Apply the new constraint to a type parameter when your generic class creates new instances of the type, as shown in the following example:

class ItemFactory<T> where T : new()
{
    public T GetNewItem()
    {
        return new T();
    }
}

When you use the new() constraint with other constraints, it must be specified last:

public class ItemFactory2<T>
    where T : IComparable, new()
{
}

For more information, see Constraints on Type Parameters (C# Programming Guide).

For more information, see the C# Language Specification.

• 4.4.3 Satisfying constraints

• 10.1.6 Type parameter constraints

Concepts

Reference

Other Resources