Add the C++17 extensions to std::search. Include the default searcher, but not the Boyer-Moore or Boyer-Moore-Horspool searcher (yet). BUT put the BM and BMH tests in place, marked to XFAIL. The other searchers will follow soon
llvm-svn: 322019
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: d835e59211883ff1f55d6e89a3e7a4f49eb17e30
diff --git a/include/functional b/include/functional
index 3e5215b..abdf451 100644
--- a/include/functional
+++ b/include/functional
@@ -2411,6 +2411,118 @@
// struct hash<T*> in <memory>
+template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
+pair<_ForwardIterator1, _ForwardIterator1>
+__search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+ _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
+ forward_iterator_tag, forward_iterator_tag)
+{
+ if (__first2 == __last2)
+ return make_pair(__first1, __first1); // Everything matches an empty sequence
+ while (true)
+ {
+ // Find first element in sequence 1 that matchs *__first2, with a mininum of loop checks
+ while (true)
+ {
+ if (__first1 == __last1) // return __last1 if no element matches *__first2
+ return make_pair(__last1, __last1);
+ if (__pred(*__first1, *__first2))
+ break;
+ ++__first1;
+ }
+ // *__first1 matches *__first2, now match elements after here
+ _ForwardIterator1 __m1 = __first1;
+ _ForwardIterator2 __m2 = __first2;
+ while (true)
+ {
+ if (++__m2 == __last2) // If pattern exhausted, __first1 is the answer (works for 1 element pattern)
+ return make_pair(__first1, __m1);
+ if (++__m1 == __last1) // Otherwise if source exhaused, pattern not found
+ return make_pair(__last1, __last1);
+ if (!__pred(*__m1, *__m2)) // if there is a mismatch, restart with a new __first1
+ {
+ ++__first1;
+ break;
+ } // else there is a match, check next elements
+ }
+ }
+}
+
+template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
+_LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_RandomAccessIterator1, _RandomAccessIterator1>
+__search(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
+ _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
+ random_access_iterator_tag, random_access_iterator_tag)
+{
+ typedef typename iterator_traits<_RandomAccessIterator1>::difference_type _D1;
+ typedef typename iterator_traits<_RandomAccessIterator2>::difference_type _D2;
+ // Take advantage of knowing source and pattern lengths. Stop short when source is smaller than pattern
+ const _D2 __len2 = __last2 - __first2;
+ if (__len2 == 0)
+ return make_pair(__first1, __first1);
+ const _D1 __len1 = __last1 - __first1;
+ if (__len1 < __len2)
+ return make_pair(__last1, __last1);
+ const _RandomAccessIterator1 __s = __last1 - (__len2 - 1); // Start of pattern match can't go beyond here
+
+ while (true)
+ {
+ while (true)
+ {
+ if (__first1 == __s)
+ return make_pair(__last1, __last1);
+ if (__pred(*__first1, *__first2))
+ break;
+ ++__first1;
+ }
+
+ _RandomAccessIterator1 __m1 = __first1;
+ _RandomAccessIterator2 __m2 = __first2;
+ while (true)
+ {
+ if (++__m2 == __last2)
+ return make_pair(__first1, __first1 + __len2);
+ ++__m1; // no need to check range on __m1 because __s guarantees we have enough source
+ if (!__pred(*__m1, *__m2))
+ {
+ ++__first1;
+ break;
+ }
+ }
+ }
+}
+
+#if _LIBCPP_STD_VER > 14
+
+// default searcher
+template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
+_LIBCPP_TYPE_VIS
+class default_searcher {
+public:
+ _LIBCPP_INLINE_VISIBILITY
+ default_searcher(_ForwardIterator __f, _ForwardIterator __l,
+ _BinaryPredicate __p = _BinaryPredicate())
+ : __first_(__f), __last_(__l), __pred_(__p) {}
+
+ template <typename _ForwardIterator2>
+ _LIBCPP_INLINE_VISIBILITY
+ pair<_ForwardIterator2, _ForwardIterator2>
+ operator () (_ForwardIterator2 __f, _ForwardIterator2 __l) const
+ {
+ return _VSTD::__search(__f, __l, __first_, __last_, __pred_,
+ typename _VSTD::iterator_traits<_ForwardIterator>::iterator_category(),
+ typename _VSTD::iterator_traits<_ForwardIterator2>::iterator_category());
+ }
+
+private:
+ _ForwardIterator __first_;
+ _ForwardIterator __last_;
+ _BinaryPredicate __pred_;
+ };
+
+#endif // _LIBCPP_STD_VER > 14
+
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP_FUNCTIONAL