Overloading extension methods by generic constraints

[alrz]

There's a trick to overload extension methods by generic constraints, however this needs an import at a different level unless the call-site is itself inside the same namespace or the extension method is declared in the global namespace.

using App.Extensions.Generic;

namespace App {
    
    using App.Extensions;
    
    class Program {
        public static void Main() {
            new object().Add<object>(); // Inner
            new object().Add<IInterface>(); // Outer
        }
    }
}

interface IInterface {}

namespace App.Extensions {
  namespace Generic {
    static class Inner {
      public static void Add<T>(this object obj)  {}
    }
  }

  static class Outer {
      public static void Add<T>(this object obj) where T : IInterface {}
  }
}

Could extension possibly help with this? Maybe through extension inheritance?

extension class Inner for object { 
   public void Add<T>() {}
}
extension class Outer for object : Inner {
   publicvoid Add<T>() where T : IInterface {}
}

[TonyValenti]

I just create two different static classes, one with each constraint, and the compiler figures it out.