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

问题

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!

回答1:

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.

回答2:

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);
}

回答3:

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

回答4:

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

来源：https://stackoverflow.com/questions/961038/how-do-i-properly-write-math-extension-methods-for-int-double-float-etc

标签

extension-methods