Remove Expressions (and just use a Vec) in coerce

[jackh726]

Let's see if this has much of a perf impact - would be nice to clean this up a bit

r? ghost

[jackh726]

@bors try

[rust-bors]

☀️ Try build successful (CI)
Build commit: e27e978 (e27e978c9e7ea46f191f8181e185d8e3f6f7af51, parent: 68f11a11b666b36137374b6e54fc0d013a3b26cf)

[jackh726]

@rust-timer build e27e978

[rust-timer]

Finished benchmarking commit (e27e978): comparison URL.

Overall result: ❌✅ regressions and improvements - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.0%	[0.0%, 0.0%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.1%	[-0.1%, -0.1%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary -3.4%, secondary 1.3%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.0%	[1.6%, 2.5%]	2
Regressions ❌ (secondary)	3.0%	[1.1%, 5.5%]	4
Improvements ✅ (primary)	-8.9%	[-15.6%, -2.1%]	2
Improvements ✅ (secondary)	-1.0%	[-1.0%, -1.0%]	3
All ❌✅ (primary)	-3.4%	[-15.6%, 2.5%]	4

Cycles

Results (primary 2.7%, secondary 0.7%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.7%	[2.7%, 2.7%]	1
Regressions ❌ (secondary)	3.3%	[2.4%, 5.0%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-6.9%	[-6.9%, -6.9%]	1
All ❌✅ (primary)	2.7%	[2.7%, 2.7%]	1

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 483.218s -> 482.848s (-0.08%)
Artifact size: 390.58 MiB -> 390.56 MiB (-0.01%)

[jackh726]

Cool, basically perf neutral, but cleaner.

r? types

[BoxyUwU]

very cool, shouldve checked myself to see if we could yeet this back when I was looking through coercions last month ✨

View changes since this review

[BoxyUwU]

r? BoxyUwU

[jackh726]

Updated :)

[BoxyUwU]

@bors r+

[bors]

📌 Commit a079cb9 has been approved by BoxyUwU

It is now in the queue for this repository.

[bors]

⌛ Testing commit a079cb9 with merge 526a91c...

[bors]

☀️ Test successful - checks-actions
Approved by: BoxyUwU
Pushing 526a91c to main...

[github-actions]

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing fcf67da (parent) -> 526a91c (this PR)

Test differences

Show 4 test diffs

4 doctest diffs were found. These are ignored, as they are noisy.

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 526a91cbcc4601b92b0587405015e07b9c0d79f6 --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

1. dist-aarch64-apple: 6944.9s -> 10044.2s (+44.6%)
2. aarch64-msvc-2: 6198.5s -> 6885.3s (+11.1%)
3. x86_64-gnu-llvm-21-2: 5315.4s -> 5900.1s (+11.0%)
4. dist-x86_64-msvc-alt: 9491.6s -> 8619.2s (-9.2%)
5. x86_64-gnu-gcc: 3244.2s -> 3541.0s (+9.1%)
6. dist-powerpc64le-linux-gnu: 5435.5s -> 4947.8s (-9.0%)
7. dist-apple-various: 4087.5s -> 4390.7s (+7.4%)
8. aarch64-gnu-llvm-20-2: 3266.1s -> 3035.5s (-7.1%)
9. x86_64-gnu-llvm-20-3: 6614.7s -> 7079.0s (+7.0%)
10. test-various: 6923.3s -> 7389.1s (+6.7%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

[rust-timer]

Finished benchmarking commit (526a91c): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results (primary 2.6%, secondary -2.1%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.6%	[1.8%, 3.4%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.1%	[-2.1%, -2.1%]	1
All ❌✅ (primary)	2.6%	[1.8%, 3.4%]	2

Cycles

Results (primary 2.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.0%	[2.0%, 2.0%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.0%	[2.0%, 2.0%]	1

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 481.593s -> 481.711s (0.02%)
Artifact size: 390.56 MiB -> 390.58 MiB (0.00%)