Using generics possible to limit supplied types to Built-In?

Question

I would like to limit the data types my method accepts using generics to built in types:

Built in types: http://msdn.microsoft.com/en-us/library/ya5y69ds(v=vs.80).aspx

The list differs from value / reference types. And I would like to only support built in, not all value types, and ofc also string, which is a reference type.

Is this possible?

EDIT:

Using constraints you can restrict to value types like this:

T GetObject<T> where T: struct;

This would not permit strings to pass through though.

Doesn't look like it: http://msdn.microsoft.com/en-us/library/d5x73970.aspx — Michiel Cornille, Oct 18 '12 at 11:48
possible duplicate of [C# Generic constraints to include value types AND strings](http://stackoverflow.com/questions/8745444/c-sharp-generic-constraints-to-include-value-types-and-strings) — cuongle, Oct 18 '12 at 11:50
Not a duplicate, I'm not looking for value+string, but built in types. — JL., Oct 18 '12 at 12:02

score 2 · Answer 1 · answered Oct 18 '12 at 11:54

2

It's not possible to do with generics.

If you need to do this and retain compile-time checking your only option is to provide overloads of your method with different parameter types so that all the built-in types are covered.

answered Oct 18 '12 at 11:54

Jon

428,835
81
738
806

Darkzaelus · Answer 2 · 2012-10-18T11:55:51.030

0

No, unfortunately it isn't possible.

The closest I think you could do is below:

T GetObject<T>()
{
    if (!(typeof(T) is typeof(int)
        || typeof(T) is typeof(uint)
        ...
        || typeof(T) is typeof(string)))
    {
        //Custom exception class for this purpose
        throw new TypeArgumentException("Invalid type parameter \"T\".");
    }

    ...
}

Not quite as nice, but does the job.

edited Oct 18 '12 at 11:55

answered Oct 18 '12 at 11:48

Darkzaelus

2,059
1
15
31

Using generics possible to limit supplied types to Built-In?

2 Answers2