Fix MemoryMarshal implicit conversion errors after Roslyn 4.14.0 update #121501
Conversation
This file contains hidden or 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
Co-authored-by: steveisok <471438+steveisok@users.noreply.github.com>
Copilot
AI
changed the title
[WIP] Update dependencies from dotnet/roslyn
Fix MemoryMarshal implicit conversion errors after Roslyn 4.14.0 update
Nov 10, 2025
Copilot stopped work on behalf of
steveisok due to an error
November 10, 2025 16:52
Member
|
No longer needed - pushed change in PR branch |
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
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Outdated suggestions cannot be applied.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.
Fixes #
main PR
Description
Roslyn 4.14.0 introduced stricter type checking for
MemoryMarshalmethods called on arrays, now returningReadOnlySpan<T>instead ofSpan<T>. This breaks code requiring writable spans.Fixed two compilation errors:
MemoryMarshal.Cast<byte, int>(newDatabase)→MemoryMarshal.Cast<byte, int>(newDatabase.AsSpan())MemoryMarshal.AsBytes<uint>(val)→MemoryMarshal.AsBytes(val.AsSpan())Both changes explicitly convert arrays to
Span<T>before calling MemoryMarshal methods to preserve write access.Customer Impact
Build failures on Roslyn 4.14.0+ due to implicit conversion errors from
ReadOnlySpan<T>toSpan<T>.Regression
Yes. Introduced by the Roslyn dependency update in this release.
Testing
Verified fix compiles and matches existing patterns in codebase (e.g., BigInteger.cs line 375, 1085).
Risk
Low. Minimal changes to preserve existing writable span semantics. Pattern already used elsewhere in affected files.
Package authoring no longer needed in .NET 9
IMPORTANT: Starting with .NET 9, you no longer need to edit a NuGet package's csproj to enable building and bump the version.
Keep in mind that we still need package authoring in .NET 8 and older versions.
✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.