Peter Dimov wrote:
the multi platform failures observed for grammar_mt_tests and owi_mt_tests seem to correlate to the recent thread lib update:
cxx: Error: ../boost/thread/pthread/thread.hpp, line 139: call of an object of a class type without appropriate operator() or conversion functions to pointer-to-function type (badcallclsobj) detected during instantiation of "void boost::thread::thread_data<F>::run() [with
F=boost::reference_wrapper<single_grammar_object_task>]" f(); ----------------^
Anyone knows what's going on?
I think I do. The new Boost.Threads implements the proposed standard interface where F is expected to be a function object; std::reference_wrapper is, but boost::reference_wrapper isn't. The old Boost.Threads did not suffer from this problem since it stored F in a boost::function, which automatically recognizes reference_wrapper and "dereferences" it before the call.
This can be fixed on the user side by wrapping the reference_wrapper in a boost::bind, or it can be fixed on the Boost.Threads side. The third option, making boost::reference_wrapper callable, is a very risky change that I would advise against.
I strongly object against silently changing the Boost.Thread interface/semantics. So I'ld vote for 2) Regards Hartmut