Stabilize pointer::align_offset

[CryZe]

Closes #44488

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[Centril]

r? @Centril @bors r+

[bors]

📌 Commit cf9d667 has been approved by Centril

[bors]

⌛ Testing commit cf9d667 with merge 597f432...

[RalfJung]

Just like with align_to, the docs should say that the method is allowed to fail (return max) even if aligning was possible -- this is a best-effort operation.

(In practice, it will always return max when running in CTFE/Miri.)

[RalfJung]

@CryZe Can you do that docs change in a follow-up PR?

[CryZe]

They already state that: https://github.com/rust-lang/rust/pull/60303/files#diff-9839f9730ca3a90d5c0ebb0a7edd67cfR1524

[RalfJung]

That doesn't say that this may happen "spuriously".

align_to says

The method does a best effort to make the middle slice the greatest length possible for a given type and input slice, but only your algorithm's performance should depend on that, not its correctness.

to make sure that this gets across.

[bors]

☀️ Test successful - checks-travis, status-appveyor
Approved by: Centril
Pushing 597f432 to master...

[czipperz]

Out of curiosity, why wasn't this included in 1.35.0? Wasn't that released nearly a full month after this?

[RalfJung]

Rust's release trains take 6 weeks. So any PR will generally enter the release that happens between 6 and 12 weeks after it landed.