2.0: Generics, excluding value types

[Jon Shemitz]

Is there a way in 2.0 to say that a generic can not be applied to a
value type?

public class Unique<T> where T: new()
{
private static T cache = default(T);

public static T Instance
{ get
{
if (cache == null)
return cache = new T();
else
return cache;
} }
}

I want to be able to do Unique<someClass> but not Unique<int>.

--

programmer, author http://www.midnightbeach.com
and father http://www.midnightbeach.com/hs

[Daniel O'Connell [C# MVP]]

"Jon Shemitz" <jo*@midnightbeach.com> wrote in message
news:41***************@midnightbeach.com...

Is there a way in 2.0 to say that a generic can not be applied to a
value type?

Yeah, use the class constraint
public class Unique<T> where T : new(), class
{
//...
}

[Jon Shemitz]

"Daniel O'Connell [C# MVP]" wrote:

Is there a way in 2.0 to say that a generic can not be applied to a
value type?

Yeah, use the class constraint
public class Unique<T> where T : new(), class

public class Unique<T> where T : class, new() // actually

Thanks! Either that's been added since "The C# Programming Language"
went to print or I just plain missed something.

--

programmer, author http://www.midnightbeach.com
and father http://www.midnightbeach.com/hs

[Daniel O'Connell [C# MVP]]

"Jon Shemitz" <jo*@midnightbeach.com> wrote in message
news:41***************@midnightbeach.com...

"Daniel O'Connell [C# MVP]" wrote:

> Is there a way in 2.0 to say that a generic can not be applied to a
> value type?
>

Yeah, use the class constraint
public class Unique<T> where T : new(), class

public class Unique<T> where T : class, new() // actually

Ya, I couldn't remember which order the new constraint had to be.