Remove unnecessary `as[_mut]_slice`/`to_string()` calls by japaric · Pull Request #19378 · rust-lang/rust

japaric · 2014-11-28T12:57:07Z

Now that we have an overloaded comparison (==) operator, and that Vec/String deref to [T]/str on method calls, many as_slice()/as_mut_slice()/to_string() calls have become redundant. This patch removes them. These were the most common patterns:

assert_eq(test_output.as_slice(), "ground truth") -> assert_eq(test_output, "ground truth")
assert_eq(test_output, "ground truth".to_string()) -> assert_eq(test_output, "ground truth")
vec.as_mut_slice().sort() -> vec.sort()
vec.as_slice().slice(from, to) -> vec.slice(from_to)

Note that e.g. a_string.push_str(b_string.as_slice()) has been left untouched in this PR, since we first need to settle down whether we want to favor the &*b_string or the b_string[] notation.

This is rebased on top of #19167

cc @alexcrichton @aturon

rust-highfive · 2014-11-28T12:57:13Z

Warning

These commits modify unsafe code. Please review it carefully!

bstrie · 2014-11-28T22:10:58Z

src/libcollections/vec.rs

Can you explain why the impls above and below compare &**self, whereas this only compares *self?

These three implementations merely defer their job to the impl PartialEq<[B]> for [A] one, where the signature of eq is fn eq(&Self = &[A], &[B]). The *self vs &**self is just about playing the deref game:

In this case self has type &&[A] so *self has type &[A]

In case above, self has type &Vec<A>, *self has type Vec<A>, and the next * actually triggers Deref<[A]>, so &**self has type &[A].

In case below, self has type &&mut [A], *self has type "&mut [A]" (yes, I know the compiler won't actually let you do that), and the next&*is a "explicit immutable reborrow" to get&[A]`.

Equivalently, I could have written &**self in all these three cases.

japaric · 2014-11-28T23:07:01Z

BTW, @bstrie your questions belong to the PR #19167, where the == was overloaded. This PR is only about removing some method calls that became redundant after that change.

alexcrichton · 2014-11-30T07:14:56Z

This is awesome, thanks @japaric! r=me, just waiting on @aturon for #19167

aturon · 2014-12-01T04:18:02Z

Hey! I've been offline for Thanksgiving but just got back to #19167. Hopefully we can move this through quickly.

aturon · 2014-12-04T06:12:42Z

@alexcrichton just a heads-up, #19167 has been approved.

japaric · 2014-12-04T12:19:44Z

@alexcrichton rebased, and tested.

@alexcrichton

Now that we have an overloaded comparison (`==`) operator, and that `Vec`/`String` deref to `[T]`/`str` on method calls, many `as_slice()`/`as_mut_slice()`/`to_string()` calls have become redundant. This patch removes them. These were the most common patterns: - `assert_eq(test_output.as_slice(), "ground truth")` -> `assert_eq(test_output, "ground truth")` - `assert_eq(test_output, "ground truth".to_string())` -> `assert_eq(test_output, "ground truth")` - `vec.as_mut_slice().sort()` -> `vec.sort()` - `vec.as_slice().slice(from, to)` -> `vec.slice(from_to)` --- Note that e.g. `a_string.push_str(b_string.as_slice())` has been left untouched in this PR, since we first need to settle down whether we want to favor the `&*b_string` or the `b_string[]` notation. This is rebased on top of #19167 cc @alexcrichton @aturon

@alexcrichton

Now that we have an overloaded comparison (`==`) operator, and that `Vec`/`String` deref to `[T]`/`str` on method calls, many `as_slice()`/`as_mut_slice()`/`to_string()` calls have become redundant. This patch removes them. These were the most common patterns: - `assert_eq(test_output.as_slice(), "ground truth")` -> `assert_eq(test_output, "ground truth")` - `assert_eq(test_output, "ground truth".to_string())` -> `assert_eq(test_output, "ground truth")` - `vec.as_mut_slice().sort()` -> `vec.sort()` - `vec.as_slice().slice(from, to)` -> `vec.slice(from_to)` --- Note that e.g. `a_string.push_str(b_string.as_slice())` has been left untouched in this PR, since we first need to settle down whether we want to favor the `&*b_string` or the `b_string[]` notation. This is rebased on top of #19167 cc @alexcrichton @aturon

japaric · 2014-12-07T05:45:29Z

Ahh, sorry, a recent PR modified an existing test, and I missed that change during my last rebase. I've now amended my mistake and make checked the whole thing. @alexcrichton re-r?

japaric · 2014-12-07T14:00:11Z

😢 A syntax error on the android tests, which didn't get parsed when I ran make check. I grepped each commit diff for the same sort of error, but didn't find any other occurrence. r? @alexcrichton

@alexcrichton

Now that we have an overloaded comparison (`==`) operator, and that `Vec`/`String` deref to `[T]`/`str` on method calls, many `as_slice()`/`as_mut_slice()`/`to_string()` calls have become redundant. This patch removes them. These were the most common patterns: - `assert_eq(test_output.as_slice(), "ground truth")` -> `assert_eq(test_output, "ground truth")` - `assert_eq(test_output, "ground truth".to_string())` -> `assert_eq(test_output, "ground truth")` - `vec.as_mut_slice().sort()` -> `vec.sort()` - `vec.as_slice().slice(from, to)` -> `vec.slice(from_to)` --- Note that e.g. `a_string.push_str(b_string.as_slice())` has been left untouched in this PR, since we first need to settle down whether we want to favor the `&*b_string` or the `b_string[]` notation. This is rebased on top of #19167 cc @alexcrichton @aturon

…ru-at-end-of-analysis-stats analysis-stats: run Salsa's LRU at the end of analysis

bstrie reviewed Nov 28, 2014
View reviewed changes

japaric force-pushed the no-as-slice branch from d36ca67 to 61306ae Compare December 4, 2014 12:17

japaric force-pushed the no-as-slice branch 3 times, most recently from 4ae48bd to f569d5c Compare December 5, 2014 23:09

Jorge Aparicio added 15 commits December 6, 2014 19:05

libcollections: remove unnecessary as_slice() calls

f2af07e

liballoc: remove unnecessary as_slice() calls

0ac3b16

libcoretest: remove unnecessary as_slice() calls

5257a5b

libflate: remove unnecessary as_slice() calls

0f54f32

libfmt_macros: remove unnecessary as_slice() calls

a796013

libgetops: remove unnecessary as_slice() calls

6efc879

libgraphviz: remove unnecessary as_slice() calls

c0ef959

liblog: remove unnecessary as_slice calls

0ea3134

libregex: remove unnecessary as_slice calls

89e6a81

libregex_macros: remove unnecessary as_slice calls

ae555a9

librustc: remove unnecessary as_slice() calls

00f3c3f

librustc_back: remove unnecessary as_slice() calls

7d8eabb

librustc_trans: remove unnecessary as_slice calls

8bb5ef9

librustdoc: remove unnecessary as_slice() calls

e6bd217

libserialize: remove unnecessary as_slice() calls

09f7713

japaric force-pushed the no-as-slice branch from f569d5c to 912ee98 Compare December 7, 2014 00:09

Jorge Aparicio added 19 commits December 6, 2014 23:53

libstd: remove unnecessary as_slice() calls

60338d9

libsyntax: remove unnecessary as_slice() calls

39f44c0

libterm: remove unnecessary as_slice() calls

53b479c

libtest: remove unnecessary as_slice() calls

a0621f8

libcollections: remove unnecessary as_mut_slice() calls

5a24058

librustc: remove unnecessary as_mut_slice calls

d64fd22

librustc_trans: remove unnecessary as_mut_slice calls

a0a354f

librustdoc: remove unnecessary as_mut_slice calls

5172981

libstd: remove unnecessary as_mut_slice calls

6132a90

libtest: remove unnecessary as_mut_slice() calls

976660f

libcollections: remove unnecessary to_string() calls

98ae637

libgetopts: remove unnecessary to_string() calls

8379d72

librustc_back: remove unnecessary to_string() calls

71d8d57

libserialize: remove unnecessary to_string() calls

ba01ea3

libstd: remove unnecessary to_string() calls

c2da923

libsyntax: remove unnecessary to_string() calls

93e99b5

libterm: remove unnecessary to_string() calls

00c7786

libtest: remove unnecessary to_string() calls

66f52f4

libtime: remove unnecessary to_string() calls

2ed42bf

japaric force-pushed the no-as-slice branch from 912ee98 to 2ed42bf Compare December 7, 2014 05:43

Fix syntax error on android tests

1fea900

bors closed this Dec 8, 2014

japaric deleted the no-as-slice branch December 16, 2014 02:10

lnicola pushed a commit to lnicola/rust that referenced this pull request Apr 28, 2025

Merge pull request rust-lang#19378 from davidbarsky/davidbarsky/run-l…

5cc6d29

…ru-at-end-of-analysis-stats analysis-stats: run Salsa's LRU at the end of analysis

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Remove unnecessary `as[_mut]_slice`/`to_string()` calls#19378

Remove unnecessary `as[_mut]_slice`/`to_string()` calls#19378
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