Thread: Instantiating a template class

Heeeelllooo... !


Okay, I have this pretty weird problem, or so I think

I have a CDLDAList Class, its declaration is:

Code:

template <class Type> class CDLDAList
{
private:
    /**
     * @brief Friend class declaration for CDLIterator
     */
    template <class Type> friend class CDLIterator;
//..... declaration of private stuff
public:

    /**
     * @brief    Default constructor
     * @pre        true
     * @post    Empty list constructed
     */
    CDLDAList<Type>();
//.... rest of public thingies
}

and its constructor is defined as follows:

Code:

template <class Type> CDLDAList<Type>::CDLDAList<Type>()
{
    nMaxIterators=100;
    nIterators=0;
    pHead=NULL;
    pTail=NULL;
    pIterators=new CDLIterator<Type>[nDeltaIterators];
    nItems=0;
}

now I have another class which has an attribute of type CDLDAList<int>, like this:

Code:

class CFacade
{
private:
    /**
     * @brief    List of Integers
     */
    CDLDAList<int> lList;
//rest of class declaration
}

Now, trying to compile this, with two different compilers, gives different errors

With Visual Studio .NET 2003 it gives me linker errors saying none of CDLDAList<int>'s member functions I'm using could be found by the linker

Something among this line

Originally Posted by Visual Studio

TallerListas1_09 error LNK2019: unresolved external symbol "public: __thiscall CDLDAList<int>::~CDLDAList<int>(void)" (??1?$CDLDAList@H@@QAE@XZ) referenced in function "public: __thiscall CFacade::~CFacade(void)" (??1CFacade@@QAE@XZ)

TallerListas1_09 error LNK2019: unresolved external symbol "public: bool __thiscall CDLDAList<int>::eraseItem(class CDLIterator<int>)" (?eraseItem@?$CDLDAList@H@@QAE_NV?$CDLIterator@H@@ @Z) referenced in function "public: enum Result __thiscall CFacade::srvEraseItem(class CDLIterator<int>)" (?srvEraseItem@CFacade@@QAE?AW4Result@@V?$CDLItera tor@H@@@Z)

and so on

--------------------------

Borland C++Builder 6.0 "stands" where I will make the text bold:

template <class Type> CDLDAList<Type>::CDLDAList<Type>()
{
//constructor code here
}

saying

Originally Posted by Borland

[C++ Error] DLDAList.cpp(14): E2040 Declaration terminated incorrectly

Now, if I change it so it says template <class Type> CDLDAList<Type>::CDLDAList() instead, it will give me a linker error, just like MSVS.NET's, saying there's an unresolved external ( CDLDAList<int>::CDLDAList<int>() )

I dunno if I'm not following proper syntax or what, but I'm pretty confused about what to do and I think I'm doing it how it's supposed to be done... I dunno


Miguel Andrés

i don't think the link errors are caused by the codes.
plz show us more codes

show us the destructor of CDLDAList and CFacade

is it that you can not contain the DLDAList.cpp in your project?

The problem is that you have to define templated classes and such in your header or you will get linker errors. Just happened to my not to long ago.