I am trying to compile a Cocoa app in xcode 4.0 and I'm getting this error...
fatal error: 'string' file not found
...when trying to compile to .pch file on this line:
#include <string>
I have another xcode project that does the same thing, but does not get the error. I have scoured the build settings for some different, but I can't find one. The only difference is that the project that compiles OK was started as a command line project, not a Cocoa project, but the build setting are the same.
The target OS is Mac OS X 10.6
The error happens when compiling the precompiled header and doesn't get to any of the other files. The only framework that the compiling version has is Foundation.framework and the non-compiling one has it as well.
Why is it not finding in one project and not the other? Any advice?
What is the extension of your source files? If it is ".m", try to change it to obj-cpp ".mm", so that Xcode will deduce correct language.
Or just put c++-specific headers inside "#ifdef __cplusplus" block
Update
The guard must exist for each language compiled in the project because this specific include is in the pch. IOW, if it were all c++ and/or objc++ there would be no error. Evidently, there is at least one file that does not recognize C++ (e.g. C or ObjC sources are also compiled in the target). Therefore, you simply guard it like so:
// MONPrefix.pch
#ifdef __cplusplus
#include <string>
#endif
// same for objc, so your C and C++ sources compile with no error:
#ifdef __OBJC__
#include <Foundation/Foundation.h>
#endif
string is a C++ header (for std::string). If you are looking for stuff like strcpy you need to include string.h
