Move placement new operators to module.

2 files changed, 130 insertions, 119 deletions

diff --git a/src/libcore/ops/mod.rs b/src/libcore/ops/mod.rs
index fdc1b5fc235..d05365a8fdd 100644
--- a/src/libcore/ops/mod.rs
+++ b/src/libcore/ops/mod.rs
@@ -150,17 +150,16 @@
 mod arith;
 mod bit;
 mod function;
+mod place;
 mod range;
 
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use self::arith::{Add, Sub, Mul, Div, Rem, Neg};
-
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
 pub use self::arith::{AddAssign, SubAssign, MulAssign, DivAssign, RemAssign};
 
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use self::bit::{Not, BitAnd, BitOr, BitXor, Shl, Shr};
-
 #[stable(feature = "op_assign_traits", since = "1.8.0")]
 pub use self::bit::{BitAndAssign, BitOrAssign, BitXorAssign, ShlAssign, ShrAssign};
 
@@ -173,6 +172,9 @@ pub use self::range::{Range, RangeFrom, RangeFull, RangeTo};
 #[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
 pub use self::range::{RangeInclusive, RangeToInclusive};
 
+#[unstable(feature = "placement_new_protocol", issue = "27779")]
+pub use self::place::{Place, Placer, InPlace, Boxed, BoxPlace};
+
 use marker::Unsize;
 
 /// The `Drop` trait is used to run some code when a value goes out of scope.
@@ -592,123 +594,6 @@ impl<T: ?Sized+Unsize<U>, U: ?Sized> CoerceUnsized<*const U> for *mut T {}
 #[unstable(feature = "coerce_unsized", issue = "27732")]
 impl<T: ?Sized+Unsize<U>, U: ?Sized> CoerceUnsized<*const U> for *const T {}
 
-/// Both `PLACE <- EXPR` and `box EXPR` desugar into expressions
-/// that allocate an intermediate "place" that holds uninitialized
-/// state.  The desugaring evaluates EXPR, and writes the result at
-/// the address returned by the `pointer` method of this trait.
-///
-/// A `Place` can be thought of as a special representation for a
-/// hypothetical `&uninit` reference (which Rust cannot currently
-/// express directly). That is, it represents a pointer to
-/// uninitialized storage.
-///
-/// The client is responsible for two steps: First, initializing the
-/// payload (it can access its address via `pointer`). Second,
-/// converting the agent to an instance of the owning pointer, via the
-/// appropriate `finalize` method (see the `InPlace`.
-///
-/// If evaluating EXPR fails, then it is up to the destructor for the
-/// implementation of Place to clean up any intermediate state
-/// (e.g. deallocate box storage, pop a stack, etc).
-#[unstable(feature = "placement_new_protocol", issue = "27779")]
-pub trait Place<Data: ?Sized> {
-    /// Returns the address where the input value will be written.
-    /// Note that the data at this address is generally uninitialized,
-    /// and thus one should use `ptr::write` for initializing it.
-    fn pointer(&mut self) -> *mut Data;
-}
-
-/// Interface to implementations of  `PLACE <- EXPR`.
-///
-/// `PLACE <- EXPR` effectively desugars into:
-///
-/// ```rust,ignore
-/// let p = PLACE;
-/// let mut place = Placer::make_place(p);
-/// let raw_place = Place::pointer(&mut place);
-/// let value = EXPR;
-/// unsafe {
-///     std::ptr::write(raw_place, value);
-///     InPlace::finalize(place)
-/// }
-/// ```
-///
-/// The type of `PLACE <- EXPR` is derived from the type of `PLACE`;
-/// if the type of `PLACE` is `P`, then the final type of the whole
-/// expression is `P::Place::Owner` (see the `InPlace` and `Boxed`
-/// traits).
-///
-/// Values for types implementing this trait usually are transient
-/// intermediate values (e.g. the return value of `Vec::emplace_back`)
-/// or `Copy`, since the `make_place` method takes `self` by value.
-#[unstable(feature = "placement_new_protocol", issue = "27779")]
-pub trait Placer<Data: ?Sized> {
-    /// `Place` is the intermedate agent guarding the
-    /// uninitialized state for `Data`.
-    type Place: InPlace<Data>;
-
-    /// Creates a fresh place from `self`.
-    fn make_place(self) -> Self::Place;
-}
-
-/// Specialization of `Place` trait supporting `PLACE <- EXPR`.
-#[unstable(feature = "placement_new_protocol", issue = "27779")]
-pub trait InPlace<Data: ?Sized>: Place<Data> {
-    /// `Owner` is the type of the end value of `PLACE <- EXPR`
-    ///
-    /// Note that when `PLACE <- EXPR` is solely used for
-    /// side-effecting an existing data-structure,
-    /// e.g. `Vec::emplace_back`, then `Owner` need not carry any
-    /// information at all (e.g. it can be the unit type `()` in that
-    /// case).
-    type Owner;
-
-    /// Converts self into the final value, shifting
-    /// deallocation/cleanup responsibilities (if any remain), over to
-    /// the returned instance of `Owner` and forgetting self.
-    unsafe fn finalize(self) -> Self::Owner;
-}
-
-/// Core trait for the `box EXPR` form.
-///
-/// `box EXPR` effectively desugars into:
-///
-/// ```rust,ignore
-/// let mut place = BoxPlace::make_place();
-/// let raw_place = Place::pointer(&mut place);
-/// let value = EXPR;
-/// unsafe {
-///     ::std::ptr::write(raw_place, value);
-///     Boxed::finalize(place)
-/// }
-/// ```
-///
-/// The type of `box EXPR` is supplied from its surrounding
-/// context; in the above expansion, the result type `T` is used
-/// to determine which implementation of `Boxed` to use, and that
-/// `<T as Boxed>` in turn dictates determines which
-/// implementation of `BoxPlace` to use, namely:
-/// `<<T as Boxed>::Place as BoxPlace>`.
-#[unstable(feature = "placement_new_protocol", issue = "27779")]
-pub trait Boxed {
-    /// The kind of data that is stored in this kind of box.
-    type Data;  /* (`Data` unused b/c cannot yet express below bound.) */
-    /// The place that will negotiate the storage of the data.
-    type Place: BoxPlace<Self::Data>;
-
-    /// Converts filled place into final owning value, shifting
-    /// deallocation/cleanup responsibilities (if any remain), over to
-    /// returned instance of `Self` and forgetting `filled`.
-    unsafe fn finalize(filled: Self::Place) -> Self;
-}
-
-/// Specialization of `Place` trait supporting `box EXPR`.
-#[unstable(feature = "placement_new_protocol", issue = "27779")]
-pub trait BoxPlace<Data: ?Sized> : Place<Data> {
-    /// Creates a globally fresh place.
-    fn make_place() -> Self;
-}
-
 /// This trait has been superseded by the `Try` trait, but must remain
 /// here as `?` is still lowered to it in stage0 .
 #[cfg(stage0)]
diff --git a/src/libcore/ops/place.rs b/src/libcore/ops/place.rs
new file mode 100644
index 00000000000..996a741c96f
--- /dev/null
+++ b/src/libcore/ops/place.rs
@@ -0,0 +1,126 @@
+// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+/// Both `PLACE <- EXPR` and `box EXPR` desugar into expressions
+/// that allocate an intermediate "place" that holds uninitialized
+/// state.  The desugaring evaluates EXPR, and writes the result at
+/// the address returned by the `pointer` method of this trait.
+///
+/// A `Place` can be thought of as a special representation for a
+/// hypothetical `&uninit` reference (which Rust cannot currently
+/// express directly). That is, it represents a pointer to
+/// uninitialized storage.
+///
+/// The client is responsible for two steps: First, initializing the
+/// payload (it can access its address via `pointer`). Second,
+/// converting the agent to an instance of the owning pointer, via the
+/// appropriate `finalize` method (see the `InPlace`.
+///
+/// If evaluating EXPR fails, then it is up to the destructor for the
+/// implementation of Place to clean up any intermediate state
+/// (e.g. deallocate box storage, pop a stack, etc).
+#[unstable(feature = "placement_new_protocol", issue = "27779")]
+pub trait Place<Data: ?Sized> {
+    /// Returns the address where the input value will be written.
+    /// Note that the data at this address is generally uninitialized,
+    /// and thus one should use `ptr::write` for initializing it.
+    fn pointer(&mut self) -> *mut Data;
+}
+
+/// Interface to implementations of  `PLACE <- EXPR`.
+///
+/// `PLACE <- EXPR` effectively desugars into:
+///
+/// ```rust,ignore
+/// let p = PLACE;
+/// let mut place = Placer::make_place(p);
+/// let raw_place = Place::pointer(&mut place);
+/// let value = EXPR;
+/// unsafe {
+///     std::ptr::write(raw_place, value);
+///     InPlace::finalize(place)
+/// }
+/// ```
+///
+/// The type of `PLACE <- EXPR` is derived from the type of `PLACE`;
+/// if the type of `PLACE` is `P`, then the final type of the whole
+/// expression is `P::Place::Owner` (see the `InPlace` and `Boxed`
+/// traits).
+///
+/// Values for types implementing this trait usually are transient
+/// intermediate values (e.g. the return value of `Vec::emplace_back`)
+/// or `Copy`, since the `make_place` method takes `self` by value.
+#[unstable(feature = "placement_new_protocol", issue = "27779")]
+pub trait Placer<Data: ?Sized> {
+    /// `Place` is the intermedate agent guarding the
+    /// uninitialized state for `Data`.
+    type Place: InPlace<Data>;
+
+    /// Creates a fresh place from `self`.
+    fn make_place(self) -> Self::Place;
+}
+
+/// Specialization of `Place` trait supporting `PLACE <- EXPR`.
+#[unstable(feature = "placement_new_protocol", issue = "27779")]
+pub trait InPlace<Data: ?Sized>: Place<Data> {
+    /// `Owner` is the type of the end value of `PLACE <- EXPR`
+    ///
+    /// Note that when `PLACE <- EXPR` is solely used for
+    /// side-effecting an existing data-structure,
+    /// e.g. `Vec::emplace_back`, then `Owner` need not carry any
+    /// information at all (e.g. it can be the unit type `()` in that
+    /// case).
+    type Owner;
+
+    /// Converts self into the final value, shifting
+    /// deallocation/cleanup responsibilities (if any remain), over to
+    /// the returned instance of `Owner` and forgetting self.
+    unsafe fn finalize(self) -> Self::Owner;
+}
+
+/// Core trait for the `box EXPR` form.
+///
+/// `box EXPR` effectively desugars into:
+///
+/// ```rust,ignore
+/// let mut place = BoxPlace::make_place();
+/// let raw_place = Place::pointer(&mut place);
+/// let value = EXPR;
+/// unsafe {
+///     ::std::ptr::write(raw_place, value);
+///     Boxed::finalize(place)
+/// }
+/// ```
+///
+/// The type of `box EXPR` is supplied from its surrounding
+/// context; in the above expansion, the result type `T` is used
+/// to determine which implementation of `Boxed` to use, and that
+/// `<T as Boxed>` in turn dictates determines which
+/// implementation of `BoxPlace` to use, namely:
+/// `<<T as Boxed>::Place as BoxPlace>`.
+#[unstable(feature = "placement_new_protocol", issue = "27779")]
+pub trait Boxed {
+    /// The kind of data that is stored in this kind of box.
+    type Data;  /* (`Data` unused b/c cannot yet express below bound.) */
+    /// The place that will negotiate the storage of the data.
+    type Place: BoxPlace<Self::Data>;
+
+    /// Converts filled place into final owning value, shifting
+    /// deallocation/cleanup responsibilities (if any remain), over to
+    /// returned instance of `Self` and forgetting `filled`.
+    unsafe fn finalize(filled: Self::Place) -> Self;
+}
+
+/// Specialization of `Place` trait supporting `box EXPR`.
+#[unstable(feature = "placement_new_protocol", issue = "27779")]
+pub trait BoxPlace<Data: ?Sized> : Place<Data> {
+    /// Creates a globally fresh place.
+    fn make_place() -> Self;
+}