Function insertion_sort

src/fl/stl/algorithm.h:298–312

// Insertion sort implementation for small arrays
template <typename Iterator, typename Compare>
void insertion_sort(Iterator first, Iterator last, Compare comp) FL_NOEXCEPT {
    if (first == last) return;
    
    for (Iterator i = first + 1; i != last; ++i) {
        auto value = fl::move(*i);
        Iterator j = i;
        
        while (j != first && comp(value, *(j - 1))) {
            *j = fl::move(*(j - 1));
            --j;
        }
        
        *j = fl::move(value);
    }
}

// Median-of-three pivot selection
template <typename Iterator, typename Compare>