Lua实现__add方法重载示例

实现加法(__add)重载代码示例：

do

 local Infor_class = {};

 function Infor_class.create(_t)

  local newTable = {};

  setmetatable(newTable, Infor_class); --set the metatable

  for i, v in pairs(_t) do

   newTable[i] = v;

  end

  return newTable;

 end
 function Infor_class.sum(c1, c2)

  if(#c1 ~= #c2) then

   return nil;

  else

   local result = {};

   local len = #c1;

   for i = 1, len do

    result[i] = c1[i] + c2[i];

   end

   print("result");

   return result;

  end

  print("nil");

  return nil;

 end
 Infor_class.__add = Infor_class.sum --override the _add
 r1 = Infor_class.create{3, 4}

 r2 = Infor_class.create{5, 6};
 result = r1 + r2;

 print(unpack(result));

end