net6.0-windows 
namespace System.Runtime.CompilerServices
{
    [InterpolatedStringHandler]
    public struct DefaultInterpolatedStringHandler
    {
        public override string! ToString();
    }
}
.NET
6.07.08.09.010.0
Information specific to net6.0
Assembly

System.Runtime , Version=6.0.0.0, PublicKeyToken=b03f5f7f11d50a3a

Referencing

Your project needs a package reference to System.Runtime.Experimental.

Package System.Runtime.Experimental (6.0.2) net6.0
Platform Restrictions

This API is supported on all platforms.

  • Built-in API
  • Package-provided API