Implement P0253R1: Fixing a design mistake in the searchers interface.
llvm-svn: 262928
diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
index 7dba11e..f439396 100644
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -1421,20 +1421,20 @@
// search
template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
-_ForwardIterator1
+pair<_ForwardIterator1, _ForwardIterator1>
__search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
_ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
forward_iterator_tag, forward_iterator_tag)
{
if (__first2 == __last2)
- return __first1; // Everything matches an empty sequence
+ 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 __last1;
+ return make_pair(__last1, __last1);
if (__pred(*__first1, *__first2))
break;
++__first1;
@@ -1445,9 +1445,9 @@
while (true)
{
if (++__m2 == __last2) // If pattern exhausted, __first1 is the answer (works for 1 element pattern)
- return __first1;
+ return make_pair(__first1, __m1);
if (++__m1 == __last1) // Otherwise if source exhaused, pattern not found
- return __last1;
+ return make_pair(__last1, __last1);
if (!__pred(*__m1, *__m2)) // if there is a mismatch, restart with a new __first1
{
++__first1;
@@ -1458,20 +1458,21 @@
}
template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator1
+_LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_RandomAccessIterator1, _RandomAccessIterator1>
__search(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
- _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
+ _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
random_access_iterator_tag, random_access_iterator_tag)
{
- typedef typename std::iterator_traits<_RandomAccessIterator1>::difference_type _D1;
- typedef typename std::iterator_traits<_RandomAccessIterator2>::difference_type _D2;
+ 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
- _D2 __len2 = __last2 - __first2;
+ const _D2 __len2 = __last2 - __first2;
if (__len2 == 0)
- return __first1;
- _D1 __len1 = __last1 - __first1;
+ return make_pair(__first1, __first1);
+ const _D1 __len1 = __last1 - __first1;
if (__len1 < __len2)
- return __last1;
+ return make_pair(__last1, __last1);
const _RandomAccessIterator1 __s = __last1 - (__len2 - 1); // Start of pattern match can't go beyond here
while (true)
{
@@ -1479,7 +1480,7 @@
while (true)
{
if (__first1 == __s)
- return __last1;
+ return make_pair(__last1, __last1);
if (__pred(*__first1, *__first2))
break;
++__first1;
@@ -1511,7 +1512,7 @@
if (__pred(*__first1, *__first2))
break;
case 0:
- return __last1;
+ return make_pair(__last1, __last1);
}
__phase2:
#endif // !_LIBCPP_UNROLL_LOOPS
@@ -1521,7 +1522,7 @@
while (true)
{
if (++__m2 == __last2)
- return __first1;
+ 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))
{
@@ -1561,7 +1562,7 @@
if (!__pred(*__m1, *__m2))
break;
case 0:
- return __first1;
+ return make_pair(__first1, __first1 + __len2);
}
__continue:
++__first1;
@@ -1577,8 +1578,9 @@
{
return _VSTD::__search<typename add_lvalue_reference<_BinaryPredicate>::type>
(__first1, __last1, __first2, __last2, __pred,
- typename std::iterator_traits<_ForwardIterator1>::iterator_category(),
- typename std::iterator_traits<_ForwardIterator2>::iterator_category());
+ typename iterator_traits<_ForwardIterator1>::iterator_category(),
+ typename iterator_traits<_ForwardIterator2>::iterator_category())
+ .first;
}
template <class _ForwardIterator1, class _ForwardIterator2>
@@ -1587,8 +1589,8 @@
search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
_ForwardIterator2 __first2, _ForwardIterator2 __last2)
{
- typedef typename std::iterator_traits<_ForwardIterator1>::value_type __v1;
- typedef typename std::iterator_traits<_ForwardIterator2>::value_type __v2;
+ typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
+ typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
return _VSTD::search(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
}
