fixup

src/core.cpp

@@ -34,7 +34,13 @@ public:
             {
                 size_t h1 = std::hash<size_t>{}(p.first);
                 size_t h2 = std::hash<size_t>{}(p.second);
-                h1 ^= h2 + 0x9e3779b9 + (h1 << 6) + (h1 >> 2);
+                size_t golden_ratio;
+                if constexpr (sizeof(size_t) < 8) {
+                    golden_ratio = 0x9e3779b9;
+                } else {
+                    golden_ratio = 0x9e3779b97f4a7c15;
+                }
+                h1 ^= h2 + golden_ratio + (h1 << 6) + (h1 >> 2);
                 return h1;
             }
     };