[ox/model] Add preloadable attribute to type descriptor

deps/ox/src/ox/model/desctypes.hpp

@@ -106,6 +106,7 @@ struct DescriptorType {
 	// - number of bytes for integer and float types
 	// - number of fields for structs and lists
 	int64_t length = 0;
+	bool preloadable = false;
 
 	DescriptorType() = default;
 
@@ -125,6 +126,7 @@ Error model(T *io, DescriptorType *type) {
 	err |= io->field("primitiveType", &type->primitiveType);
 	err |= io->field("fieldList", &type->fieldList);
 	err |= io->field("length", &type->length);
+	err |= io->field("preloadable", &type->preloadable);
 	return err;
 }
 

deps/ox/src/ox/model/descwrite.cpp

@@ -12,6 +12,26 @@
 
 namespace ox {
 
+namespace detail {
+
+struct preloadable_type {
+	static constexpr auto Preloadable = true;
+};
+
+struct non_preloadable_type {
+	static constexpr auto Preloadable = false;
+};
+
+struct non_preloadable_type2 {
+};
+
+static_assert(preloadable<preloadable_type>::value);
+static_assert(!preloadable<non_preloadable_type>::value);
+static_assert(!preloadable<non_preloadable_type2>::value);
+
+}
+
+
 static_assert([] {
 	int i = 0;
 	return indirectionLevels(i) == 0;

deps/ox/src/ox/model/descwrite.hpp

@@ -21,6 +21,22 @@
 
 namespace ox {
 
+namespace detail {
+
+template<bool>
+struct BoolWrapper {
+};
+
+template<typename T, typename = BoolWrapper<true>>
+struct preloadable: false_type {};
+
+template<typename T>
+struct preloadable<T, BoolWrapper<T::Preloadable>> {
+	static constexpr bool value = T::Preloadable;
+};
+
+}
+
 template<typename T>
 static constexpr int indirectionLevels(T) {
 	return 0;
@@ -187,11 +203,12 @@ void TypeDescWriter::setTypeInfo(const char *name, int) {
 	}
 	m_type = t;
 	m_type->typeName = name;
-	if (ox::is_union_v<T>) {
+	if (is_union_v<T>) {
 		m_type->primitiveType = PrimitiveType::Union;
 	} else {
 		m_type->primitiveType = PrimitiveType::Struct;
 	}
+	m_type->preloadable = detail::preloadable<T>::value;
 }
 
 template<typename T>