OpenE2K
/
gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

libstdc++: Implement remaining piece of LWG 3448 

Almost all of the proposed resolution for LWG 3448 is already
implemented; the only part left is to adjust the return type of
transform_view::sentinel::operator-.

libstdc++-v3/ChangeLog:

	PR libstdc++/95322
	* include/std/ranges (transform_view::sentinel::__distance_from):
	Give this a deduced return type.
	(transform_view::sentinel::operator-): Adjust the return type so
	that it's based on the constness of the iterator rather than
	that of the sentinel.
	* testsuite/std/ranges/adaptors/95322.cc: Refer to LWG 3488.
This commit is contained in:
Patrick Palka 2020-08-26 21:51:48 -04:00
parent 4be16d1c1c
commit 3ae0cd94ab
2 changed files with 10 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
libstdc++-v3/include/std/ranges
View File

@ -1865,7 +1865,7 @@ namespace views
using _Base = __detail::__maybe_const_t<_Const, _Vp>;
template<bool _Const2>
constexpr range_difference_t<_Base>
constexpr auto
__distance_from(const _Iterator<_Const2>& __i) const
{ return _M_end - __i._M_current; }
@ -1902,17 +1902,17 @@ namespace views
operator==(const _Iterator<_Const2>& __x, const _Sentinel& __y)
{ return __y.__equal(__x); }
template<bool _Const2>
requires sized_sentinel_for<sentinel_t<_Base>,
iterator_t<__detail::__maybe_const_t<_Const2, _Vp>>>
friend constexpr range_difference_t<_Base>
template<bool _Const2,
typename _Base2 = __detail::__maybe_const_t<_Const2, _Vp>>
requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
friend constexpr range_difference_t<_Base2>
operator-(const _Iterator<_Const2>& __x, const _Sentinel& __y)
{ return -__y.__distance_from(__x); }
template<bool _Const2>
requires sized_sentinel_for<sentinel_t<_Base>,
iterator_t<__detail::__maybe_const_t<_Const2, _Vp>>>
friend constexpr range_difference_t<_Base>
template<bool _Const2,
typename _Base2 = __detail::__maybe_const_t<_Const2, _Vp>>
requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base2>>
friend constexpr range_difference_t<_Base2>
operator-(const _Sentinel& __y, const _Iterator<_Const2>& __x)
{ return __y.__distance_from(__x); }

2
libstdc++-v3/testsuite/std/ranges/adaptors/95322.cc
View File

@ -26,7 +26,7 @@ using __gnu_test::test_forward_range;
void
test01()
{
// PR libstdc++/95322
// PR libstdc++/95322 and LWG 3488
int a[2]{1, 2};
test_forward_range<int> v{a};
auto view1 = v | std::views::take(2);