В C# это легко :
using System;
// This attribute is valid on a generic type parameter.
[AttributeUsage(AttributeTargets.GenericParameter)]
public class GenericParameterTargetAttribute : Attribute { }
public class X<[GenericParameterTarget] T> {}
Аналог на Nemerle не работает:
using System;
// This attribute is valid on a generic type parameter.
[AttributeUsage(AttributeTargets.GenericParameter)]
public class GenericParameterTargetAttribute : Attribute { }
public class X[ [GenericParameterTarget] T] {}
error : parse error near identifier `T': unexpected token after group of tokens (you forget a closing bracket?).
error: expecting simple identifier instead of `[GenericParameterTarget]'