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I have a C++ class I would like to use in an iPhone/iPad project.
I created this file in different ways (like with "New File" => C++) and the error is always the same.

When I compile the project without having any #import (of the .h C++ class), it's ok.

But as soon as I #import the header file in one of my header objective-c file, I get error like :

error: vector: No such file or directory

or

error: expected '=', ',', ';', 'asm' or 'attribute' before ':' token"

I tried setting different values to the file type (of C++ class) in File Info, renaming my objc class in .mm etc, but it doesn't seem to work.

So I must have missed something about importing the .h c++ class in the objc header file, but what :p ^^

SOLUTION thanks to Vlad
1°) To include the header c++ file :

#ifdef __cplusplus
    #include "Triangulate.h"
#endif

2°) Renaming the objc file in .mm AND in his File Info (right clic) setting file type as sourcecode.cpp.objcpp

Thanks for helping !
Vincent

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  • Are you sure that your Objective-C++ files has .mm extension? Commented Oct 8, 2010 at 12:50
  • Yeah I tried #include with/without the .mm extension in the implementation file. It doesn't change at all the errors. The c++ source codes are these one : flipcode.com/archives/Efficient_Polygon_Triangulation.shtml Commented Oct 8, 2010 at 12:53
  • Oh, man. .h file in ObjC headers is a different story. I extended my answer, please see the last paragraph. Commented Oct 8, 2010 at 12:59

1 Answer 1

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Note: Xcode requires that file names have a “.mm” extension for the Objective-C++ extensions to be enabled by the compiler.

Trying to use C++ in Objective-C code residing in a file with .m extension is the most probable cause of the problem because compiler just does not recognize C++ constructs according to the error message. Renaming your .m file to .mm should help.

For more details, see Using C++ with Objective-C.

Assuming you want to use an Objective-C class in an Objective-C++ source file, there's no problem at all. The only restriction is that your .h file must be Objective-C clean. This means that you can't use any C++-isms in it, or that if you do you must wrap them all in #ifdef __cplusplus. The header will be compiled in ObjC mode when it's #included by a plain Objective-C file, so it has to eliminate any C++isms for that situation (1). So your Objective-C header file should include C++ header like this:

#ifdef __cplusplus
# include MyCPPHeader.h
#endif
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10 Comments

As I said in my question, I tried. And it doesn't work. Maybe I missed something.
See the last paragraph I've just added. If you mix .m and .mm, you have to wrap C++ inclusions so that .m files will not see C++ included in Objective-C++.
My My My. I tried things but it doesn't work :-( I have read all the cocoadev.com page and maybe my solution is to recode all the c++ class in objc -- I tried using "#ifdef __cplusplus" then in the .mm the compiler doesn't recognize the new c++ class -- All without thinking that after I need to use this .mm class in objc basic files. So first solution, I forget about using c++ here xD second solution I get a miracle xD
If I wrap the include with "#ifdef __cplusplus", then I don't get error. But if I use a c++ class name then in the .mm, I get error saying my object doesn't exist :/ I tried wrapping it too, but nothing is called during the run :/ (I put a NSLog), any idea ?
Yeah, it looks like you messed up with stuff... It should work out of the box if none of those problems exist. Try to rename .h file into .hpp maybe? Who knows, maybe your compiler treats .h header as C source instead of C++ :) IDK...
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