August 30, 2008 04:28am pdt

Member Login

Hall of Fame

Yearly

1evilrix 62,007
2jkr 58,950
3jaime_oliv... 45,143
4TheLearn... 24,275
5Gurudenis 24,085
6DanRollins 23,100
7AndyAins... 21,242
8alb66 18,922
9Infinity08 17,830
10itsmeandn... 11,814
11JohnGaby 9,550
12LordOfPo... 8,700
13roytal 6,536
14Zoppo 4,975
15Ichijo 4,600
15bandyt1... 4,600
17angelIII 4,000
17mahesh1... 4,000
17oxyoo 4,000
17SteveH_UK 4,000
21mjoachia... 3,875
22DaveHowe 3,800
23junges 3,500
24peetm 3,370
25jcoehoorn 3,200

	[x] Attachment Details

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

Zones: Microsoft Visual C++.Net, .NET

Tags: C++/CLI

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

         
           
             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>();            
        }
};

           
         

Start your free trial to view this solution

[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

Question Stats

Zone: Programming

Question Asked By: thwein

Solution Provided By: evilrix

Participating Experts: 1

Solution Grade: C

Translate:

Loading Advertisement...

20080723-EE-VQP-34 / EE_QW_2_20070628