You cannot consume .NET generic classes or generic methods in conditional code blocks. The .NET Framework 2.0 introduced generics to act as templates that allow classes, structures, interfaces, methods, and delegates to be declared and defined with unspecified or generic type parameters instead of specific types. Several namespaces, such as System Namespace and System.Collections.Generic, provide generic classes and methods.
The System.Nullable type is a standard representation of optional values and as such it is also classified as generic and therefore cannot be consumed in PowerBuilder .NET applications.
In .NET Assembly and Web service targets, you can select a check box to map PowerBuilder standard datatypes to .NET nullable datatypes. Nullable datatypes are not Common Type System (CTS) compliant, but they can be used with .NET Generic classes if a component accepts or returns null arguments or if reference arguments are set to null.
