PR libstdc++/52681
	* src/c++11/thread.cc (thread::_M_start_thread): Improve error text
	when threads are not enabled.
From-SVN: r190330
+2012-08-12  Jonathan Wakely  <jwakely.gcc@gmail.com>
+
+       PR libstdc++/52681
+       * src/c++11/thread.cc (thread::_M_start_thread): Improve error text
+       when threads are not enabled.
+
 2012-08-09  Jonathan Wakely  <jwakely.gcc@gmail.com>
 
        * acinclude.m4: Update references to final C++11 standard.
 
   thread::_M_start_thread(__shared_base_type __b)
   {
     if (!__gthread_active_p())
+#if __EXCEPTIONS
+      throw system_error(make_error_code(errc::operation_not_permitted),
+                        "Enable multithreading to use std::thread");
+#else
       __throw_system_error(int(errc::operation_not_permitted));
+#endif
 
     __b->_M_this_ptr = __b;
     int __e = __gthread_create(&_M_id._M_thread,