remove unwanted copies

alib2algo/src/automaton/properties/SynchronizingWordExistence.h

@@ -66,7 +66,7 @@ bool SynchronizingWordExistence::exists ( const automaton::DFA < SymbolType, Sta
 	std::queue < ext::pair < StateType, StateType > > q;
 	ext::set < ext::pair < StateType, StateType > > visited;
-	for ( const ext::pair < StateType, StateType > state: cart.getStates ( ) ) {
+	for ( const ext::pair < StateType, StateType > & state: cart.getStates ( ) ) {
 		if ( state.first != state.second )
 			continue;
@@ -78,7 +78,7 @@ bool SynchronizingWordExistence::exists ( const automaton::DFA < SymbolType, Sta
 		const ext::pair < StateType, StateType > cstate = std::move ( q.front ( ) );
 		q.pop ( );
-		for ( const auto transition : cart.getTransitionsToState ( cstate ) ) {
+		for ( const auto & transition : cart.getTransitionsToState ( cstate ) ) {
 			const auto & srcState = transition.first.first;
 			if ( visited.count ( srcState ) == 0 ) {

alib2algo/src/stringology/matching/GeneralizedLevenshteinSequenceMatchingAutomaton.h

@@ -72,7 +72,7 @@ template < class SymbolType >
 automaton::EpsilonNFA < SymbolType, ext::pair<unsigned int, unsigned int> > GeneralizedLevenshteinSequenceMatchingAutomaton::construct(const string::WildcardLinearString < SymbolType > & pattern, unsigned int allowed_errors) {
 	auto result = stringology::matching::GeneralizedLevenshteinMatchingAutomaton::construct(pattern, allowed_errors);
-	SymbolType wildcard = pattern.getWildcardSymbol();
+	const SymbolType& wildcard = pattern.getWildcardSymbol();
 	ext::set<SymbolType> alphabet_without_wildcard = pattern.getAlphabet();
 	alphabet_without_wildcard.erase(wildcard);

alib2algo/src/stringology/matching/HammingSequenceMatchingAutomaton.h

@@ -61,7 +61,7 @@ template < class SymbolType >
 automaton::NFA < SymbolType, ext::pair<unsigned int, unsigned int> > HammingSequenceMatchingAutomaton::construct(const string::WildcardLinearString < SymbolType > & pattern, unsigned int allowed_errors) {
 	automaton::NFA < SymbolType, ext::pair<unsigned int, unsigned int > > result = stringology::matching::HammingMatchingAutomaton::construct(pattern, allowed_errors);
-	SymbolType wildcard = pattern.getWildcardSymbol();
+	const SymbolType& wildcard = pattern.getWildcardSymbol();
 	ext::set<SymbolType> alphabet_without_wildcard = pattern.getAlphabet();
 	alphabet_without_wildcard.erase(wildcard);

alib2data_experimental/src/indexes/stringology/SuffixTrieNodeTerminatingSymbol.cpp

@@ -64,7 +64,7 @@ SuffixTrieNodeTerminatingSymbol & SuffixTrieNodeTerminatingSymbol::operator =( S
 }
 SuffixTrieNodeTerminatingSymbol::~SuffixTrieNodeTerminatingSymbol ( ) noexcept {
-	for ( auto element : m_children )
+	for ( const auto& element : m_children )
 		delete element.second;
 	m_children.clear ( );

alib2graph_algo/src/maximum_flow/FordFulkerson.cpp

@@ -161,15 +161,15 @@ static Flow fordfulkerson_impl_dir(const DirectedGraph &graph,
     updateFlow_dir(source, sink, ctx);
   // assign negative flow for the reversed pairs of nodes ?
-  for (auto u : ctx.flow)
-    for (auto v : u.second)
+  for (auto& u : ctx.flow)
+    for (auto& v : u.second)
       if (ctx.flow[u.first][v.first] != 0)
         ctx.flow[v.first][u.first] = -ctx.flow[u.first][v.first];
   return ctx.flow;
 }
-static Flow fordfulkerson_impl_undir(const UndirectedGraph &ugraph, node::Node source, node::Node sink) {
+static Flow fordfulkerson_impl_undir(const UndirectedGraph &ugraph, const node::Node& source, const node::Node& sink) {
   DirectedGraph graph;
   for (auto &node: ugraph.getNodes()) {