25 Algorithms library [algorithms]

25.5 Non-modifying sequence operations [alg.nonmodifying]

25.5.13 Search [alg.search]

template<class ForwardIterator1, class ForwardIterator2> constexpr ForwardIterator1 search(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, ForwardIterator2 last2); template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2> ForwardIterator1 search(ExecutionPolicy&& exec, ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, ForwardIterator2 last2); template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate> constexpr ForwardIterator1 search(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred); template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2, class BinaryPredicate> ForwardIterator1 search(ExecutionPolicy&& exec, ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
Returns: The first iterator i in the range [first1, last1 - (last2-first2)) such that for every non-negative integer n less than last2 - first2 the following corresponding conditions hold: *(i + n) == *(first2 + n), pred(*(i + n), *(first2 + n)) != false.
Returns first1 if [first2, last2) is empty, otherwise returns last1 if no such iterator is found.
Complexity: At most (last1 - first1) * (last2 - first2) applications of the corresponding predicate.
template<ForwardIterator I1, Sentinel<I1> S1, ForwardIterator I2, Sentinel<I2> S2, class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity> requires IndirectlyComparable<I1, I2, Pred, Proj1, Proj2> constexpr subrange<I1> ranges::search(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {}); template<ForwardRange R1, ForwardRange R2, class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity> requires IndirectlyComparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2> constexpr safe_subrange_t<R1> ranges::search(R1&& r1, R2&& r2, Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
Returns:
  • {i, i + (last2 - first2)}, where i is the first iterator in the range [first1, last1 - (last2 - first2)) such that for every non-negative integer n less than last2 - first2 the condition
    bool(invoke(pred, invoke(proj1, *(i + n)), invoke(proj2, *(first2 + n))))
    
    is true:
  • Returns {last1, last1} if no such iterator exists.
Complexity: At most (last1 - first1) * (last2 - first2) applications of the corresponding predicate and projections.
template<class ForwardIterator, class Size, class T> constexpr ForwardIterator search_n(ForwardIterator first, ForwardIterator last, Size count, const T& value); template<class ExecutionPolicy, class ForwardIterator, class Size, class T> ForwardIterator search_n(ExecutionPolicy&& exec, ForwardIterator first, ForwardIterator last, Size count, const T& value); template<class ForwardIterator, class Size, class T, class BinaryPredicate> constexpr ForwardIterator search_n(ForwardIterator first, ForwardIterator last, Size count, const T& value, BinaryPredicate pred); template<class ExecutionPolicy, class ForwardIterator, class Size, class T, class BinaryPredicate> ForwardIterator search_n(ExecutionPolicy&& exec, ForwardIterator first, ForwardIterator last, Size count, const T& value, BinaryPredicate pred);
Requires: The type Size shall be convertible to integral type ([conv.integral], [class.conv]).
Returns: The first iterator i in the range [first, last-count) such that for every non-negative integer n less than count the following corresponding conditions hold: *(i + n) == value, pred(*(i + n),value) != false.
Returns last if no such iterator is found.
Complexity: At most last - first applications of the corresponding predicate.
template<ForwardIterator I, Sentinel<I> S, class T, class Pred = ranges::equal_to, class Proj = identity> requires IndirectlyComparable<I, const T*, Pred, Proj> constexpr subrange<I> ranges::search_n(I first, S last, iter_difference_t<I> count, const T& value, Pred pred = {}, Proj proj = {}); template<ForwardRange R, class T, class Pred = ranges::equal_to, class Proj = identity> requires IndirectlyComparable<iterator_t<R>, const T*, Pred, Proj> constexpr safe_subrange_t<R> ranges::search_n(R&& r, iter_difference_t<iterator_t<R>> count, const T& value, Pred pred = {}, Proj proj = {});
Returns: {i, i + count} where i is the first iterator in the range [first, last - count) such that for every non-negative integer n less than count, the following condition holds: invoke(pred, invoke(proj, *(i + n)), value).
Returns {last, last} if no such iterator is found.
Complexity: At most last - first applications of the corresponding predicate and projection.
template<class ForwardIterator, class Searcher> constexpr ForwardIterator search(ForwardIterator first, ForwardIterator last, const Searcher& searcher);
Effects: Equivalent to: return searcher(first, last).first;
Remarks: Searcher need not meet the Cpp17CopyConstructible requirements.