What is the "base class" for C# numeric value types?

Question

Say I want to have a method that takes any kind of number, is there a base class (or some other concept) that I can use?

As far as I know I have to make overloads for all the different numeric types (Int32, Int16, Byte, UInt32, Double, Float, Decimal, etc). This seems awfully tedious. Either that or use the type "object" and throw exceptions if they are not convertable or assignable to a double - which is pretty bad as it means no compile time checking.

UPDATE: OK thanks for the comments, you are right Scarecrow and Marc, in fact declaring it as Double actually works for all except Decimal.

So the answer I was looking for is Double - it acts like a base class here since most numeric types are assignable to it. (I guess Decimal is not assignable to Double, as it could get too big.)

public void TestFormatDollars() {     int i = 5;     string str = FormatDollars(i);   // this is OK     byte b = 5;     str = FormatDollars(b);     // this is OK     decimal d = 5;     str = FormatDollars(d);     // this does not compile - decimal is not assignable to double }  public static string FormatDollars(double num) {     return "$" + num; } 

Answer 1

The answer is: you don't need to provide overloads for ALL the numeric types, just for Double and Decimal. All others (except maybe some very unusually large ones) will be automatically converted to these.

Not a base class but in fact that was the red herring. The base class System.ValueType doesn't help much as it includes types that are not numerics. The language reference i was reading was what got me confused in the first place :)

(I was just looking for who to attribute the answer to and it was a combination of Scarecrow and Marc Gravell, but since they were comments i have put the answer here)