How to do all permutations in C++? [duplicate]

Sorry but I don't think I am using the correct terminology.

std::next_permutation(v.begin(), v.end());

I have tried this line of code but it gets the permutation with all the values, but I also need the permutation without some values, for example, if I have the vector with the values 1,2,3,4,5,6 I would also like to get 1,2,4,5 for example. Thanks for your help!