match type in loop

alib2common/src/abstraction/AlgorithmRegistry.cpp

@@ -115,7 +115,7 @@ std::shared_ptr < abstraction::OperationAbstraction > AlgorithmRegistry::getAbst
 	// intersection of everything together finds indexes which are better or of the same quality for all params over all overloads
 	ext::set < unsigned > winner { ext::sequence < unsigned > ( 0 ).begin ( ), ext::sequence < unsigned > ( compatibilityData.size ( ) ).end ( ) };
-	for ( const std::set < unsigned > & best : winnerList ) {
+	for ( const ext::set < unsigned > & best : winnerList ) {
 		ext::set < unsigned > filtered;
 		std::set_intersection ( winner.begin ( ), winner.end ( ), best.begin ( ), best.end ( ), std::inserter ( filtered, filtered.end ( ) ) );
 		winner = std::move ( filtered );