Pathfind/Teleport: made getters return their sets rather than taking them as arguments

Implementations were cleaned up in the process.

src/actions/move.cpp

@@ -469,8 +469,7 @@ namespace { // Private helpers for move_unit()
 				// block the tunnel if pass_allied_units=true. Whether the teleport is possible
 				// is checked by getting the teleport map with the see_all flag set to true.
 				const pathfind::teleport_map teleports = pathfind::get_teleport_locations(*move_it_, *current_team_, true, false, false);
-				std::set<map_location> allowed_teleports;
-				teleports.get_adjacents(allowed_teleports, prev_hex);
+				auto allowed_teleports = teleports.get_adjacents(prev_hex);
 
 				bool found_valid_teleport = false;
 				std::set<map_location>::const_iterator it = allowed_teleports.begin();

src/pathfind/astarsearch.cpp

@@ -85,8 +85,7 @@ struct node {
 		if (teleports && !teleports->empty()) {
 
 			double new_srch = 1.0;
-			std::set<map_location> sources;
-			teleports->get_sources(sources);
+			auto sources = teleports->get_sources();
 
 			std::set<map_location>::const_iterator it = sources.begin();
 			for(; it != sources.end(); ++it) {
@@ -94,10 +93,8 @@ struct node {
 				if (tmp_srch < new_srch) { new_srch = tmp_srch; }
 			}
 
-
 			double new_dsth = 1.0;
-			std::set<map_location> targets;
-			teleports->get_targets(targets);
+			auto targets = teleports->get_targets();
 
 			for(it = targets.begin(); it != targets.end(); ++it) {
 				const double tmp_dsth = heuristic(*it, dst);
@@ -188,9 +185,7 @@ plain_route a_star_search(const map_location& src, const map_location& dst,
 		std::vector<map_location> locs(6);
 
 		if (teleports && !teleports->empty()) {
-
-			std::set<map_location> allowed_teleports;
-			teleports->get_adjacents(allowed_teleports, n.curr);
+			auto allowed_teleports = teleports->get_adjacents(n.curr);
 			locs.insert(locs.end(), allowed_teleports.begin(), allowed_teleports.end());
 		}
 

src/pathfind/pathfind.cpp

@@ -354,8 +354,7 @@ static void find_routes(
 		adj_locs.erase(off_board_it, adj_locs.end());
 
 		if ( teleporter ) {
-			std::set<map_location> allowed_teleports;
-			teleports.get_adjacents(allowed_teleports, cur_hex);
+			auto allowed_teleports = teleports.get_adjacents(cur_hex);
 			adj_locs.insert(adj_locs.end(), allowed_teleports.begin(), allowed_teleports.end());
 		}
 		for ( int i = adj_locs.size()-1; i >= 0; --i ) {

src/pathfind/teleport.cpp

@@ -226,36 +226,41 @@ teleport_map::teleport_map(
 	}
 }
 
-void teleport_map::get_adjacents(std::set<map_location>& adjacents, map_location loc) const {
-
-	if (teleport_map_.count(loc) == 0) {
-		return;
-	} else {
-		const std::set<std::string>& keyset = (teleport_map_.find(loc)->second);
-		for(std::set<std::string>::const_iterator it = keyset.begin(); it != keyset.end(); ++it) {
-
-			const std::set<map_location>& target = targets_.find(*it)->second;
-			adjacents.insert(target.begin(), target.end());
-		}
+std::set<map_location> teleport_map::get_adjacents(map_location loc) const
+{
+	const auto iter = teleport_map_.find(loc);
+	if(iter == teleport_map_.end()) {
+		return {};
 	}
+
+	std::set<map_location> res;
+	for(const std::string& key : iter->second) {
+		const auto& target = targets_.find(key)->second;
+		res.insert(target.begin(), target.end());
+	}
+
+	return res;
 }
 
-void teleport_map::get_sources(std::set<map_location>& sources) const {
-
-	std::map<std::string, std::set<map_location>>::const_iterator it;
-	for(it = sources_.begin(); it != sources_.end(); ++it) {
-		sources.insert(it->second.begin(), it->second.end());
+std::set<map_location> teleport_map::get_sources() const
+{
+	std::set<map_location> res;
+	for(const auto& src : sources_) {
+		res.insert(src.second.begin(), src.second.end());
 	}
+
+	return res;
 }
 
-void teleport_map::get_targets(std::set<map_location>& targets) const {
-
-	std::map<std::string, std::set<map_location>>::const_iterator it;
-	for(it = targets_.begin(); it != targets_.end(); ++it) {
-		targets.insert(it->second.begin(), it->second.end());
+std::set<map_location> teleport_map::get_targets() const
+{
+	std::set<map_location> res;
+	for(const auto& tgt : targets_) {
+		res.insert(tgt.second.begin(), tgt.second.end());
 	}
-}
 
+	return res;
+}
 
 const teleport_map get_teleport_locations(const unit &u,
 	const team &viewing_team,

src/pathfind/teleport.hpp

@@ -114,19 +114,17 @@ public:
 	teleport_map() :
 		teleport_map_(), sources_(), targets_() {}
 
-	/*
-	 * @param adjacents		used to return the adjacent hexes
+	/**
 	 * @param loc			the map location for which we want to know the adjacent hexes
+	 * @todo what does this function actually have to do with adjacent hexes?
 	 */
-	void get_adjacents(std::set<map_location>& adjacents, map_location loc) const;
-	/*
-	 * @param sources	used to return the locations that are an entrance of the tunnel
-	 */
-	void get_sources(std::set<map_location>& sources) const;
-	/*
-	 * @param targets	used to return the locations that are an exit of the tunnel
-	 */
-	void get_targets(std::set<map_location>& targets) const;
+	std::set<map_location> get_adjacents(map_location loc) const;
+
+	/** Returns the locations that are an entrance of the tunnel. */
+	std::set<map_location> get_sources() const;
+
+	/** Returns the locations that are an exit of the tunnel. */
+	std::set<map_location> get_targets() const;
 
 	/*
 	 * @returns whether the teleport_map does contain any defined tunnel