toggle between tile and tcl layout with tile layout keybind

config.def.h

@@ -356,7 +356,7 @@ static Key keys[] = {
 	{Mod1Mask,                              XK_F4,              killclient,           {0}},
 	{MODKEY,                                XK_F1,              spawn,                {.v = helpcmd}},
 	{MODKEY,                                XK_F2,              toggleprefix,         {0}},
-	{MODKEY,                                XK_t,               setlayout,            {.v = &layouts[0]}},
+	{MODKEY,                                XK_t,               settcltilelayout,     {.v = &layouts[0]}},
 	{MODKEY,                                XK_f,               setlayout,            {.v = &layouts[2]}},
 	{MODKEY,                                XK_m,               setlayout,            {.v = &layouts[3]}},
 	{MODKEY|ShiftMask,                      XK_m,               movemouse,            {0}},

instantwm.c

@@ -4092,6 +4092,15 @@ commandlayout(const Arg *arg) {
     setlayout(larg);
 }
 
+void
+settcltilelayout(const Arg *arg)
+{
+	if (strcmp(selmon->lt[selmon->sellt]->symbol, layouts[0].symbol) != 0)
+		setlayout(arg);
+	else
+		setlayout(&((Arg) { .v = &layouts[4]}));
+}
+
 void
 setlayout(const Arg *arg)
 {

instantwm.h

@@ -277,6 +277,7 @@ int getxtag(int ix);
 void setclientstate(Client *c, long state);
 void setfocus(Client *c);
 void setfullscreen(Client *c, int fullscreen);
+void settcltilelayout(const Arg *arg);
 void setlayout(const Arg *arg);
 void commandlayout(const Arg *arg);
 void commandprefix(const Arg *arg);