[clang-tools-extra] [clang-tidy] Teach `modernize-type-traits` about more type traits (PR #147074)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-tidy

Author: Victor Chernyakin (localspook)

<details>
<summary>Changes</summary>

These new traits come from various standard versions:

C++14:

 - `tuple_element_t`

C++17:

- `is_placeholder_v`
- `is_bind_expression_v`

- `ratio_equal_v`
- `ratio_not_equal_v`
- `ratio_less_v`
- `ratio_less_equal_v`
- `ratio_greater_v`
- `ratio_greater_equal_v`
- `is_error_code_enum_v`
- `is_error_condition_enum_v`
- `is_execution_policy_v`
- `tuple_size_v`
- `variant_size_v`
- `uses_allocator_v`

- `variant_alternative_t`

C++20:

  - `compare_three_way_result_t`
  - `common_comparison_category_t`
  - `unwrap_ref_decay_t`
  - `unwrap_reference_t`

C++23:

- `is_implicit_lifetime_v`

C++26:

- `is_nothrow_relocatable_v`
- `is_replaceable_v`
- `is_trivially_relocatable_v`
- `is_virtual_base_of_v`

This doesn't add `treat_as_floating_point_v` or `is_clock_v` because they require more invasive changes; instead I've opened #<!-- -->147072 to track them.

---
Full diff: https://github.com/llvm/llvm-project/pull/147074.diff


2 Files Affected:

- (modified) clang-tools-extra/clang-tidy/modernize/TypeTraitsCheck.cpp (+27) 
- (modified) clang-tools-extra/docs/ReleaseNotes.rst (+3) 


``````````diff
diff --git a/clang-tools-extra/clang-tidy/modernize/TypeTraitsCheck.cpp b/clang-tools-extra/clang-tidy/modernize/TypeTraitsCheck.cpp
index c0766395ec5cc..92e6f61a6d9d4 100644
--- a/clang-tools-extra/clang-tidy/modernize/TypeTraitsCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/TypeTraitsCheck.cpp
@@ -28,8 +28,10 @@ static const llvm::StringSet<> ValueTraits = {
     "is_array",
     "is_assignable",
     "is_base_of",
+    "is_bind_expression",
     "is_bounded_array",
     "is_class",
+    "is_clock",
     "is_compound",
     "is_const",
     "is_constructible",
@@ -40,10 +42,14 @@ static const llvm::StringSet<> ValueTraits = {
     "is_destructible",
     "is_empty",
     "is_enum",
+    "is_error_code_enum",
+    "is_error_condition_enum",
+    "is_execution_policy",
     "is_final",
     "is_floating_point",
     "is_function",
     "is_fundamental",
+    "is_implicit_lifetime",
     "is_integral",
     "is_invocable",
     "is_invocable_r",
@@ -65,14 +71,17 @@ static const llvm::StringSet<> ValueTraits = {
     "is_nothrow_invocable_r",
     "is_nothrow_move_assignable",
     "is_nothrow_move_constructible",
+    "is_nothrow_relocatable",
     "is_nothrow_swappable",
     "is_nothrow_swappable_with",
     "is_null_pointer",
     "is_object",
+    "is_placeholder",
     "is_pointer",
     "is_pointer_interconvertible_base_of",
     "is_polymorphic",
     "is_reference",
+    "is_replaceable",
     "is_rvalue_reference",
     "is_same",
     "is_scalar",
@@ -91,15 +100,27 @@ static const llvm::StringSet<> ValueTraits = {
     "is_trivially_destructible",
     "is_trivially_move_assignable",
     "is_trivially_move_constructible",
+    "is_trivially_relocatable",
     "is_unbounded_array",
     "is_union",
     "is_unsigned",
+    "is_virtual_base_of",
     "is_void",
     "is_volatile",
     "negation",
     "rank",
+    "ratio_equal",
+    "ratio_greater_equal",
+    "ratio_greater",
+    "ratio_less_equal",
+    "ratio_less",
+    "ratio_not_equal",
     "reference_constructs_from_temporary",
     "reference_converts_from_temporary",
+    "treat_as_floating_point",
+    "tuple_size",
+    "uses_allocator",
+    "variant_size",
 };
 
 static const llvm::StringSet<> TypeTraits = {
@@ -130,6 +151,12 @@ static const llvm::StringSet<> TypeTraits = {
     "result_of",
     "invoke_result",
     "type_identity",
+	"tuple_element",
+	"variant_alternative",
+	"compare_three_way_result",
+	"common_comparison_category",
+	"unwrap_ref_decay",
+	"unwrap_reference",
 };
 
 static DeclarationName getName(const DependentScopeDeclRefExpr &D) {
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index f8f183e9de1cc..3d554733ad3fd 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -276,6 +276,9 @@ Changes in existing checks
   excluding variables with ``thread_local`` storage class specifier from being
   matched.
 
+- Improved :doc:`modernize-type-traits
+  <clang-tidy/checks/modernize/type-traits>` check by detecting more type traits.
+
 - Improved :doc:`modernize-use-default-member-init
   <clang-tidy/checks/modernize/use-default-member-init>` check by matching
   arithmetic operations, ``constexpr`` and ``static`` values, and detecting

``````````

</details>


https://github.com/llvm/llvm-project/pull/147074