function CountedTable(x)
  assert(type(x) == 'table', 'bad parameter #1: must be table')

  local mt = {}
  -- `keys`  will represent the number of non integral indexes
  -- `indxs` will represent the number of integral indexes
  -- `all`   will represent the number of both 
  local keys, indxs, all = 0, 0, 0
   
  for k, v in pairs(x) do
    if (type(k) == 'number') and (k == math.floor(k)) then indxs = indxs + 1
    else keys = keys + 1 end

    all = all + 1
  end
 
  mt.__newindex = function(t, k, v)
    if (type(k) == 'number') and (k == math.floor(k)) then indxs = indxs + 1
    else keys = keys + 1 end

    all = all + 1
    t[k] = v
  end

  mt.__index = function(t, k)
    if k == 'keyCount' then return keys 
    elseif k == 'indexCount' then return indxs 
    elseif k == 'totalCount' then return all end
  end

  return setmetatable(x, mt)
end



-- Note `36.35433` would NOT be counted as an integral index.
local foo = CountedTable { 1, 2, 3, 4, [36.35433] = 36.35433, [54] = 54 }
local bar = CountedTable { x = 23, y = 43, z = 334, [true] = true }
local foobar = CountedTable { 1, 2, 3, x = 'x', [true] = true, [64] = 64 }

print(foo.indexCount) 
print(bar.keyCount)
print(foobar.totalCount)

5
4
6