Method constraint must be super of class generic












0















How can I do the following?



I have a method which I need to say its generic type must be the super of the classes generic type.



Here is an example:



class Logger : ILogger, IStartable {}

///use
new FluentBuilder<Logger>().As<ILogger>().As<IStartable>();


This shows my intent, however does not work (as it is not syntactically incorrect):



public class FluentBuilder<TService> where TService : class
{
public FluentBuilder<TService> As<TContract>() where TService : TContract
{
return this;
}
}









share|improve this question

























  • Still it's unclear to me; why would you need As<Ilogger> and As<IStartable> (at the same time)?

    – Stefan
    Nov 18 '18 at 12:02













  • @Stefan updated my example, re the 2 As statements, it is an example consider Logger implements 2 interfaces (that we are interested in) and we want to describe that with the As<TContract>() method

    – dbones
    Nov 18 '18 at 12:56
















0















How can I do the following?



I have a method which I need to say its generic type must be the super of the classes generic type.



Here is an example:



class Logger : ILogger, IStartable {}

///use
new FluentBuilder<Logger>().As<ILogger>().As<IStartable>();


This shows my intent, however does not work (as it is not syntactically incorrect):



public class FluentBuilder<TService> where TService : class
{
public FluentBuilder<TService> As<TContract>() where TService : TContract
{
return this;
}
}









share|improve this question

























  • Still it's unclear to me; why would you need As<Ilogger> and As<IStartable> (at the same time)?

    – Stefan
    Nov 18 '18 at 12:02













  • @Stefan updated my example, re the 2 As statements, it is an example consider Logger implements 2 interfaces (that we are interested in) and we want to describe that with the As<TContract>() method

    – dbones
    Nov 18 '18 at 12:56














0












0








0


0






How can I do the following?



I have a method which I need to say its generic type must be the super of the classes generic type.



Here is an example:



class Logger : ILogger, IStartable {}

///use
new FluentBuilder<Logger>().As<ILogger>().As<IStartable>();


This shows my intent, however does not work (as it is not syntactically incorrect):



public class FluentBuilder<TService> where TService : class
{
public FluentBuilder<TService> As<TContract>() where TService : TContract
{
return this;
}
}









share|improve this question
















How can I do the following?



I have a method which I need to say its generic type must be the super of the classes generic type.



Here is an example:



class Logger : ILogger, IStartable {}

///use
new FluentBuilder<Logger>().As<ILogger>().As<IStartable>();


This shows my intent, however does not work (as it is not syntactically incorrect):



public class FluentBuilder<TService> where TService : class
{
public FluentBuilder<TService> As<TContract>() where TService : TContract
{
return this;
}
}






c# .net generics






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Nov 18 '18 at 12:53







dbones

















asked Nov 18 '18 at 11:52









dbonesdbones

3,02222644




3,02222644













  • Still it's unclear to me; why would you need As<Ilogger> and As<IStartable> (at the same time)?

    – Stefan
    Nov 18 '18 at 12:02













  • @Stefan updated my example, re the 2 As statements, it is an example consider Logger implements 2 interfaces (that we are interested in) and we want to describe that with the As<TContract>() method

    – dbones
    Nov 18 '18 at 12:56



















  • Still it's unclear to me; why would you need As<Ilogger> and As<IStartable> (at the same time)?

    – Stefan
    Nov 18 '18 at 12:02













  • @Stefan updated my example, re the 2 As statements, it is an example consider Logger implements 2 interfaces (that we are interested in) and we want to describe that with the As<TContract>() method

    – dbones
    Nov 18 '18 at 12:56

















Still it's unclear to me; why would you need As<Ilogger> and As<IStartable> (at the same time)?

– Stefan
Nov 18 '18 at 12:02







Still it's unclear to me; why would you need As<Ilogger> and As<IStartable> (at the same time)?

– Stefan
Nov 18 '18 at 12:02















@Stefan updated my example, re the 2 As statements, it is an example consider Logger implements 2 interfaces (that we are interested in) and we want to describe that with the As<TContract>() method

– dbones
Nov 18 '18 at 12:56





@Stefan updated my example, re the 2 As statements, it is an example consider Logger implements 2 interfaces (that we are interested in) and we want to describe that with the As<TContract>() method

– dbones
Nov 18 '18 at 12:56












1 Answer
1






active

oldest

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0














This is not exactlywhat you want, but maybe a step in the correct direction. You can implement your As method as extension method:



public static class Ex
{
public static FluentBuilder<TService> As<TService, TContract>(this FluentBuilder<TService> that)
where TContract : class
where TService : class, TContract
{
return that;
}
}


The usage syntax is then:



new FluentBuilder<Logger>().As<Logger, ILogger>().As<Logger, IStartable>();






share|improve this answer























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    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    0














    This is not exactlywhat you want, but maybe a step in the correct direction. You can implement your As method as extension method:



    public static class Ex
    {
    public static FluentBuilder<TService> As<TService, TContract>(this FluentBuilder<TService> that)
    where TContract : class
    where TService : class, TContract
    {
    return that;
    }
    }


    The usage syntax is then:



    new FluentBuilder<Logger>().As<Logger, ILogger>().As<Logger, IStartable>();






    share|improve this answer




























      0














      This is not exactlywhat you want, but maybe a step in the correct direction. You can implement your As method as extension method:



      public static class Ex
      {
      public static FluentBuilder<TService> As<TService, TContract>(this FluentBuilder<TService> that)
      where TContract : class
      where TService : class, TContract
      {
      return that;
      }
      }


      The usage syntax is then:



      new FluentBuilder<Logger>().As<Logger, ILogger>().As<Logger, IStartable>();






      share|improve this answer


























        0












        0








        0







        This is not exactlywhat you want, but maybe a step in the correct direction. You can implement your As method as extension method:



        public static class Ex
        {
        public static FluentBuilder<TService> As<TService, TContract>(this FluentBuilder<TService> that)
        where TContract : class
        where TService : class, TContract
        {
        return that;
        }
        }


        The usage syntax is then:



        new FluentBuilder<Logger>().As<Logger, ILogger>().As<Logger, IStartable>();






        share|improve this answer













        This is not exactlywhat you want, but maybe a step in the correct direction. You can implement your As method as extension method:



        public static class Ex
        {
        public static FluentBuilder<TService> As<TService, TContract>(this FluentBuilder<TService> that)
        where TContract : class
        where TService : class, TContract
        {
        return that;
        }
        }


        The usage syntax is then:



        new FluentBuilder<Logger>().As<Logger, ILogger>().As<Logger, IStartable>();







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 18 '18 at 12:10









        Klaus GütterKlaus Gütter

        2,3781321




        2,3781321






























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