Update utility.hlsl

Author: CrabExtra

include/nbl/builtin/hlsl/utility.hlsl

@@ -8,11 +8,41 @@
 #include <nbl/builtin/hlsl/type_traits.hlsl>
 
 
-// for now we only implement declval
 namespace nbl
 {
 namespace hlsl
 {
+
+template<typename T1, typename T2>
+struct pair
+{
+	using first_type = T1;
+	using second_type = T2;
+
+	first_type first;
+	second_type second;
+};
+
+template<typename T1, typename T2>
+pair<T1, T2> make_pair(T1 f, T2 s)
+{
+	pair<T1, T2> p;
+	p.first = f;
+	p.second = s;
+	return p;
+}
+
+template<typename T1, typename T2>
+void swap(NBL_REF_ARG(pair<T1, T2>) a, NBL_REF_ARG(pair<T1, T2>) b)
+{
+	T1 temp_first = a.first;
+	T2 temp_second = a.second;
+	a.first = b.first;
+	a.second = b.second;
+	b.first = temp_first;
+	b.second = temp_second;
+}
+
 template<typename T>
 const static bool always_true = true;
 #ifndef __HLSL_VERSION