Permutations
std::prev_permutation and std::next_permutation return the previous smaller or next bigger permutation of the newly ordered range. If a smaller or bigger permutation is not available, the algorithms return false. Both algorithms need bidirectional iterators. Per default the predefined sorting criterion std::less is used. If you use your sorting criterion, it has to obey the strict weak ordering. If not, the program is undefined.
Applies the previous permutation to the range:
bool prev_permutation(BiIt first, BiIt last)
bool prev_permutation(BiIt first, BiIt last, BiPred pre))
Applies the next permutation to the range:
bool next_permutation(BiIt first, BiIt last)
bool next_permutation(BiIt first, BiIt last, BiPred pre)
You can easily generate with both algorithms all permutations of the range.
// permutation.cpp
...
#include <algorithm>...
std::vector<int> myInts{1, 2, 3};
do{
for (auto i: myInts) std::cout <...