C# Method Attribute cannot contain a Lambda Expression?

IntelliSense is telling me "Expression cannot contain anonymous methods or lambda expressions." Really? I was not aware of this imposed limitation. Is this correct? I guess I'm looking for a sanity check here...

public deleg开发者_JAVA技巧ate bool Bar(string s);

[AttributeUsage(AttributeTargets.All)]
public class Foo : Attribute
{
    public readonly Bar bar;

    public Foo(Bar bar)
    {
        this.bar = bar;
    }
}

public class Usage
{
    [Foo(b => b == "Hello World!")]        // IntelliSense Complains here
    public Usage()
    {
    }
}

Yes this is correct. Attribute values are limited to constants of the following types

• Simple types (bool, byte, char, short, int, long, float, and double)
• string
• System.Type
• enums
• object (The argument to an attribute parameter of type object must be a constant value of one of the above types.)
• One-dimensional arrays of any of the above types

Reference: http://msdn.microsoft.com/en-us/library/aa288454(VS.71).aspx