2540070fd4
Documents that `BikeshedIntrinsicFrom` models transmute-via-union,
which is slightly more expressive than the transmute-via-cast
implemented by `transmute_copy`. Additionally, we provide an
implementation of transmute-via-union as a method on the
`BikeshedIntrinsicFrom` trait with additional documentation on
the boundary between trait invariants and caller obligations.
Whether or not transmute-via-union is the right kind of transmute
to model remains up for discussion [1]. Regardless, it seems wise
to document the present behavior.
[1] 426331967
17 lines
473 B
Diff
17 lines
473 B
Diff
- // MIR for `transmute_uninhabited` before LowerIntrinsics
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+ // MIR for `transmute_uninhabited` after LowerIntrinsics
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fn transmute_uninhabited(_1: ()) -> Never {
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debug u => _1;
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let mut _0: Never;
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let mut _2: ();
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bb0: {
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StorageLive(_2);
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_2 = copy _1;
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- _0 = std::intrinsics::transmute::<(), Never>(move _2) -> unwind unreachable;
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+ _0 = move _2 as Never (Transmute);
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+ unreachable;
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}
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}
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