Hi, I have some concerns about the lifetime of the coroutine parameters. Surprisingly (well not really), the following example doesn't fails at *1*. This is because the coroutine have access to its coroutine parameters *2*, which has a sens only for the first time the coroutine is called. Once the first call to yield return, the memory these parameter *3* can point to trash, as the example shows. typedef int TT; typedef boost::coro::coroutine< void(TT&) > coro_TT; void lifetime( coro_TT::self_t & self, TT& i ) // *2* { i=1; TT& j = self.yield(); std::cout << i << j << std::endl; i=2; // *3* UNSAFE access to i self.yield(); } void test_lifetime() { coro_TT c( boost::bind( lifetime, _1, _2) ); { int k = 0; c( k ); BOOST_CHECK(k = 1); } { int k = 0; int i = 0; c( i ); BOOST_CHECK(k = 2); // *1* std::cout << i << k << std::endl; } } This could hide errors that are difficult to catch. In addition to merit to be mentioned in the documentation as a limitation of the current library interface I really think that it merits to see if this can be solved. Best, Vicente