Avoid allocations due to use of Keys/Values instead of GetEnumerator #19126
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@dotnet/roslyn-compiler for review (let me know if anyone else should be added) Please note the comment regarding the first commit overlapping with #19125. |
jaredpar
approved these changes
May 1, 2017
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| isSuppressed = diagnosticOptions[diag.Id] == ReportDiagnostic.Suppress; |
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We really sohuld have an analyzer fro that pattern
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@MeiChin-Tsai for ask mode (at the request of @jaredpar) |
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approved. |
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Nice |
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@jcouv I think this is my favorite use of C# 7 to date. It totally resolved something I previously found rather frustrating. 😄 |
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ImmutableDictionary<TKey, TValue>provides a non-allocating implementation ofGetEnumerator(), but does not offer non-allocating implementations of theKeysorValuesproperties (dotnet/corefx#249 and linked issues). This pull request adds aDeconstructextension method forKeyValuePair<TKey, TValue>, leveraging a new C# feature to provide almost identical use-site code for these properties without actually incurring the allocation overhead.📝 This pull request builds on the change in #19125 to avoid merge conflicts (
the first commit in the branch overlaps) (edit: no longer applies).Ask Mode
Customer scenario
No observable changes.
GetEnumerator()instead ofKeyswhere applicableGetEnumerator()instead ofValueswhere applicableDeconstructextension method so the above changes can be implemented with minimal changes to the actual code structureBugs this fixes:
N/A
Workarounds, if any
None needed.
Risk
Low (no behavior changes).
Performance impact
Performance is improved by eliminating unnecessary allocations.
Is this a regression from a previous update?
No.
Root cause analysis:
Missed during code review?
How was the bug found?
Internal code review.