[libcxx-commits] [libcxx] [libc++][NFC] Comment cleanup for `<type_traits>` (PR #130422)
via libcxx-commits
libcxx-commits at lists.llvm.org
Sat Mar 8 07:52:45 PST 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libcxx
Author: A. Jiang (frederick-vs-ja)
<details>
<summary>Changes</summary>
- Aligns all version comments to line 65.
- Consistently uses `// since C++` instead of `// C++`, in lowercase as used in most version comments.
- Consistently uses `class` to introduce type template parameters.
- Consistently uses `inline constexpr` for variable templates.
- Corrects the comment for `bool_constant` to `// since C++17` as it's a C++17 feature.
- Changes the class-key of `result_of` to `struct`, which follows N4659 [depr.meta.types] and the actual usage in libc++.
- Adds missed `// since C++17` for `is_(nothrow_)invocable(_r)`.
- Moves the comments for `is_nothrow_convertible_v` to the part for variable templates.
- Removes duplicated comments for `true_type` and `false_type`.
---
Patch is 34.89 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/130422.diff
1 Files Affected:
- (modified) libcxx/include/type_traits (+180-155)
``````````diff
diff --git a/libcxx/include/type_traits b/libcxx/include/type_traits
index e09a911eeb313..a03a60917cd54 100644
--- a/libcxx/include/type_traits
+++ b/libcxx/include/type_traits
@@ -18,13 +18,11 @@ namespace std
// helper class:
template <class T, T v> struct integral_constant;
- typedef integral_constant<bool, true> true_type; // C++11
- typedef integral_constant<bool, false> false_type; // C++11
+ typedef integral_constant<bool, true> true_type; // since C++11
+ typedef integral_constant<bool, false> false_type; // since C++11
- template <bool B> // C++14
- using bool_constant = integral_constant<bool, B>; // C++14
- typedef bool_constant<true> true_type; // C++14
- typedef bool_constant<false> false_type; // C++14
+ template <bool B>
+ using bool_constant = integral_constant<bool, B>; // since C++17
// helper traits
template <bool, class T = void> struct enable_if;
@@ -32,7 +30,7 @@ namespace std
// Primary classification traits:
template <class T> struct is_void;
- template <class T> struct is_null_pointer; // C++14
+ template <class T> struct is_null_pointer; // since C++14
template <class T> struct is_integral;
template <class T> struct is_floating_point;
template <class T> struct is_array;
@@ -51,7 +49,7 @@ namespace std
template <class T> struct is_arithmetic;
template <class T> struct is_fundamental;
template <class T> struct is_member_pointer;
- template <class T> struct is_scoped_enum; // C++23
+ template <class T> struct is_scoped_enum; // since C++23
template <class T> struct is_scalar;
template <class T> struct is_object;
template <class T> struct is_compound;
@@ -75,9 +73,9 @@ namespace std
template <class T> struct remove_pointer;
template <class T> struct add_pointer;
- template<class T> struct type_identity; // C++20
+ template<class T> struct type_identity; // since C++20
template<class T>
- using type_identity_t = typename type_identity<T>::type; // C++20
+ using type_identity_t = typename type_identity<T>::type; // since C++20
// Integral properties:
template <class T> struct is_signed;
@@ -91,20 +89,20 @@ namespace std
template <class T> struct remove_extent;
template <class T> struct remove_all_extents;
- template <class T> struct is_bounded_array; // C++20
- template <class T> struct is_unbounded_array; // C++20
+ template <class T> struct is_bounded_array; // since C++20
+ template <class T> struct is_unbounded_array; // since C++20
// Member introspection:
template <class T> struct is_trivial;
- template <class T> struct is_pod; // Deprecated in C++20
+ template <class T> struct is_pod; // deprecated in C++20
template <class T> struct is_trivially_copyable;
template <class T> struct is_standard_layout;
- template <class T> struct is_literal_type; // Deprecated in C++17; removed in C++20
+ template <class T> struct is_literal_type; // deprecated in C++17; removed in C++20
template <class T> struct is_empty;
template <class T> struct is_polymorphic;
template <class T> struct is_abstract;
- template <class T> struct is_final; // C++14
- template <class T> struct is_aggregate; // C++17
+ template <class T> struct is_final; // since C++14
+ template <class T> struct is_aggregate; // since C++17
template <class T, class... Args> struct is_constructible;
template <class T> struct is_default_constructible;
@@ -113,8 +111,8 @@ namespace std
template <class T, class U> struct is_assignable;
template <class T> struct is_copy_assignable;
template <class T> struct is_move_assignable;
- template <class T, class U> struct is_swappable_with; // C++17
- template <class T> struct is_swappable; // C++17
+ template <class T, class U> struct is_swappable_with; // since C++17
+ template <class T> struct is_swappable; // since C++17
template <class T> struct is_destructible;
template <class T, class... Args> struct is_trivially_constructible;
@@ -133,301 +131,328 @@ namespace std
template <class T, class U> struct is_nothrow_assignable;
template <class T> struct is_nothrow_copy_assignable;
template <class T> struct is_nothrow_move_assignable;
- template <class T, class U> struct is_nothrow_swappable_with; // C++17
- template <class T> struct is_nothrow_swappable; // C++17
+ template <class T, class U>
+ struct is_nothrow_swappable_with; // since C++17
+ template <class T>
+ struct is_nothrow_swappable; // since C++17
template <class T> struct is_nothrow_destructible;
- template<class T> struct is_implicit_lifetime; // Since C++23
+ template <class T> struct is_implicit_lifetime; // since C++23
template <class T> struct has_virtual_destructor;
- template<class T> struct has_unique_object_representations; // C++17
+ template <class T>
+ struct has_unique_object_representations; // since C++17
- template<class T, class U> struct reference_constructs_from_temporary; // Since C++23
- template<class T, class U> struct reference_converts_from_temporary; // Since C++23
+ template<class T, class U>
+ struct reference_constructs_from_temporary; // since C++23
+ template<class T, class U>
+ struct reference_converts_from_temporary; // since C++23
// Relationships between types:
template <class T, class U> struct is_same;
template <class Base, class Derived> struct is_base_of;
- template <class Base, class Derived> struct is_virtual_base_of; // C++26
+ template <class Base, class Derived>
+ struct is_virtual_base_of; // since C++26
template <class From, class To> struct is_convertible;
- template <typename From, typename To> struct is_nothrow_convertible; // C++20
- template <typename From, typename To> inline constexpr bool is_nothrow_convertible_v; // C++20
+ template <class From, class To>
+ struct is_nothrow_convertible; // since C++20
- template <class Fn, class... ArgTypes> struct is_invocable;
- template <class R, class Fn, class... ArgTypes> struct is_invocable_r;
+ template <class Fn, class... ArgTypes> struct is_invocable; // since C++17
+ template <class R, class Fn, class... ArgTypes>
+ struct is_invocable_r; // since C++17
- template <class Fn, class... ArgTypes> struct is_nothrow_invocable;
- template <class R, class Fn, class... ArgTypes> struct is_nothrow_invocable_r;
+ template <class Fn, class... ArgTypes>
+ struct is_nothrow_invocable; // since C++17
+ template <class R, class Fn, class... ArgTypes>
+ struct is_nothrow_invocable_r; // since C++17
// Alignment properties and transformations:
template <class T> struct alignment_of;
template <size_t Len, size_t Align = most_stringent_alignment_requirement>
- struct aligned_storage; // deprecated in C++23
+ struct aligned_storage; // deprecated in C++23
template <size_t Len, class... Types> struct aligned_union; // deprecated in C++23
- template <class T> struct remove_cvref; // C++20
+ template <class T> struct remove_cvref; // since C++20
template <class T> struct decay;
template <class... T> struct common_type;
template <class T> struct underlying_type;
- template <class> class result_of; // undefined; deprecated in C++17; removed in C++20
- template <class Fn, class... ArgTypes> class result_of<Fn(ArgTypes...)>; // deprecated in C++17; removed in C++20
- template <class Fn, class... ArgTypes> struct invoke_result; // C++17
+ template <class> struct result_of; // undefined; deprecated in C++17; removed in C++20
+ template <class Fn, class... ArgTypes>
+ struct result_of<Fn(ArgTypes...)>; // deprecated in C++17; removed in C++20
+ template <class Fn, class... ArgTypes>
+ struct invoke_result; // since C++17
// const-volatile modifications:
template <class T>
- using remove_const_t = typename remove_const<T>::type; // C++14
+ using remove_const_t = typename remove_const<T>::type; // since C++14
template <class T>
- using remove_volatile_t = typename remove_volatile<T>::type; // C++14
+ using remove_volatile_t
+ = typename remove_volatile<T>::type; // since C++14
template <class T>
- using remove_cv_t = typename remove_cv<T>::type; // C++14
+ using remove_cv_t = typename remove_cv<T>::type; // since C++14
template <class T>
- using add_const_t = typename add_const<T>::type; // C++14
+ using add_const_t = typename add_const<T>::type; // since C++14
template <class T>
- using add_volatile_t = typename add_volatile<T>::type; // C++14
+ using add_volatile_t = typename add_volatile<T>::type; // since C++14
template <class T>
- using add_cv_t = typename add_cv<T>::type; // C++14
+ using add_cv_t = typename add_cv<T>::type; // since C++14
// reference modifications:
template <class T>
- using remove_reference_t = typename remove_reference<T>::type; // C++14
+ using remove_reference_t
+ = typename remove_reference<T>::type; // since C++14
template <class T>
- using add_lvalue_reference_t = typename add_lvalue_reference<T>::type; // C++14
+ using add_lvalue_reference_t
+ = typename add_lvalue_reference<T>::type; // since C++14
template <class T>
- using add_rvalue_reference_t = typename add_rvalue_reference<T>::type; // C++14
+ using add_rvalue_reference_t
+ = typename add_rvalue_reference<T>::type; // since C++14
// sign modifications:
template <class T>
- using make_signed_t = typename make_signed<T>::type; // C++14
+ using make_signed_t = typename make_signed<T>::type; // since C++14
template <class T>
- using make_unsigned_t = typename make_unsigned<T>::type; // C++14
+ using make_unsigned_t = typename make_unsigned<T>::type; // since C++14
// array modifications:
template <class T>
- using remove_extent_t = typename remove_extent<T>::type; // C++14
+ using remove_extent_t
+ = typename remove_extent<T>::type; // since C++14
template <class T>
- using remove_all_extents_t = typename remove_all_extents<T>::type; // C++14
+ using remove_all_extents_t
+ = typename remove_all_extents<T>::type; // since C++14
template <class T>
inline constexpr bool is_bounded_array_v
- = is_bounded_array<T>::value; // C++20
+ = is_bounded_array<T>::value; // since C++20
inline constexpr bool is_unbounded_array_v
- = is_unbounded_array<T>::value; // C++20
+ = is_unbounded_array<T>::value; // since C++20
// pointer modifications:
template <class T>
- using remove_pointer_t = typename remove_pointer<T>::type; // C++14
+ using remove_pointer_t
+ = typename remove_pointer<T>::type; // since C++14
template <class T>
- using add_pointer_t = typename add_pointer<T>::type; // C++14
+ using add_pointer_t = typename add_pointer<T>::type; // since C++14
// other transformations:
template <size_t Len, size_t Align=default-alignment>
- using aligned_storage_t = typename aligned_storage<Len,Align>::type; // C++14
+ using aligned_storage_t
+ = typename aligned_storage<Len,Align>::type; // since C++14
template <size_t Len, class... Types>
- using aligned_union_t = typename aligned_union<Len,Types...>::type; // C++14
+ using aligned_union_t
+ = typename aligned_union<Len,Types...>::type; // since C++14
template <class T>
- using remove_cvref_t = typename remove_cvref<T>::type; // C++20
+ using remove_cvref_t
+ = typename remove_cvref<T>::type; // since C++20
template <class T>
- using decay_t = typename decay<T>::type; // C++14
+ using decay_t = typename decay<T>::type; // since C++14
template <bool b, class T=void>
- using enable_if_t = typename enable_if<b,T>::type; // C++14
+ using enable_if_t = typename enable_if<b,T>::type; // since C++14
template <bool b, class T, class F>
- using conditional_t = typename conditional<b,T,F>::type; // C++14
+ using conditional_t
+ = typename conditional<b,T,F>::type; // since C++14
template <class... T>
- using common_type_t = typename common_type<T...>::type; // C++14
+ using common_type_t
+ = typename common_type<T...>::type; // since C++14
template <class T>
- using underlying_type_t = typename underlying_type<T>::type; // C++14
+ using underlying_type_t
+ = typename underlying_type<T>::type; // since C++14
template <class T>
- using result_of_t = typename result_of<T>::type; // C++14; deprecated in C++17; removed in C++20
+ using result_of_t = typename result_of<T>::type; // since C++14; deprecated in C++17; removed in C++20
template <class Fn, class... ArgTypes>
- using invoke_result_t = typename invoke_result<Fn, ArgTypes...>::type; // C++17
+ using invoke_result_t
+ = typename invoke_result<Fn, ArgTypes...>::type; // since C++17
template <class...>
- using void_t = void; // C++17
+ using void_t = void; // since C++17
// See C++14 20.10.4.1, primary type categories
template <class T> inline constexpr bool is_void_v
- = is_void<T>::value; // C++17
+ = is_void<T>::value; // since C++17
template <class T> inline constexpr bool is_null_pointer_v
- = is_null_pointer<T>::value; // C++17
+ = is_null_pointer<T>::value; // since C++17
template <class T> inline constexpr bool is_integral_v
- = is_integral<T>::value; // C++17
+ = is_integral<T>::value; // since C++17
template <class T> inline constexpr bool is_floating_point_v
- = is_floating_point<T>::value; // C++17
+ = is_floating_point<T>::value; // since C++17
template <class T> inline constexpr bool is_array_v
- = is_array<T>::value; // C++17
+ = is_array<T>::value; // since C++17
template <class T> inline constexpr bool is_pointer_v
- = is_pointer<T>::value; // C++17
+ = is_pointer<T>::value; // since C++17
template <class T> inline constexpr bool is_lvalue_reference_v
- = is_lvalue_reference<T>::value; // C++17
+ = is_lvalue_reference<T>::value; // since C++17
template <class T> inline constexpr bool is_rvalue_reference_v
- = is_rvalue_reference<T>::value; // C++17
+ = is_rvalue_reference<T>::value; // since C++17
template <class T> inline constexpr bool is_member_object_pointer_v
- = is_member_object_pointer<T>::value; // C++17
+ = is_member_object_pointer<T>::value; // since C++17
template <class T> inline constexpr bool is_member_function_pointer_v
- = is_member_function_pointer<T>::value; // C++17
+ = is_member_function_pointer<T>::value; // since C++17
template <class T> inline constexpr bool is_enum_v
- = is_enum<T>::value; // C++17
+ = is_enum<T>::value; // since C++17
template <class T> inline constexpr bool is_union_v
- = is_union<T>::value; // C++17
+ = is_union<T>::value; // since C++17
template <class T> inline constexpr bool is_class_v
- = is_class<T>::value; // C++17
+ = is_class<T>::value; // since C++17
template <class T> inline constexpr bool is_function_v
- = is_function<T>::value; // C++17
+ = is_function<T>::value; // since C++17
// See C++14 20.10.4.2, composite type categories
template <class T> inline constexpr bool is_reference_v
- = is_reference<T>::value; // C++17
+ = is_reference<T>::value; // since C++17
template <class T> inline constexpr bool is_arithmetic_v
- = is_arithmetic<T>::value; // C++17
+ = is_arithmetic<T>::value; // since C++17
template <class T> inline constexpr bool is_fundamental_v
- = is_fundamental<T>::value; // C++17
+ = is_fundamental<T>::value; // since C++17
template <class T> inline constexpr bool is_object_v
- = is_object<T>::value; // C++17
+ = is_object<T>::value; // since C++17
template <class T> inline constexpr bool is_scalar_v
- = is_scalar<T>::value; // C++17
+ = is_scalar<T>::value; // since C++17
template <class T> inline constexpr bool is_compound_v
- = is_compound<T>::value; // C++17
+ = is_compound<T>::value; // since C++17
template <class T> inline constexpr bool is_member_pointer_v
- = is_member_pointer<T>::value; // C++17
+ = is_member_pointer<T>::value; // since C++17
template <class T> inline constexpr bool is_scoped_enum_v
- = is_scoped_enum<T>::value; // C++23
+ = is_scoped_enum<T>::value; // since C++23
// See C++14 20.10.4.3, type properties
template <class T> inline constexpr bool is_const_v
- = is_const<T>::value; // C++17
+ = is_const<T>::value; // since C++17
template <class T> inline constexpr bool is_volatile_v
- = is_volatile<T>::value; //...
[truncated]
``````````
</details>
https://github.com/llvm/llvm-project/pull/130422
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