Implement LWG#2353: std::next is over-constrained
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@252407 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/iterator b/include/iterator
index c06ef8f..8dd6bd5 100644
--- a/include/iterator
+++ b/include/iterator
@@ -513,12 +513,12 @@
return __distance(__first, __last, typename iterator_traits<_InputIter>::iterator_category());
}
-template <class _ForwardIter>
+template <class _InputIter>
inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIter
-next(_ForwardIter __x,
- typename iterator_traits<_ForwardIter>::difference_type __n = 1,
- typename enable_if<__is_forward_iterator<_ForwardIter>::value>::type* = 0)
+_InputIter
+next(_InputIter __x,
+ typename iterator_traits<_InputIter>::difference_type __n = 1,
+ typename enable_if<__is_input_iterator<_InputIter>::value>::type* = 0)
{
_VSTD::advance(__x, __n);
return __x;
diff --git a/test/std/iterators/iterator.primitives/iterator.operations/next.pass.cpp b/test/std/iterators/iterator.primitives/iterator.operations/next.pass.cpp
index f584110..0952588 100644
--- a/test/std/iterators/iterator.primitives/iterator.operations/next.pass.cpp
+++ b/test/std/iterators/iterator.primitives/iterator.operations/next.pass.cpp
@@ -12,6 +12,8 @@
// template <InputIterator Iter>
// Iter next(Iter x, Iter::difference_type n = 1);
+// LWG #2353 relaxed the requirement on next from ForwardIterator to InputIterator
+
#include <iterator>
#include <cassert>
@@ -34,11 +36,13 @@
int main()
{
const char* s = "1234567890";
+ test(input_iterator<const char*>(s), 10, input_iterator<const char*>(s+10));
test(forward_iterator<const char*>(s), 10, forward_iterator<const char*>(s+10));
test(bidirectional_iterator<const char*>(s), 10, bidirectional_iterator<const char*>(s+10));
test(random_access_iterator<const char*>(s), 10, random_access_iterator<const char*>(s+10));
test(s, 10, s+10);
+ test(input_iterator<const char*>(s), input_iterator<const char*>(s+1));
test(forward_iterator<const char*>(s), forward_iterator<const char*>(s+1));
test(bidirectional_iterator<const char*>(s), bidirectional_iterator<const char*>(s+1));
test(random_access_iterator<const char*>(s), random_access_iterator<const char*>(s+1));
diff --git a/www/cxx1z_status.html b/www/cxx1z_status.html
index 5617d87..afd9050 100644
--- a/www/cxx1z_status.html
+++ b/www/cxx1z_status.html
@@ -164,7 +164,7 @@
<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2259">2259</a></td><td>Issues in 17.6.5.5 rules for member functions</td><td>Kona</td><td>Complete</td></tr>
<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2273">2273</a></td><td><tt>regex_match</tt> ambiguity</td><td>Kona</td><td></td></tr>
<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2336">2336</a></td><td><tt>is_trivially_constructible/is_trivially_assignable</tt> traits are always false</td><td>Kona</td><td></td></tr>
- <tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2353">2353</a></td><td><tt>std::next</tt> is over-constrained</td><td>Kona</td><td></td></tr>
+ <tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2353">2353</a></td><td><tt>std::next</tt> is over-constrained</td><td>Kona</td><td>Complete</td></tr>
<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2367">2367</a></td><td><tt>pair</tt> and <tt>tuple</tt> are not correctly implemented for <tt>is_constructible</tt> with no args</td><td>Kona</td><td>Patch Ready</td></tr>
<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2380">2380</a></td><td>May <tt><cstdlib></tt> provide <tt>long ::abs(long)</tt> and <tt>long long ::abs(long long)</tt>?</td><td>Kona</td><td>Complete</td></tr>
<tr><td><a href="http://cplusplus.github.io/LWG/lwg-defects.html#2384">2384</a></td><td>Allocator's <tt>deallocate</tt> function needs better specification</td><td>Kona</td><td>Complete</td></tr>