Made use of std::tie for certain unit_map operations

src/actions/create.cpp

@@ -626,10 +626,14 @@ place_recruit_result place_recruit(unit_ptr u, const map_location &recruit_locat
 	const map_location leader_loc = !show ? map_location::null_location() :
 			find_recruit_leader(u->side(), recruit_location, recruited_from);
 	u->set_location(recruit_location);
+
+	unit_map::unit_iterator new_unit_itor;
+	bool success = false;
+
 	// Add the unit to the board.
-	std::pair<unit_map::iterator, bool> add_result = resources::gameboard->units().insert(u);
-	assert(add_result.second);
-	unit_map::iterator & new_unit_itor = add_result.first;
+	std::tie(new_unit_itor, success) = resources::gameboard->units().insert(u);
+	assert(success);
+
 	map_location current_loc = recruit_location;
 
 	if (facing == map_location::NDIRECTIONS) {

src/actions/move.cpp

@@ -522,14 +522,15 @@ namespace { // Private helpers for move_unit()
 		// Invalidate before moving so we invalidate neighbor hexes if needed.
 		move_it_->anim_comp().invalidate(disp);
 
-		// Attempt actually moving.
-		// (Fails if *step_to is occupied).
-		std::pair<unit_map::iterator, bool> move_result =
-			resources::gameboard->units().move(*move_loc_, *step_to);
-		if ( move_result.second )
-		{
+		// Attempt actually moving. Fails if *step_to is occupied.
+		unit_map::unit_iterator unit_it;
+		bool success = false;
+
+		std::tie(unit_it, success) = resources::gameboard->units().move(*move_loc_, *step_to);
+
+		if(success) {
 			// Update the moving unit.
-			move_it_ = move_result.first;
+			move_it_ = unit_it;
 			move_it_->set_facing(step_from->get_relative_dir(*step_to));
 			// Disable bars. The expectation here is that the animation
 			// unit_mover::finish() will clean after us at a later point. Ugly,
@@ -546,7 +547,7 @@ namespace { // Private helpers for move_unit()
 			disp.redraw_minimap();
 		}
 
-		return move_result.second;
+		return success;
 	}
 
 

src/ai/simulated_actions.cpp

@@ -94,19 +94,24 @@ bool simulated_attack(const map_location& attacker_loc, const map_location& defe
 	return true;
 }
 
-bool simulated_move(int side, const map_location& from, const map_location& to, int steps, map_location& unit_location){
+bool simulated_move(int side, const map_location& from, const map_location& to, int steps, map_location& unit_location)
+{
 	LOG_AI_SIM_ACTIONS << "Simulated move" << std::endl;
 
+	unit_map::unit_iterator move_unit;
+	bool success = false;
+
 	// In simulation, AI should not know if there is a enemy's ambusher.
-	std::pair<unit_map::unit_iterator, bool> unit_move = resources::gameboard->units().move(from, to);
-	bool is_ok = unit_move.second;
-	if(!is_ok){
-		unit_location = to;	// This happened because in some CAs like get_village_phase and move_leader_to_keep phase,
-							// if the destination is already occupied will not be checked before execute. Just silent
-							// errors in ai/actions and tell rca the game state isn't changed.
+	std::tie(move_unit, success) = resources::gameboard->units().move(from, to);
+
+	if(!success) {
+		// This happened because in some CAs like get_village_phase and move_leader_to_keep phase,
+		// if the destination is already occupied will not be checked before execute. Just silent
+		// errors in ai/actions and tell rca the game state isn't changed.
+		unit_location = to;
 		return false;
 	}
-	unit_map::unit_iterator move_unit = unit_move.first;
+
 	move_unit->set_movement(move_unit->movement_left()-steps);	// Following original logic, remove_movement_ will be considered outside.
 
 	unit_location = move_unit->get_location();	// For check_after.
@@ -216,9 +221,11 @@ void helper_place_unit(const unit& u, const map_location& loc){
 	new_unit->heal_fully();
 	new_unit->set_location(loc);
 
-	std::pair<unit_map::iterator, bool> add_result = resources::gameboard->units().insert(new_unit);
-	assert(add_result.second);
-	unit_map::iterator& new_unit_itor = add_result.first;
+	unit_map::unit_iterator new_unit_itor;
+	bool success = false;
+
+	std::tie(new_unit_itor, success) = resources::gameboard->units().insert(new_unit);
+	assert(success);
 
 	if(resources::gameboard->map().is_village(loc)){
 		helper_check_village(loc, new_unit_itor->side());

src/scripting/lua_unit.cpp

@@ -70,10 +70,14 @@ unit_ptr lua_unit::get_shared()
 bool lua_unit::put_map(const map_location &loc)
 {
 	if (ptr) {
-		std::pair<unit_map::unit_iterator, bool> res = resources::gameboard->units().replace(loc, ptr);
-		if (res.second) {
+		unit_map::unit_iterator unit_it;
+		bool success = false;
+
+		std::tie(unit_it, success) = resources::gameboard->units().replace(loc, ptr);
+
+		if(success) {
 			ptr.reset();
-			uid = res.first->underlying_id();
+			uid = unit_it->underlying_id();
 		} else {
 			ERR_LUA << "Could not move unit " << ptr->underlying_id() << " onto map location " << loc << '\n';
 			return false;

src/synced_commands.cpp

@@ -483,8 +483,12 @@ SYNCED_COMMAND_HANDLER_FUNCTION(debug_create_unit, child,  use_undo, /*show*/, e
 	// Create the unit.
 	unit_ptr created(new unit(*u_type, side_num, true, gender));
 	created->new_turn();
+
+	unit_map::unit_iterator unit_it;
+
 	// Add the unit to the board.
-	std::pair<unit_map::iterator, bool> add_result = resources::gameboard->units().replace(loc, created);
+	std::tie(unit_it, std::ignore) = resources::gameboard->units().replace(loc, created);
+
 	game_display::get_singleton()->invalidate_unit();
 	resources::game_events->pump().fire("unit_placed", loc);
 	unit_display::unit_recruited(loc);
@@ -498,8 +502,8 @@ SYNCED_COMMAND_HANDLER_FUNCTION(debug_create_unit, child,  use_undo, /*show*/, e
 	actions::shroud_clearer clearer;
 	clearer.clear_unit(loc, *created);
 	clearer.fire_events();
-	if ( add_result.first.valid() ) // In case sighted events messed with the unit.
-		actions::actor_sighted(*add_result.first);
+	if (unit_it.valid() ) // In case sighted events messed with the unit.
+		actions::actor_sighted(*unit_it);
 
 	return true;
 }