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c++randomboostc++14

Is there a std::sample equivalent in boost?

I'm still using C++14. So std::sample is out of reach. Is there something equivalent in boost? I do not want to copy my std::multiset which isn't reorderable.

Solution

  • As far as I know, there is not such a thing in boost. But you may write a simple one, yourself:

    template<typename T>
std::vector<T> sample_items(const std::multiset<T> & ms, int samples) 
{
   std::vector<T> ret_value;
   std::random_device rd;
   std::mt19937 gen(rd());
   std::uniform_int_distribution<> dis(0, ms.size() - 1);

   for (int i = 0; i < samples; i++)
   {
      auto first = std::begin(ms);
      auto offset = dis(gen);

      std::advance(first, offset);
      ret_value.push_back(*first);
   }

   return ret_value;
}

    I do not want to copy my std::multiset which isn't reorderable.

    If still prefer not to send your multiset to a function, just change the function in order to work with iterators.