24 Ranges library [ranges]

24.7 Range adaptors [range.adaptors]

24.7.9 Take while view [range.take.while]

24.7.9.1 Overview [range.take.while.overview]

Given a unary predicate pred and a view r, take_­while_­view produces a view of the range [begin(r), ranges​::​find_­if_­not(r, pred)).
The name views​::​take_­while denotes a range adaptor object ([range.adaptor.object]).
Given subexpressions E and F, the expression views​::​take_­while(E, F) is expression-equivalent to take_­while_­view(E, F).
[Example 1: auto input = istringstream{"0 1 2 3 4 5 6 7 8 9"}; auto small = [](const auto x) noexcept { return x < 5; }; auto small_ints = istream_view<int>(input) | views::take_while(small); for (const auto i : small_ints) { cout << i << ' '; // prints 0 1 2 3 4 } auto i = 0; input >> i; cout << i; // prints 6 — end example]