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Another problem:
How can I create a library (.a) with DEV-Cpp?
Somebody could tell me where I can find a tool which converts the .lib in .a
?
Thanks a lot.

Hi

Here I'll attempt to give you a possible explanation of the error messages 
that you get.

I hope to make my explanation clearer by writing a trivial version of your 
program.

dynarray.hpp                  dynarray.cpp
-------------------------     -------------------------
#ifndef dynarray_hpp          #include "dynarray.hpp"
#define dynarray_hpp          ////////////////////////////
                               DynArray::DynArray(int size)
class DynArray                {
{                                 n = size;
    int n;     // size             p = new double[n];
    double *p; // memory       }

public:                       ////////////////////////////
    DynArray(int);             DynArray::~DynArray()
    ~DynArray();               {
}                                delete[] p;
#endif                        }
-------------------------     -------------------------

main.cpp
-------------------------
#include "dynarray.hpp"
int
main()
{
    DynArray a(3);
    ...
}

dynarray.hpp is an header file, it will be included, by a source file, when 
the class DynArray is used by code placed in the source file (in fact it is 
included by dynarray.cpp that defines the functions of the class and by 
main.cpp that uses the class).


Probably your version of the class DynArray looks like this:

dynarray.hpp                  dynarray.cpp
-------------------------     -------------------------
#ifndef dynarray_hpp          #include "dynarray.hpp"
#define dynarray_hpp          ////////////////////////////
                               DynArray::~DynArray()
class DynArray                {
{                               delete[] p;
    int n;     // size         }
    double *p; // memory       -------------------------

public:
    DynArray(int);
    ~DynArray();
}
#endif

////////////////////////////
DynArray::DynArray(int size)
{
    n = size;
    p = new double[n];
}
-------------------------

As you can see, in this case a definition of the constructor is found in 
all the files that include the header file; in your program that means: one 
definition in dynarray.cpp and one in main.cpp.

If you only compile the source files, you will get no error, the problem 
arises when you attempt to build the binary file, in fact the linker will 
find 2 definitions of the constructor: one in the object file created 
compiling dynarray.cpp (dynarray.o) and one in the object file created from 
main.cpp (main.o), since it knows that there must be only one definition, 
it will point out the error.

A way to avoid the error, still keeping the definition of the constructor 
in the header file, is to turn the constructor in an inline function: I 
prefer to do so by placing the definition inside the class declaration, 
instead of using the "inline" reserved word (but that is a question of 
taste); so I would have written:

dynarray.hpp                  dynarray.cpp
-------------------------     -------------------------
#ifndef dynarray_hpp          #include "dynarray.hpp"
#define dynarray_hpp          ////////////////////////////
                               DynArray::~DynArray()
class DynArray                {
{                               delete[] p;
    int n;     // size         }
    double *p; // memory       -------------------------

public:
    DynArray(int size)
    { n = size; p = new double[size]; }
    ~DynArray();
}
#endif
-------------------------


I hope the above helps.

At 10.38 09/12/01 -0500, Danny wrote:
>Hello again,
>I have managed to make some progress, only to run into larger problems.
>After including the files in one project and compiling, the Linker returns a
>long list of complaints:
>
>
>c:\cpp\array1\dynarray.o: In function `_8DynArrayi':
>file://file://c/cpp/array1/dynarray.cpp:25: multiple definition of
>`DynArray::DynArray(int)'
>c:\cpp\array1\main.o://C/cpp/array1/dynarray.cpp:25: first defined here
>c:\cpp\array1\dynarray.o: In function `_8DynArrayRC8DynArray':
>file://c/cpp/array1/dynarray.cpp:41: multiple definition of
>`DynArray::DynArray(DynArray const &)'
>c:\cpp\array1\main.o://C/cpp/array1/dynarray.cpp:41: first defined here
>
>
>It seems that I get this type of complaint for each function in the
>implementation file.  What is the cause of this?  Any ideas on what to do to
>solve this problem?
>  ...
>
>Danny

--
gisan
gi...@li...