libstdc++: Implement C++20 changes to insert iterators
std::insert_iterator and std::inserter need to be adjusted for C++20, so that they use ranges::iterator_t. That alias template requires ranges::begin to be defined. Rather than moving the whole of ranges::begin (and related details like ranges::enable_borrowed_range) into <iterator>, this defines a new, simpler version of ranges::begin that is sufficient for ranges::iterator_t to be defined. This works because ranges::iterator_t uses an lvalue reference type, so the logic in ranges::begin for non-lvalue ranges (i.e. borrowed ranges) isn't needed. This also adds the missing constexpr specifiers to the other insert iterators. * 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.
This commit is contained in:
Jonathan Wakely
parent
0302a2de7f
commit
ae6076b5bc
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@ -1,5 +1,24 @@
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2020-03-27 Jonathan Wakely <jwakely@redhat.com>
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* include/bits/iterator_concepts.h (__detail::__decay_copy)
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(__detail::__member_begin, __detail::__adl_begin): Move here from
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<bits/range_access.h>.
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(__detail::__ranges_begin, __detail::__range_iter_t): Define.
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* bits/range_access.h (__cust_access::__decay_copy)
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(__cust_access::__member_begin, __cust_access::__adl_begin): Move to
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<bits/iterator_concepts.h>.
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(ranges::iterator_t): Use __detail::__range_iter_t.
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* include/bits/stl_iterator.h (back_insert_iterator): Simplify
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conditional compilation. Add _GLIBCXX20_CONSTEXPR to all members.
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(front_insert_iterator): Likewise.
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(insert_iterator): Implement changes from P0896R4 for C++20.
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* testsuite/24_iterators/back_insert_iterator/constexpr.cc: New test.
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* testsuite/24_iterators/front_insert_iterator/constexpr.cc: New test.
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* testsuite/24_iterators/headers/iterator/synopsis_c++17.cc: Adjust
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for inclusion in synopsis_c++20.cc which expects different signatures
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for some function templates.
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* testsuite/24_iterators/insert_iterator/constexpr.cc: New test.
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* include/std/type_traits (__is_array_convertible): Move definition
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to immediately after is_convertible.
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@ -835,6 +835,56 @@ namespace ranges
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struct default_sentinel_t { };
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inline constexpr default_sentinel_t default_sentinel{};
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namespace __detail
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{
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template<typename _Tp>
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constexpr decay_t<_Tp>
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__decay_copy(_Tp&& __t)
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noexcept(is_nothrow_convertible_v<_Tp, decay_t<_Tp>>)
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{ return std::forward<_Tp>(__t); }
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template<typename _Tp>
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concept __member_begin = requires(_Tp& __t)
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{
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{ __detail::__decay_copy(__t.begin()) } -> input_or_output_iterator;
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};
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void begin(auto&) = delete;
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void begin(const auto&) = delete;
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template<typename _Tp>
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concept __adl_begin = __class_or_enum<remove_reference_t<_Tp>>
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&& requires(_Tp& __t)
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{
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{ __detail::__decay_copy(begin(__t)) } -> input_or_output_iterator;
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};
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// Simplified version of std::ranges::begin that only supports lvalues,
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// for use by __range_iter_t below.
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template<typename _Tp>
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requires is_array_v<_Tp> || __member_begin<_Tp&> || __adl_begin<_Tp&>
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auto
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__ranges_begin(_Tp& __t)
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{
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if constexpr (is_array_v<_Tp>)
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{
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static_assert(sizeof(remove_all_extents_t<_Tp>) != 0,
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"not array of incomplete type");
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return __t + 0;
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}
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else if constexpr (__member_begin<_Tp&>)
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return __t.begin();
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else
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return begin(__t);
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}
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// Implementation of std::ranges::iterator_t, without using ranges::begin.
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template<typename _Tp>
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using __range_iter_t
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= decltype(__detail::__ranges_begin(std::declval<_Tp&>()));
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} // namespace __detail
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_GLIBCXX_END_NAMESPACE_VERSION
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} // namespace std
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#endif // C++20 library concepts
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@ -372,28 +372,9 @@ namespace ranges
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{
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using std::ranges::__detail::__maybe_borrowed_range;
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using std::__detail::__class_or_enum;
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template<typename _Tp>
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constexpr decay_t<_Tp>
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__decay_copy(_Tp&& __t)
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noexcept(is_nothrow_convertible_v<_Tp, decay_t<_Tp>>)
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{ return std::forward<_Tp>(__t); }
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template<typename _Tp>
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concept __member_begin = requires(_Tp& __t)
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{
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{ __decay_copy(__t.begin()) } -> input_or_output_iterator;
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};
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void begin(auto&) = delete;
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void begin(const auto&) = delete;
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template<typename _Tp>
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concept __adl_begin = __class_or_enum<remove_reference_t<_Tp>>
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&& requires(_Tp& __t)
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{
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{ __decay_copy(begin(__t)) } -> input_or_output_iterator;
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};
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using std::__detail::__decay_copy;
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using std::__detail::__member_begin;
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using std::__detail::__adl_begin;
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struct _Begin
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{
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@ -889,7 +870,7 @@ namespace ranges
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= range<_Tp> && __detail::__maybe_borrowed_range<_Tp>;
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template<typename _Tp>
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using iterator_t = decltype(ranges::begin(std::declval<_Tp&>()));
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using iterator_t = std::__detail::__range_iter_t<_Tp>;
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template<range _Range>
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using sentinel_t = decltype(ranges::end(std::declval<_Range&>()));
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@ -76,6 +76,7 @@
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#if __cplusplus > 201703L
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# include <compare>
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# include <new>
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# include <bits/iterator_concepts.h>
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#endif
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namespace std _GLIBCXX_VISIBILITY(default)
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@ -496,25 +497,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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: public iterator<output_iterator_tag, void, void, void, void>
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{
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protected:
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#if __cplusplus <= 201703L
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_Container* container;
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#else
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_Container* container = nullptr;
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#endif
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public:
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/// A nested typedef for the type of whatever container you used.
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typedef _Container container_type;
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#if __cplusplus > 201703L
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using difference_type = ptrdiff_t;
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#endif
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#if __cplusplus > 201703L
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constexpr back_insert_iterator() noexcept = default;
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constexpr back_insert_iterator() noexcept : container(nullptr) { }
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#endif
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/// The only way to create this %iterator is with a container.
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explicit
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explicit _GLIBCXX20_CONSTEXPR
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back_insert_iterator(_Container& __x)
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: container(std::__addressof(__x)) { }
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@ -537,6 +532,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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return *this;
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}
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#else
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_GLIBCXX20_CONSTEXPR
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back_insert_iterator&
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operator=(const typename _Container::value_type& __value)
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{
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@ -544,6 +540,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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return *this;
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}
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_GLIBCXX20_CONSTEXPR
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back_insert_iterator&
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operator=(typename _Container::value_type&& __value)
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{
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@ -553,16 +550,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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#endif
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/// Simply returns *this.
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_GLIBCXX20_CONSTEXPR
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back_insert_iterator&
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operator*()
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{ return *this; }
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/// Simply returns *this. (This %iterator does not @a move.)
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_GLIBCXX20_CONSTEXPR
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back_insert_iterator&
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operator++()
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{ return *this; }
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/// Simply returns *this. (This %iterator does not @a move.)
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_GLIBCXX20_CONSTEXPR
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back_insert_iterator
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operator++(int)
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{ return *this; }
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@ -580,6 +580,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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* types for you.
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*/
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template<typename _Container>
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_GLIBCXX20_CONSTEXPR
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inline back_insert_iterator<_Container>
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back_inserter(_Container& __x)
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{ return back_insert_iterator<_Container>(__x); }
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@ -599,25 +600,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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: public iterator<output_iterator_tag, void, void, void, void>
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{
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protected:
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#if __cplusplus <= 201703L
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_Container* container;
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#else
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_Container* container = nullptr;
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#endif
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public:
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/// A nested typedef for the type of whatever container you used.
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typedef _Container container_type;
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#if __cplusplus > 201703L
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using difference_type = ptrdiff_t;
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#endif
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#if __cplusplus > 201703L
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constexpr front_insert_iterator() noexcept = default;
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constexpr front_insert_iterator() noexcept : container(nullptr) { }
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#endif
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/// The only way to create this %iterator is with a container.
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explicit front_insert_iterator(_Container& __x)
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explicit _GLIBCXX20_CONSTEXPR
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front_insert_iterator(_Container& __x)
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: container(std::__addressof(__x)) { }
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/**
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@ -639,6 +635,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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return *this;
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}
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#else
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_GLIBCXX20_CONSTEXPR
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front_insert_iterator&
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operator=(const typename _Container::value_type& __value)
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{
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@ -646,6 +643,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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return *this;
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}
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_GLIBCXX20_CONSTEXPR
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front_insert_iterator&
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operator=(typename _Container::value_type&& __value)
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{
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@ -655,16 +653,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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#endif
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/// Simply returns *this.
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_GLIBCXX20_CONSTEXPR
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front_insert_iterator&
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operator*()
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{ return *this; }
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/// Simply returns *this. (This %iterator does not @a move.)
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_GLIBCXX20_CONSTEXPR
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front_insert_iterator&
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operator++()
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{ return *this; }
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/// Simply returns *this. (This %iterator does not @a move.)
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_GLIBCXX20_CONSTEXPR
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front_insert_iterator
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operator++(int)
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{ return *this; }
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@ -682,6 +683,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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* types for you.
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*/
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template<typename _Container>
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_GLIBCXX20_CONSTEXPR
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inline front_insert_iterator<_Container>
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front_inserter(_Container& __x)
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{ return front_insert_iterator<_Container>(__x); }
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@ -704,19 +706,36 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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class insert_iterator
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: public iterator<output_iterator_tag, void, void, void, void>
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{
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#if __cplusplus > 201703L && defined __cpp_lib_concepts
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using _Iter = std::__detail::__range_iter_t<_Container>;
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protected:
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_Container* container = nullptr;
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_Iter iter = _Iter();
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#else
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typedef typename _Container::iterator _Iter;
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protected:
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_Container* container;
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typename _Container::iterator iter;
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_Iter iter;
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#endif
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public:
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/// A nested typedef for the type of whatever container you used.
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typedef _Container container_type;
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#if __cplusplus > 201703L && defined __cpp_lib_concepts
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using difference_type = ptrdiff_t;
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insert_iterator() = default;
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#endif
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/**
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* The only way to create this %iterator is with a container and an
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* initial position (a normal %iterator into the container).
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*/
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insert_iterator(_Container& __x, typename _Container::iterator __i)
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_GLIBCXX20_CONSTEXPR
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insert_iterator(_Container& __x, _Iter __i)
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: container(std::__addressof(__x)), iter(__i) {}
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/**
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@ -751,6 +770,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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return *this;
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}
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#else
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_GLIBCXX20_CONSTEXPR
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insert_iterator&
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operator=(const typename _Container::value_type& __value)
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{
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@ -759,6 +779,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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return *this;
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}
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_GLIBCXX20_CONSTEXPR
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insert_iterator&
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operator=(typename _Container::value_type&& __value)
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{
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@ -769,16 +790,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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#endif
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/// Simply returns *this.
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_GLIBCXX20_CONSTEXPR
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insert_iterator&
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operator*()
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{ return *this; }
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/// Simply returns *this. (This %iterator does not @a move.)
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_GLIBCXX20_CONSTEXPR
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insert_iterator&
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operator++()
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{ return *this; }
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/// Simply returns *this. (This %iterator does not @a move.)
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_GLIBCXX20_CONSTEXPR
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insert_iterator&
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operator++(int)
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{ return *this; }
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@ -796,6 +820,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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* template parameter deduction, making the compiler match the correct
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* types for you.
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*/
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#if __cplusplus > 201703L && defined __cpp_lib_concepts
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template<typename _Container>
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constexpr insert_iterator<_Container>
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inserter(_Container& __x, std::__detail::__range_iter_t<_Container> __i)
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{ return insert_iterator<_Container>(__x, __i); }
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#else
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template<typename _Container, typename _Iterator>
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inline insert_iterator<_Container>
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inserter(_Container& __x, _Iterator __i)
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@ -803,6 +833,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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return insert_iterator<_Container>(__x,
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typename _Container::iterator(__i));
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}
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#endif
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// @} group iterators
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@ -0,0 +1,54 @@
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// Copyright (C) 2020 Free Software Foundation, Inc.
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//
|
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// This file is part of the GNU ISO C++ Library. This library is free
|
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// 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)
|
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// 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
|
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// <http://www.gnu.org/licenses/>.
|
||||
|
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// { dg-options "-std=gnu++2a" }
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// { dg-do compile { target c++2a } }
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#include <iterator>
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struct container
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{
|
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using value_type = int;
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|
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constexpr int* begin() { return std::begin(data); }
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constexpr int* end() { return next; }
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constexpr void push_back(int val)
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{
|
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if (next == std::end(data))
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throw val;
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*next++ = val;
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}
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|
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int data[3];
|
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int* next = std::begin(data);
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};
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constexpr bool
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test01()
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{
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container c;
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std::back_insert_iterator<container> iter;
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iter = std::back_inserter(c);
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*iter++ = 1;
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int i = 2;
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*iter = i;
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*++iter = 3;
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return c.data[0] == 1 && c.data[1] == 2 && c.data[2] == 3;
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}
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|
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static_assert( test01() );
|
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|
|
@ -0,0 +1,54 @@
|
|||
// 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() );
|
||||
|
|
@ -45,6 +45,10 @@ namespace std {
|
|||
// 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,
|
||||
|
|
@ -74,6 +78,7 @@ namespace std {
|
|||
constexpr
|
||||
bool operator<=(const reverse_iterator<Iterator1>& x,
|
||||
const reverse_iterator<Iterator2>& y);
|
||||
#endif // C++17
|
||||
|
||||
template <class Iterator1, class Iterator2>
|
||||
constexpr auto
|
||||
|
|
@ -92,18 +97,30 @@ namespace std {
|
|||
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>
|
||||
|
|
@ -135,6 +152,7 @@ namespace std {
|
|||
constexpr
|
||||
bool operator>=(const move_iterator<Iterator1>& x,
|
||||
const move_iterator<Iterator2>& y);
|
||||
#endif // C++17
|
||||
|
||||
template <class Iterator1, class Iterator2>
|
||||
constexpr
|
||||
|
|
|
|||
|
|
@ -0,0 +1,57 @@
|
|||
// 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() );
|
||||
Loading…
Reference in New Issue