Scott McMurray 89a18cb600 Add unsigned_offset_from on pointers ... Like we have `add`/`sub` which are the `usize` version of `offset`, this adds the `usize` equivalent of `offset_from`. Like how `.add(d)` replaced a whole bunch of `.offset(d as isize)`, you can see from the changes here that it's fairly common that code actually knows the order between the pointers and *wants* a `usize`, not an `isize`. As a bonus, this can do `sub nuw`+`udiv exact`, rather than `sub`+`sdiv exact`, which can be optimized slightly better because it doesn't have to worry about negatives. That's why the slice iterators weren't using `offset_from`, though I haven't updated that code in this PR because slices are so perf-critical that I'll do it as its own change. This is an intrinsic, like `offset_from`, so that it can eventually be allowed in CTFE. It also allows checking the extra safety condition -- see the test confirming that CTFE catches it if you pass the pointers in the wrong order.		2022-05-11 17:16:25 -07:00
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benches	Avoid use of rand::thread_rng in stdlib benchmarks	2022-05-02 00:08:21 -07:00
src	Add unsigned_offset_from on pointers	2022-05-11 17:16:25 -07:00
tests	Rollup merge of #94126 - ssomers:alloc_prep_1, r=Mark-Simulacrum	2022-05-02 10:41:54 +09:00
Cargo.toml	Switch all libraries to the 2021 edition	2021-12-23 19:03:47 +08:00