From e1a85099ef1bb34cfe85be5a2bd0362516e115d4 Mon Sep 17 00:00:00 2001
From: Niels Lohmann <mail@nlohmann.me>
Date: Fri, 9 Oct 2026 16:01:50 +0200
Subject: [PATCH] Regenerate the amalgamated headers

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---
 single_include/nlohmann/json.hpp | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index 93ffdd25b..7ba4bc8b8 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -8793,8 +8793,9 @@ NLOHMANN_JSON_NAMESPACE_END
 
 
 #include <cstdint> // uint64_t
-#if !defined(__SIZEOF_INT128__) && defined(_MSC_VER) && (defined(_M_X64) || defined(_M_ARM64))
-    #include <intrin0.h> // __umulh, _umul128
+#include <cstring> // memcpy
+#if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_ARM64)) && (!defined(__SIZEOF_INT128__) || (!defined(__GNUC__) && !defined(__clang__)))
+    #include <intrin0.h> // __umulh, _umul128, _BitScanForward64, _BitScanReverse64
 #endif
 
 // #include <nlohmann/detail/abi_macros.hpp>
@@ -8813,6 +8814,10 @@ inline int count_leading_zeros(std::uint64_t x) noexcept
 {
 #if defined(__GNUC__) || defined(__clang__)
     return __builtin_clzll(x);
+#elif defined(_MSC_VER) && (defined(_M_X64) || defined(_M_ARM64))
+    unsigned long index = 0;
+    _BitScanReverse64(&index, x);
+    return 63 - static_cast<int>(index);
 #else
     int n = 0;
     for (int shift = 32; shift != 0; shift >>= 1)
@@ -8832,6 +8837,10 @@ inline int count_trailing_zeros(std::uint64_t x) noexcept
 {
 #if defined(__GNUC__) || defined(__clang__)
     return __builtin_ctzll(x);
+#elif defined(_MSC_VER) && (defined(_M_X64) || defined(_M_ARM64))
+    unsigned long index = 0;
+    _BitScanForward64(&index, x);
+    return static_cast<int>(index);
 #else
     int n = 0;
     for (int shift = 32; shift != 0; shift >>= 1)
@@ -8879,14 +8888,20 @@ inline uint128_parts full_multiplication(std::uint64_t a, std::uint64_t b) noexc
 #endif
 }
 
-/// eight bytes as a little-endian word (compilers fold this into one load on
-/// little-endian targets)
+/// eight bytes as a little-endian word (a single load on little-endian targets)
 inline std::uint64_t read_eight_bytes(const unsigned char* b) noexcept
 {
+#if defined(_MSC_VER) || defined(__x86_64__) || defined(__i386__) || (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+    // the byte order already matches (all MSVC targets are little-endian)
+    std::uint64_t result = 0;
+    std::memcpy(&result, b, sizeof(result));
+    return result;
+#else
     return static_cast<std::uint64_t>(b[0]) | (static_cast<std::uint64_t>(b[1]) << 8u)
            | (static_cast<std::uint64_t>(b[2]) << 16u) | (static_cast<std::uint64_t>(b[3]) << 24u)
            | (static_cast<std::uint64_t>(b[4]) << 32u) | (static_cast<std::uint64_t>(b[5]) << 40u)
            | (static_cast<std::uint64_t>(b[6]) << 48u) | (static_cast<std::uint64_t>(b[7]) << 56u);
+#endif
 }
 
 /// eight bytes as a little-endian word