source: thomson/elec/CrO2/software/iupplusplus.h@ f9263dd

/* CrO2 datassette emulator
 * Copyright 2012, Adrien Destugues <pulkomandy@pulkomandy.ath.cx>
 *
 * Distributed under the terms of the MIT licence.
 */

#include <iup.h>

template<class Handler, typename... Args> class Callback
{
        typedef int(Handler::*T)(Args... args);

        public:
                static int destroy(Ihandle* that)
                {
                        Callback* call = (Callback*)IupGetAttribute(that, "LCALLBACK");
                        delete call;
                        return IUP_DEFAULT;
                }

                static void create(Ihandle* handle, const char* name, Handler* self, T what)
                {
                        Callback* cb = new Callback(self, what);
                        IupSetAttribute(handle, "LCALLBACK", (char*)cb);
                        IupSetCallback(handle, name, (Icallback)Callback::call);
                        IupSetCallback(handle, "LDESTROY_CB", Callback::destroy);
                }

                static int call(Ihandle* that, Args... args)
                {
                        Callback* call = (Callback*)IupGetAttribute(that, "LCALLBACK");
                        return ((call->self)->*(call->what))(args...);
                }

        private:
                Callback(Handler* self, T what)
                {
                        this->self = self;
                        this->what = what;
                }

                Callback(); // do not use

                Handler* self;
                T what;
};