度量單位型別引數

[<Measure>] 屬性可用於型別引數，以宣告與度量單位相關的通用型別：

type CylinderSize<[<Measure>] 'u> =
    { Radius : float<'u>
      Height : float<'u> }

測試用法：

open Microsoft.FSharp.Data.UnitSystems.SI.UnitSymbols

/// This has type CylinderSize<m>.
let testCylinder =
    { Radius = 14.<m>
      Height =  1.<m> }