Creates a user element in IUP, which is not associated to any interface element. It is used to map an external element to a IUP element. Its use is usually for additional elements, but you can use it to create an Ihandle* to store private attributes.
It is also a void container. Its children can be dynamically added using IupAppend or IupInsert.
Ihandle* IupUser(void); [in C]
iup.user{} -> (ih: ihandle) [in Lua]
user() [in LED]
Returns: the identifier of the created element, or NULL if an error occurs.
CLEARATTRIBUTES (write-only, non inheritable): it will clear all attributes stored internally and remove all references. (since 3.0)