1 files changed, 69 insertions, 1 deletions
diff --git a/modules/codec/c++/forst.tmpl.hpp b/modules/codec/c++/forst.tmpl.hpp
index 30d18ef..bfcafae 100644
--- a/modules/codec/c++/forst.tmpl.hpp
+++ b/modules/codec/c++/forst.tmpl.hpp
@@ -1,7 +1,75 @@
 namespace saw {
 namespace impl {
-struct forst_decode {
 
+/**
+ * This class provides
+ */
+template<typename Schema>
+struct forst_codec_info {
+	static_assert(always_false<Schema>, "Not supported.");
+};
+
+template<typename T, uint64_t N>
+struct forst_codec_info<schema::Primitive<T,N>> {
+private:
+public:
+	static constexpr uint64_t layers = 0u;
+};
+
+template<>
+struct forst_codec_info<schema::String> {
+public:
+	static constexpr uint64_t layers = 1u;
+};
+
+template<typename T, uint64_t N>
+struct forst_codec_info<schema::Array<T,N>> {
+public:
+	static constexpr uint64_t layers = 1u + forst_codec_info<T>::layers;
+};
+
+template<typename... Members>
+struct forst_codec_info<schema::Struct<Members...> > {
+public:
+	template<uint64_t i>
+	static uint64_t max_layers() constexpr noexcept {
+		if constexpr ( i < sizeof...(Members) ) {
+			using MT = typename parameter_pack_type<i, Members...>::type;
+
+			constexpr uint64_t layer_i = forst_codec_info<typename MT::Type>::layers;
+
+			constexpr uint64_t layer_next = max_layers<i+1u>();
+
+			constexpr uint64_t layer_val = layer_i > layer_next ? layer_i : layer_next;
+
+			return layer_val;
+		}
+		return 0u;
+	}
+public:
+	static constexpr uint64_t layers = max_layers<0>();
+};
+
+template<typename... T>
+struct forst_codec_info<schema::Tuple<T...>> {
+public:
+	template<uint64_t i>
+	static uint64_t max_layers() constexpr noexcept {
+		if constexpr ( i < sizeof...(Members) ) {
+			using MT = typename parameter_pack_type<i, T...>::type;
+
+			constexpr uint64_t layer_i = forst_codec_info<MT>::layers;
+
+			constexpr uint64_t layer_next = max_layers<i+1u>();
+
+			constexpr uint64_t layer_val = layer_i > layer_next ? layer_i : layer_next;
+
+			return layer_val;
+		}
+		return 0u;
+	}
+public:
+	static constexpr uint64_t layers = max_layers<0>();
 };
 }
 }