Following [the collections reform RFC](https://github.com/rust-lang/rfcs/pull/235), this PR:
* Adds a new `borrow` module to libcore. The module contains traits for borrowing data (`BorrowFrom` and `BorrowFromMut`), generalized cloning (`ToOwned`), and a clone-on-write smartpointer (`Cow`).
* Deprecates the `_equiv` family of methods on `HashMap` and `HashSet` by instead generalizing the "normal" methods like `get` and `remove` to use the new `std::borrow` infrastructure.
* Generalizes `TreeMap`, `TreeSet`, `BTreeMap` and `BTreeSet` to use the new `std::borrow` infrastructure for lookups.
[breaking-change]
This is especially useful for declaring a static with external linkage in an executable. There isn't any way to do that currently since we mark everything in an executable as internal by default.
Also, a quick fix to have the no-compiler-rt target option respected when building staticlibs as well.
This breaks code that referred to variant names in the same namespace as
their enum. Reexport the variants in the old location or alter code to
refer to the new locations:
```
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
=>
```
pub use self::Foo::{A, B};
pub enum Foo {
A,
B
}
fn main() {
let a = A;
}
```
or
```
pub enum Foo {
A,
B
}
fn main() {
let a = Foo::A;
}
```
[breaking-change]
This was a simple case of substitutions being applied inconsistently. I haven't investigated why type parameters are actually showing up in the closure type here, but trans needs to handle them correctly in any case.
This implements a considerable portion of rust-lang/rfcs#369 (tracked in #18640). Some interpretations had to be made in order to get this to work. The breaking changes are listed below:
[breaking-change]
- `core::num::{Num, Unsigned, Primitive}` have been deprecated and their re-exports removed from the `{std, core}::prelude`.
- `core::num::{Zero, One, Bounded}` have been deprecated. Use the static methods on `core::num::{Float, Int}` instead. There is no equivalent to `Zero::is_zero`. Use `(==)` with `{Float, Int}::zero` instead.
- `Signed::abs_sub` has been moved to `std::num::FloatMath`, and is no longer implemented for signed integers.
- `core::num::Signed` has been removed, and its methods have been moved to `core::num::Float` and a new trait, `core::num::SignedInt`. The methods now take the `self` parameter by value.
- `core::num::{Saturating, CheckedAdd, CheckedSub, CheckedMul, CheckedDiv}` have been removed, and their methods moved to `core::num::Int`. Their parameters are now taken by value. This means that
- `std::time::Duration` no longer implements `core::num::{Zero, CheckedAdd, CheckedSub}` instead defining the required methods non-polymorphically.
- `core::num::{zero, one, abs, signum}` have been deprecated. Use their respective methods instead.
- The `core::num::{next_power_of_two, is_power_of_two, checked_next_power_of_two}` functions have been deprecated in favor of methods defined a new trait, `core::num::UnsignedInt`
- `core::iter::{AdditiveIterator, MultiplicativeIterator}` are now only implemented for the built-in numeric types.
- `core::iter::{range, range_inclusive, range_step, range_step_inclusive}` now require `core::num::Int` to be implemented for the type they a re parametrized over.
This patch tweaks the stability inheritance infrastructure so that
`#{stable]` attributes are not inherited. Doing so solves two problems:
1. It allows us to mark module *names* as stable without accidentally
marking the items they contain as stable.
2. It means that a `#[stable]` attribution must always appear directly
on the item it applies to, which makes it easier for reviewers to catch
changes to stable APIs.
Fixes#17484
Adds a method for printing a fatal error and also a help message to the
parser and uses this in a variety of places to improve error messages.
Closes#12213.
This commit deprecates the entire libtime library in favor of the
externally-provided libtime in the rust-lang organization. Users of the
`libtime` crate as-is today should add this to their Cargo manifests:
[dependencies.time]
git = "https://github.com/rust-lang/time"
To implement this transition, a new function `Duration::span` was added to the
`std::time::Duration` time. This function takes a closure and then returns the
duration of time it took that closure to execute. This interface will likely
improve with `FnOnce` unboxed closures as moving in and out will be a little
easier.
Due to the deprecation of the in-tree crate, this is a:
[breaking-change]
cc #18855, some of the conversions in the `src/test/bench` area may have been a
little nicer with that implemented
This PR includes a sequence of commits that gradually dismantles the `librustrt` `rtio` system -- the main trait previously used to abstract over green and native io. It also largely dismantles `libnative`, moving much of its code into `libstd` and refactoring as it does so.
TL;DR:
* Before this PR: `rustc hello.rs && wc -c hello` produces 715,996
* After this PR: `rustc hello.rs && wc -c hello` produces 368,100
That is, this PR reduces the footprint of hello world by ~50%.
This is a major step toward #17325 (i.e. toward implementing the [runtime removal RFC](https://github.com/rust-lang/rfcs/pull/230).) What remains is to pull out the scheduling, synchronization and task infrastructure, and to remove `libgreen`. These will be done soon in a follow-up PR.
Part of the work here is eliminating the `rtio` abstraction, which in many cases means bringing the implementation of io closer to the actual API presented in `std::io`.
Another aspect of this PR is the creation of two new, *private* modules within `std` that implement io:
* The `sys` module, which represents a platform-specific implementation of a number of low-level abstractions that are used directly within `std::io` and `std::os`. These "abstractions" are left largely the same as they were in `libnative` (except for the removal of `Arc` in file descriptors), but they are expected to evolve greatly over time. Organizationally, there are `sys/unix/` and `sys/windows/` directories which both implement the entire `sys` module hierarchy; this means that nearly all of the platform-specific code is isolated and you can get a handle on each platform in isolation.
* The `sys_common` module, which is rooted at `sys/common`, and provides a few pieces of private, low-level, but cross-platform functionality.
In the long term, the `sys` modules will provide hooks for exposing high-level platform-specific APIs as part of `libstd`. The first such API will be access to file descriptors from `std::io` abstractions, but a bit of design work remains before that step can be taken.
The `sys_common` module includes some traits (like `AsFileDesc`) which allow communication of private details between modules in disparate locations in the hierarchy; this helps overcome the relatively simple hierarchical privacy system in Rust.
To emphasize: the organization in `sys` is *very preliminary* and the main goal was to migrate away from `rtio` as quickly and simply as possible. The design will certainly evolve over time, and all of the details are currently private.
Along the way, this PR also entirely removes signal handling, since it was only supported on `librustuv` which was removed a while ago.
Because of the removal of APIs from `libnative` and `librustrt`, and the removal of signal handling, this is a:
[breaking-change]
Some of these APIs will return in public from from `std` over time.
r? @alexcrichton
