2020-03-27 Jonathan Wakely <jwakely@redhat.com>
+ * include/bits/iterator_concepts.h (__detail::__decay_copy)
+ (__detail::__member_begin, __detail::__adl_begin): Move here from
+ <bits/range_access.h>.
+ (__detail::__ranges_begin, __detail::__range_iter_t): Define.
+ * bits/range_access.h (__cust_access::__decay_copy)
+ (__cust_access::__member_begin, __cust_access::__adl_begin): Move to
+ <bits/iterator_concepts.h>.
+ (ranges::iterator_t): Use __detail::__range_iter_t.
+ * include/bits/stl_iterator.h (back_insert_iterator): Simplify
+ conditional compilation. Add _GLIBCXX20_CONSTEXPR to all members.
+ (front_insert_iterator): Likewise.
+ (insert_iterator): Implement changes from P0896R4 for C++20.
+ * testsuite/24_iterators/back_insert_iterator/constexpr.cc: New test.
+ * testsuite/24_iterators/front_insert_iterator/constexpr.cc: New test.
+ * testsuite/24_iterators/headers/iterator/synopsis_c++17.cc: Adjust
+ for inclusion in synopsis_c++20.cc which expects different signatures
+ for some function templates.
+ * testsuite/24_iterators/insert_iterator/constexpr.cc: New test.
+
* include/std/type_traits (__is_array_convertible): Move definition
to immediately after is_convertible.
struct default_sentinel_t { };
inline constexpr default_sentinel_t default_sentinel{};
+ namespace __detail
+ {
+ template<typename _Tp>
+ constexpr decay_t<_Tp>
+ __decay_copy(_Tp&& __t)
+ noexcept(is_nothrow_convertible_v<_Tp, decay_t<_Tp>>)
+ { return std::forward<_Tp>(__t); }
+
+ template<typename _Tp>
+ concept __member_begin = requires(_Tp& __t)
+ {
+ { __detail::__decay_copy(__t.begin()) } -> input_or_output_iterator;
+ };
+
+ void begin(auto&) = delete;
+ void begin(const auto&) = delete;
+
+ template<typename _Tp>
+ concept __adl_begin = __class_or_enum<remove_reference_t<_Tp>>
+ && requires(_Tp& __t)
+ {
+ { __detail::__decay_copy(begin(__t)) } -> input_or_output_iterator;
+ };
+
+ // Simplified version of std::ranges::begin that only supports lvalues,
+ // for use by __range_iter_t below.
+ template<typename _Tp>
+ requires is_array_v<_Tp> || __member_begin<_Tp&> || __adl_begin<_Tp&>
+ auto
+ __ranges_begin(_Tp& __t)
+ {
+ if constexpr (is_array_v<_Tp>)
+ {
+ static_assert(sizeof(remove_all_extents_t<_Tp>) != 0,
+ "not array of incomplete type");
+ return __t + 0;
+ }
+ else if constexpr (__member_begin<_Tp&>)
+ return __t.begin();
+ else
+ return begin(__t);
+ }
+
+ // Implementation of std::ranges::iterator_t, without using ranges::begin.
+ template<typename _Tp>
+ using __range_iter_t
+ = decltype(__detail::__ranges_begin(std::declval<_Tp&>()));
+
+ } // namespace __detail
+
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif // C++20 library concepts
{
using std::ranges::__detail::__maybe_borrowed_range;
using std::__detail::__class_or_enum;
-
- template<typename _Tp>
- constexpr decay_t<_Tp>
- __decay_copy(_Tp&& __t)
- noexcept(is_nothrow_convertible_v<_Tp, decay_t<_Tp>>)
- { return std::forward<_Tp>(__t); }
-
- template<typename _Tp>
- concept __member_begin = requires(_Tp& __t)
- {
- { __decay_copy(__t.begin()) } -> input_or_output_iterator;
- };
-
- void begin(auto&) = delete;
- void begin(const auto&) = delete;
-
- template<typename _Tp>
- concept __adl_begin = __class_or_enum<remove_reference_t<_Tp>>
- && requires(_Tp& __t)
- {
- { __decay_copy(begin(__t)) } -> input_or_output_iterator;
- };
+ using std::__detail::__decay_copy;
+ using std::__detail::__member_begin;
+ using std::__detail::__adl_begin;
struct _Begin
{
= range<_Tp> && __detail::__maybe_borrowed_range<_Tp>;
template<typename _Tp>
- using iterator_t = decltype(ranges::begin(std::declval<_Tp&>()));
+ using iterator_t = std::__detail::__range_iter_t<_Tp>;
template<range _Range>
using sentinel_t = decltype(ranges::end(std::declval<_Range&>()));
#if __cplusplus > 201703L
# include <compare>
# include <new>
+# include <bits/iterator_concepts.h>
#endif
namespace std _GLIBCXX_VISIBILITY(default)
: public iterator<output_iterator_tag, void, void, void, void>
{
protected:
-#if __cplusplus <= 201703L
_Container* container;
-#else
- _Container* container = nullptr;
-#endif
public:
/// A nested typedef for the type of whatever container you used.
typedef _Container container_type;
#if __cplusplus > 201703L
using difference_type = ptrdiff_t;
-#endif
-#if __cplusplus > 201703L
- constexpr back_insert_iterator() noexcept = default;
+ constexpr back_insert_iterator() noexcept : container(nullptr) { }
#endif
/// The only way to create this %iterator is with a container.
- explicit
+ explicit _GLIBCXX20_CONSTEXPR
back_insert_iterator(_Container& __x)
: container(std::__addressof(__x)) { }
return *this;
}
#else
+ _GLIBCXX20_CONSTEXPR
back_insert_iterator&
operator=(const typename _Container::value_type& __value)
{
return *this;
}
+ _GLIBCXX20_CONSTEXPR
back_insert_iterator&
operator=(typename _Container::value_type&& __value)
{
#endif
/// Simply returns *this.
+ _GLIBCXX20_CONSTEXPR
back_insert_iterator&
operator*()
{ return *this; }
/// Simply returns *this. (This %iterator does not @a move.)
+ _GLIBCXX20_CONSTEXPR
back_insert_iterator&
operator++()
{ return *this; }
/// Simply returns *this. (This %iterator does not @a move.)
+ _GLIBCXX20_CONSTEXPR
back_insert_iterator
operator++(int)
{ return *this; }
* types for you.
*/
template<typename _Container>
+ _GLIBCXX20_CONSTEXPR
inline back_insert_iterator<_Container>
back_inserter(_Container& __x)
{ return back_insert_iterator<_Container>(__x); }
: public iterator<output_iterator_tag, void, void, void, void>
{
protected:
-#if __cplusplus <= 201703L
_Container* container;
-#else
- _Container* container = nullptr;
-#endif
public:
/// A nested typedef for the type of whatever container you used.
typedef _Container container_type;
#if __cplusplus > 201703L
using difference_type = ptrdiff_t;
-#endif
-#if __cplusplus > 201703L
- constexpr front_insert_iterator() noexcept = default;
+ constexpr front_insert_iterator() noexcept : container(nullptr) { }
#endif
/// The only way to create this %iterator is with a container.
- explicit front_insert_iterator(_Container& __x)
+ explicit _GLIBCXX20_CONSTEXPR
+ front_insert_iterator(_Container& __x)
: container(std::__addressof(__x)) { }
/**
return *this;
}
#else
+ _GLIBCXX20_CONSTEXPR
front_insert_iterator&
operator=(const typename _Container::value_type& __value)
{
return *this;
}
+ _GLIBCXX20_CONSTEXPR
front_insert_iterator&
operator=(typename _Container::value_type&& __value)
{
#endif
/// Simply returns *this.
+ _GLIBCXX20_CONSTEXPR
front_insert_iterator&
operator*()
{ return *this; }
/// Simply returns *this. (This %iterator does not @a move.)
+ _GLIBCXX20_CONSTEXPR
front_insert_iterator&
operator++()
{ return *this; }
/// Simply returns *this. (This %iterator does not @a move.)
+ _GLIBCXX20_CONSTEXPR
front_insert_iterator
operator++(int)
{ return *this; }
* types for you.
*/
template<typename _Container>
+ _GLIBCXX20_CONSTEXPR
inline front_insert_iterator<_Container>
front_inserter(_Container& __x)
{ return front_insert_iterator<_Container>(__x); }
class insert_iterator
: public iterator<output_iterator_tag, void, void, void, void>
{
+#if __cplusplus > 201703L && defined __cpp_lib_concepts
+ using _Iter = std::__detail::__range_iter_t<_Container>;
+
+ protected:
+ _Container* container = nullptr;
+ _Iter iter = _Iter();
+#else
+ typedef typename _Container::iterator _Iter;
+
protected:
_Container* container;
- typename _Container::iterator iter;
+ _Iter iter;
+#endif
public:
/// A nested typedef for the type of whatever container you used.
typedef _Container container_type;
+#if __cplusplus > 201703L && defined __cpp_lib_concepts
+ using difference_type = ptrdiff_t;
+
+ insert_iterator() = default;
+#endif
+
/**
* The only way to create this %iterator is with a container and an
* initial position (a normal %iterator into the container).
*/
- insert_iterator(_Container& __x, typename _Container::iterator __i)
+ _GLIBCXX20_CONSTEXPR
+ insert_iterator(_Container& __x, _Iter __i)
: container(std::__addressof(__x)), iter(__i) {}
/**
return *this;
}
#else
+ _GLIBCXX20_CONSTEXPR
insert_iterator&
operator=(const typename _Container::value_type& __value)
{
return *this;
}
+ _GLIBCXX20_CONSTEXPR
insert_iterator&
operator=(typename _Container::value_type&& __value)
{
#endif
/// Simply returns *this.
+ _GLIBCXX20_CONSTEXPR
insert_iterator&
operator*()
{ return *this; }
/// Simply returns *this. (This %iterator does not @a move.)
+ _GLIBCXX20_CONSTEXPR
insert_iterator&
operator++()
{ return *this; }
/// Simply returns *this. (This %iterator does not @a move.)
+ _GLIBCXX20_CONSTEXPR
insert_iterator&
operator++(int)
{ return *this; }
* template parameter deduction, making the compiler match the correct
* types for you.
*/
+#if __cplusplus > 201703L && defined __cpp_lib_concepts
+ template<typename _Container>
+ constexpr insert_iterator<_Container>
+ inserter(_Container& __x, std::__detail::__range_iter_t<_Container> __i)
+ { return insert_iterator<_Container>(__x, __i); }
+#else
template<typename _Container, typename _Iterator>
inline insert_iterator<_Container>
inserter(_Container& __x, _Iterator __i)
return insert_iterator<_Container>(__x,
typename _Container::iterator(__i));
}
+#endif
// @} group iterators
--- /dev/null
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <iterator>
+
+struct container
+{
+ using value_type = int;
+
+ constexpr int* begin() { return std::begin(data); }
+ constexpr int* end() { return next; }
+
+ constexpr void push_back(int val)
+ {
+ if (next == std::end(data))
+ throw val;
+ *next++ = val;
+ }
+
+ int data[3];
+ int* next = std::begin(data);
+};
+
+constexpr bool
+test01()
+{
+ container c;
+ std::back_insert_iterator<container> iter;
+ iter = std::back_inserter(c);
+ *iter++ = 1;
+ int i = 2;
+ *iter = i;
+ *++iter = 3;
+ return c.data[0] == 1 && c.data[1] == 2 && c.data[2] == 3;
+}
+
+static_assert( test01() );
--- /dev/null
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <iterator>
+
+struct container
+{
+ using value_type = int;
+
+ constexpr int* begin() { return next; }
+ constexpr int* end() { return std::end(data); }
+
+ constexpr void push_front(int val)
+ {
+ if (next == std::begin(data))
+ throw val;
+ *--next = val;
+ }
+
+ int data[3];
+ int* next = std::end(data);
+};
+
+constexpr bool
+test01()
+{
+ container c;
+ std::front_insert_iterator<container> iter;
+ iter = std::front_inserter(c);
+ *iter++ = 1;
+ int i = 2;
+ *iter = i;
+ *++iter = 3;
+ return c.data[0] == 3 && c.data[1] == 2 && c.data[2] == 1;
+}
+
+static_assert( test01() );
// C++17 24.5, iterator adaptors:
template <class Iterator> class reverse_iterator;
+#if __cplusplus == 201703L
+ // These operators are constrained in C++20 mode and so don't match
+ // these signatures.
+
template <class Iterator1, class Iterator2>
constexpr
bool operator==(const reverse_iterator<Iterator1>& x,
constexpr
bool operator<=(const reverse_iterator<Iterator1>& x,
const reverse_iterator<Iterator2>& y);
+#endif // C++17
template <class Iterator1, class Iterator2>
constexpr auto
template <class Container> class back_insert_iterator;
template <class Container>
+#if __cplusplus > 201703L
+ constexpr
+#endif
back_insert_iterator<Container> back_inserter(Container& x);
template <class Container> class front_insert_iterator;
template <class Container>
+#if __cplusplus > 201703L
+ constexpr
+#endif
front_insert_iterator<Container> front_inserter(Container& x);
template <class Container> class insert_iterator;
+#if __cplusplus == 201703L
+ // This function template is defined differently in C++20 mode and so
+ // doesn't match this signature.
template <class Container, class Iterator>
insert_iterator<Container> inserter(Container& x, Iterator i);
+ // These operators are constrained in C++20 mode and so don't match
+ // these signatures.
+
template <class Iterator> class move_iterator;
template <class Iterator1, class Iterator2>
constexpr
bool operator>=(const move_iterator<Iterator1>& x,
const move_iterator<Iterator2>& y);
+#endif // C++17
template <class Iterator1, class Iterator2>
constexpr
--- /dev/null
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <iterator>
+
+struct container
+{
+ using value_type = int;
+
+ constexpr int* begin() { return std::begin(data); }
+ constexpr int* end() { return last; }
+
+ constexpr int* insert(int* pos, int val)
+ {
+ if (last == std::end(data))
+ throw val;
+ for (int* i = last++; i != pos; --i)
+ i[1] = i[0];
+ *pos = val;
+ return pos;
+ }
+
+ int data[3];
+ int* last = std::begin(data);
+};
+
+constexpr bool
+test01()
+{
+ container c;
+ std::insert_iterator<container> iter;
+ iter = std::inserter(c, c.begin());
+ *iter++ = 1;
+ int i = 2;
+ *iter = i;
+ *++iter = 3;
+ return c.data[0] == 1 && c.data[1] == 2 && c.data[2] == 3;
+}
+
+static_assert( test01() );
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