Modern C++ Programming Cookbook

How to do it...

Use the following general algorithms for set operations:

• std::set_union() to compute the union of two ranges into a third range:

        std::set_union(v1.cbegin(), v1.cend(),                       v2.cbegin(), v2.cend(),                       std::back_inserter(v3));        // v3 = {1, 2, 3, 3, 4, 4, 5, 6, 8}

• std::merge() to merge the content of two ranges into a third one; this is similar to std::set_union() except that it copies the entire content of the input ranges into the output one, not just their union:

        std::merge(v1.cbegin(), v1.cend(),                   v2.cbegin(), v2.cend(),                   std::back_inserter(v3));        // v3 = {1, 2, 2, 3, 3, 3, 4, 4, 4, 5, 6, 8}

• std::set_intersection() to compute the intersection of the two ranges into a third range:

 std::set_intersection(v1.cbegin(), v1.cend(), ...