# ParallelScanFunc

[req.parallel_scan_func]

A type Scan satisfies ParallelScanFunc if it meets the following requirements:

ParallelScanFunc Requirements: Pseudo-Signature, Semantics

Value Scan::operator()(const Range &r, const Value &sum, bool is_final) const

  Starting with `sum`, computes the summary and, for `is_final == true`, the scan result for range `r`. Returns the computed summary. `Value` type must be the same as a corresponding template parameter for the `parallel_scan` algorithm.

See also:

- parallel_scan algorithm