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c++scalacollections

C++ equivalent of scala's Seq.grouped?

I would like to use an idiomatic (std::algorithm or similar) version of Scala's .grouped in C++. This breaks a sequence into groups of size N where the last group may be smaller. Any ideas?

Reference: https://www.scala-lang.org/api/current/scala/collection/Seq.html#grouped(size:Int):Iterator%5BC%5D

I've successfully used a loop with std::min but I would like something built in. This is my solution for grouping into chunks of 7 (found here on SO in another answer):

std::vector<std::vector<uint64_t>> chunked;
std::vector<uint64_t> flat;

// group into chunks of 7
for (size_t i = 0; i < flat.size(); i += 7) {
    auto last = std::min(flat.size(), i + 7);
    std::vector<uint64_t> chunk =std::vector<uint64_t>(flat.begin() + i, flat.begin() + last);
    chunked.emplace_back(chunk);
}
Solution

  • std::ranges::views::chunk would do the job (but is only available "since" C++23).