Added better structure for the data server

3 files changed, 78 insertions, 0 deletions

diff --git a/modules/core/c++/reduce_templates.hpp b/modules/core/c++/reduce_templates.hpp
new file mode 100644
index 0000000..ef5fa4c
--- /dev/null
+++ b/modules/core/c++/reduce_templates.hpp
@@ -0,0 +1,41 @@
+#pragma once
+
+#include "templates.hpp"
+
+namespace saw {
+
+namespace impl {
+template<typename C, typename T>
+struct tmpl_group_reduce_match {
+	static constexpr bool has_type = false;
+	using type = saw::tmpl_group<C>;
+};
+
+template<typename T0, typename TL0, typename... TL> 
+struct tmpl_group_reduce_match<T0, tmpl_group<TL0,TL...>> {
+	static constexpr bool has_type = std::is_same_v<T0,TL0> or tmpl_group_reduce_match<T0, tmpl_group<TL...>>::has_type;
+
+	using type = typename std::conditional<has_type, tmpl_group<TL0,TL...>, tmpl_group<T0, TL0, TL...>>::type;
+};
+
+template<typename T>
+struct tmpl_group_reduce {
+	using reduced_type = T;
+};
+
+/**
+ * Reducing in outer loop
+ */
+template<typename... TL, typename T0>
+struct tmpl_group_reduce<tmpl_group<T0,TL...>> {
+	using reduced_inner_list = typename tmpl_group_reduce<tmpl_group<TL...>>::reduced_type;
+
+	using reduced_type = typename tmpl_group_reduce_match<T0,reduced_inner_list>::type;
+};
+}
+
+template<typename T>
+struct tmpl_reduce {
+	using type = typename impl::tmpl_group_reduce<T>::reduced_type;
+};
+}
diff --git a/modules/core/c++/templates.hpp b/modules/core/c++/templates.hpp
index acbaeb0..70836ae 100644
--- a/modules/core/c++/templates.hpp
+++ b/modules/core/c++/templates.hpp
@@ -5,6 +5,20 @@
 
 namespace saw {
 
+/**
+ * This type is meant for grouping of template types
+ */
+template <class... T>
+struct tmpl_group {};
+
+template<typename T, typename U>
+struct tmpl_concat;
+
+template<typename... T, typename... U>
+struct tmpl_concat<tmpl_group<T...>, tmpl_group<U...>> {
+	using type = tmpl_group<T..., U...>;
+};
+
 template <class T, class... TL> struct parameter_pack_index;
 
 template <class T, class... TL> struct parameter_pack_index<T, T, TL...> {
diff --git a/modules/core/tests/core.cpp b/modules/core/tests/core.cpp
index b1ce741..f418a07 100644
--- a/modules/core/tests/core.cpp
+++ b/modules/core/tests/core.cpp
@@ -1,6 +1,7 @@
 #include "../c++/test/suite.hpp"
 #include "../c++/id.hpp"
 #include "../c++/string_literal.hpp"
+#include "../c++/reduce_templates.hpp"
 
 namespace {
 SAW_TEST("ID functionality") {
@@ -37,4 +38,26 @@ SAW_TEST("String Literal Append"){
 
 		SAW_EXPECT(c == "foobar", "CT String sum is not \"foobar\"");
 }
+	
+SAW_TEST("Template Group Reduction"){
+	using namespace saw;
+
+	struct foo {
+		std::string name = "foo";
+	};
+	struct bar {
+		std::string name = "bar";
+	};
+	struct baz {
+		std::string name = "baz";
+	};
+
+	using grp = tmpl_group<foo, bar, baz, foo, bar, foo>;
+	using red_grp = tmpl_group<baz, bar, foo>;
+
+	using alg_red_grp = tmpl_reduce<grp>::type;
+	
+	static_assert(std::is_same_v<alg_red_grp, red_grp>, "Should be same type");
+	SAW_EXPECT((std::is_same_v<alg_red_grp, red_grp>), "Should be same type");
+}
 }