How to register a COM class in memory?

I have a COM class (e.g., CLSID_WidgetFactory) that I want to make available to anyone in my process who calls:

CoCreateInstance(CLSID_Widget, ...);

But i want to make it available without having to register it, or include it in a registration-free COM assembly manifest.

Core question

I have:

• a clsid (CLSID_Widget)
• an IClassFactory implementation

How can i register the these with the COM infrastructure so that anyone in my process can create the COM object?

Obviously I want to accomplish this:

• without registering the COM object in the HKLM\Software\Classes registry hive
• without registering the COM object in the HKCU\Software\Classes hive
• without create a registration-free COM assembly manifest

Conceptually i would have my classID, and my factory object:

class WidgetFactory : ComObject, IClassFactory
{
   //IClassFactory methods
   HRESULT CreateInstance(IUnknown unkOuter, Guid iid, out obj)
   {
      Widget widget = new Widget();

      HRESULT hr = widget.QueryInterface(iid, out obj);
      return hr;
   }
}

Then i want to register my class factory:

Guid CLSID_Widget = "{0677445E-EA9B-447A-AF2E-CCD86E49CED0}";
IClassFactory factory = new WidgetFactory();

RegisterClassFactory(CLSID_Widget, factory);

All that's left is to figure out how to register a COM Class in-memory:

void RegisterClassFactory(Guid clsid, IClassFactory classfactory)
{
   //...
}

Search terms

• How to register a COM object in memory
• How to register a COM class in my process
• How to register a CLSID in memory
• How to register IClassFactory in my application

Note: I know the answer. But i can't figure out the correct set of search terms that would trigger a hit.

Bonus Reading

• Can I create and use a COM class without registering it in the registry?
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