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

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@322019 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Marshall Clow
2018-01-08 19:18:00 +00:00
parent 4b1bc157d4
commit 334063336b
14 changed files with 1414 additions and 82 deletions

View File

@@ -641,6 +641,7 @@ template <class BidirectionalIterator, class Compare>
#include <cstring>
#include <utility> // needed to provide swap_ranges.
#include <memory>
#include <functional>
#include <iterator>
#include <cstddef>
@@ -1545,88 +1546,7 @@ is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
#endif
// search
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;
}
}
}
}
// __search is in <functional>
template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
inline _LIBCPP_INLINE_VISIBILITY
@@ -1652,6 +1572,14 @@ search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
return _VSTD::search(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
}
#if _LIBCPP_STD_VER > 14
template <class _ForwardIterator, class _Searcher>
_LIBCPP_INLINE_VISIBILITY
_ForwardIterator search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher &__s)
{ return __s(__f, __l).first; }
#endif
// search_n
template <class _BinaryPredicate, class _ForwardIterator, class _Size, class _Tp>