Question

I would like to create generic function Math.Abs() but i don’t know how to make this.
if i create a class Math i can’t create method Abs for T value because i don’t know the type of T.

If someone know how to do this ?

Thanks

Answer 1

Six options:

• Use reflection based on the execution-time type of T
• Use an overload for each type you care about
• Use if/else for every type you care about
• Create a Dictionary<Type, Func<object, object>> containing a delegate for every type you care about

• Use dynamic in .NET 4:

  public T Foo<T>(T value)
  {
      dynamic d = value;
      return Math.Abs(d);
  }
  

• Use something like Marc Gravell’s generic operators part of MiscUtil

I’d probably go for the overload option if possible. It will constrain you appropriately at compile-time, and avoid any potentially time-consuming boxing/reflection.