Generic Addition Required

[jehugaleahsa]

Is there a generic means of adding two values together in C# using the
+ operator?

I would like to be able to write one method for int, double, decimal,
all the other numeric types.

Given that, could the same thing be performed on a string.

Thanks,
Travis

 

[Paul E Collins]

Is there a generic means of adding two values together
in C# using the + operator?

No, because System.Object doesn't implement the + operator.

I would like to be able to write one method for int,
double, decimal, all the other numeric types.

I suppose you could do Convert.ToDouble, add those, and cast the
result back. This does not sound very useful. What are you trying to
achieve, more generally?

Eq.

 

[jehugaleahsa]

No, because System.Object doesn't implement the + operator.


I suppose you could do Convert.ToDouble, add those, and cast the
result back. This does not sound very useful. What are you trying to
achieve, more generally?

Eq.

Essentially, I was hoping there was a way to write an accumulate
method without needed to overload it.

 

[Andreas Mueller]

Essentially, I was hoping there was a way to write an accumulate
method without needed to overload it.

You are not alone with this wish. Here's an related article on
codeproject and a feature request to ms:
http://www.codeproject.com/csharp/genericnumerics.asp
http://tinyurl.com/2pghky

Here's a sample showing how I worked around this to implement accumulate
in my port of the C++ STL (www.codeplex.com/nstl):

using System.Collections.Generic;

namespace ConsoleApplication11
{
internal delegate Result
BinaryFunction<Arg1, Arg2, Result>(Arg1 lhs, Arg2 rhs);
static class Plus
{
public static BinaryFunction<int, int, int> Int32()
{
return delegate(int lhs, int rhs) { return lhs + rhs; };
}
public static BinaryFunction<string, string, string> String()
{
return delegate(string lhs, string rhs){return lhs + rhs; };
}
}
static class Algorithm
{
public static T
Accumulate<T>(IEnumerable<T> range, T init,
BinaryFunction<T, T, T> binaryOp)
{
foreach(T t in range)
init = binaryOp(init, t);
return init;
}
}
class Program
{
static void Main(string[] args)
{
IEnumerable<int> ints = new int[] {0, 1, 2, 3, 4, 5};
int zero = Algorithm.Accumulate(ints, -15, Plus.Int32());
}
}
}



HTH,
Andy