Change: Add ability to save/load std::deque<> containers.

src/saveload/saveload.h

@@ -195,6 +195,7 @@ enum SaveLoadTypes {
 	SL_ARR         =  2, ///< Save/load an array.
 	SL_STR         =  3, ///< Save/load a string.
 	SL_LST         =  4, ///< Save/load a list.
+	SL_DEQUE       =  5, ///< Save/load a deque.
 	/* non-normal save-load types */
 	SL_WRITEBYTE   =  8,
 	SL_VEH_INCLUDE =  9,
@@ -287,6 +288,16 @@ typedef SaveLoad SaveLoadGlobVarList;
  */
 #define SLE_CONDLST(base, variable, type, from, to) SLE_GENERAL(SL_LST, base, variable, type, 0, from, to)
 
+/**
+ * Storage of a deque in some savegame versions.
+ * @param base     Name of the class or struct containing the list.
+ * @param variable Name of the variable in the class or struct referenced by \a base.
+ * @param type     Storage of the data in memory and in the savegame.
+ * @param from     First savegame version that has the list.
+ * @param to       Last savegame version that has the list.
+ */
+#define SLE_CONDDEQUE(base, variable, type, from, to) SLE_GENERAL(SL_DEQUE, base, variable, type, 0, from, to)
+
 /**
  * Storage of a variable in every version of a savegame.
  * @param base     Name of the class or struct containing the variable.