Add a note to the condition_variable::wait_for(..., pred) overload. fiber_specific_ptr::reset() has no default argument. Remove mention of launch policy deferred, since no API accepts a launch policy argument. Copy construction or copy assignment of a shared_future leaves other.valid() unchanged. It won't be 'true' unless it was 'true' before. Mention that [shared_]future::get_exception_ptr() does not invalidate. Note that 'blocks' and 'suspends' are used interchangeably. Add some cross-references; add link to std::allocator_arg_t. Clarify the cross-reference to the paragraph describing BOOST_FIBERS_NO_ATOMICS. Reformat some overly-long source lines.
boost.fiber
boost.fiber provides a framework for micro-/userland-threads (fibers) scheduled cooperativly. The API contains classes and functions to manage and synchronize fibers similiar to boost.thread.
A fiber is able to store the current execution state, including all registers and CPU flags, the instruction pointer, and the stack pointer and later restore this state. The idea is to have multiple execution paths running on a single thread using a sort of cooperative scheduling (threads are preemptively scheduled) - the running fiber decides explicitly when its yields to allow another fiber to run (context switching).
A context switch between threads costs usally thousends of CPU cycles on x86 compared to a fiber switch with less than 100 cycles. A fiber can only run on a single thread at any point in time.
Building: Detailed instructions can be found at https://svn.boost.org/trac/boost/wiki/TryModBoost.
boost.fiber is C++14-only!