Template function in C# - Return Type?

SMUsamaShah picture SMUsamaShah · Jun 15, 2010 · Viewed 88.7k times · Source

It seems that c# does not support c++ like templates. For example

template <class myType>
myType GetMax (myType a, myType b) {
 return (a>b?a:b);
}

I want my function to have return type based on its parameters, how can i achieve this in c#? How to use templates in C#

EDIT: Can i use object and getType for the almost same purpose?

Answer

Jon Skeet picture Jon Skeet · Jun 15, 2010

The closest to C++ templates in C# is generics - but they're not very close. In particular, you can't use operators like > between generic type values, because the compiler doesn't know about them (and you can't constrain types based on operators). On the other hand, you can write:

public T GetMax<T>(T lhs, T rhs)
{
    return Comparer<T>.Default.Compare(lhs, rhs) > 0 ? lhs : rhs;
}

or

public T GetMax<T>(T lhs, T rhs) where T : IComparable<T>
{
    return lhs.CompareTo(rhs) > 0 ? lhs : rhs;
}

Note that the first of these is null-safe; the second isn't.

A full description of generics is well beyond the scope of a Stack Overflow answer; MSDN has some information, or consult your favourite C# book.