- attaching user command queue failure now throws a `set_default_queue_error` exception
- default_queue() now takes optional const reference of user queue instead of pointer to user queue
- add missing items in documentation
By doing so, the associated default device and context will automatically match the user-provided command queue. It
Guarantees unique default queue/device/context is returned when calling from multiple threads (requires config macro BOOST_COMPUTE_THREAD_SAFE)
Resolves issue #827
The find_device check in core.system is invalid. It could fail when same
device is supported by several platforms. In my case this happens for
Intel CPU when both AMD and Intel platforms are installed. The CPU
returned by boost::compute::system::default_device() is served by the
AMD platform, and the CPU returned by
boost::compute::system::find_device(name) is served by Intel SDK. The
only thing that could be safely asserted here is that both devices have
the same name.
