static I1 sized_impl()

in include/range/v3/algorithm/search.hpp [56:89]

• 32 lines of code
• 8 McCabe index (conditional complexity)

            static I1 sized_impl(I1 const begin1_, S1 end1, D1 const d1_, I2 begin2, S2 end2, D2 d2,
                C &pred, P1 &proj1, P2 &proj2)
            {
                D1 d1 = d1_;
                auto begin1 = uncounted(begin1_);
                while(true)
                {
                    // Find begin element in sequence 1 that matches *begin2, with a mininum of loop checks
                    while(true)
                    {
                        if(d1 < d2)  // return the end if we've run out of room
                            return ranges::next(recounted(begin1_, std::move(begin1), d1_ - d1), std::move(end1));
                        if(pred(proj1(*begin1), proj2(*begin2)))
                            break;
                        ++begin1;
                        --d1;
                    }
                    // *begin1 matches *begin2, now match elements after here
                    auto m1 = begin1;
                    I2 m2 = begin2;
                    while(true)
                    {
                        if(++m2 == end2)  // If pattern exhausted, begin1 is the answer (works for 1 element pattern)
                            return recounted(begin1_, std::move(begin1), d1_ - d1);
                        ++m1;  // No need to check, we know we have room to match successfully
                        if(!pred(proj1(*m1), proj2(*m2)))  // if there is a mismatch, restart with a new begin1
                        {
                            ++begin1;
                            --d1;
                            break;
                        }  // else there is a match, check next elements
                    }
                }
            }