use chars instead of strings where applicable

[matthiaskrgr]

No description provided.

[rustbot]

r? @GuillaumeGomez

(rustbot has picked a reviewer for you, use r? to override)

[ChrisDenton]

Can I ask why?

[matthiaskrgr]

we have specializations of these functions so they run faster on chars

[GuillaumeGomez]

Just in case:

@bors try @rust-timer queue

[bors]

⌛ Trying commit 0400c68 with merge ddcb22e59e1c19d757d303194d1146af8cd7c408...

[matthiaskrgr]

Had a quick look with godbolt and a

pub fn main() {
    let x = String::from("hello world");
    let _ = x.replace('x', &x);
}

emits only around half of the number instructions of

pub fn main() {
    let x = String::from("hello world");
    let _ = x.replace("x", &x);
}

with opt-level=3

[bors]

☀️ Try build successful - checks-actions
Build commit: ddcb22e59e1c19d757d303194d1146af8cd7c408 (ddcb22e59e1c19d757d303194d1146af8cd7c408)

[rust-timer]

Finished benchmarking commit (ddcb22e59e1c19d757d303194d1146af8cd7c408): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

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

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.6%	[-1.6%, -1.6%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	3.7%	[3.7%, 3.7%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.6%	[-3.6%, -1.7%]	2
All ❌✅ (primary)	-	-	0

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.2%	[2.2%, 2.3%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

[GuillaumeGomez]

@bors r+ rollup

[bors]

📌 Commit 0400c68 has been approved by GuillaumeGomez

It is now in the queue for this repository.