[pointer][transmute] Support generic TransmuteFrom #1910
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This was referenced Oct 15, 2024
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
from
99a8250 to
19f7378
Compare
joshlf
force-pushed
the
Ifc49755af0d90eeefe7822d755d508403c266bda
branch
from
3b9ac7b to
c88e77f
Compare
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
from
19f7378 to
140f430
Compare
joshlf
force-pushed
the
Ifc49755af0d90eeefe7822d755d508403c266bda
branch
from
c88e77f to
c3a2206
Compare
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
from
140f430 to
ac39cec
Compare
joshlf
force-pushed
the
Ifc49755af0d90eeefe7822d755d508403c266bda
branch
from
c3a2206 to
7643459
Compare
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
from
ac39cec to
41cd8a9
Compare
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
from
41cd8a9 to
90c2f64
Compare
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
from
90c2f64 to
65c71f6
Compare
joshlf
force-pushed
the
Ifc49755af0d90eeefe7822d755d508403c266bda
branch
from
7643459 to
b36cb1c
Compare
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
from
65c71f6 to
a1fc228
Compare
joshlf
force-pushed
the
Ifc49755af0d90eeefe7822d755d508403c266bda
branch
from
b36cb1c to
4bd33fb
Compare
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
3 times, most recently
from
a6e7783 to
af10d3d
Compare
joshlf
changed the base branch from
Ifc49755af0d90eeefe7822d755d508403c266bda
to
I1ac2ae177a235083e33b09fc848423220d3da042
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
from
af10d3d to
235702a
Compare
joshlf
force-pushed
the
I1ac2ae177a235083e33b09fc848423220d3da042
branch
from
ac629d9 to
53deb0a
Compare
joshlf
changed the title
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
from
235702a to
f0fc37e
Compare
Codecov ReportAttention: Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## I1ac2ae177a235083e33b09fc848423220d3da042 #1910 +/- ##
============================================================================
Coverage ? 89.76%
============================================================================
Files ? 17
Lines ? 5806
Branches ? 0
============================================================================
Hits ? 5212
Misses ? 594
Partials ? 0 ☔ View full report in Codecov by Sentry. |
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
from
f0fc37e to
9b71dc8
Compare
joshlf
force-pushed
the
I1ac2ae177a235083e33b09fc848423220d3da042
branch
from
53deb0a to
4795dcd
Compare
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
from
9b71dc8 to
1bee133
Compare
This prepares us to rename `TransparentWrapper` to `TransmuteFrom`, which we'll do in a follow-up commit to preserve nice git diffs. Makes progress on #1122 gherrit-pr-id: Ifc49755af0d90eeefe7822d755d508403c266bda
We previously used `AliasingMapping`s and `Inaccessible` to model `UnsafeCell` agreement. This abuses the notion of a mapping since one doesn't ever actually want to change the aliasing of a pointer (and certainly not to `Inaccessible`) - really this was meant to model pointer casts which should never be performed. In addition to being an awkward fit, the presence of `Inaccessible` meant that code could not assume that any `Aliasing` invariant permitted reading, and so we had to add extra machinery to work around this. Future commits will use a different, simpler model for denoting `UnsafeCell` agreement or disagreement. While we're here, make `Read` slightly more permissive, implemented for `A: Aliasing, T: Immutable` rather than just `A: Reference, T: Immutable`. Makes progress on #1122, #1866 gherrit-pr-id: I1ac2ae177a235083e33b09fc848423220d3da042
This commit replaces the `TransparentWrapper` trait with a more generic, bidirectional `TransmuteFrom<T>` trait. `U: TransmuteFrom<T>` indicates that `T` and `U` have the same sizes and that `T` can be transmuted into `U` given certain alignment and validity invariant mappings. Makes progress on #1122 gherrit-pr-id: I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
joshlf
force-pushed
the
I1ac2ae177a235083e33b09fc848423220d3da042
branch
from
4795dcd to
94165e5
Compare
joshlf
force-pushed
the
I7af68cdaa5ea47ab245a942d1cbd8bc5e6407223
branch
from
1bee133 to
4ea2f82
Compare
joshlf
force-pushed
the
I1ac2ae177a235083e33b09fc848423220d3da042
branch
3 times, most recently
from
33fc89f to
48f1450
Compare
joshlf
force-pushed
the
I1ac2ae177a235083e33b09fc848423220d3da042
branch
from
48f1450 to
355531d
Compare
joshlf
force-pushed
the
I1ac2ae177a235083e33b09fc848423220d3da042
branch
2 times, most recently
from
d89fa0f to
08771d7
Compare
Base automatically changed from
I1ac2ae177a235083e33b09fc848423220d3da042
to
Ifc49755af0d90eeefe7822d755d508403c266bda
February 5, 2025 19:55
joshlf
force-pushed
the
Ifc49755af0d90eeefe7822d755d508403c266bda
branch
3 times, most recently
from
2b2f66a to
34eb2a3
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This commit replaces the
TransparentWrappertrait with a more generic,bidirectional
TransmuteFrom<T>trait.U: TransmuteFrom<T>indicatesthat
TandUhave the same sizes and thatTcan be transmuted intoUgiven certain alignment and validity invariant mappings.Makes progress on #1122
This PR is on branch ptr-overhaul.