collection resolver progress

include/matador/object/collection_proxy.hpp

@@ -24,7 +24,7 @@ public:
 
   // Eager
   collection_proxy(std::weak_ptr<collection_resolver<Type>> resolver, std::vector<Type> items)
-  : items_(std::move(items)), resolver_(std::move(resolver)) {}
+  : loaded_{true}, items_(std::move(items)), resolver_(std::move(resolver)) {}
 
   // Transient
   explicit collection_proxy(std::vector<Type> items)

include/matador/object/collection_utils.hpp

@@ -0,0 +1,20 @@
+#ifndef MATADOR_COLLECTION_UTILS_HPP
+#define MATADOR_COLLECTION_UTILS_HPP
+
+#include <string>
+#include <typeindex>
+
+namespace matador::object {
+struct collection_composite_key {
+  std::type_index root_type;
+  std::type_index type;
+  std::string name;
+
+  bool operator==(const collection_composite_key& other) const;
+};
+
+struct collection_composite_key_hash {
+  std::size_t operator()(const collection_composite_key& k) const noexcept;
+};
+}
+#endif //MATADOR_COLLECTION_UTILS_HPP