• quakkels (27/27) Jul 05 2014 I'm going through Adam Wilson's talk 'C# to D' and I've gotten
• quakkels (3/7) Jul 05 2014 This is actually:
• Vlad Levenfeld (2/29) Jul 05 2014 try SomeClass (T): BaseClass
• quakkels (6/7) Jul 05 2014 Not sure which line you want me to change. I don't want SomeClass
• Vlad Levenfeld (9/16) Jul 05 2014 ah, sorry, I misunderstood. It looks like you need to change the
• quakkels (19/27) Jul 05 2014 Thanks. That did it.

"quakkels" <_ example.com> writes:

hung up by one of his examples regarding generic programming in 
D. Specifically, I'm trying to implement the code example found 
here: http://youtu.be/6_xdfSVRrKo?t=16m44s.

I created a templateExp.d file that looks like this:

	public class BaseClass {}
	public class OtherClass : BaseClass {}

	class SomeClass(T : BaseClass)
	{
		public T[] values;
		public void add(T input) { values ~= input; }
	}

	void main()
	{
		auto sc = new SomeClass();
		OtherClass oc1 = new OtherClass();
		OtherClass oc2 = new OtherClass();

		sc.add(oc1);
		sc.add(oc2);

		import std.stdio;
		writefln("value count", sc.values.length);
	}

When I run the dmd compiler, I get this error:

	>dmd templateExp.d
	teamplteExp.d(12): Error: class teamplteExp.SomeClass(T : 
BaseClass) is used as a type

How can I initialize this class correctly?

"quakkels" <_ example.com> writes:

 When I run the dmd compiler, I get this error:

 	>dmd templateExp.d
 	teamplteExp.d(12): Error: class teamplteExp.SomeClass(T : 
 BaseClass) is used as a type

This is actually:
	templateExp.d(12): Error: class templateExp.SomeClass(T : 
BaseClass) is used as a type

"Vlad Levenfeld" <vlevenfeld gmail.com> writes:

On Saturday, 5 July 2014 at 16:47:32 UTC, quakkels wrote:

 hung up by one of his examples regarding generic programming in 
 D. Specifically, I'm trying to implement the code example found 
 here: http://youtu.be/6_xdfSVRrKo?t=16m44s.

 I created a templateExp.d file that looks like this:

 	public class BaseClass {}
 	public class OtherClass : BaseClass {}

 	class SomeClass(T : BaseClass)
 	{
 		public T[] values;
 		public void add(T input) { values ~= input; }
 	}

 	void main()
 	{
 		auto sc = new SomeClass();
 		OtherClass oc1 = new OtherClass();
 		OtherClass oc2 = new OtherClass();

 		sc.add(oc1);
 		sc.add(oc2);

 		import std.stdio;
 		writefln("value count", sc.values.length);
 	}

 When I run the dmd compiler, I get this error:

 	>dmd templateExp.d
 	teamplteExp.d(12): Error: class teamplteExp.SomeClass(T : 
 BaseClass) is used as a type

 How can I initialize this class correctly?

try SomeClass (T): BaseClass

"quakkels" <_ example.com> writes:

 try SomeClass (T): BaseClass

Not sure which line you want me to change. I don't want SomeClass 
to inherit from BaseClass. Rather, I want T to be restricted to 
classes that inherit from BaseClass.

When I change `class SomeClass(T : BaseClass)` to `class 
SomeClass(T) : BaseClass` I still get the "class 
templateExp.SomeClass(T) is used as a type" error.

"Vlad Levenfeld" <vlevenfeld gmail.com> writes:

On Saturday, 5 July 2014 at 17:17:03 UTC, quakkels wrote:
 try SomeClass (T): BaseClass

 Not sure which line you want me to change. I don't want 
 SomeClass to inherit from BaseClass. Rather, I want T to be 
 restricted to classes that inherit from BaseClass.

 When I change `class SomeClass(T : BaseClass)` to `class 
 SomeClass(T) : BaseClass` I still get the "class 
 templateExp.SomeClass(T) is used as a type" error.

ah, sorry, I misunderstood. It looks like you need to change the 
lin

auto sc = new SomeClass ();

to

auto sc = new SomeClass!BaseClass ();

The compiler complains because SomeClass is a template when you 
call SomeClass() without !() template parameters. It only becomes 
a type once instantiated with parameters.

"quakkels" <_ example.com> writes:

 ah, sorry, I misunderstood. It looks like you need to change 
 the lin

 auto sc = new SomeClass ();

 to

 auto sc = new SomeClass!BaseClass ();

 The compiler complains because SomeClass is a template when you 
 call SomeClass() without !() template parameters. It only 
 becomes a type once instantiated with parameters.

Thanks. That did it.

Here's my working program.

	public class BaseClass {}
	public class OtherClass : BaseClass {}

	class SomeClass(T : BaseClass)
	{
		public T[] values;
		public void add(T input) { values ~= input; }
	}

	void main()
	{
		auto sc = new SomeClass!BaseClass();
		OtherClass oc1 = new OtherClass();
		OtherClass oc2 = new OtherClass();

		sc.add(oc1);
		sc.add(oc2);

		import std.stdio;
		writefln("value count: %d", sc.values.length);
	}