std::experi...es::find_end(3)

💅 NAME

okay so bestie, welcome to std::experi...es::find_end(3) — the manual page for the C++ Standard Library thing. The name is literally:

std::experimental::ranges::find_end — std::experimental::ranges::find_end

yes, both lines are the same, and no, that's not a typo, that's just how this page said it. We're keeping it. periodt.

✨ Synopsis

First things first: it's defined in header <experimental/ranges/algorithm>.

Here are the declarations, copied exactly because bestie we do not mess with code:

          Defined in header <experimental/ranges/algorithm>
          template< ForwardIterator I1, Sentinel<I1> S1, ForwardIterator I2,
          Sentinel<I2> S2,

                    class Proj = ranges::identity,
                    IndirectRelation<I2, projected<I1, Proj>> Pred =
       (1) (ranges TS)
          ranges::equal_to<> >
          I1 find_end( I1 first1, S1 last1, I2 first2, S2 last2,

                       Pred pred = Pred{}, Proj proj = Proj{} );
          template< ForwardRange R1, ForwardRange R2, class Proj =
          ranges::identity,

                    IndirectRelation<ranges::iterator_t<R2>,
                                     projected<ranges::iterator_t<R1>, Proj>>
       (2) (ranges TS)
          Pred = ranges::equal_to<> >
          ranges::safe_iterator_t<R1> find_end( Rng1&& rng1, Rng2&& rng2,

                                                Pred pred = Pred{}, Proj proj
          = Proj{} );

• (1) searches for the last occurrence of the sequence [first2, last2) in the range [first1, last1) (after projection with proj).
• (2) same as (1), but uses r1 as the first source range and r2 as the second source range, as if using ranges::begin(r1) as first1, ranges::end(r1) as last1, ranges::begin(r2) as first2, and ranges::end(r2) as last2.

Okay, real talk: notwithstanding the declarations depicted above, the actual number and order of template parameters for algorithm declarations is unspecified. Thus, if explicit template arguments are used when calling an algorithm, the program is probably non-portable. That's the warning, bestie — don't play yourself. 💀

🫶 Parameters

• first1, last1 — the range of elements to examine.
• r1 — the range of elements to examine.
• first2, last2 — the range of elements to search for.
• r2 — the range of elements to search for.
• pred — predicate to compare the elements.
• proj — projection to apply to the elements in the first range.

🎀 Return value

An iterator to the beginning of the last occurrence of the sequence [first2, last2) in range [first1, last1) (after projection with proj).

If [first2, last2) is empty or if no such sequence is found, you get an iterator that compares equal to last1. That's the vibe.

🦋 Complexity

At most S * (N - S + 1) applications of the predicate and projection, where S = last2 - first2 and N = last1 - first1.

🌸 Notes

The projection is only applied to the range [first1, last1). periodt.

🧚 Possible implementation

Here's the possible implementation, exactly as the page gives it:

          template<ForwardIterator I1, Sentinel<I1> S1, ForwardIterator I2,
       Sentinel<I2> S2,
                   class Proj = ranges::identity,
                   IndirectRelation<I2, projected<I1, Proj>> Pred =
       ranges::equal_to<>>
          I1 find_end(I1 first1, S1 last1, I2 first2, S2 last2,
                      Pred pred = Pred{}, Proj proj = Proj{})
          {
              I1 result = ranges::next(first1, last1);
              if (first2 == last2)
                  return result;
              while (true)
              {
                  I1 new_result = ranges::search(first1, last1, first2, last2,
       pred, proj);
                  if (new_result == last1)
                      break;
                  else
                  {
                      result = new_result;
                      first1 = result;
                      ++first1;
                  }
              }
              return result;
          }

🍓 Example

This section is incomplete Reason: no example

no example, bestie. We're not inventing one. 🙈

🌈 See also

• find_end — finds the last sequence of elements in a certain range (function template)
• search — searches for a range of elements (function template)
• includes — returns true if one set is a subset of another (function template)
• adjacent_find — finds the first two adjacent items that are equal (or satisfy a given predicate) (function template)
• find — finds the first element satisfying specific criteria (function template)
• find_if — (function template)
• find_if_not — (function template)
• find_first_of — searches for any one of a set of elements (function template)
• search_n — searches for a number consecutive copies of an element in a range (function template)

🏷️ Category

• * Todo no example

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💖 source/version/date check, bestie: http://cppreference.com, 2024.06.10, and the manual page is std::experi...es::find_end(3). mwah 💅