The Useful DLL
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Not sure I see your point. The Class is sealed - therefore it can not be inherited. The constructor is internal and the class is in a DLL, therefore you can't create an instance of the class either. ClassNameBase has nothing to do with anything at all.
VentsyV wrote:
ClassNameBase has nothing to do with anything at all.
Actually, it does. It's the constructor that has nothing to do with it. You could create this with:
ClassNameBase myclass = new ClassNameBase(); ClassName concreteImpl = myClass;I'm not sure how useful this would be, but it could be done.
Deja View - the feeling that you've seen this post before.
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Not sure I see your point. The Class is sealed - therefore it can not be inherited. The constructor is internal and the class is in a DLL, therefore you can't create an instance of the class either. ClassNameBase has nothing to do with anything at all.
VentsyV wrote:
The constructor is internal and the class is in a DLL, therefore you can't create an instance of the class either.
That is correct, but it's likely the library writer wants to expose the instance via a member, but still disallow instantiation. IMO, this shows a very good knowledge of the language/platform being dealt with (unless it really was a mistake!).
xacc.ide - now with IronScheme support
IronScheme - 1.0 alpha 2 out now -
VentsyV wrote:
ClassNameBase has nothing to do with anything at all.
Actually, it does. It's the constructor that has nothing to do with it. You could create this with:
ClassNameBase myclass = new ClassNameBase(); ClassName concreteImpl = myClass;I'm not sure how useful this would be, but it could be done.
Deja View - the feeling that you've seen this post before.
Pete O'Hanlon wrote:
ClassNameBase myclass = new ClassNameBase();ClassName concreteImpl = myClass; I'm not sure how useful this would be, but it could be done.
Actually it cant be done :p You would need an implicit cast from a base class to it's parent derivation, and the CLR does not permit that. ;P See my post for the likely explanation why it is sealed with an internal constructor.
xacc.ide - now with IronScheme support
IronScheme - 1.0 alpha 2 out now -
VentsyV wrote:
The constructor is internal and the class is in a DLL, therefore you can't create an instance of the class either.
That is correct, but it's likely the library writer wants to expose the instance via a member, but still disallow instantiation. IMO, this shows a very good knowledge of the language/platform being dealt with (unless it really was a mistake!).
xacc.ide - now with IronScheme support
IronScheme - 1.0 alpha 2 out nowIf the class is laid out without any other members (as in the OP) then this wouldn't be it.
Deja View - the feeling that you've seen this post before.
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Pete O'Hanlon wrote:
ClassNameBase myclass = new ClassNameBase();ClassName concreteImpl = myClass; I'm not sure how useful this would be, but it could be done.
Actually it cant be done :p You would need an implicit cast from a base class to it's parent derivation, and the CLR does not permit that. ;P See my post for the likely explanation why it is sealed with an internal constructor.
xacc.ide - now with IronScheme support
IronScheme - 1.0 alpha 2 out nowYou're right of course. How could I have missed that? A 5 for spotting my stupidity.
Deja View - the feeling that you've seen this post before.
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If the class is laid out without any other members (as in the OP) then this wouldn't be it.
Deja View - the feeling that you've seen this post before.
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Pete O'Hanlon wrote:
If the class is laid out without any other members (as in the OP) then this wouldn't be it.
You missed the '//Stuff' bit? ;P
xacc.ide - now with IronScheme support
IronScheme - 1.0 alpha 2 out nowDamn - I did :doh: . If I'd seen that, I'd have answered the same as you - I guess I have "stuff" blindness (I'd normally put this in as // Do Something here).
Deja View - the feeling that you've seen this post before.
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VentsyV wrote:
The constructor is internal and the class is in a DLL, therefore you can't create an instance of the class either.
That is correct, but it's likely the library writer wants to expose the instance via a member, but still disallow instantiation. IMO, this shows a very good knowledge of the language/platform being dealt with (unless it really was a mistake!).
xacc.ide - now with IronScheme support
IronScheme - 1.0 alpha 2 out nowleppie wrote:
That is correct, but it's likely the library writer wants to expose the instance via a member, but still disallow instantiation
Can you explain this ?? I can't make sense out of it. What instance ?? There is no way you can create any instance of this class, as it is in assembly by itself.
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leppie wrote:
That is correct, but it's likely the library writer wants to expose the instance via a member, but still disallow instantiation
Can you explain this ?? I can't make sense out of it. What instance ?? There is no way you can create any instance of this class, as it is in assembly by itself.
VentsyV wrote:
There is no way you can create any instance of this class, as it is in assembly by itself.
First off, if this class in an assembly by itself and the assembly does not have any friend assemblies, the rest that follow is irrelevant. Then it means he uses reflection for something stupid. You need to understand that you dont need to create an instance. Lets take a 'real world' example (this is in xacc.ide, not sure how real world it is ;P ):
public sealed class TextBuffer
{
internal TextBuffer(AdvancedTextBox atb) { ... }
}public class AdvancedTextBox
{
public TextBuffer Buffer {get {return buffer;}}
public AdvancedTextBox()
{
buffer = new TextBuffer(this);
}
}Now I dont want anyone to use the TextBuffer class without using my AdvancedTextBox class. In other words, the author states the class is not usable without accessing it thought an AdvancedTextBox instance, for whatever reason that may be (perhaps unstable, restricted, propriety, etc). Note: the example is not exactly like it is in xacc.ide, I rather use the better approach of making TextBuffer a nested class of AdvancedTextBox, thus giving me even more flexibility on usage. ;)
xacc.ide - now with IronScheme support
IronScheme - 1.0 alpha 2 out now -
VentsyV wrote:
There is no way you can create any instance of this class, as it is in assembly by itself.
First off, if this class in an assembly by itself and the assembly does not have any friend assemblies, the rest that follow is irrelevant. Then it means he uses reflection for something stupid. You need to understand that you dont need to create an instance. Lets take a 'real world' example (this is in xacc.ide, not sure how real world it is ;P ):
public sealed class TextBuffer
{
internal TextBuffer(AdvancedTextBox atb) { ... }
}public class AdvancedTextBox
{
public TextBuffer Buffer {get {return buffer;}}
public AdvancedTextBox()
{
buffer = new TextBuffer(this);
}
}Now I dont want anyone to use the TextBuffer class without using my AdvancedTextBox class. In other words, the author states the class is not usable without accessing it thought an AdvancedTextBox instance, for whatever reason that may be (perhaps unstable, restricted, propriety, etc). Note: the example is not exactly like it is in xacc.ide, I rather use the better approach of making TextBuffer a nested class of AdvancedTextBox, thus giving me even more flexibility on usage. ;)
xacc.ide - now with IronScheme support
IronScheme - 1.0 alpha 2 out nowMight there be a factory method?
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Might there be a factory method?
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No, he states that there are no static members.
xacc.ide - now with IronScheme support
IronScheme - 1.0 alpha 2 out nowOh, yeah, I knew that... :doh:
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VentsyV wrote:
There is no way you can create any instance of this class, as it is in assembly by itself.
First off, if this class in an assembly by itself and the assembly does not have any friend assemblies, the rest that follow is irrelevant. Then it means he uses reflection for something stupid. You need to understand that you dont need to create an instance. Lets take a 'real world' example (this is in xacc.ide, not sure how real world it is ;P ):
public sealed class TextBuffer
{
internal TextBuffer(AdvancedTextBox atb) { ... }
}public class AdvancedTextBox
{
public TextBuffer Buffer {get {return buffer;}}
public AdvancedTextBox()
{
buffer = new TextBuffer(this);
}
}Now I dont want anyone to use the TextBuffer class without using my AdvancedTextBox class. In other words, the author states the class is not usable without accessing it thought an AdvancedTextBox instance, for whatever reason that may be (perhaps unstable, restricted, propriety, etc). Note: the example is not exactly like it is in xacc.ide, I rather use the better approach of making TextBuffer a nested class of AdvancedTextBox, thus giving me even more flexibility on usage. ;)
xacc.ide - now with IronScheme support
IronScheme - 1.0 alpha 2 out nowThats exactly what I've been saying all along. The class is in assembly by itself and there are no friend assemblies declared. There are no static members either. I'm not an expert in C# but to me that makes no sense whatsoever. Also, in the example you gave, you did create an instance of TextBuffer, and by the way, you have to declare buffer (lowercase 'b') somewhere or you'll get a compiler error.