Make UnsafeCell, RefCell, Mutex, and RwLock accept DSTs

[ftxqxd]

This + DST coercions (#24619) would allow code like Rc<RefCell<Box<Trait>>> to be simplified to Rc<RefCell<Trait>>.

[rust-highfive]

r? @huonw

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[bstrie]

Would this be a backward-compatible change? In other words, is it an argument for cherry-picking #24619 into beta?

[steveklabnik]

It allows strictly more programs, IIRC, and so is backwards compatible.

[nrc]

Doing Arc would be cool too, if anyone feels like it :-) And no, it shouldn't be cherry picked, too risky.

[luqmana]

@bors r+

[bors]

📌 Commit 17876ec has been approved by luqmana

[bors]

⌛ Testing commit 17876ec with merge c22693d...

[bors]

💔 Test failed - auto-mac-64-opt

[ftxqxd]

Sorry, I mustn’t have run the tests thoroughly enough. It should be fixed now. r?

[alexcrichton]

@bors: r=luqmana aed293a

[bors]

⌛ Testing commit aed293a with merge 4389a3b...

[bors]

💔 Test failed - auto-mac-64-opt

[ftxqxd]

Ugh, I somehow missed that one. make check definitely passes now.

[alexcrichton]

@bors: r+ 57d8289

[bors]

⌛ Testing commit 57d8289 with merge c512850...

[bors]

💔 Test failed - auto-linux-64-x-android-t

[ftxqxd]

The failure doesn’t seem related (and doesn’t occur locally). Is this a known spurious failure?

[alexcrichton]

@bors: retry

On Sat, May 2, 2015 at 1:55 AM, P1start notifications@github.com wrote:

The failure doesn’t seem related (and doesn’t occur locally). Is this a
known spurious failure?

—
Reply to this email directly or view it on GitHub
#24737 (comment).

[bors]

⌛ Testing commit 57d8289 with merge 1fb4ecc...

[bors]

💔 Test failed - auto-linux-64-opt

[alexcrichton]

@bors: retry

On Sun, May 3, 2015 at 7:06 AM, bors notifications@github.com wrote:

[image: 💔] Test failed - auto-linux-64-opt
http://buildbot.rust-lang.org/builders/auto-linux-64-opt/builds/4777

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Reply to this email directly or view it on GitHub
#24737 (comment).

[bors]

⌛ Testing commit 57d8289 with merge 1a60dc4...

[bors]

☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-x-android-t, auto-mac-32-opt, auto-mac-64-nopt-t, auto-mac-64-opt, auto-win-32-nopt-t, auto-win-32-opt, auto-win-64-nopt-t, auto-win-64-opt