Boost C++ Libraries: Ticket #7061: xcode 4.5 does not compile code which uses boost::statechart

Andreas Huber — Mon, 09 Jul 2012 08:03:44 GMT

In the state_base type, I'm forward-declaring types that ultimately derive from state_base. This is a circular dependency, so the declarations for these types cannot be simply #included. In state_base, I'm also declaring a std::list typedef, which is then used as a by-reference parameter of a pure-virtual function. It seems that XCode for some reason tries to call functions of the element type at this point. Note that state_base does not call any std::list functions so I'm not really sure why XCodes std::list implementation would try to call any functions on the element type.

To cut a long story short, I don't think there's an easy workaround for this. Moreover, the response from the "apple guys" seems to suggest that this problem is caused by a *defect* in the XCode std library.

Thu, 19 Jul 2012 07:53:41 GMT

Thank you for your answer. I have unsuccessfully tried to reproduce this issue by creating a short piece of C++ code, which does not use any boost code at all. As you have investigated this problem, could you please provide such an example? Thanks.

Tue, 31 Jul 2012 07:53:06 GMT

The problem also exists in xcode 4.4 version which is production version, not beta or DP.

Tue, 31 Jul 2012 10:06:48 GMT

JFYI, I have tracked down boost src code to this:

#include <list>
template <class Alloc> class leaf;
template<class Alloc>
class base
{
public:
    typedef std::list<leaf<Alloc>> list_type;
    void remove(typename list_type::iterator & stateEnd) {};
};
template <class Alloc>
class leaf : public base<Alloc>
{
};
class Null {};
typedef base<Null>::list_type list_type;
int main(int argc, const char * argv[])
{
    return 0;
}

Marshall Clow — Wed, 31 Oct 2012 16:43:58 GMT

Just tested this with both the clang that comes with Xcode 4.5.1 [ aka Apple clang version 4.1 (tags/Apple/clang-421.11.66) (based on LLVM 3.1svn) ] and clang built from sources this morning [ aka clang version 3.2 (trunk 167013) ]

Failed on Apple's clang - but only with libc++

Worked on TOT clang

status changed; resolution set

Andreas Huber — Sun, 09 Jun 2013 18:08:56 GMT

status new → closed
resolution → wontfix

XCode defect, see previous comments.