Subj : Re: C++ and C libraries
To   : borland.public.cpp.borlandcpp
From : Ed Mulroy [TeamB]
Date : Tue Apr 27 2004 09:15 am

This derives from the way C++ handles public names.

C++ supports function overloading, more than one function with the
same name but each has a different argument list.

To implement that the public names of C++ functions have characters
indicating the argument list types added to the end of their name.
The names are said to be 'mangled'.  C forms the public names by
inserting a leading underscore in the name.

In C
int Doit(int) public name is _Doit
int Doit(char*, int) public name is _Doit

In C++
int Doit(int) public name is @Doit$qi
int Doit(char*, int) public name is @Doit$qpci

The C++ language specifies a way to indicate that a public name be
formed in the manner used by C.

In C++
extern "C" Doit(int) public name is _Doit
extern "C" int Doit(char*, int) public name is _Doit

A curly braced block can be used to make the extern "C" apply to a
group of items.

If you take the header files used for that library and modify them in
this manner I think the problem will dissapear.

----start of header file-------
#ifdef __cplusplus
extern "C" {
#endif

----current contents of the header file---

#ifdef __cplusplus
  }
#endif
----end of header file-------


If you look in the compiler supplied header files such as stdio.h you
can see this technique in use.

..  Ed

> Luigi Fonti wrote in message
> news:408e0cef$1@newsgroups.borland.com...
>
> I have an application developed for MSDOS using Borland
> C++ 4.0 Now, to add network functionalities to it, I should
> link a TCPIP library written just for Borland environments
> (wattcp). I got libraries (for different memmory models) and
> sources, too. Unhappily if I insert in my sources some calls
> to TCPIP functions, the libraries are not linked, and the
> called fuctions remains unresolved.
> ...
> The problem seens to be in source types: the application
> sources are .cpp, while the TCPIP library sources are .c
> ...

.