[libc++][ranges] P3059R2: Making user-defined constructors of view iterators/sentinels private by H-G-Hristov · Pull Request #193891 · llvm/llvm-project

H-G-Hristov · 2026-04-24T03:54:06Z

Implements https://wg21.link/P3059R2 (DR)

Closes #189599

Made constructors of iterator and sentinel types of the following views private:

iota_view
basic_istream_view
filter_view
transform_view
take_view
take_while_view
join_view
lazy_split_view
split_view
elements_view

Updated all relevant tests to fix the usages of the now private constructor, including:
1. Removed now obsolete tests (files and cases).
2. Updated all relevant tests to get the iterators and the sentinels via begin() and end(), wherever applicable .
3. Added test cases to confirm that P3059R2 was implemented properly.
4. Minor other (necessary) tweaks.

github-actions · 2026-04-24T03:55:22Z

✅ With the latest revision this PR passed the C/C++ code formatter.

Pre-requisite for: #193891

Pre-requisite for: llvm/llvm-project#193891

As a pre-requisite for llvm#193891

As a pre-requisite for #193891

…ests (#210687) As a pre-requisite for llvm/llvm-project#193891

Zingam · 2026-07-22T06:44:41Z

The current CI failures appear unrelated.

…211252) As a pre-requisite to: #193891

….pass.cpp` (#211252) As a pre-requisite to: llvm/llvm-project#193891

Zingam · 2026-07-30T14:57:04Z

@frederick-vs-ja Thank you. I'd like to do an NFC follow-up to this PR to use concepts, instead of type traits consistently and add the necessary includes, which are missing here and there too.

…0 merge (#213062) Consistency improvements and other small tweaks. A follow-up to #193891 - the changes were deferred to reduce the size of an already large and approved PR.

… after P3050 merge (#213062) Consistency improvements and other small tweaks. A follow-up to llvm/llvm-project#193891 - the changes were deferred to reduce the size of an already large and approved PR.

…0 merge (#213062) Consistency improvements and other small tweaks. A follow-up to llvm/llvm-project#193891 - the changes were deferred to reduce the size of an already large and approved PR. Signed-off-by: Hafidz Muzakky <ais.muzakky@gmail.com>

…0 merge (llvm#213062) Consistency improvements and other small tweaks. A follow-up to llvm#193891 - the changes were deferred to reduce the size of an already large and approved PR.

… after P3050 merge (#213062) Consistency improvements and other small tweaks. A follow-up to llvm/llvm-project#193891 - the changes were deferred to reduce the size of an already large and approved PR.

…erators/sentinels private (llvm#193891) Implements https://wg21.link/P3059R2 (DR) Closes llvm#189599 1. Made constructors of iterator and sentinel types of the following views private: - `iota_view` - `basic_istream_view` - `filter_view` - `transform_view` - `take_view` - `take_while_view` - `join_view` - `lazy_split_view` - `split_view` - `elements_view` 2. Updated all relevant tests to fix the usages of the now private constructor, including: 1. Removed now obsolete tests (files and cases). 2. Updated all relevant tests to get the iterators and the sentinels via `begin()` and `end()`, wherever applicable . 3. Added test cases to confirm that P3059R2 was implemented properly. 4. Minor other (necessary) tweaks. --------- Co-authored-by: Hristo Hristov <zingam@outlook.com> Co-authored-by: A. Jiang <de34@live.cn>

…0 merge (llvm#213062) Consistency improvements and other small tweaks. A follow-up to llvm#193891 - the changes were deferred to reduce the size of an already large and approved PR.

) The previous test was dereferencing `begin()` iterator on empty view which is UB, because `begin() == end()`. A new test case was suggested in a post-merge feedback in #193891, which verifies LWG3568 through constant evaluation. Such a `constexpr` `basic_istream_view` variable can only be created if it is completely initialized, including its exposition-only _`value_`_ member. The existing test case is changed to use a non-empty stream and a testing class type for which `operator>>` is no-op. The state of the class object stored in `basic_istream_view` is unchanged even after the initial `operator>>` call. This avoids dereferencing a past-the-end iterator while testing LWG3568.

…#215589) The previous test was dereferencing `begin()` iterator on empty view which is UB, because `begin() == end()`. A new test case was suggested in a post-merge feedback in llvm#193891, which verifies LWG3568 through constant evaluation. Such a `constexpr` `basic_istream_view` variable can only be created if it is completely initialized, including its exposition-only _`value_`_ member. The existing test case is changed to use a non-empty stream and a testing class type for which `operator>>` is no-op. The state of the class object stored in `basic_istream_view` is unchanged even after the initial `operator>>` call. This avoids dereferencing a past-the-end iterator while testing LWG3568.

Zingam added ranges Issues related to `<ranges>` c++29 labels Jul 11, 2026

H-G-Hristov force-pushed the hgh/libcxx/P3059R2-Making-user-defined-constructors-of-view-iterators-sentinels-private branch 2 times, most recently from 7499890 to 8284cc0 Compare July 17, 2026 18:28

Zingam added c++26 and removed c++29 labels Jul 20, 2026

Zingam mentioned this pull request Jul 20, 2026

[libc++][ranges][NFC] Format lazy_split_view #210644

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Zingam pushed a commit that referenced this pull request Jul 20, 2026

[libc++][ranges][NFC] Format lazy_split_view (#210644)

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Pre-requisite for: #193891

H-G-Hristov force-pushed the hgh/libcxx/P3059R2-Making-user-defined-constructors-of-view-iterators-sentinels-private branch from c70379e to 19f8cb6 Compare July 20, 2026 09:28

frederick-vs-ja reviewed Jul 20, 2026

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Comment thread libcxx/test/std/ranges/range.adaptors/range.elements/iterator/base.pass.cpp Outdated

llvm-sync Bot pushed a commit to arm/arm-toolchain that referenced this pull request Jul 20, 2026

Automerge: [libc++][ranges][NFC] Format lazy_split_view (#210644)

b179159

Pre-requisite for: llvm/llvm-project#193891

llvm-upstreamsync Bot pushed a commit to qualcomm/cpullvm-toolchain that referenced this pull request Jul 20, 2026

Automerge: [libc++][ranges][NFC] Format lazy_split_view (#210644)

c7c7709

Pre-requisite for: llvm/llvm-project#193891

H-G-Hristov mentioned this pull request Jul 20, 2026

[libc++][ranges][NFC] Format a couple of elements_view tests #210687

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H-G-Hristov added a commit to H-G-Hristov/llvm-project that referenced this pull request Jul 20, 2026

[libc++][ranges][NFC] Format a few elements_view tests

67da176

As a pre-requisite for llvm#193891

Zingam pushed a commit that referenced this pull request Jul 20, 2026

[libc++][ranges][NFC] Format a couple of elements_view tests (#210687)

8d5788c

As a pre-requisite for #193891

H-G-Hristov force-pushed the hgh/libcxx/P3059R2-Making-user-defined-constructors-of-view-iterators-sentinels-private branch from 56482d8 to 7c2c8f1 Compare July 20, 2026 21:04

llvm-upstreamsync Bot pushed a commit to qualcomm/cpullvm-toolchain that referenced this pull request Jul 20, 2026

Automerge: [libc++][ranges][NFC] Format a couple of elements_view t…

03fdc4d

…ests (#210687) As a pre-requisite for llvm/llvm-project#193891

llvm-sync Bot pushed a commit to arm/arm-toolchain that referenced this pull request Jul 20, 2026

Automerge: [libc++][ranges][NFC] Format a couple of elements_view t…

0170315

…ests (#210687) As a pre-requisite for llvm/llvm-project#193891

H-G-Hristov force-pushed the hgh/libcxx/P3059R2-Making-user-defined-constructors-of-view-iterators-sentinels-private branch from f0e3fd0 to 95ea87f Compare July 21, 2026 18:49

Zingam changed the title ~~WIP [libc++][ranges] P3059R2: Making user-defined constructors of view iterators/sentinels private~~ [libc++][ranges] P3059R2: Making user-defined constructors of view iterators/sentinels private Jul 22, 2026

H-G-Hristov force-pushed the hgh/libcxx/P3059R2-Making-user-defined-constructors-of-view-iterators-sentinels-private branch from 95ea87f to db256d5 Compare July 22, 2026 06:16

Zingam marked this pull request as ready for review July 22, 2026 07:58

Zingam requested a review from a team as a code owner July 22, 2026 07:58

H-G-Hristov force-pushed the hgh/libcxx/P3059R2-Making-user-defined-constructors-of-view-iterators-sentinels-private branch from 78f944f to 98ad281 Compare July 22, 2026 07:59

H-G-Hristov mentioned this pull request Jul 22, 2026

[libc++][ranges][test-suite][NFC] Formatted and moved transform_view's sentinel.pass.cpp #211252

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ldionne pushed a commit that referenced this pull request Jul 22, 2026

[libc++][NFC] Format and move transform_view's sentinel.pass.cpp (#…

045c898

…211252) As a pre-requisite to: #193891

llvm-upstreamsync Bot pushed a commit to qualcomm/cpullvm-toolchain that referenced this pull request Jul 22, 2026

Automerge: [libc++][NFC] Format and move transform_view's `sentinel…

3da1718

….pass.cpp` (#211252) As a pre-requisite to: llvm/llvm-project#193891

llvm-sync Bot pushed a commit to arm/arm-toolchain that referenced this pull request Jul 22, 2026

Automerge: [libc++][NFC] Format and move transform_view's `sentinel…

1b5d9b3

….pass.cpp` (#211252) As a pre-requisite to: llvm/llvm-project#193891

H-G-Hristov added 10 commits July 30, 2026 13:02

Added missing test join_view

ba73c41

Update tests split_view

2f4a7d4

Fixed test

4b7ed09

Added missing transform_view tests

2e22271

Try to fix the tests

67392d1

Formatting

e692e9b

More fixes

ddb5c85

More fixes

2e1494c

Clean-up tests

71723ab

Clean-up elements_view

f5c82b2

H-G-Hristov force-pushed the hgh/libcxx/P3059R2-Making-user-defined-constructors-of-view-iterators-sentinels-private branch from 034d1ad to f5c82b2 Compare July 30, 2026 10:03

frederick-vs-ja approved these changes Jul 30, 2026

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Zingam merged commit 11b58f0 into llvm:main Jul 30, 2026
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H-G-Hristov deleted the hgh/libcxx/P3059R2-Making-user-defined-constructors-of-view-iterators-sentinels-private branch July 30, 2026 15:33

H-G-Hristov mentioned this pull request Jul 30, 2026

[libc++][ranges][test-suite][NFC] Consistency improvements after P3050 merge #213062

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StephanTLavavej mentioned this pull request Jul 30, 2026

P3059R2: Making user-defined constructors of view iterators/sentinels private. microsoft/STL#6382

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StephanTLavavej mentioned this pull request Aug 4, 2026

Update llvm-project microsoft/STL#6395

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frederick-vs-ja reviewed Aug 7, 2026

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Comment thread libcxx/test/std/ranges/range.factories/range.istream.view/ctor.pass.cpp

iskandarem mentioned this pull request Aug 11, 2026

[libc++][ranges] Fix the LWG 3568 test for basic_istream_view #215589

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[libc++][ranges] P3059R2: Making user-defined constructors of view iterators/sentinels private - #193891

[libc++][ranges] P3059R2: Making user-defined constructors of view iterators/sentinels private#193891
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