p.s. i am using boost 1.55 official release. but in boost 1.56, lockfree queue also has the same requirement. .Hzj_jie From: hzj_jie@hotmail.com To: boost-users@lists.boost.org Subject: why lockfree/queue.hpp requires has_trivial_assign and has_trivial_destructor to template type T Date: Mon, 4 Aug 2014 09:39:36 +0000 hi, all,as new to boost, i am looking for a solution to combine boost::lockfree::queue with std::function, i.e. boot::lockfree::queue<std::function>, but unfortunately, the implementation of the lockfree queue required the T to be trivial assignable and trivial destructible.with some basic investigation to the implementation of boost::lockfree::queue, the assignment operator is using when pop or unsynchronized_pop, it calls detail::copy_payload, which is using operator= or constructor and operator=. though overloaded assignment operator may use more time and cause the pop function to wait for longer time, i do not see it would block the logic.for the destruction, queue implementation always calls pool.template destruct instead deallocate, which means even for a default destructor, it will also be called. so is this a defect or by-design behavior of the lockfree queue? thank you in advanced. .Hzj_jie