use constexpr_switch elsewhere

alib2abstraction/src/common/AbstractionHelpers.hpp

@@ -50,33 +50,29 @@ struct CheckInput {
 };
 template < class ... Params >
-struct ParamType;
-template < >
-struct ParamType < > {
-	static ext::type_index paramType ( unsigned ) {
-		throw std::logic_error ( "Out of types to check" );
-	}
-	static ext::set < abstraction::ParamQualifiers::ParamQualifier > paramTypeQualifiers ( unsigned ) {
-		throw std::logic_error ( "Out of types to check" );
-	}
-};
-template < class Param, class ... Params >
-struct ParamType < Param, Params ... > {
-	static ext::type_index paramType ( unsigned index ) {
-		if ( index == 0 )
-			return ext::type_index ( typeid ( Param ) );
-		else
-			return ParamType < Params ... >::paramType ( index - 1 );
+struct ParamType {
+	static ext::type_index paramType ( unsigned index ) {
+		ext::type_index res ( typeid ( void ) );
+		auto lambda = [ & ] ( auto I ) {
+			res = ext::type_index ( typeid ( std::tuple_element_t < decltype ( I )::value, std::tuple < Params ... > > ) );
+		};
+		ext::constexpr_switch < sizeof ... ( Params ) > ( index, lambda );
+		return res;
 	}
 	static ext::set < abstraction::ParamQualifiers::ParamQualifier > paramTypeQualifiers ( unsigned index ) {
-		if ( index == 0 )
-			return abstraction::ParamQualifiers::paramQualifiers < Param > ( );
-		else
-			return ParamType < Params ... >::paramTypeQualifiers ( index - 1 );
+		ext::set < abstraction::ParamQualifiers::ParamQualifier > res;
+
+		auto lambda = [ & ] ( auto I ) {
+			res = abstraction::ParamQualifiers::paramQualifiers < std::tuple_element_t < decltype ( I )::value, std::tuple < Params ... > > > ( );
+		};
+
+		ext::constexpr_switch < sizeof ... ( Params ) > ( index, lambda );
+
+		return res;
 	}
 };