[libcxx-commits] [libcxx] [libc++] Make __is_less_than_compatable a variable template (PR #202525)

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llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libcxx

Author: Nikolas Klauser (philnik777)

<details>
<summary>Changes</summary>

This makes the code a bit more readable and improves compile times a bit, since variable templates are faster to instantiate than class templates.


---
Full diff: https://github.com/llvm/llvm-project/pull/202525.diff


1 Files Affected:

- (modified) libcxx/include/__utility/is_pointer_in_range.h (+5-5) 


``````````diff
diff --git a/libcxx/include/__utility/is_pointer_in_range.h b/libcxx/include/__utility/is_pointer_in_range.h
index 8e1b86b16df8b..8daa12e935239 100644
--- a/libcxx/include/__utility/is_pointer_in_range.h
+++ b/libcxx/include/__utility/is_pointer_in_range.h
@@ -26,13 +26,13 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp, class _Up, class = void>
-struct __is_less_than_comparable : false_type {};
+inline const bool __is_less_than_comparable_v = false;
 
 template <class _Tp, class _Up>
-struct __is_less_than_comparable<_Tp, _Up, __void_t<decltype(std::declval<_Tp>() < std::declval<_Up>())> > : true_type {
-};
+inline const bool
+    __is_less_than_comparable_v<_Tp, _Up, __void_t<decltype(std::declval<_Tp>() < std::declval<_Up>())> > = true;
 
-template <class _Tp, class _Up, __enable_if_t<__is_less_than_comparable<const _Tp*, const _Up*>::value, int> = 0>
+template <class _Tp, class _Up, __enable_if_t<__is_less_than_comparable_v<const _Tp*, const _Up*>, int> = 0>
 _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_SANITIZE("address") bool
 __is_pointer_in_range(const _Tp* __begin, const _Tp* __end, const _Up* __ptr) {
   _LIBCPP_ASSERT_VALID_INPUT_RANGE(std::__is_valid_range(__begin, __end), "[__begin, __end) is not a valid range");
@@ -47,7 +47,7 @@ __is_pointer_in_range(const _Tp* __begin, const _Tp* __end, const _Up* __ptr) {
   return !__less<>()(__ptr, __begin) && __less<>()(__ptr, __end);
 }
 
-template <class _Tp, class _Up, __enable_if_t<!__is_less_than_comparable<const _Tp*, const _Up*>::value, int> = 0>
+template <class _Tp, class _Up, __enable_if_t<!__is_less_than_comparable_v<const _Tp*, const _Up*>, int> = 0>
 _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_SANITIZE("address") bool
 __is_pointer_in_range(const _Tp* __begin, const _Tp* __end, const _Up* __ptr) {
   if (__libcpp_is_constant_evaluated())

``````````

</details>


https://github.com/llvm/llvm-project/pull/202525