family id for infos

headers/meta.hpp/meta_class.hpp

@@ -22,7 +22,7 @@ namespace meta_hpp
     class class_ {
     public:
         explicit class_(std::string id)
-        : info_(std::move(id)) {}
+        : info_{get_family_id<Class>(), std::move(id)} {}
 
         const class_info& info() const noexcept {
             return info_;

headers/meta.hpp/meta_class_info.hpp

@@ -27,9 +27,14 @@ namespace meta_hpp
         class_info& operator=(class_info&&) = default;
         class_info& operator=(const class_info&) = default;
 
-        class_info(std::string id)
+        class_info(family_id fid, std::string id)
-        : id_(std::move(id)) {}
+        : fid_(std::move(fid))
+        , id_(std::move(id)) {}
     public:
+        const family_id& fid() const noexcept {
+            return fid_;
+        }
+
         const std::string& id() const noexcept {
             return id_;
         }
@@ -114,6 +119,7 @@ namespace meta_hpp
             detail::merge_with(variables_, other.variables_, &variable_info::merge_with_);
         }
     private:
+        family_id fid_;
         std::string id_;
         std::map<std::string, class_info, std::less<>> classes_;
         std::map<std::string, data_info, std::less<>> datas_;

headers/meta.hpp/meta_field.hpp

@@ -20,7 +20,7 @@ namespace meta_hpp
         static_assert(std::is_member_object_pointer_v<decltype(Field)>);
 
         explicit field_(std::string id)
-        : info_(std::move(id)) {
+        : info_{get_family_id<decltype(Field)>(), std::move(id)} {
             info_.getter_ = &field_detail::getter<Field>;
             info_.setter_ = &field_detail::setter<Field>;
         }

headers/meta.hpp/meta_field_info.hpp

@@ -68,9 +68,14 @@ namespace meta_hpp
         field_info& operator=(field_info&&) = default;
         field_info& operator=(const field_info&) = default;
 
-        field_info(std::string id)
+        field_info(family_id fid, std::string id)
-        : id_(std::move(id)) {}
+        : fid_(std::move(fid))
+        , id_(std::move(id)) {}
     public:
+        const family_id& fid() const noexcept {
+            return fid_;
+        }
+
         const std::string& id() const noexcept {
             return id_;
         }
@@ -105,6 +110,7 @@ namespace meta_hpp
             detail::merge_with(datas_, other.datas_, &data_info::merge_with_);
         }
     private:
+        family_id fid_;
         std::string id_;
         value(*getter_)(const void*);
         void(*setter_)(void*, value);

headers/meta.hpp/meta_function.hpp

@@ -20,7 +20,7 @@ namespace meta_hpp
         static_assert(std::is_function_v<std::remove_pointer_t<decltype(Function)>>);
 
         explicit function_(std::string id)
-        : info_(std::move(id)) {
+        : info_{get_family_id<decltype(Function)>(), std::move(id)} {
             info_.invoke_ = &function_detail::invoke<Function>;
         }
 

headers/meta.hpp/meta_function_info.hpp

@@ -75,9 +75,14 @@ namespace meta_hpp
         function_info& operator=(function_info&&) = default;
         function_info& operator=(const function_info&) = default;
 
-        function_info(std::string id)
+        function_info(family_id fid, std::string id)
-        : id_(std::move(id)) {}
+        : fid_(std::move(fid))
+        , id_(std::move(id)) {}
     public:
+        const family_id& fid() const noexcept {
+            return fid_;
+        }
+
         const std::string& id() const noexcept {
             return id_;
         }
@@ -112,6 +117,7 @@ namespace meta_hpp
             detail::merge_with(datas_, other.datas_, &data_info::merge_with_);
         }
     private:
+        family_id fid_;
         std::string id_;
         value(*invoke_)(value*, std::size_t);
         std::map<std::string, data_info, std::less<>> datas_;

headers/meta.hpp/meta_fwd.hpp

@@ -8,6 +8,7 @@
 
 #include <any>
 #include <array>
+#include <cassert>
 #include <cstddef>
 #include <cstdint>
 #include <functional>
@@ -44,6 +45,48 @@ namespace meta_hpp
     template < auto Variable > class variable_;
 }
 
+namespace meta_hpp
+{
+    struct family_id {
+        using underlying_type = std::size_t;
+        underlying_type id{};
+
+        friend bool operator<(family_id l, family_id r) noexcept {
+            return l.id < r.id;
+        }
+    };
+
+    namespace family_id_detail
+    {
+        template < typename Void = void >
+        class type_family_base {
+            static_assert(
+                std::is_void_v<Void>,
+                "unexpected internal error");
+        protected:
+            static family_id::underlying_type last_id_;
+        };
+
+        template < typename T >
+        class type_family final : public type_family_base<> {
+        public:
+            static family_id id() noexcept {
+                static family_id self_id{++last_id_};
+                assert(self_id.id > 0u && "family_id overflow");
+                return self_id;
+            }
+        };
+
+        template < typename Void >
+        family_id::underlying_type type_family_base<Void>::last_id_{};
+    }
+
+    template < typename T >
+    family_id get_family_id() noexcept {
+        return family_id_detail::type_family<T>::id();
+    }
+}
+
 namespace meta_hpp
 {
     template < typename Signature >

headers/meta.hpp/meta_method.hpp

@@ -20,7 +20,7 @@ namespace meta_hpp
         static_assert(std::is_member_function_pointer_v<decltype(Method)>);
 
         explicit method_(std::string id)
-        : info_(std::move(id)) {
+        : info_{get_family_id<decltype(Method)>(), std::move(id)} {
             info_.invoke_ = &method_detail::invoke<Method>;
             info_.cinvoke_ = &method_detail::cinvoke<Method>;
         }

headers/meta.hpp/meta_method_info.hpp

@@ -132,9 +132,14 @@ namespace meta_hpp
         method_info& operator=(method_info&&) = default;
         method_info& operator=(const method_info&) = default;
 
-        method_info(std::string id)
+        method_info(family_id fid, std::string id)
-        : id_(std::move(id)) {}
+        : fid_(std::move(fid))
+        , id_(std::move(id)) {}
     public:
+        const family_id& fid() const noexcept {
+            return fid_;
+        }
+
         const std::string& id() const noexcept {
             return id_;
         }
@@ -171,6 +176,7 @@ namespace meta_hpp
             detail::merge_with(datas_, other.datas_, &data_info::merge_with_);
         }
     private:
+        family_id fid_;
         std::string id_;
         value(*invoke_)(void*, value*, std::size_t);
         value(*cinvoke_)(const void*, value*, std::size_t);

headers/meta.hpp/meta_variable.hpp

@@ -18,7 +18,7 @@ namespace meta_hpp
     class variable_ {
     public:
         explicit variable_(std::string id)
-        : info_(std::move(id)) {
+        : info_{get_family_id<decltype(Variable)>(), std::move(id)} {
             info_.getter_ = &variable_detail::getter<Variable>;
             info_.setter_ = &variable_detail::setter<Variable>;
         }

headers/meta.hpp/meta_variable_info.hpp

@@ -63,9 +63,14 @@ namespace meta_hpp
         variable_info& operator=(variable_info&&) = default;
         variable_info& operator=(const variable_info&) = default;
 
-        variable_info(std::string id)
+        variable_info(family_id fid, std::string id)
-        : id_(std::move(id)) {}
+        : fid_(std::move(fid))
+        , id_(std::move(id)) {}
     public:
+        const family_id& fid() const noexcept {
+            return fid_;
+        }
+
         const std::string& id() const noexcept {
             return id_;
         }
@@ -103,6 +108,7 @@ namespace meta_hpp
             detail::merge_with(datas_, other.datas_, &data_info::merge_with_);
         }
     private:
+        family_id fid_;
         std::string id_;
         value(*getter_)();
         void(*setter_)(value);