Algorithms & ranges over raw loops

Lambdas finally make <algorithm> ergonomic; all_of/any_of/none_of, find_if, count_if replace hand loops that merely scan.

bool ok = std::all_of(v.begin(), v.end(),
                       [](const Job& j) { return j.done(); });

Generic lambdas ([](const auto& x)) decouple call sites from element types; std::mismatch/equal get proper two-range overloads.

Parallel execution policies bolt onto the same algorithms; std::sample, clamp, reduce, transform_reduce fill gaps.

std::sort(std::execution::par_unseq, v.begin(), v.end());
auto total = std::transform_reduce(std::execution::par,
                                   v.begin(), v.end(), 0.0,
                                   std::plus<>{}, area);

Ranges: whole-container calls, projections, and lazy composable views with |. The raw loop survives only where it is genuinely clearer.

std::ranges::sort(people, {}, &Person::name);     // projection

auto names = people
           | std::views::filter(&Person::active)
           | std::views::transform(&Person::name);

The gaps close: views::zip, enumerate, chunk, slide, adjacent, join_with; ranges::to<Container> materializes pipelines; fold_left family lands.

auto top = scores
         | std::views::enumerate
         | std::views::take(10)
         | std::ranges::to<std::vector>();

views::concat joins heterogeneous ranges, and parallel range algorithms (P3179) marry the C++17 policies to the C++20 interface.

for (auto&& x : std::views::concat(header, body, footer)) emit(x);

Direction: more views, SIMD-aware algorithm execution, and tighter ranges/std::execution integration are the active pipeline.