Advertisement

05.21.2008 at 12:37AM PDT, ID: 23419856
[x]
Attachment Details
[x]
The Solution Rating System

With so many solutions, how can you tell which solutions are most likely to help you and which ones are not? To provide you with a tool to use, we rate our solutions based on various elements that most accurately determine if a solution is a quality solution. To explain what factors affect the solution rating, here are the elements we take into consideration when formulating our solution rating.

  • The Grade of the Solution
  • The Zone Rank of the Expert Providing the Solution
  • The Number of Author and Expert Comments
  • The Number of Experts Contributing
  • The Feedback of the Community

Your Input Matters
Because of the way the system is set up, the most important variable in this equation is you. As a member of Experts Exchange, you are able to cast your vote on the quality of the solutions in regard to how complete, accurate, helpful and easy to understand each solution is. When you provide your feedback, each rating is adjusted accordingly. So, if you see a solution that has a poor rating that you think is a good solution, let us know by rating it. As you do, the rating will be adjusted and will become more accurate for other members of our site.

If you have any suggestions that you would like to make for our rating system, please ask a question in the Suggestions Zone of Community Support.

Thank you!

7.5

Managed C++. Template causes class type redefinition when used in multiple DLLs

Asked by thwein in Microsoft Visual C++.Net, .NET

Tags:

Who can explain me the following issue:

I have two DLLs. For the first (product) DLL I created a template ref class Foo (see code below). Foo has a member of ref class Bar which is located in the same DLL. The template is used in class Main still in the samew DLL.
'Til now every thing is fine. I can compile that first DLL without problems.

But I have to use this template additionally from a second (test) DLL. There the template is used by class Test. When I try to compile that Test DLL I get the following error:
Bar.h(4) : error C2011: 'X::Bar' : 'class' type redefinition

I can prevent that error by removing the public declaration  of class Bar, but I want to understand why that error occurs when Bar is public.
Can anyone explain that issue to me?

Thanks


Start Free Trial
1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:
35:
36:
37:
38:
39:
40:
41:
42:
43:
44:
45:
46:
47:
48:
49:
50:
51:
52:
53:
54:
55:
56:
57:
58:
59:
60:
//============Source of DLL Product===================
//-------------Foo.h----------------------------------
#pragma once
#include "Bar.h"
namespace X{ 
    template <typename T>
    public ref class Foo
	{
	public:
		Foo(void)
        {
            myMember = gcnew Bar(10);
        }
		virtual T Add(T i, T j)
        {
            return i + j;
        }
    private:
        Bar^ myMember;
    };
}
//-------------Bar.h----------------------------------
#pragma once
namespace X{
    public ref class Bar
	{
    private:
        int myIndex;
	public:
        Bar(int idx);
        virtual property int Index
        {
            int get();
        }
    };
}
//-------------Main.cpp----------------------------------
#pragma once
#include "Foo.h"
namespace X{
    public ref class Main
    {
        Main(){
            Foo<int>^ f = gcnew Foo<int>();   
        }
    };
}
//============Source of DLL Test ========================
//-------------Test.cpp----------------------------------
#pragma once
#include "Foo.h"
using namespace X;
class Test
{
    public:
        Test()
        {
            Foo<double>^ f = gcnew Foo<double>();            
        }
};
 
 
[+][-]05.21.2008 at 07:51AM PDT, ID: 21615684

Experts Exchange has a courteous staff of administrators who help members get the most out of the website by means of administrative comments like this one.

Start your 14-day free trial to view this Administrative Comment or ask the Experts your question.

 
[+][-]05.25.2008 at 04:47PM PDT, ID: 21644006

View this solution now by starting your 14-day free trial. Setting up your free trial is quick, easy, and secure. We will return you to this solution, unlocked, when you're done.

 

About this solution

Zones: Microsoft Visual C++.Net, .NET
Tags: C++/CLI
Sign Up Now!
Solution Provided By: evilrix
Participating Experts: 1
Solution Grade: C
 
 
[+][-]06.03.2008 at 04:51AM PDT, ID: 21699371

Often, when Experts are collaborating with members who have asked questions, they will request additional information about the problem. Askers respond with an author comment like this one.

Start your 14-day free trial to view this Author Comment or ask the Experts your question.

 
[+][-]06.03.2008 at 04:58AM PDT, ID: 21699421

At Experts Exchange, members can ask their questions to thousands of technology professionals, also known as Experts. Experts compete and collaborate to answer those questions by leaving comments like this one.

Start your 14-day free trial to view this Expert Comment or ask the Experts your question.

 
 
Loading Advertisement...
20081112-EE-VQP-43 / EE_QW_2_20070628