[libcxx-commits] [libcxx] [libc++] Simplify the implementation of __next_prime a bit (PR #143512)

[Nikolas Klauser via libcxx-commits]

https://github.com/philnik777 created https://github.com/llvm/llvm-project/pull/143512

None

>From 5cdbcbbcbfcbba04e45b0213433b0fd7c1614e6f Mon Sep 17 00:00:00 2001
From: Nikolas Klauser <nikolasklauser at berlin.de>
Date: Tue, 10 Jun 2025 13:59:15 +0200
Subject: [PATCH] [libc++] Simplify the implementation of __next_prime a bit

---
 libcxx/src/hash.cpp | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/libcxx/src/hash.cpp b/libcxx/src/hash.cpp
index 41c4eb480a5fc..50d8cf9f9f539 100644
--- a/libcxx/src/hash.cpp
+++ b/libcxx/src/hash.cpp
@@ -9,7 +9,6 @@
 #include <__hash_table>
 #include <algorithm>
 #include <stdexcept>
-#include <type_traits>
 
 _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wtautological-constant-out-of-range-compare")
 
@@ -52,16 +51,15 @@ const unsigned indices[] = {
 // are fewer potential primes to search, and fewer potential primes to divide
 // against.
 
-template <size_t _Sz = sizeof(size_t)>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<_Sz == 4, void>::type __check_for_overflow(size_t N) {
-  if (N > 0xFFFFFFFB)
-    std::__throw_overflow_error("__next_prime overflow");
-}
-
-template <size_t _Sz = sizeof(size_t)>
-inline _LIBCPP_HIDE_FROM_ABI typename enable_if<_Sz == 8, void>::type __check_for_overflow(size_t N) {
-  if (N > 0xFFFFFFFFFFFFFFC5ull)
-    std::__throw_overflow_error("__next_prime overflow");
+inline void __check_for_overflow(size_t N) {
+  if constexpr (sizeof(size_t) == 4) {
+    if (N > 0xFFFFFFFB)
+      std::__throw_overflow_error("__next_prime overflow");
+  } else {
+    static_assert(sizeof(size_t) == 8);
+    if (N > 0xFFFFFFFFFFFFFFC5ull)
+      std::__throw_overflow_error("__next_prime overflow");
+  }
 }
 
 size_t __next_prime(size_t n) {