Merge branch 'esmstore-round-2' into 'master'

More ESMStore cleanup

See merge request OpenMW/openmw!2383

apps/openmw/mwworld/esmstore.cpp

@@ -316,13 +316,6 @@ void ESMStore::setIdType(const std::string& id, ESM::RecNameInts type)
     mStoreImp->mIds[id] = type;
 }
 
-static std::size_t sTypeIndexCounter = 0;
-
-std::size_t ESMStore::geNextTypeIndex()
-{
-    return sTypeIndexCounter++;
-}
-
 ESM::LuaScriptsCfg ESMStore::getLuaScriptsCfg() const
 {
     ESM::LuaScriptsCfg cfg;

apps/openmw/mwworld/esmstore.hpp

@@ -8,6 +8,7 @@
 
 #include <components/esm/luascripts.hpp>
 #include <components/esm3/loadgmst.hpp>
+#include <components/misc/tuplemeta.hpp>
 
 #include "store.hpp"
 
@@ -125,22 +126,11 @@ namespace MWWorld
             // Special entry which is hardcoded and not loaded from an ESM
             Store<ESM::Attribute >>;
 
-        template <class T, class Tuple>
-        struct HasMember;
-
-        template <class T, class ... Args>
-        struct HasMember<T, std::tuple<Store<Args> ...>> {
-            static constexpr bool value = (std::is_same_v<T, Args> || ...);
-        };
-
-        static std::size_t geNextTypeIndex();
-
         template<typename T> 
-        static std::size_t getTypeIndex()
+        static constexpr std::size_t getTypeIndex()
         {
-            static_assert(HasMember<T, StoreTuple>::value);
-            static std::size_t sIndex = geNextTypeIndex();
-            return sIndex;
+            static_assert(Misc::TupleHasType<Store<T>, StoreTuple>::value);
+            return Misc::TupleTypeIndex<Store<T>, StoreTuple>::value;
         }
 
         std::unique_ptr<ESMStoreImp> mStoreImp;

components/misc/tuplemeta.hpp

@@ -0,0 +1,35 @@
+#ifndef OPENMW_COMPONENTS_MISC_META_H
+#define OPENMW_COMPONENTS_MISC_META_H
+
+#include <cstddef>
+#include <tuple>
+#include <type_traits>
+
+namespace Misc
+{
+    template <class T, class Tuple>
+    struct TupleHasType;
+
+    template <class T, class... Args>
+    struct TupleHasType<T, std::tuple<Args...>>
+    {
+        static constexpr bool value = (std::is_same_v<T, Args> || ...);
+    };
+
+    template <class T, class Tuple>
+    struct TupleTypeIndex;
+
+    template <class T, class... Types>
+    struct TupleTypeIndex<T, std::tuple<T, Types...>>
+    {
+        static constexpr std::size_t value = 0;
+    };
+
+    template <class T, class U, class... Types>
+    struct TupleTypeIndex<T, std::tuple<U, Types...>>
+    {
+        static constexpr std::size_t value = 1 + TupleTypeIndex<T, std::tuple<Types...>>::value;
+    };
+}
+
+#endif