vconfig optimisation

src/ai/lua/lua_object.cpp

@@ -47,8 +47,7 @@ namespace ai {
 		}
 		lua_getfield(L, n, "own");
 		if(lua_istable(L, -1)) {
-			config cfg;
-			vconfig vcfg(cfg, true);
+			vconfig vcfg(config(), true);
 			if(luaW_tovconfig(L, -1, vcfg)) {
 				att->filter_own_.reset(new unit_filter(vcfg, resources::filter_con));
 			}
@@ -59,8 +58,7 @@ namespace ai {
 		}
 		lua_getfield(L, n, "enemy");
 		if(lua_istable(L, -1)) {
-			config cfg;
-			vconfig vcfg(cfg, true);
+			vconfig vcfg(config(), true);
 			if(luaW_tovconfig(L, -1, vcfg)) {
 				att->filter_enemy_.reset(new unit_filter(vcfg, resources::filter_con));
 			}

src/scripting/lua_common.cpp

@@ -799,7 +799,7 @@ bool luaW_tovconfig(lua_State *L, int index, vconfig &vcfg)
 			config cfg;
 			bool ok = luaW_toconfig(L, index, cfg);
 			if (!ok) return false;
-			vcfg = vconfig(cfg, true);
+			vcfg = vconfig(std::move(cfg));
 			break;
 		}
 		case LUA_TUSERDATA:

src/variable.cpp

@@ -124,16 +124,17 @@ vconfig vconfig::unconstructed_vconfig()
  * It is perfectly safe to call this for a vconfig that already manages its memory.
  * This does not work on a null() vconfig.
  */
-void vconfig::make_safe() const
+const vconfig& vconfig::make_safe() const
 {
 	// Nothing to do if we already manage our own memory.
 	if ( memory_managed() )
-		return;
+		return *this;
 
 	// Make a copy of our config.
 	cache_.reset(new config(*cfg_));
 	// Use our copy instead of the original.
 	cfg_ = cache_.get();
+	return *this;
 }
 
 config vconfig::get_parsed_config() const

src/variable.hpp

@@ -60,6 +60,7 @@ class vconfig
 	/// Equivalent to vconfig(cfg, false).
 	/// Do not use if the vconfig will persist after @a cfg is destroyed!
 	explicit vconfig(const config &cfg) : cache_(), cfg_(&cfg) {}
+	explicit vconfig(config &&cfg) : cache_(new config(std::move(cfg))), cfg_(cache_.get()) { }
 	vconfig(const config &cfg, bool manage_memory);
 	~vconfig();
 
@@ -70,7 +71,7 @@ class vconfig
 	explicit operator bool() const	{ return !null(); }
 
 	bool null() const { assert(cfg_); return cfg_ == &default_empty_config; }
-	void make_safe() const; //!< instruct the vconfig to make a private copy of its underlying data.
+	const vconfig& make_safe() const; //!< instruct the vconfig to make a private copy of its underlying data.
 	const config& get_config() const { return *cfg_; }
 	config get_parsed_config() const;