expose drop_in_place as ptr::drop_in_place

[Gankra]

This intrinsic is necessary to drop DSTs and should generally be the way to drop memory before manually deallocating it. As such, it should be properly exposed by the standard library.

[rust-highfive]

r? @pcwalton

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

[alexcrichton]

extra tabbing in these comments

[Gankra]

The outstanding issue for this is ptr::drop_in_place vs mem::drop_in_place and whether it should take a *mut or an &mut.

mem seems more consistent with mem::drop, but ptr is strictly more flexible (&mut coerces to *mut).

[huonw]

(This will need a tracking issue and an issue = "..." to land.)

[alexcrichton]

In addition to what @huonw said about this needing issue= now this'll also need to be applied to the definition in the intrinsics module itself to work (we don't look at reexports themselves)

[alexcrichton]

r=me with @huonw's and my tweaks to the stability attribute

[Gankra]

@bors r=alexcrichton

[bors]

📌 Commit 46986bf has been approved by alexcrichton

[Gankra]

@bors r=alexcrichton

(making the feature gate actually do a thing broke stuff)

[bors]

📌 Commit be29f00 has been approved by alexcrichton

[Gankra]

fsk how did that conflict even happen

[Gankra]

@bors r-

[Gankra]

@bors r=alexcrichton

(This branch was super old, that's how!)

[bors]

📌 Commit 5c6f2c5 has been approved by alexcrichton

[alexcrichton]

(looks like travis is unhappy)

[Gankra]

augh run-pass test using the intrinsic

[Gankra]

@bors r-

[Gankra]

@bors r=alexcrichton

[bors]

📌 Commit 3547e8c has been approved by alexcrichton

[Gankra]

(actually did a local make-check)

[bors]

⌛ Testing commit 3547e8c with merge 58d247a...

[bors]

💔 Test failed - auto-win-msvc-64-opt

[bors]

☔ The latest upstream changes (presumably #28306) made this pull request unmergeable. Please resolve the merge conflicts.

[apasel422]

What's the status of this?

[Gankra]

@apasel422 I'm kinda AWOL; feel free to rebase if you want this to land!

[apasel422]

Will do!