Problem when #import C++ Header File in iPhone/iPa

问题:

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

回答1:

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