The C++ language is not officially supported by RadControls for Winforms as well as by the other component suites that we offer such as Silverlight, WPF. These components are implemented using Common Language Specification. CLS compliance generally refers to the claim that CLS rules and restrictions are being followed. That said, we support C# and VB.NET. The C++ language with examples may officially be supported in our new modern UI control suite build for the new Windows 8 OS, but still I cannot give any guarantees about that.
Feel free to ask if you have any additional questions.
the Telerik team