# filter_mode

[algorithms.parallel_pipeline.filter_mode]

A `filter_mode` enumeration represents an execution mode of a `filter` in a `parallel_pipeline` algorithm.

Its enumerated values and their meanings are as follows:

- A `parallel` filter can process multiple items in parallel and without a particular order.

- A `serial_out_of_order` filter processes items one at a time and without a particular order.

- A `serial_in_order` filter processes items one at a time. The order in which items are processed is implicitly set by the first serial_in_order filter and respected by all other such filters in the pipeline.

    // Defined in header <oneapi/tbb/parallel_pipeline.h>

    namespace oneapi {
        namespace tbb {

            enum class filter_mode {
                parallel = /*implementation-defined*/,
                serial_in_order = /*implementation-defined*/,
                serial_out_of_order = /*implementation-defined*/
            };

        } // namespace tbb
    } // namespace oneapi