Re: c interface with c++ implementation

From:

"comp.lang.c++.moderated" <dhb2000@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Mon, 09 Jul 2007 03:48:14 -0700

Message-ID:

<1183978094.300827.105680@a26g2000pre.googlegroups.com>

On 7 9 , 5 24 , zade <zhaohongc...@gmail.com> wrote:

I want to create a library with c interface but with c++
implementation. But I don't know if there exist some potential
problems.
Any advice? thanks!

There's no potential problem, As far as I did in my previous project

Here's a small example

//A.h
class A {
public:
    A(char);
    int Func(int);
};

// c_interface.h
#ifdef __cplusplus
extern "C" {
#endif // __cplusplus

typedef void* A_HANDLE;

A_HANDLE create_A(char c);

void destroy_A(A_HANDLE h);

int c_func(A_HANDLE, int);
// other C functions ...
#ifdef __cplusplus
}
#endif // __cplusplus

// a.cpp
#include "a.h"
#include "c_interface.h"

A::A(char c) {
}

int A::Func(int i) {

}

A_HANDLE create_A(char c) {
    new A(c);
}

void destroy_A(A_HANDLE h) {
    delete static_cast<A*>(h);
}

int c_func(A_HANDLE h, int i) {
    A* pA = static_cast<A*>(h);
    return pA->Func(i);
}

//test.c
#include "c_interface.h"
A_HANDLE hA = create_A('a');

int ret = c_func(10);

destroy_A(hA);