windows - Can I mix C and C++ exports in a single DLL header? -

help me out here, because i'm half convinced can't want , half convinced there should suitable workaround.

i have dll that's implemented in c++ , exports classes other c++ modules link it. that's fine. want link dll c module (another dll), provide "flattened" c interface , handle c++ stuff internally. that's fine.

the problem want supply c or c++ clients single .h , associated .lib. have similar following in dll:

#ifdef dll_exports #define dll_api __declspec(dllexport) #else #define dll_api __declspec(dllimport) #endif  // export class c++ clients class dll_api cexportedclass  { public:     cexportedclass();      // etc. etc. };  // export flattened c interface non-c++ clients #ifdef __cplusplus extern "c" { #endif  dll_api void dosomethinginternally(); // i.e. implementation uses cexportedclass  #ifdef __cplusplus } #endif 

of course, works fine when imported c++ module, fails compile when imported c module because doesn't recognise class declaration.

so wrong think can this? need split 2 headers? correct , acceptable use #ifdef __cplusplus around class declarations (or other kind of #ifdef)?

really struggling "clean" answer here.

there couple of articles on msdn mixing c , c++:

• http://msdn.microsoft.com/en-us/library/aa270933%28v=vs.60%29.aspx

• http://msdn.microsoft.com/en-us/library/s6y4zxec%28v=vs.60%29.aspx

i think can take @ windows.h or similar headers, works fine both c , c++ without problems.

basically how works:

at beginning of header file

#ifndef _myheader__h #define _myheader__h  #ifdef __cplusplus extern "c" { #endif   //decalrations //........ //........   //bottom of header  #ifdef __cplusplus } #endif #endif  

so header should looks this:

#ifdef dll_exports #define dll_api __declspec(dllexport) #else #define dll_api __declspec(dllimport) #endif  #ifdef __cplusplus //this part of header not visible ansi c compiler // export class c++ clients class dll_api cexportedclass  { public:     cexportedclass();      // etc. etc. }; #endif   #ifdef __cplusplus extern "c" { #endif    dll_api void dosomethinginternally(); // i.e. implementation uses cexportedclass  #ifdef __cplusplus       } #endif 

this how looks ansi c compiler:

#ifdef dll_exports #define dll_api __declspec(dllexport) #else #define dll_api __declspec(dllimport) #endif dll_api void dosomethinginternally();  

this how looks c++ compiler:

#ifdef dll_exports #define dll_api __declspec(dllexport) #else #define dll_api __declspec(dllimport) #endif  class dll_api cexportedclass  { public:     cexportedclass();      // etc. etc. }; extern "c" {      dll_api void dosomethinginternally();  } 

however, declare class in header, c compiler not happy this, should place out of "c" declarations.

take here:

http://www.parashift.com/c++-faq/mixing-c-and-cpp.html