// @nuget: StructureMap -Version 4.7.0

using System;

using StructureMap;

public class Program

{

    public static void Main()

    {

        var container = new Container();

        container.Configure(x =>

        {

            x.For<SingletonConcreteType>().Singleton();

        });

        var instance1 = container.GetInstance<SingletonConcreteType>();

        var instance2 = container.GetInstance<SingletonConcreteType>();

        Console.WriteLine(instance1 == instance2);

        Console.WriteLine(instance1.Id == instance2.Id);

        var instance3 = container.GetInstance<ConcreteType>();

        var instance4 = container.GetInstance<ConcreteType>();

​

        Console.WriteLine(instance3.Id == instance4.Id);

    }

    public class SingletonConcreteType

    {

        public Guid Id = Guid.NewGuid();    

    }

    public class ConcreteType

    {

        public Guid Id = Guid.NewGuid();

    }

}