Add utils::erase to complement erase_if

Both can be replaced with their standard library counterparts once we use C++20 by default.

src/ai/default/ca.cpp

@@ -933,7 +933,7 @@ bool get_villages_phase::remove_village(
 	bool result = false;
 	treachmap::iterator itor = reachmap.begin();
 	while(itor != reachmap.end()) {
-		itor->second.erase(std::remove(itor->second.begin(), itor->second.end(), village), itor->second.end());
+		utils::erase(itor->second, village);
 		if(itor->second.empty()) {
 			result = true;
 			itor = remove_unit(reachmap, moves, itor);

src/draw_manager.cpp

@@ -329,8 +329,7 @@ static void tidy_drawables()
 {
 	// Remove all invalidated TLDs from the list.
 	DBG_DM << "tidying " << top_level_drawables_.size() << " drawables";
-	auto& vec = top_level_drawables_;
-	vec.erase(std::remove(vec.begin(), vec.end(), nullptr), vec.end());
+	utils::erase(top_level_drawables_, nullptr);
 	DBG_DM << top_level_drawables_.size() << " after tidying";
 }
 

src/events.cpp

@@ -226,7 +226,7 @@ pump_monitor::pump_monitor()
 
 pump_monitor::~pump_monitor()
 {
-	pump_monitors.erase(std::remove(pump_monitors.begin(), pump_monitors.end(), this), pump_monitors.end());
+	utils::erase(pump_monitors, this);
 }
 
 event_context::event_context()

src/fake_unit_manager.cpp

@@ -19,6 +19,7 @@
 #include "log.hpp"
 #include "units/unit.hpp"
 #include "units/animation_component.hpp"
+#include "utils/general.hpp"
 
 static lg::log_domain log_engine("engine");
 #define ERR_NG LOG_STREAM(err, log_engine)
@@ -44,12 +45,8 @@ int fake_unit_manager::remove_temporary_unit(internal_ptr_type u)
 	int removed = 0;
 	if (fake_units_.empty())
 		return removed;
-	std::deque<internal_ptr_type>::iterator it =
-			std::remove(fake_units_.begin(), fake_units_.end(), u);
-	if (it != fake_units_.end()) {
-		removed = std::distance(it, fake_units_.end());
-		//std::remove doesn't remove anything without using erase afterwards.
-		fake_units_.erase(it, fake_units_.end());
+	removed = utils::erase(fake_units_, u);
+	if (removed > 0) {
 		my_display_.invalidate(u->get_location());
 		// Redraw with no location to get rid of haloes
 		u->anim_comp().clear_haloes();

src/gui/dialogs/editor/edit_pbl.cpp

@@ -123,7 +123,7 @@ void editor_edit_pbl::pre_show()
 	std::vector<config> addons_list;
 	filesystem::get_files_in_dir(filesystem::get_addons_dir(), nullptr, &dirs_, filesystem::name_mode::FILE_NAME_ONLY);
 	if(dirs_.size() > 0 && std::find(dirs_.begin(), dirs_.end(), current_addon_) != dirs_.end()) {
-		dirs_.erase(std::remove(dirs_.begin(), dirs_.end(), current_addon_));
+		utils::erase(dirs_, current_addon_);
 	}
 
 	for(const std::string& dir : dirs_) {

src/hotkey/hotkey_item.cpp

@@ -24,6 +24,7 @@
 #include "log.hpp"
 #include "sdl/input.hpp" // for sdl::get_mods
 #include "serialization/unicode.hpp"
+#include "utils/general.hpp"
 
 #include <boost/algorithm/string.hpp>
 
@@ -327,7 +328,7 @@ bool hotkey_keyboard::bindings_equal_helper(hotkey_ptr other) const
 void del_hotkey(hotkey_ptr item)
 {
 	if(!hotkeys_.empty()) {
-		hotkeys_.erase(std::remove(hotkeys_.begin(), hotkeys_.end(), item));
+		utils::erase(hotkeys_, item);
 	}
 }
 

src/map/map.cpp

@@ -28,6 +28,7 @@
 #include "serialization/string_utils.hpp"
 #include "terrain/terrain.hpp"
 #include "terrain/type_data.hpp"
+#include "utils/general.hpp"
 #include "wml_exception.hpp"
 
 #include <algorithm>
@@ -411,7 +412,7 @@ void gamemap::set_terrain(const map_location& loc, const t_translation::terrain_
 		const bool new_village = tdata_->is_village(new_terrain);
 
 		if(old_village && !new_village) {
-			villages_.erase(std::remove(villages_.begin(),villages_.end(),loc),villages_.end());
+			utils::erase(villages_, loc);
 		} else if(!old_village && new_village) {
 			villages_.push_back(loc);
 		}

src/preferences/preferences.cpp

@@ -1217,7 +1217,7 @@ void prefs::add_recent_files_entry(const std::string& path)
 
 	// Enforce uniqueness. Normally shouldn't do a thing unless somebody
 	// has been tampering with the preferences file.
-	mru.erase(std::remove(mru.begin(), mru.end(), path), mru.end());
+	utils::erase(mru, path);
 
 	mru.insert(mru.begin(), path);
 	mru.resize(std::min(editor_mru_limit(), mru.size()));

src/server/wesnothd/game.cpp

@@ -547,7 +547,7 @@ void game::transfer_side_control(player_iterator player, const simple_wml::node&
 		observers_.push_back(*old_player);
 
 		(*old_player)->info().set_status(player::OBSERVING);
-		players_.erase(std::remove(players_.begin(), players_.end(), old_player), players_.end());
+		utils::erase(players_, old_player);
 
 		// Tell others that the player becomes an observer.
 		send_and_record_server_message(old_player_name + " becomes an observer.");
@@ -564,7 +564,7 @@ void game::transfer_side_control(player_iterator player, const simple_wml::node&
 	if(is_observer(*newplayer)) {
 		players_.push_back(*newplayer);
 		(*newplayer)->info().set_status(player::PLAYING);
-		observers_.erase(std::remove(observers_.begin(), observers_.end(), newplayer), observers_.end());
+		utils::erase(observers_, newplayer);
 		// Send everyone but the new player the observer_quit message.
 		send_observerquit(*newplayer);
 	}
@@ -759,7 +759,7 @@ void game::unmute_observer(const simple_wml::node& unmute, player_iterator unmut
 	LOG_GAME << unmuter->client_ip() << "\t" << game::username(unmuter) << " unmuted: " << username << " ("
 	         << (*user)->client_ip() << ")\tin game:\t\"" << name_ << "\" (" << id_ << ", " << db_id_ << ")";
 
-	muted_observers_.erase(std::remove(muted_observers_.begin(), muted_observers_.end(), user), muted_observers_.end());
+	utils::erase(muted_observers_, user);
 	send_and_record_server_message(username.to_string() + " has been unmuted.");
 }
 
@@ -868,8 +868,8 @@ void game::unban_user(const simple_wml::node& unban, player_iterator unbanner)
 		<< "\tunbanned: " << username << " (" << (*user)->client_ip() << ")\tfrom game:\t\"" << name_ << "\" ("
 		<< id_ << ", " << db_id_ << ")";
 
-	bans_.erase(std::remove(bans_.begin(), bans_.end(), (*user)->client_ip()), bans_.end());
-	name_bans_.erase(std::remove(name_bans_.begin(), name_bans_.end(), username.to_string()), name_bans_.end());
+	utils::erase(bans_, (*user)->client_ip());
+	utils::erase(name_bans_, username.to_string());
 	send_and_record_server_message(username.to_string() + " has been unbanned.");
 }
 
@@ -1447,8 +1447,8 @@ bool game::remove_player(player_iterator player, const bool disconnect, const bo
 	const bool host = (player == owner_);
 	const bool observer = is_observer(player);
 
-	players_.erase(std::remove(players_.begin(), players_.end(), player), players_.end());
-	observers_.erase(std::remove(observers_.begin(), observers_.end(), player), observers_.end());
+	utils::erase(players_, player);
+	utils::erase(observers_, player);
 	players_not_advanced_.erase(&*player);
 
 	const bool game_ended = players_.empty() || (host && !started_);
@@ -1515,7 +1515,7 @@ bool game::remove_player(player_iterator player, const bool disconnect, const bo
 		if(!is_player(owner_)) {
 			DBG_GAME << "making the owner a player...";
 			owner_->info().set_status(player::PLAYING);
-			observers_.erase(std::remove(observers_.begin(), observers_.end(), owner_), observers_.end());
+			utils::erase(observers_, owner_);
 			players_.push_back(owner_);
 			send_observerquit(owner_);
 		}

src/terrain/terrain.cpp

@@ -18,7 +18,7 @@
 #include "gettext.hpp"
 #include "log.hpp"
 #include "terrain/terrain.hpp"
-
+#include "utils/general.hpp"
 
 static lg::log_domain log_config("config");
 #define ERR_G LOG_STREAM(err, lg::general())
@@ -169,11 +169,8 @@ terrain_type::terrain_type(const config& cfg)
 	union_type_.insert( union_type_.end(), vision_type_.begin(), vision_type_.end() );
 
 	// remove + and -
-	union_type_.erase(std::remove(union_type_.begin(), union_type_.end(),
-				t_translation::MINUS), union_type_.end());
-
-	union_type_.erase(std::remove(union_type_.begin(), union_type_.end(),
-				t_translation::PLUS), union_type_.end());
+	utils::erase(union_type_, t_translation::MINUS);
+	utils::erase(union_type_, t_translation::PLUS);
 
 	// remove doubles
 	std::sort(union_type_.begin(),union_type_.end());
@@ -266,11 +263,8 @@ terrain_type::terrain_type(const terrain_type& base, const terrain_type& overlay
 	union_type_.insert( union_type_.end(), vision_type_.begin(), vision_type_.end() );
 
 	// remove + and -
-	union_type_.erase(std::remove(union_type_.begin(), union_type_.end(),
-				t_translation::MINUS), union_type_.end());
-
-	union_type_.erase(std::remove(union_type_.begin(), union_type_.end(),
-				t_translation::PLUS), union_type_.end());
+	utils::erase(union_type_, t_translation::MINUS);
+	utils::erase(union_type_, t_translation::PLUS);
 
 	// remove doubles
 	std::sort(union_type_.begin(),union_type_.end());

src/units/unit.cpp

@@ -1709,7 +1709,7 @@ void unit::set_loyal(bool loyal)
 		overlays_.push_back("misc/loyal-icon.png");
 	} else {
 		upkeep_ = upkeep_full{};
-		overlays_.erase(std::remove(overlays_.begin(), overlays_.end(), "misc/loyal-icon.png"), overlays_.end());
+		utils::erase(overlays_, "misc/loyal-icon.png");
 	}
 }
 
@@ -2306,7 +2306,7 @@ void unit::apply_builtin_effect(std::string apply_to, const config& effect)
 		}
 		if(!remove.empty()) {
 			for(const auto& to_remove : utils::parenthetical_split(remove, ',')) {
-				overlays_.erase(std::remove(overlays_.begin(), overlays_.end(), to_remove), overlays_.end());
+				utils::erase(overlays_, to_remove);
 			}
 		}
 		if(add.empty() && remove.empty() && !replace.empty()) {

src/utils/general.hpp

@@ -105,6 +105,20 @@ void erase_if(Container& container, const Predicate& predicate)
 	container.erase(std::remove_if(container.begin(), container.end(), predicate), container.end());
 }
 
+/**
+ * Convenience wrapper for using std::remove on a container.
+ *
+ * @todo C++20: use std::erase
+ */
+template<typename Container, typename Value>
+std::size_t erase(Container& container, const Value& value)
+{
+	auto iter = std::remove(container.begin(), container.end(), value);
+	auto num_removed = container.end() - iter;
+	container.erase(iter, container.end());
+	return num_removed;
+}
+
 /**
  * Convenience wrapper for using std::sort on a container.
  *

src/whiteboard/highlighter.cpp

@@ -38,6 +38,7 @@
 #include "units/unit.hpp"
 #include "units/animation_component.hpp"
 #include "units/map.hpp"
+#include "utils/general.hpp"
 #include "utils/ranges.hpp"
 
 namespace wb
@@ -225,7 +226,7 @@ void highlighter::find_secondary_highlights()
 	std::deque<action_ptr> actions = find_actions_of(*owner_unit_);
 
 	// Remove main_highlight_ if present
-	actions.erase(std::remove(actions.begin(), actions.end(), main_highlight_.lock()), actions.end());
+	utils::erase(actions, main_highlight_.lock());
 
 	// Copy in secondary_highlights_
 	std::copy(actions.begin(), actions.end(), std::back_inserter(secondary_highlights_));