hash_pair fix (#227)

* fix: hash_pair function

* linter report

* ci: update artifact

* ci: fix action

* CI: update macos version to 14

Author: suvorovrain

.github/workflows/build.yml

@@ -49,9 +49,9 @@ jobs:
         run: cmake --build ${{ env.build_dir }}
 
       - name: Upload binary
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
-          name: ${{env.artifact}}
+          name: windows-${{env.artifact}}
           path: ${{env.build_dir}}/spla_x64.dll
 
 
@@ -75,13 +75,13 @@ jobs:
         run: cmake --build ${{ env.build_dir }}
 
       - name: Upload binary
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
-          name: ${{env.artifact}}
+          name: linux-${{env.artifact}}
           path: ${{env.build_dir}}/libspla_x64.so
 
   macos:
-    runs-on: macos-11
+    runs-on: macos-14
     steps:
       - uses: actions/checkout@v2
         with:
@@ -105,9 +105,9 @@ jobs:
         run: cmake --build ${{ env.build_dir }}
 
       - name: Upload binary
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
-          name: ${{env.artifact}}
+          name: macos-${{env.artifact}}
           path: |
             ${{env.build_dir}}/libspla_x64.dylib
             ${{env.build_dir}}/libspla_arm64.dylib

src/util/pair_hash.hpp

@@ -37,11 +37,20 @@ namespace spla {
      * @{
      */
 
+    template<class T>
+    inline void hash_combine(std::size_t& seed, const T& v) {
+        std::hash<T> hasher;
+        seed ^= hasher(v) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+    }
+
     struct pair_hash {
     public:
         template<typename T, typename U>
         std::size_t operator()(const std::pair<T, U>& x) const {
-            return std::hash<T>()(x.first) ^ std::hash<U>()(x.second);
+            std::size_t seed = 0;
+            hash_combine(seed, x.first);
+            hash_combine(seed, x.second);
+            return seed;
         }
     };