C# language proposal: loose keyword

example.cs

webserviceproxynamespace.LatLng latlng = new webserviceProxy().GetLatLng("Orlando, FL, 32803");

anotherproxynamespace.LatLng latlng2 = new anotherwebservice().GetPosition("Orlando", "FL", "32803");

//this other library wants a LatLng object
var map = new Mapping.MapManager();
map.MarkPosition(loose latlng);   //parameter type is Mapping.LatLng but latlng is webserviceproxynamespace.LatLng type, should work!
map.MarkPosition(loose latlng2);  //parameter type is Mapping.LatLng but latlng2 is anotherproxynamespace.LatLng type, should work!

//how does this work?
//loose keyword says maybe c# compiler automaps via dynamic object and runtime IL
//key is, for most simple types, being able to pass these object with the same shape (names of properties) 
//currently this is always handled by automappers or repititive map coding

//type definitions
namespace Mapping
{
  public class record LatLng(double Lat, double Lng);
  public class Mapper
  {
     public bool MarkPosition(Mapping.LatLng latlng) => return true;
  }
}
namespace webserviceproxynamespace
{
  public class LatLng(decimal Lat, decimal Lng);
  public class WebserviceProxy
  {
     public LatLng GetLatLng(string locationDefinition) => return new LatLng(0,0);
   }
 }
 namespace anotherproxynamespace
 {
   public class LatLng(float Lat, float Lng);
   public class anotherwebservice
   {
     public LatLng GetPosition(string city, string state, string zip) => return new LatLng(1,1);
   }
 }