test_generic_locks.cpp doesn't compiles any more on gcc3.4 cygwin

[viboes]

After modification on the locks algorithm, test_generic_locks.cpp doesn't compiles any more on gcc3.4 cygwin.

gcc.compile.c++ ../../../bin.v2/libs/thread/test/test_generic_locks.test/gcc-3.4.4/debug/threading-multi/test_generic_locks.o ../../../boost/thread/locks.hpp: In instantiation of `boost::detail::has_member_called_try_lock<dummy_iterator, true>::derived': ../../../boost/thread/locks.hpp:65: instantiated from `boost::detail::has_member_called_try_lock<dummy_iterator, true>' ../../../boost/thread/locks.hpp:145: instantiated from `boost::is_mutex_type<dummy_iterator>' ../../../boost/thread/locks.hpp:1280: instantiated from `void boost::lock(const MutexType1&, const MutexType2&) [with MutexType1 = dummy_iterator, MutexType2 = dummy_iterator]' test_generic_locks.cpp:356: instantiated from here ../../../boost/thread/locks.hpp:65: error: base `dummy_iterator' with only non-default constructor in class without a constructor

[viboes]

The dummy_iterator default constructor is missing:

    dummy_iterator(): p(0) {}

[Anthony Williams]

Adding a constructor to dummy_iterator will just mask the issue. The "derived" class in question has no instances, so we can just declare an unimplemented default constructor to stop the compiler complaining.

Fixed on trunk.