Skip to content

[libc++][test] Test LWG3819: reference_meows_from_temporary should not use is_meowible #143474

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 3 commits into
base: main
Choose a base branch
from
+65 −1
Open

[libc++][test] Test LWG3819: reference_meows_from_temporary should not use is_meowible #143474

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
25aeb85
[libc++][test] Test LWG3819: `reference_meows_from_temporary` should …
frederick-vs-ja Jun 4, 2025
016ae31
Address @philnik777's review comments and tweak macro guards
frederick-vs-ja Sep 1, 2025
1b464b6
Merge branch 'main' into test-lwg-3819
frederick-vs-ja Sep 3, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion libcxx/docs/Status/Cxx23Issues.csv
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -261,7 +261,7 @@
"`LWG3733 <https://wg21.link/LWG3733>`__","``ranges::to`` misuses ``cpp17-input-iterator``","2023-02 (Issaquah)","|Complete|","17",""
"`LWG3742 <https://wg21.link/LWG3742>`__","``deque::prepend_range`` needs to permute","2023-02 (Issaquah)","","",""
"`LWG3790 <https://wg21.link/LWG3790>`__","`P1467 <https://wg21.link/P1467>`__ accidentally changed ``nexttoward``'s signature","2023-02 (Issaquah)","","",""
"`LWG3819 <https://wg21.link/LWG3819>`__","``reference_meows_from_temporary`` should not use ``is_meowible``","2023-02 (Issaquah)","","",""
"`LWG3819 <https://wg21.link/LWG3819>`__","``reference_meows_from_temporary`` should not use ``is_meowible``","2023-02 (Issaquah)","|Complete|","22","Changes are made in compilers but not libraries. The version number corresponds to Clang."
"`LWG3821 <https://wg21.link/LWG3821>`__","``uses_allocator_construction_args`` should have overload for ``pair-like``","2023-02 (Issaquah)","|Complete|","18",""
"`LWG3834 <https://wg21.link/LWG3834>`__","Missing ``constexpr`` for ``std::intmax_t`` math functions in ``<cinttypes>``","2023-02 (Issaquah)","","",""
"`LWG3839 <https://wg21.link/LWG3839>`__","``range_formatter``'s ``set_separator``, ``set_brackets``, and ``underlying`` functions should be ``noexcept``","2023-02 (Issaquah)","|Complete|","17",""
Expand Down
8 changes: 8 additions & 0 deletions libcxx/test/std/utilities/meta/meta.unary/meta.unary.prop/common.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -85,6 +85,14 @@ class ExplicitConversionRef {
explicit operator int&();
};

struct NonMovable {
NonMovable(NonMovable&&) = delete;
};

struct ConvertsFromNonMovable {
ConvertsFromNonMovable(NonMovable);
};

#endif

#endif // TEST_META_UNARY_COMP_COMMON_H
28 changes: 28 additions & 0 deletions ...td/utilities/meta/meta.unary/meta.unary.prop/reference_constructs_from_temporary.pass.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -58,6 +58,7 @@ constexpr bool test() {
assert((std::is_constructible_v<const int&, ConvertsToRef<long, long&>>));
test_reference_constructs_from_temporary<const int&, ConvertsToRef<long, long&>, true>();
#ifndef TEST_COMPILER_GCC
// TODO: Remove this guard once https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120529 gets fixed.
test_reference_constructs_from_temporary<const int&, ConvertsToRefPrivate<long, long&>, false>();
#endif

Expand All @@ -66,6 +67,33 @@ constexpr bool test() {

test_reference_constructs_from_temporary<const int&, long, true>();

#if defined(TEST_COMPILER_GCC) || \
(defined(TEST_CLANG_VER) && \
((!defined(__ANDROID__) && TEST_CLANG_VER >= 2100) || (defined(__ANDROID__) && TEST_CLANG_VER >= 2200))) || \
(defined(TEST_APPLE_CLANG_VER) && TEST_APPLE_CLANG_VER >= 1800)
// TODO: Bump the version numbers if newer Apple Clang or Android Clang hasn't implemented LWG3819 yet.
// TODO: Remove this guard once no supported Clang is affected by https://llvm.org/PR114344.

// Test function references.
test_reference_constructs_from_temporary<void (&)(), void(), false>();
test_reference_constructs_from_temporary<void (&&)(), void(), false>();

// Test cv-qualification dropping for scalar prvalues. LWG3819 also covers this.
test_reference_constructs_from_temporary<int&&, const int, true>();
test_reference_constructs_from_temporary<int&&, volatile int, true>();
#endif

#if !defined(TEST_COMPILER_GCC) && \
((defined(TEST_CLANG_VER) && \
((!defined(__ANDROID__) && TEST_CLANG_VER >= 2100) || (defined(__ANDROID__) && TEST_CLANG_VER >= 2200))) || \
(defined(TEST_APPLE_CLANG_VER) && TEST_APPLE_CLANG_VER >= 1800))
// TODO: Bump the version numbers if newer Apple Clang or Android Clang hasn't implemented LWG3819 yet.
// TODO: Remove this guard once supported Clang and GCC have LWG3819 implemented.

// Test LWG3819: reference_meows_from_temporary should not use is_meowible.
test_reference_constructs_from_temporary<ConvertsFromNonMovable&&, NonMovable, true>();
#endif

// Additional checks
test_reference_constructs_from_temporary<const Base&, Derived, true>();
test_reference_constructs_from_temporary<int&&, int, true>();
Expand Down
28 changes: 28 additions & 0 deletions .../std/utilities/meta/meta.unary/meta.unary.prop/reference_converts_from_temporary.pass.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -58,6 +58,7 @@ constexpr bool test() {
assert((std::is_constructible_v<const int&, ConvertsToRef<long, long&>>));
test_reference_converts_from_temporary<const int&, ConvertsToRef<long, long&>, true>();
#ifndef TEST_COMPILER_GCC
// TODO: Remove this guard once https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120529 gets fixed.
test_reference_converts_from_temporary<const int&, ConvertsToRefPrivate<long, long&>, false>();
#endif

Expand All @@ -66,6 +67,33 @@ constexpr bool test() {

test_reference_converts_from_temporary<const int&, long, true>();

#if defined(TEST_COMPILER_GCC) || \
(defined(TEST_CLANG_VER) && \
((!defined(__ANDROID__) && TEST_CLANG_VER >= 2100) || (defined(__ANDROID__) && TEST_CLANG_VER >= 2200))) || \
(defined(TEST_APPLE_CLANG_VER) && TEST_APPLE_CLANG_VER >= 1800)
// TODO: Bump the version numbers if newer Apple Clang or Android Clang hasn't implemented LWG3819 yet.
// TODO: Remove this guard once no supported Clang is affected by https://llvm.org/PR114344.

// Test function references.
test_reference_converts_from_temporary<void (&)(), void(), false>();
test_reference_converts_from_temporary<void (&&)(), void(), false>();

// Test cv-qualification dropping for scalar prvalues. LWG3819 also covers this.
test_reference_converts_from_temporary<int&&, const int, true>();
test_reference_converts_from_temporary<int&&, volatile int, true>();
#endif

#if !defined(TEST_COMPILER_GCC) && \
((defined(TEST_CLANG_VER) && \
((!defined(__ANDROID__) && TEST_CLANG_VER >= 2100) || (defined(__ANDROID__) && TEST_CLANG_VER >= 2200))) || \
(defined(TEST_APPLE_CLANG_VER) && TEST_APPLE_CLANG_VER >= 1800))
// TODO: Bump the version numbers if newer Apple Clang or Android Clang hasn't implemented LWG3819 yet.
// TODO: Remove this guard once supported Clang and GCC have LWG3819 implemented.

// Test LWG3819: reference_meows_from_temporary should not use is_meowible.
test_reference_converts_from_temporary<ConvertsFromNonMovable&&, NonMovable, true>();
#endif

// Additional checks
test_reference_converts_from_temporary<const Base&, Derived, true>();
test_reference_converts_from_temporary<int&&, int, true>();
Expand Down
Loading