local function class()
	local T = {}
	T.__index = T
	return T
end

local function extend(Base)
	local T = {}
	T.__index = T
	for k,v in pairs(Base) do
		if k:sub(1,2) == "__" and k~="__index" then
			T[k]=v
		end
	end
	setmetatable(T,{__index=Base})
end

return setmetatable({
	class=class,
	extend=extend
},{__call=class})