Merge pull request #145 from steveklabnik/1.15-announcement

Rust 1.15 release announcment

Author: steveklabnik

_posts/2017-02-02-Rust-1.15.md

@@ -0,0 +1,294 @@
+---
+layout: post
+title: "Announcing Rust 1.15"
+author: The Rust Core Team
+---
+
+The Rust team is happy to announce the latest version of Rust, 1.15.0. Rust is a
+systems programming language focused on safety, speed, and concurrency.
+
+If you have a previous version of Rust installed, getting Rust 1.15 is as easy as:
+
+```bash
+$ rustup update stable
+```
+
+If you don't have it already, you can [get `rustup`][install] from the
+appropriate page on our website, and check out the [detailed release notes for
+1.15.0][notes] on GitHub. 1443 patches were landed in this release.
+
+[install]: https://www.rust-lang.org/install.html
+[notes]: https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1150-2017-02-02
+
+### What's in 1.15.0 stable
+
+Rust 1.15 sees an _extremely_ eagerly-awaited feature land on stable: custom
+derive! To review, in Rust, you've always been able to automatically implement
+some traits through the `derive` attribute:
+
+```rust
+#[derive(Debug)]
+struct Pet {
+    name: String,
+}
+```
+
+The `Debug` trait is then implemented for `Pet`, with vastly less boilerplate.
+However, this only worked for traits provided as part of the standard library;
+it was not customizable. With Rust 1.15, it now is. That means, if you want to
+turn your `Pet` into JSON, it's as easy as adding [Serde][serde] to your
+`Cargo.toml`:
+
+```toml
+[dependencies]
+serde = "0.9"
+serde_derive = "0.9"
+serde_json = "0.9"
+```
+
+[serde]: https://serde.rs
+
+And adding another trait to your `Pet`:
+
+```rust
+#[macro_use]
+extern crate serde_derive;
+
+extern crate serde_json;
+
+#[derive(Serialize, Deserialize, Debug)]
+struct Pet {
+    name: String,
+}
+
+fn main() {
+    let pet = Pet { name: String::from("Ferris") };
+
+    let serialized = serde_json::to_string(&pet).unwrap();
+    println!("serialized = {}", serialized);
+
+    let deserialized: Pet = serde_json::from_str(&serialized).unwrap();
+    println!("deserialized = {:?}", deserialized);
+}
+```
+
+This will output:
+
+```text
+serialized = {"name":"Ferris"}
+deserialized = Pet { name: "Ferris" }
+```
+
+Another common use-case is [Diesel][diesel]. Say we had a database of `Pet`s.
+We could fetch them like this:
+
+```rust
+// some extern crate and use lines elided here
+
+#[derive(Queryable)]
+struct Pet {
+    name: String,
+}
+
+fn main() {
+    use diesel_demo::schema::pets::dsl::*;
+
+    let connection = establish_connection();
+    let results = pets 
+        .limit(5)
+        .load::<Pet>(&connection)
+        .expect("Error loading pets");
+
+    println!("Displaying {} pets", results.len());
+    for pet in results {
+        println!("{}", pet.name);
+    }
+}
+```
+
+For full instructions, see [the website][diesel].
+
+[diesel]: http://diesel.rs
+
+These kinds of libraries are extremely powerful, but rely on custom derive for
+ergonomics. While these libraries _worked_ on Rust stable previously, they were
+not as nice to use, so much so that we often heard from users "I only use
+nightly because of Serde and Diesel." The use of custom derive is one of the
+most widely used nightly-only features. As such, [RFC 1681] was opened in July
+of last year to support this use-case. The RFC was merged in August, underwent
+a lot of development and testing, and now reaches stable today!
+
+[RFC 1681]: https://github.com/rust-lang/rfcs/pull/1681
+
+To find out how to write your own custom derives, see [the chapter of "The Rust
+Programming Language"](https://doc.rust-lang.org/book/procedural-macros.html).
+
+While we've said "Serde and Diesel" a number of times here, there's a lot of
+other cool things you can do with custom derive: see
+[`derive-new`](https://crates.io/crates/derive-new) for another example. See
+[the `syn` crate's reverse dependencies for more.][syn-deps] (`syn` is
+important for writing custom derives, see the book chapter, linked above, for
+more.) Custom derive was also known as "macros 1.1", as it includes the
+infrastructure for supporting even more compile-time powers of Rust, nicknamed
+"macros 2.0." Expect to hear more about this space in future releases.
+
+[syn-deps]: https://crates.io/crates/syn/reverse_dependencies
+
+#### Other improvements
+
+The build system for Rust [has been re-written in Rust, using
+Cargo][rustbuild]. It is now the default. This process has been long, but has
+finally borne fruit. Given that all Rust development happens on the master
+branch, we've been using it since December of last year, and it's working well.
+There is an open PR [to remove the Makefiles entirely][rustbuild-only], landing
+in Rust 1.17. This will pave the way for `rustc` to use packages from
+`crates.io` in the compiler like any other Rust project, and is a further
+demonstration of the maturity of Cargo.
+
+[rustbuild]: https://github.com/rust-lang/rust/pull/37817
+[rustbuild-only]: https://github.com/rust-lang/rust/pull/39431
+
+Rust has gained [Tier 3 support][tiers] for [`i686-unknown-openbsd`], [`MSP430`],
+and [`ARMv5TE`].
+
+[tiers]: https://forge.rust-lang.org/platform-support.html
+[`i686-unknown-openbsd`]: https://github.com/rust-lang/rust/pull/38086
+[`MSP430`]: https://github.com/rust-lang/rust/pull/37627
+[`ARMv5TE`]: https://github.com/rust-lang/rust/pull/37615
+
+[A number of compiler performance improvements have
+landed](https://github.com/rust-lang/rust/blob/master/RELEASES.md#compiler-performance).
+We continue to work on making the compiler faster. Expect to see more in the
+future!
+
+As a smaller improvement, [`?Sized` can now be used in `where`
+clauses](https://github.com/rust-lang/rust/pull/37791). In other words:
+
+```rust
+struct Foo<T: ?Sized> {
+    f: T,
+}
+
+struct Foo<T> where T: ?Sized {
+    f: T,
+}
+```
+
+This second form is now accepted, and is equivalent to the first.
+
+
+See the [detailed release notes][notes] for more.
+
+#### Library stabilizations
+
+The `slice::sort` algorithm [has been rewritten][38192], and is much, much,
+much faster. It is a hybrid merge sort, drawing influences from Timsort.
+Previously it was a straightforward merge sort.
+
+If you had a `Vec<T>` where `T: Copy`, and you called `extend` on it,
+your code will [now be a lot faster][38182].
+
+Speaking of things getting faster, [`chars().count()`][37888],
+[`chars().last()`, and `char_indices().last()`][37882] are too!
+
+[Chinese characters now display correctly in `fmt::Debug`][37855].
+
+[38192]: https://github.com/rust-lang/rust/pull/38192
+[38182]: https://github.com/rust-lang/rust/pull/38182
+[37888]: https://github.com/rust-lang/rust/pull/37888
+[37882]: https://github.com/rust-lang/rust/pull/37882
+[37855]: https://github.com/rust-lang/rust/pull/37855
+
+There were a number of functions stabilized as well:
+
+* [`std::iter::Iterator::min_by`] and [`std::iter::Iterator::max_by`]
+* [`std::os::*::fs::FileExt`]
+* [`std::sync::atomic::Atomic*::get_mut`] and [`std::sync::atomic::Atomic*::into_inner`]
+* [`std::vec::IntoIter::as_slice`] and [`std::vec::IntoIter::as_mut_slice`]
+* [`std::sync::mpsc::Receiver::try_iter`]
+* [`std::os::unix::process::CommandExt::before_exec`]
+* [`std::rc::Rc::strong_count`] and [`std::rc::Rc::weak_count`]
+* [`std::sync::Arc::strong_count`] and [`std::sync::Arc::weak_count`]
+* [`std::char::encode_utf8`] and [`std::char::encode_utf16`]
+* [`std::cell::Ref::clone`]
+* [`std::io::Take::into_inner`]
+
+[`std::iter::Iterator::min_by`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.min_by
+[`std::iter::Iterator::max_by`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.max_by
+[`std::os::*::fs::FileExt`]: https://doc.rust-lang.org/std/os/unix/fs/trait.FileExt.html
+[`std::sync::atomic::Atomic*::get_mut`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicU8.html#method.get_mut
+[`std::sync::atomic::Atomic*::into_inner`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicU8.html#method.into_inner
+[`std::vec::IntoIter::as_slice`]: https://doc.rust-lang.org/std/vec/struct.IntoIter.html#method.as_slice
+[`std::vec::IntoIter::as_mut_slice`]: https://doc.rust-lang.org/std/vec/struct.IntoIter.html#method.as_mut_slice
+[`std::sync::mpsc::Receiver::try_iter`]: https://doc.rust-lang.org/std/sync/mpsc/struct.Receiver.html#method.try_iter
+[`std::os::unix::process::CommandExt::before_exec`]: https://doc.rust-lang.org/std/os/unix/process/trait.CommandExt.html#tymethod.before_exec
+[`std::rc::Rc::strong_count`]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.strong_count
+[`std::rc::Rc::weak_count`]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.weak_count
+[`std::sync::Arc::strong_count`]: https://doc.rust-lang.org/std/sync/struct.Arc.html#method.strong_count
+[`std::sync::Arc::weak_count`]: https://doc.rust-lang.org/std/sync/struct.Arc.html#method.weak_count
+[`std::char::encode_utf8`]: https://doc.rust-lang.org/std/primitive.char.html#method.encode_utf8
+[`std::char::encode_utf16`]: https://doc.rust-lang.org/std/primitive.char.html#method.encode_utf16
+[`std::cell::Ref::clone`]: https://doc.rust-lang.org/std/cell/struct.Ref.html#method.clone
+[`std::io::Take::into_inner`]: https://doc.rust-lang.org/std/io/struct.Take.html#method.into_inner
+
+See the [detailed release notes][notes] for more.
+
+#### Cargo features
+
+Cargo will now [emit a warning][cargo/3361] if you have a file named `build.rs`
+at the top level of a package, but don't have a `build = "build.rs"`
+annotation. This is in anticipation of inferring that `build.rs` at the top
+level is always a build script, but is a warning right now for compatibility
+reasons. Previously, all build scripts required configuration, but this
+convention was strong within the community, so we're going to encode it into
+Cargo.
+
+[cargo/3361]: https://github.com/rust-lang/cargo/pull/3361
+
+In this release, [Cargo build scripts no longer have access to the `OUT_DIR`
+environment variable at build time via `env!("OUT_DIR")`][cargo/3368]. They
+should instead check the variable at runtime with `std::env`. That the value
+was set at build time was a bug, and incorrect when cross-compiling. Please
+check what your packages are doing and update to use `std::env`!
+
+[cargo/3368]:  https://github.com/rust-lang/cargo/pull/3368
+
+The `cargo test` command has [gained support for a `--all` flag][cargo/3321],
+which is useful when you have a workspace.
+
+[cargo/3321]: https://github.com/rust-lang/cargo/pull/3321
+
+We now [Compile statically against the MSVC CRT][cargo/3363] on Windows, and
+[Link OpenSSL statically][cargo/3311] on Mac OS X.
+
+[cargo/3363]: https://github.com/rust-lang/cargo/pull/3363
+[cargo/3311]: https://github.com/rust-lang/cargo/pull/3311
+
+See the [detailed release notes][notes] for more.
+
+### Contributors to 1.15.0
+
+In this part of the release announcements, we usually post a list of
+contributors. However, we've recently started a new initiative, "Thanks!", to
+do this in a more comprehensive way. One issue with this section is that it
+only counted contributions to the `rust-lang/rust` repository; those who
+committed to Cargo weren't thanked, for example. We also had to manually
+generate this list, which wasn't terrible, but running the correct git commands
+to determine who contributed is exactly what code is good for!
+
+As such, you can now visit
+[https://thanks.rust-lang.org/](https://thanks.rust-lang.org/) to see more
+comprehensive contribution calculations. If you prefer, we also have an alias
+at [https://❤.rust-lang.org](https://❤.rust-lang.org) as well. For now, this
+will only show what we've shown in previous release posts. We do have one
+additional feature, which is an all-time contributions list, sorted by commit
+count. That's located here:
+[https://thanks.rust-lang.org/rust/all-time](https://thanks.rust-lang.org/rust/all-time)
+
+We have done some of the needed backend work to enable more repositories than
+only `rust-lang/rust`, but it's not quite done yet. If you'd like to get
+involved, please [check out thanks on
+GitHub](https://github.com/rust-lang-nursery/thanks)!
+
+We had 136 individuals contribute to Rust 1.15.
+[Thanks!](https://thanks.rust-lang.org/rust/1.15.0)