Function luaB_newproxy

Source/Misc/lua/src/lua.c:11285–11308

static int luaB_newproxy (lua_State *L) {
lua_settop(L, 1);
lua_newuserdata(L, 0);  /* create proxy */
if (lua_toboolean(L, 1) == 0)
return 1;  /* no metatable */
else if (lua_isboolean(L, 1)) {
lua_newtable(L);  /* create a new metatable `m' ... */
lua_pushvalue(L, -1);  /* ... and mark `m' as a valid metatable */
lua_pushboolean(L, 1);
lua_rawset(L, lua_upvalueindex(1));  /* weaktable[m] = true */
}
else {
int validproxy = 0;  /* to check if weaktable[metatable(u)] == true */
if (lua_getmetatable(L, 1)) {
lua_rawget(L, lua_upvalueindex(1));
validproxy = lua_toboolean(L, -1);
lua_pop(L, 1);  /* remove value */
}
luaL_argcheck(L, validproxy, 1, "boolean or proxy expected");
lua_getmetatable(L, 1);  /* metatable is valid; get it */
}
lua_setmetatable(L, 2);
return 1;
}


static const luaL_Reg base_funcs[] = {