From 9b5859aea199d5f34a4d4b5ae7112c5c41f3b242 Mon Sep 17 00:00:00 2001 From: Aidan Hobson Sayers Date: Sun, 18 Feb 2018 17:39:40 +0000 Subject: Remove all unstable placement features Closes #22181, #27779 --- src/libcore/ops/mod.rs | 4 -- src/libcore/ops/place.rs | 143 ----------------------------------------------- 2 files changed, 147 deletions(-) delete mode 100644 src/libcore/ops/place.rs (limited to 'src/libcore') diff --git a/src/libcore/ops/mod.rs b/src/libcore/ops/mod.rs index 0b480b618fc..ce4f45762de 100644 --- a/src/libcore/ops/mod.rs +++ b/src/libcore/ops/mod.rs @@ -161,7 +161,6 @@ mod drop; mod function; mod generator; mod index; -mod place; mod range; mod try; mod unsize; @@ -200,8 +199,5 @@ pub use self::try::Try; #[unstable(feature = "generator_trait", issue = "43122")] pub use self::generator::{Generator, GeneratorState}; -#[unstable(feature = "placement_new_protocol", issue = "27779")] -pub use self::place::{Place, Placer, InPlace, Boxed, BoxPlace}; - #[unstable(feature = "coerce_unsized", issue = "27732")] pub use self::unsize::CoerceUnsized; diff --git a/src/libcore/ops/place.rs b/src/libcore/ops/place.rs deleted file mode 100644 index b3dcf4e7ee9..00000000000 --- a/src/libcore/ops/place.rs +++ /dev/null @@ -1,143 +0,0 @@ -// 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 or the MIT license -// , 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 unsafe trait Place { - /// 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. - /// - /// This function must return a pointer through which a value - /// of type `Data` can be written. - fn pointer(&mut self) -> *mut Data; -} - -/// Interface to implementations of `PLACE <- EXPR`. -/// -/// `PLACE <- EXPR` effectively desugars into: -/// -/// ``` -/// # #![feature(placement_new_protocol, box_heap)] -/// # use std::ops::{Placer, Place, InPlace}; -/// # #[allow(non_snake_case)] -/// # fn main() { -/// # let PLACE = std::boxed::HEAP; -/// # let EXPR = 1; -/// 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 { - /// `Place` is the intermediate agent guarding the - /// uninitialized state for `Data`. - type Place: InPlace; - - /// 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: Place { - /// `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: -/// -/// ``` -/// # #![feature(placement_new_protocol)] -/// # use std::ops::{BoxPlace, Place, Boxed}; -/// # #[allow(non_snake_case)] -/// # fn main() { -/// # let EXPR = 1; -/// let mut place = BoxPlace::make_place(); -/// let raw_place = Place::pointer(&mut place); -/// let value = EXPR; -/// # let _: Box<_> = -/// 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 -/// `` in turn dictates determines which -/// implementation of `BoxPlace` to use, namely: -/// `<::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; - - /// 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 : Place { - /// Creates a globally fresh place. - fn make_place() -> Self; -} -- cgit 1.4.1-3-g733a5