Add hint::assert_unchecked
#119133
Add hint::assert_unchecked
#119133
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library/core/src/hint.rs
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| #[unstable(feature = "hint_assert_unchecked", issue = "119131")] | ||
| pub const unsafe fn assert_unchecked(cond: bool) { | ||
| // SAFETY: The caller promised this is true. | ||
| unsafe { crate::intrinsics::assume(cond) } |
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Do we want to use assert_unsafe_precondition here like in other unchecked fns like unreachable_unchecked?
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Yeah, I suppose it should. Done.
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@the8472 Sure (The reciprocal mention will have to wait for stabilization.) |
| /// benefit to `let n = u32::count_ones(x); assert_unchecked(n <= u32::BITS);`. | ||
| /// | ||
| /// If ever you're tempted to write `assert_unchecked(false)`, then you're | ||
| /// actually looking for [`unreachable_unchecked()`]. |
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Is it worth mentioning that this is logically entirely equivalent to if !cond { unreachable_unchecked(); }?
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☀️ Test successful - checks-actions |
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Finished benchmarking commit (e1fadb2): comparison URL. Overall result: no relevant changes - no action needed@rustbot label: -perf-regression Instruction countThis benchmark run did not return any relevant results for this metric. Max RSS (memory usage)ResultsThis is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.
CyclesResultsThis is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.
Binary sizeThis benchmark run did not return any relevant results for this metric. Bootstrap: 670.004s -> 670.607s (0.09%) |
Libs-API expressed interest, modulo bikeshedding, in rust-lang/libs-team#315 (comment)
I think that means this is good for nightly, since we can always rename it before stabilization.
Tracking issue: #119131