From 144dfc68d0c0f5b99a0cd0a14b211f82afed88c6 Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Mon, 2 Mar 2020 19:39:46 -0500 Subject: [PATCH] libstdc++: Move-only input iterator support in algorithms (LWG 3355) This adds support for move-only input iterators in the ranges::unitialized_* algorithms defined in , as per LWG 3355. The only changes needed are to add calls to std::move in the appropriate places and to use operator- instead of ranges::distance because the latter cannot be used with a move-only iterator that has a sized sentinel, as is the case here. (This issue with ranges::distance is LWG 3392.) libstdc++-v3/ChangeLog: LWG 3355 The memory algorithms should support move-only input iterators introduced by P1207 * include/bits/ranges_uninitialized.h (__uninitialized_copy_fn::operator()): Use std::move to avoid attempting to copy __ifirst, which could be a move-only input iterator. Use operator- instead of ranges::distance to compute distance from a sized sentinel. (__uninitialized_copy_n_fn::operator()): Likewise. (__uninitialized_move_fn::operator()): Likewise. (__uninitialized_move_n_fn::operator()): Likewise. (__uninitialized_destroy_fn::operator()): Use std::move to avoid attempting to copy __first. (__uninitialized_destroy_n_fn::operator()): Likewise. * testsuite/20_util/specialized_algorithms/destroy/constrained.cc: Augment test. * .../specialized_algorithms/uninitialized_copy/constrained.cc: Likewise. * .../specialized_algorithms/uninitialized_move/constrained.cc: Likewise. --- libstdc++-v3/ChangeLog | 20 +++++++++++ .../include/bits/ranges_uninitialized.h | 34 ++++++++++--------- .../destroy/constrained.cc | 15 ++++++++ .../uninitialized_copy/constrained.cc | 25 ++++++++++++++ .../uninitialized_move/constrained.cc | 25 ++++++++++++++ 5 files changed, 103 insertions(+), 16 deletions(-) diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index ca5f0d0f3f8..3e4e58c1a7c 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,5 +1,25 @@ 2020-03-04 Patrick Palka + LWG 3355 The memory algorithms should support move-only input iterators + introduced by P1207 + * include/bits/ranges_uninitialized.h + (__uninitialized_copy_fn::operator()): Use std::move to avoid attempting + to copy __ifirst, which could be a move-only input iterator. Use + operator- instead of ranges::distance to compute distance from a sized + sentinel. + (__uninitialized_copy_n_fn::operator()): Likewise. + (__uninitialized_move_fn::operator()): Likewise. + (__uninitialized_move_n_fn::operator()): Likewise. + (__uninitialized_destroy_fn::operator()): Use std::move to avoid + attempting to copy __first. + (__uninitialized_destroy_n_fn::operator()): Likewise. + * testsuite/20_util/specialized_algorithms/destroy/constrained.cc: + Augment test. + * .../specialized_algorithms/uninitialized_copy/constrained.cc: + Likewise. + * .../specialized_algorithms/uninitialized_move/constrained.cc: + Likewise. + * testsuite/util/testsuite_iterators.h (test_range::get_iterator): Make protected instead of private. (test_sized_range_sized_sent): New. diff --git a/libstdc++-v3/include/bits/ranges_uninitialized.h b/libstdc++-v3/include/bits/ranges_uninitialized.h index f97a07a9b4a..d758078fc03 100644 --- a/libstdc++-v3/include/bits/ranges_uninitialized.h +++ b/libstdc++-v3/include/bits/ranges_uninitialized.h @@ -272,9 +272,10 @@ namespace ranges && is_nothrow_assignable_v<_OutType&, iter_reference_t<_Iter>>) { - auto __d1 = ranges::distance(__ifirst, __ilast); - auto __d2 = ranges::distance(__ofirst, __olast); - return ranges::copy_n(__ifirst, std::min(__d1, __d2), __ofirst); + auto __d1 = __ilast - __ifirst; + auto __d2 = __olast - __ofirst; + return ranges::copy_n(std::move(__ifirst), std::min(__d1, __d2), + __ofirst); } else { @@ -283,7 +284,7 @@ namespace ranges ++__ofirst, (void)++__ifirst) ::new (__detail::__voidify(*__ofirst)) _OutType(*__ifirst); __guard.release(); - return {__ifirst, __ofirst}; + return {std::move(__ifirst), __ofirst}; } } @@ -319,8 +320,9 @@ namespace ranges && is_nothrow_assignable_v<_OutType&, iter_reference_t<_Iter>>) { - auto __d = ranges::distance(__ofirst, __olast); - return ranges::copy_n(__ifirst, std::min(__n, __d), __ofirst); + auto __d = __olast - __ofirst; + return ranges::copy_n(std::move(__ifirst), std::min(__n, __d), + __ofirst); } else { @@ -329,7 +331,7 @@ namespace ranges ++__ofirst, (void)++__ifirst, (void)--__n) ::new (__detail::__voidify(*__ofirst)) _OutType(*__ifirst); __guard.release(); - return {__ifirst, __ofirst}; + return {std::move(__ifirst), __ofirst}; } } }; @@ -357,10 +359,10 @@ namespace ranges && is_nothrow_assignable_v<_OutType&, iter_rvalue_reference_t<_Iter>>) { - auto __d1 = ranges::distance(__ifirst, __ilast); - auto __d2 = ranges::distance(__ofirst, __olast); + auto __d1 = __ilast - __ifirst; + auto __d2 = __olast - __ofirst; auto [__in, __out] - = ranges::copy_n(std::make_move_iterator(__ifirst), + = ranges::copy_n(std::make_move_iterator(std::move(__ifirst)), std::min(__d1, __d2), __ofirst); return {std::move(__in).base(), __out}; } @@ -372,7 +374,7 @@ namespace ranges ::new (__detail::__voidify(*__ofirst)) _OutType(ranges::iter_move(__ifirst)); __guard.release(); - return {__ifirst, __ofirst}; + return {std::move(__ifirst), __ofirst}; } } @@ -409,9 +411,9 @@ namespace ranges && is_nothrow_assignable_v<_OutType&, iter_rvalue_reference_t<_Iter>>) { - auto __d = ranges::distance(__ofirst, __olast); + auto __d = __olast - __ofirst; auto [__in, __out] - = ranges::copy_n(std::make_move_iterator(__ifirst), + = ranges::copy_n(std::make_move_iterator(std::move(__ifirst)), std::min(__n, __d), __ofirst); return {std::move(__in).base(), __out}; } @@ -423,7 +425,7 @@ namespace ranges ::new (__detail::__voidify(*__ofirst)) _OutType(ranges::iter_move(__ifirst)); __guard.release(); - return {__ifirst, __ofirst}; + return {std::move(__ifirst), __ofirst}; } } }; @@ -524,7 +526,7 @@ namespace ranges __destroy_fn::operator()(_Iter __first, _Sent __last) const noexcept { if constexpr (is_trivially_destructible_v>) - return ranges::next(__first, __last); + return ranges::next(std::move(__first), __last); else { for (; __first != __last; ++__first) @@ -549,7 +551,7 @@ namespace ranges operator()(_Iter __first, iter_difference_t<_Iter> __n) const noexcept { if constexpr (is_trivially_destructible_v>) - return ranges::next(__first, __n); + return ranges::next(std::move(__first), __n); else { for (; __n > 0; ++__first, (void)--__n) diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/destroy/constrained.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/destroy/constrained.cc index c04049de0b5..89085d381ed 100644 --- a/libstdc++-v3/testsuite/20_util/specialized_algorithms/destroy/constrained.cc +++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/destroy/constrained.cc @@ -29,6 +29,9 @@ #include #include +using __gnu_test::test_range; +using __gnu_test::input_iterator_wrapper_nocopy; + namespace ranges = std::ranges; struct X @@ -69,6 +72,18 @@ test01() } } +void +test02() +{ + // LWG 3355 + { + int x[3] = {0}; + test_range rx(x); + ranges::destroy(rx); + ranges::destroy_n(rx.begin(), 3); + } +} + int main() { diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/constrained.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/constrained.cc index c1a50c45df9..ac5d74558d2 100644 --- a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/constrained.cc +++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_copy/constrained.cc @@ -31,6 +31,9 @@ using __gnu_test::test_input_range; using __gnu_test::test_forward_range; +using __gnu_test::test_range; +using __gnu_test::test_sized_range_sized_sent; +using __gnu_test::input_iterator_wrapper_nocopy; namespace ranges = std::ranges; @@ -150,6 +153,28 @@ test02() } } +void +test03() +{ + // LWG 3355 + { + int x[3] = {0}; + int y[3]; + test_sized_range_sized_sent rx(x); + ranges::uninitialized_copy(rx, y); + ranges::uninitialized_copy_n(rx.begin(), 3, y, y+3); + } + + { + int x[3] = {0}; + int y[3]; + test_range rx(x); + test_forward_range ry(y); + ranges::uninitialized_copy(rx, y); + ranges::uninitialized_copy_n(rx.begin(), 3, ry.begin(), ry.end()); + } +} + int main() { diff --git a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc index a7d6fd39b38..6b3544edc55 100644 --- a/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc +++ b/libstdc++-v3/testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc @@ -31,6 +31,9 @@ using __gnu_test::test_input_range; using __gnu_test::test_forward_range; +using __gnu_test::test_range; +using __gnu_test::test_sized_range_sized_sent; +using __gnu_test::input_iterator_wrapper_nocopy; namespace ranges = std::ranges; @@ -160,6 +163,28 @@ test02() } } +void +test03() +{ + // LWG 3355 + { + int x[3] = {0}; + int y[3]; + test_sized_range_sized_sent rx(x); + ranges::uninitialized_move(rx, y); + ranges::uninitialized_move_n(rx.begin(), 3, y, y+3); + } + + { + int x[3] = {0}; + int y[3]; + test_range rx(x); + test_forward_range ry(y); + ranges::uninitialized_move(rx, y); + ranges::uninitialized_move_n(rx.begin(), 3, ry.begin(), ry.end()); + } +} + int main() { -- 2.30.2