Question

I am looking for an elegant way to call a function based on the type of parameter that is passed as parameter.

In other words, I want the EntryPoint method (below) to dynamically call the appropriate myFunc method, based on the type of the template parameter.

public void EntryPoint(object template)
{
    missingMethod(template);//This is the code in question that should call myFunc
}

private void myFunc(TemplateA template)
{
    doSomething(template);
}

private void myFunc(TemplateB template)
{
    doSomethingElse(template);
}

private void myFunc(object template)
{
    throw new NotImplementedException(template.GetType());
}

Answer 1

Three options:

• A series of if/else statements (ugly but simple and easy to understand)
• Double dispatch with the visitor pattern (can be awkward)
• Wait until C# 4 and use dynamic typing (might not be feasible in your case)

Personally I’d try to think of an alternative design which didn’t require this in the first place, but obviously that’s not always realistic.