Clarify auto type for MSVC

mabraham · Sep 5, 2024 · 35dddf8 · 35dddf8
1 parent b48a0e9
commit 35dddf8
Showing 1 changed file with 14 additions and 6 deletions.
diff --git a/src/gromacs/hardware/tests/device_management.cpp b/src/gromacs/hardware/tests/device_management.cpp
@@ -112,30 +112,38 @@ std::string uuidToString(const std::array<std::byte, 16>& uuid)
     // xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, where every x represents 4 bits
     std::string result;
     result.reserve(37);
-    const auto* uuidIt = uuid.cbegin();
+#ifdef _MSVC
+    // Somehow MSVC won't cast from the return type of cbegin():
+    //
+    // error C2440: 'static_cast': cannot convert from 'std::_Array_const_iterator<_Ty,16>'
+    // to 'const unsigned int *' with [ _Ty=std::byte ]
+    const auto *uuidIt = static_cast<const unsigned int*>(&uuid[0]);
+#else
+    const auto* uuidIt = static_cast<const unsigned int*>(uuid.cbegin());
+#endif
     for (int i = 0; i < 4; ++i, ++uuidIt)
     {
-        result += gmx::formatString("%2.2x", static_cast<unsigned int>(*uuidIt));
+        result += gmx::formatString("%2.2x", *uuidIt);
     }
     result.append(1, '-');
     for (int i = 0; i < 2; ++i, ++uuidIt)
     {
-        result += gmx::formatString("%2.2x", static_cast<unsigned int>(*uuidIt));
+        result += gmx::formatString("%2.2x", *uuidIt);
     }
     result.append(1, '-');
     for (int i = 0; i < 2; ++i, ++uuidIt)
     {
-        result += gmx::formatString("%2.2x", static_cast<unsigned int>(*uuidIt));
+        result += gmx::formatString("%2.2x", *uuidIt);
     }
     result.append(1, '-');
     for (int i = 0; i < 2; ++i, ++uuidIt)
     {
-        result += gmx::formatString("%2.2x", static_cast<unsigned int>(*uuidIt));
+        result += gmx::formatString("%2.2x", *uuidIt);
     }
     result.append(1, '-');
     for (int i = 0; i < 6; ++i, ++uuidIt)
     {
-        result += gmx::formatString("%2.2x", static_cast<unsigned int>(*uuidIt));
+        result += gmx::formatString("%2.2x", *uuidIt);
     }
     return result;
 }