Add core::ops::Range*::contains() as per rust-lang/rust#32311

[nodakai]

No description provided.

[rust-highfive]

r? @brson

(rust_highfive has picked a reviewer for you, use r? to override)

[nodakai]

I wish to have

impl<Idx: PartialOrd<Idx>> RangeFull {
  fn contains(&self, _: Idx) -> bool { true }
}

so that

(..).contains(42) // true
(..).contains("forty-two".to_string()) // true

but it seems like it's not allowed:

error: the type parameter `Idx` is not constrained by the impl trait, self type, or predicates [E0207]

[alexcrichton]

Travis failures look non-spurious:

---- ops::RangeInclusive_0 stdout ----
        <anon>:5:16: 5:19 error: unresolved name `arr` [E0425]
<anon>:5     assert_eq!(arr[ ...2], [0,1,2  ]);
                        ^~~
<anon>:5:5: 5:39 note: in this expansion of assert_eq! (defined in <std macros>)
<std macros>:5:8: 5:18 error: the type of this value must be known in this context
<std macros>:5 if ! ( * left_val == * right_val ) {
                      ^~~~~~~~~~
<anon>:5:5: 5:39 note: in this expansion of assert_eq! (defined in <std macros>)
<std macros>:5:22: 5:33 error: the type of this value must be known in this context
<std macros>:5 if ! ( * left_val == * right_val ) {
                                    ^~~~~~~~~~~
<anon>:5:5: 5:39 note: in this expansion of assert_eq! (defined in <std macros>)
error: aborting due to previous error(s)
thread 'ops::RangeInclusive_0' panicked at 'Box<Any>', src/librustc/session/mod.rs:153
note: Run with `RUST_BACKTRACE=1` for a backtrace.

---- ops::RangeToInclusive_0 stdout ----
        <anon>:4:5: 4:13 error: unresolved name `Examples` [E0425]
<anon>:4     Examples
             ^~~~~~~~
error: aborting due to previous error(s)
thread 'ops::RangeToInclusive_0' panicked at 'Box<Any>', src/librustc/session/mod.rs:153

---- ops::RangeToInclusive_1 stdout ----
        <anon>:5:21: 5:25 error: inclusive range syntax is experimental (see issue #28237)
<anon>:5     assert_eq!(arr[ ...2], [0,1,2  ]);  // RangeToInclusive
                             ^~~~
<anon>:5:5: 5:39 note: in this expansion of assert_eq! (defined in <std macros>)
<anon>:5:21: 5:25 help: add #![feature(inclusive_range_syntax)] to the crate attributes to enable
<anon>:6:20: 6:25 error: inclusive range syntax is experimental (see issue #28237)
<anon>:6     assert_eq!(arr[1...2], [  1,2  ]);
                            ^~~~~
<anon>:6:5: 6:39 note: in this expansion of assert_eq! (defined in <std macros>)
<anon>:6:20: 6:25 help: add #![feature(inclusive_range_syntax)] to the crate attributes to enable
error: aborting due to previous error(s)
thread 'ops::RangeToInclusive_1' panicked at 'Box<Any>', src/librustc/session/mod.rs:153


failures:
    ops::RangeInclusive_0
    ops::RangeToInclusive_0
    ops::RangeToInclusive_1

Also cc @steveklabnik, quite extensive docs! Not sure if they're idiomatic though?

[durka]

copy/paste error?

[nodakai]

Oops, I accidentally rewound my working branch

• https://travis-ci.org/rust-lang/rust/builds/117442252
• https://s3.amazonaws.com/archive.travis-ci.org/jobs/117442253/log.txt

[durka]

typo

[nodakai]

Fixed typo
Changed #[unstable] to impl-wide; not much difference when each impl has a single method.

[durka]

Wait does #[unstable] on an impl actually do anything?

[petrochenkov]

@durka

Wait does #[unstable] on an impl actually do anything?

It passes the unstability to all the child items.

[durka]

OK, I remembered something about trait impls being insta-stable. But inherent impls are different I guess.

[nodakai]

The outputs look like this:
http://pauli.matrix.jp/doc-a21c5f267a722b6c80790a559bf272942b946cd4/std/ops/struct.Range.html

[alexcrichton]

@bors: r+ a21c5f2

[bors]

⌛ Testing commit a21c5f2 with merge 37e3ac0...

[alexcrichton]

@bors: retry force

[bors]

⌛ Testing commit a21c5f2 with merge 40deb27...

[bors]

☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-debug-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-opt-mir, auto-linux-64-opt-rustbuild, auto-linux-64-x-android-t, auto-linux-64-x-armhf, auto-linux-64-x-armsf, auto-linux-64-x-freebsd, auto-linux-64-x-netbsd, auto-linux-cross-opt, auto-linux-musl-64-opt, auto-mac-32-opt, auto-mac-64-nopt-t, auto-mac-64-opt, auto-mac-ios-opt, auto-win-gnu-32-nopt-t, auto-win-gnu-32-opt, auto-win-gnu-32-opt-rustbuild, auto-win-gnu-64-nopt-t, auto-win-gnu-64-opt, auto-win-msvc-32-opt, auto-win-msvc-64-opt, auto-win-msvc-64-opt-mir, auto-win-msvc-64-opt-rustbuild