Function lua_setmetatable

Source/Misc/lua/src/lua.c:2546–2580

LUA_API int lua_setmetatable (lua_State *L, int objindex) {
TValue *obj;
Table *mt;
lua_lock(L);
api_checknelems(L, 1);
obj = index2adr(L, objindex);
api_checkvalidindex(L, obj);
if (ttisnil(L->top - 1))
mt = NULL;
else {
api_check(L, ttistable(L->top - 1));
mt = hvalue(L->top - 1);
}
switch (ttype(obj)) {
case LUA_TTABLE: {
hvalue(obj)->metatable = mt;
if (mt)
luaC_objbarriert(L, hvalue(obj), mt);
break;
}
case LUA_TUSERDATA: {
uvalue(obj)->metatable = mt;
if (mt)
luaC_objbarrier(L, rawuvalue(obj), mt);
break;
}
default: {
G(L)->mt[ttype(obj)] = mt;
break;
}
}
L->top--;
lua_unlock(L);
return 1;
}


LUA_API int lua_setfenv (lua_State *L, int idx) {