<xstd/bits/bit_algorithm/bit_transform.hpp>

bit_transform

As ranges::transform in [alg.transform], with:

• Constraints: R, or R1 and R2, are sequences of ours, windows included; O is an output iterator of ours; invocable<F&, bool>, or invocable<F&, bool, bool>, is modeled and its result converts to bool. A function taking bool&, or answering a string, is turned away.
• Effects: The unary form calls f(false) and f(true) once each; the binary form calls f once at each of the four pairs. The answers make a truth table that is applied as one block expression, a block of the destination at a time as bit_copy writes it: for the unary form (x & T) | (~x & U), where T and U are all ones or all zeros as f(true) and f(false) answer. The binary form goes as far as the shorter input. out may be ranges::begin(r1), as [alg.transform] allows.
• Complexity: Exactly two applications of f for the unary form and four for the binary, whatever N, an empty input included; O(N/D) block operations.
• Remarks: The positions written are those ranges::transform writes; a function with side effects sees two or four calls where ranges::transform makes one per element.