How do I properly write Math extension methods for int, double, float, etc.?

Question

I want to write a series of Extension methods to simplify math operations. For example:

Instead of

Math.Pow(2, 5)

I'd like to be able to write

2.Power(5)

which is (in my mind) clearer.

The problem is: how do I deal with the different numeric types when writing Extension Methods? Do I need to write an Extension Method for each type:

public static double Power(this double number, double power) {
    return Math.Pow(number, power);
}
public static double Power(this int number, double power) {
    return Math.Pow(number, power);
}
public static double Power(this float number, double power) {
    return Math.Pow(number, power);
}

Or is there a trick to allow a single Extension Method work for any numeric type?

Thanks!

+1 Yeah, I'm surprised that wasn't part of the framework to begin with. — Mark Carpenter, Jun 07 '09 at 14:16
**Caveat** when using such extension methods: **`-10.Power(2) == -100`**. The minus sign get applied to the result of `10.Power(2)`. — HugoRune, Feb 24 '17 at 09:40
@HugoRune: Interesting point! But I do think that the OP would still be using variables rather than explicit values. The hardcoded values in the question seem to be a matter of example rather than intended usage. — Flater, Sep 29 '17 at 15:15

score 2 · Accepted Answer · answered Jun 07 '09 at 02:14

Unfortunately I think you are stuck with the three implementations. The only way to get multiple typed methods out of a single definition is using generics, but it is not possible to write a generic method that can do something useful specifically for numeric types.

score 1 · Answer 2 · edited May 23 '17 at 12:00

1

You only need to override Decimal and Double as is noted in this question: here

edited May 23 '17 at 12:00

Community

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answered Sep 16 '10 at 18:21

Woot4Moo

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score 1 · Answer 3 · answered Sep 29 '17 at 14:36

1

One solution I use is to make the extension on object. This makes this possible, but unfortunately it will be visible on all objects.

public static double Power(this object number, double power) 
{
    return Math.Pow((double) number, power);
}

answered Sep 29 '17 at 14:36

user168345

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score 0 · Answer 4 · answered Jun 07 '09 at 02:23

0

I dont think its possible with C# 3.0. Looks like you might be able to do it C# 4.0

http://blogs.msdn.com/lucabol/archive/2009/02/05/simulating-inumeric-with-dynamic-in-c-4-0.aspx

answered Jun 07 '09 at 02:23

Vasu Balakrishnan

1,751
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Good point... I'm not sure that the performance hit is going to be worth the price in the general case though. – jerryjvl Jun 07 '09 at 02:25
the linked artikle does not use dynamic as it was designed, trading type safety for comfort is not the right way i think – quadroid Mar 31 '14 at 07:19

How do I properly write Math extension methods for int, double, float, etc.?

4 Answers4

Linked