait MutPtrExt {
     unsafe fn as_mut<'a>(&self) -> Option<&'a mut Self::Target>;
 }
 
+#[cfg(stage0)]
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> PtrExt for *const T {
     type Target = T;
@@ -344,6 +347,7 @@ impl<T: ?Sized> PtrExt for *const T {
     }
 }
 
+#[cfg(stage0)]
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> PtrExt for *mut T {
     type Target = T;
@@ -371,6 +375,7 @@ impl<T: ?Sized> PtrExt for *mut T {
     }
 }
 
+#[cfg(stage0)]
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> MutPtrExt for *mut T {
     type Target = T;
@@ -388,6 +393,119 @@ impl<T: ?Sized> MutPtrExt for *mut T {
     }
 }
 
+#[cfg(not(stage0))]
+#[stable(feature = "rust1", since = "1.0.0")]
+#[lang = "const_ptr"]
+impl<T: ?Sized> *const T {
+    /// Returns true if the pointer is null.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
+    pub fn is_null(self) -> bool {
+        self == 0 as *const T
+    }
+
+    /// Returns `None` if the pointer is null, or else returns a reference to
+    /// the value wrapped in `Some`.
+    ///
+    /// # Safety
+    ///
+    /// While this method and its mutable counterpart are useful for
+    /// null-safety, it is important to note that this is still an unsafe
+    /// operation because the returned value could be pointing to invalid
+    /// memory.
+    #[unstable(feature = "core",
+               reason = "Option is not clearly the right return type, and we may want \
+                         to tie the return lifetime to a borrow of the raw pointer")]
+    #[inline]
+    pub unsafe fn as_ref<'a>(&self) -> Option<&'a T> {
+        if self.is_null() {
+            None
+        } else {
+            Some(&**self)
+        }
+    }
+
+    /// Calculates the offset from a pointer. `count` is in units of T; e.g. a
+    /// `count` of 3 represents a pointer offset of `3 * sizeof::<T>()` bytes.
+    ///
+    /// # Safety
+    ///
+    /// The offset must be in-bounds of the object, or one-byte-past-the-end.
+    /// Otherwise `offset` invokes Undefined Behaviour, regardless of whether
+    /// the pointer is used.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
+    pub unsafe fn offset(self, count: isize) -> *const T where T: Sized {
+        intrinsics::offset(self, count)
+    }
+}
+
+#[cfg(not(stage0))]
+#[stable(feature = "rust1", since = "1.0.0")]
+#[lang = "mut_ptr"]
+impl<T: ?Sized> *mut T {
+    /// Returns true if the pointer is null.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
+    pub fn is_null(self) -> bool {
+        self == 0 as *mut T
+    }
+
+    /// Returns `None` if the pointer is null, or else returns a reference to
+    /// the value wrapped in `Some`.
+    ///
+    /// # Safety
+    ///
+    /// While this method and its mutable counterpart are useful for
+    /// null-safety, it is important to note that this is still an unsafe
+    /// operation because the returned value could be pointing to invalid
+    /// memory.
+    #[unstable(feature = "core",
+               reason = "Option is not clearly the right return type, and we may want \
+                         to tie the return lifetime to a borrow of the raw pointer")]
+    #[inline]
+    pub unsafe fn as_ref<'a>(&self) -> Option<&'a T> {
+        if self.is_null() {
+            None
+        } else {
+            Some(&**self)
+        }
+    }
+
+    /// Calculates the offset from a pointer. `count` is in units of T; e.g. a
+    /// `count` of 3 represents a pointer offset of `3 * sizeof::<T>()` bytes.
+    ///
+    /// # Safety
+    ///
+    /// The offset must be in-bounds of the object, or one-byte-past-the-end.
+    /// Otherwise `offset` invokes Undefined Behaviour, regardless of whether
+    /// the pointer is used.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    #[inline]
+    pub unsafe fn offset(self, count: isize) -> *mut T where T: Sized {
+        intrinsics::offset(self, count) as *mut T
+    }
+
+    /// Returns `None` if the pointer is null, or else returns a mutable
+    /// reference to the value wrapped in `Some`.
+    ///
+    /// # Safety
+    ///
+    /// As with `as_ref`, this is unsafe because it cannot verify the validity
+    /// of the returned pointer.
+    #[unstable(feature = "core",
+               reason = "return value does not necessarily convey all possible \
+                         information")]
+    #[inline]
+    pub unsafe fn as_mut<'a>(&self) -> Option<&'a mut T> {
+        if self.is_null() {
+            None
+        } else {
+            Some(&mut **self)
+        }
+    }
+}
+
 // Equality for pointers
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> PartialEq for *const T {
diff --git a/src/libcore/slice.rs b/src/libcore/slice.rs
index 62cffa9b86e..c8a8dd88501 100644
--- a/src/libcore/slice.rs
+++ b/src/libcore/slice.rs
@@ -49,6 +49,7 @@ use option::Option::{None, Some};
 use result::Result;
 use result::Result::{Ok, Err};
 use ptr;
+#[cfg(stage0)]
 use ptr::PtrExt;
 use mem;
 use mem::size_of;
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 6f72890d96f..3873f305b42 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -30,6 +30,7 @@ use mem;
 use num::Int;
 use ops::{Fn, FnMut};
 use option::Option::{self, None, Some};
+#[cfg(stage0)]
 use ptr::PtrExt;
 use raw::{Repr, Slice};
 use result::Result::{self, Ok, Err};
diff --git a/src/libstd/collections/hash/table.rs b/src/libstd/collections/hash/table.rs
index 69fd0a57d5f..7812363d55e 100644
--- a/src/libstd/collections/hash/table.rs
+++ b/src/libstd/collections/hash/table.rs
@@ -24,7 +24,10 @@ use num::wrapping::{OverflowingOps, WrappingOps};
 use ops::{Deref, DerefMut, Drop};
 use option::Option;
 use option::Option::{Some, None};
+#[cfg(stage0)]
 use ptr::{self, PtrExt, Unique};
+#[cfg(not(stage0))]
+use ptr::{self, Unique};
 use rt::heap::{allocate, deallocate, EMPTY};
 use collections::hash_state::HashState;
 
diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index c89edf72842..72d014e77a7 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -20,6 +20,7 @@ use iter::Iterator;
 use marker::Sized;
 use ops::{Drop, FnOnce};
 use option::Option::{self, Some, None};
+#[cfg(stage0)]
 use ptr::PtrExt;
 use result::Result::{Ok, Err};
 use result;
diff --git a/src/libstd/old_io/extensions.rs b/src/libstd/old_io/extensions.rs
index b67ec847c79..a81275952c5 100644
--- a/src/libstd/old_io/extensions.rs
+++ b/src/libstd/old_io/extensions.rs
@@ -26,6 +26,7 @@ use num::Int;
 use ops::FnOnce;
 use option::Option;
 use option::Option::{Some, None};
+#[cfg(stage0)]
 use ptr::PtrExt;
 use result::Result::{Ok, Err};
 #[cfg(stage0)]
diff --git a/src/libstd/old_io/mod.rs b/src/libstd/old_io/mod.rs
index 89e813de5b6..2c978177c50 100644
--- a/src/libstd/old_io/mod.rs
+++ b/src/libstd/old_io/mod.rs
@@ -935,6 +935,7 @@ impl<'a> Reader for &'a mut (Reader+'a) {
 // API yet. If so, it should be a method on Vec.
 unsafe fn slice_vec_capacity<'a, T>(v: &'a mut Vec<T>, start: uint, end: uint) -> &'a mut [T] {
     use slice;
+    #[cfg(stage0)]
     use ptr::PtrExt;
 
     assert!(start <= end);
diff --git a/src/libstd/os.rs b/src/libstd/os.rs
index e04d7f3f240..fc05eb1d627 100644
--- a/src/libstd/os.rs
+++ b/src/libstd/os.rs
@@ -52,6 +52,7 @@ use option::Option::{Some, None};
 use option::Option;
 use old_path::{Path, GenericPath, BytesContainer};
 use path::{self, PathBuf};
+#[cfg(stage0)]
 use ptr::PtrExt;
 use ptr;
 use result::Result::{Err, Ok};
diff --git a/src/libstd/prelude/v1.rs b/src/libstd/prelude/v1.rs
index e21ae1657ee..4327b26260a 100644
--- a/src/libstd/prelude/v1.rs
+++ b/src/libstd/prelude/v1.rs
@@ -40,6 +40,7 @@
 #[doc(no_inline)] pub use iter::{Iterator, IteratorExt, Extend};
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)] pub use option::Option::{self, Some, None};
+#[cfg(stage0)]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)] pub use ptr::{PtrExt, MutPtrExt};
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/libstd/rt/at_exit_imp.rs b/src/libstd/rt/at_exit_imp.rs
index 08755ba829f..f6bb87f011d 100644
--- a/src/libstd/rt/at_exit_imp.rs
+++ b/src/libstd/rt/at_exit_imp.rs
@@ -12,6 +12,7 @@
 //!
 //! Documentation can be found on the `rt::at_exit` function.
 
+#[cfg(stage0)]
 use core::prelude::*;
 
 use boxed;