As an extension to what the standard requires, this also adds
conditional noexcept-specifiers to the std::to_array functions.
P0325R4 to_array from LFTS with updates
* include/experimental/array (to_array): Qualify call to __to_array.
* include/std/array (__cpp_lib_to_array, to_array): Define for C++20.
* include/std/version (__cpp_lib_to_array): Likewise.
* testsuite/23_containers/array/creation/1.cc: New test.
* testsuite/23_containers/array/creation/2.cc: New test.
* testsuite/23_containers/array/creation/3_neg.cc: New test.
* testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc:
Use zero for dg-error line number.
Another new C++20 feature. Tested x86_64-linux, committed to trunk.
commit e7545060fab47734c461ea6d0f85c12be14fbf9a
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Wed Aug 7 21:02:56 2019 +0100
P0325R4 to_array from LFTS with updates
As an extension to what the standard requires, this also adds
conditional noexcept-specifiers to the std::to_array functions.
P0325R4 to_array from LFTS with updates
* include/experimental/array (to_array): Qualify call to __to_array.
* include/std/array (__cpp_lib_to_array, to_array): Define for
C++20.
* include/std/version (__cpp_lib_to_array): Likewise.
* testsuite/23_containers/array/creation/1.cc: New test.
* testsuite/23_containers/array/creation/2.cc: New test.
* testsuite/23_containers/array/creation/3_neg.cc: New test.
*
testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc:
Use zero for dg-error line number.
diff --git a/libstdc++-v3/include/experimental/array
b/libstdc++-v3/include/experimental/array
index 5a35fd499d8..0064a0b3b3d 100644
--- a/libstdc++-v3/include/experimental/array
+++ b/libstdc++-v3/include/experimental/array
@@ -101,7 +101,7 @@ template <typename _Tp, size_t _Nm>
to_array(_Tp (&__a)[_Nm])
noexcept(is_nothrow_constructible<remove_cv_t<_Tp>, _Tp&>::value)
{
- return __to_array(__a, make_index_sequence<_Nm>{});
+ return experimental::__to_array(__a, make_index_sequence<_Nm>{});
}
// @} group make_array
diff --git a/libstdc++-v3/include/std/array b/libstdc++-v3/include/std/array
index 31eff9e8e1d..a380f523d44 100644
--- a/libstdc++-v3/include/std/array
+++ b/libstdc++-v3/include/std/array
@@ -88,7 +88,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
* Sets support random access iterators.
*
* @tparam Tp Type of element. Required to be a complete type.
- * @tparam N Number of elements.
+ * @tparam Nm Number of elements.
*/
template<typename _Tp, std::size_t _Nm>
struct array
@@ -343,6 +343,44 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
return std::move(_GLIBCXX_STD_C::get<_Int>(__arr));
}
+#if __cplusplus > 201703L
+#define __cpp_lib_to_array 201907L
+
+ template<bool _Move = false, typename _Tp, size_t... _Idx>
+ constexpr array<remove_cv_t<_Tp>, sizeof...(_Idx)>
+ __to_array(_Tp (&__a)[sizeof...(_Idx)], index_sequence<_Idx...>)
+ {
+ if constexpr (_Move)
+ return {{std::move(__a[_Idx])...}};
+ else
+ return {{__a[_Idx]...}};
+ }
+
+ template<typename _Tp, size_t _Nm>
+ constexpr array<remove_cv_t<_Tp>, _Nm>
+ to_array(_Tp (&__a)[_Nm])
+ noexcept(is_nothrow_constructible_v<_Tp, _Tp&>)
+ {
+ static_assert(!is_array_v<_Tp>);
+ static_assert(is_constructible_v<_Tp, _Tp&>);
+ if constexpr (is_constructible_v<_Tp, _Tp&>)
+ return _GLIBCXX_STD_C::__to_array(__a, make_index_sequence<_Nm>{});
+ __builtin_unreachable(); // FIXME: see PR c++/91388
+ }
+
+ template<typename _Tp, size_t _Nm>
+ constexpr array<remove_cv_t<_Tp>, _Nm>
+ to_array(_Tp (&&__a)[_Nm])
+ noexcept(is_nothrow_move_constructible_v<_Tp>)
+ {
+ static_assert(!is_array_v<_Tp>);
+ static_assert(is_move_constructible_v<_Tp>);
+ if constexpr (is_move_constructible_v<_Tp>)
+ return _GLIBCXX_STD_C::__to_array<1>(__a, make_index_sequence<_Nm>{});
+ __builtin_unreachable(); // FIXME: see PR c++/91388
+ }
+#endif // C++20
+
_GLIBCXX_END_NAMESPACE_CONTAINER
} // namespace std
diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version
index 9548725d1b7..5757568d639 100644
--- a/libstdc++-v3/include/std/version
+++ b/libstdc++-v3/include/std/version
@@ -153,6 +153,7 @@
#define __cpp_lib_atomic_ref 201806L
#define __cpp_lib_bind_front 201907L
#define __cpp_lib_bounded_array_traits 201902L
+#define __cpp_lib_constexpr_algorithms 201711L
#if __cpp_impl_destroying_delete
# define __cpp_lib_destroying_delete 201806L
#endif
@@ -164,7 +165,7 @@
#endif
#define __cpp_lib_list_remove_return_type 201806L
#define __cpp_lib_math_constants 201907L
-#define __cpp_lib_constexpr_algorithms 201711L
+#define __cpp_lib_to_array 201907L
#endif // C++2a
#endif // C++17
#endif // C++14
diff --git a/libstdc++-v3/testsuite/23_containers/array/creation/1.cc
b/libstdc++-v3/testsuite/23_containers/array/creation/1.cc
new file mode 100644
index 00000000000..6279d736353
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/array/creation/1.cc
@@ -0,0 +1,57 @@
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+// Copyright (C) 2019 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/>.
+
+#include <array>
+
+#ifndef __cpp_lib_to_array
+# error "Feature test macro for to_array is missing"
+#elif __cpp_lib_to_array < 201907L
+# error "Feature test macro for to_array has wrong value"
+#endif
+
+void test01()
+{
+ const char x[6]{};
+ std::array<char, 6> y = std::to_array(x);
+
+ constexpr char x2[] = "foo";
+ constexpr std::array<char, 4> y2 = std::to_array(x2);
+ static_assert( std::equal(y2.begin(), y2.end(), x2) );
+}
+
+void
+test02()
+{
+ struct MoveOnly
+ {
+ constexpr MoveOnly(int i = 0) : i(i) { }
+ constexpr MoveOnly(MoveOnly&& m) : i(m.i + 100) { }
+ int i;
+ };
+
+ struct X {
+ MoveOnly m[3];
+ };
+ X x;
+ std::array<MoveOnly, 3> y = std::to_array(std::move(x).m);
+
+ constexpr std::array<MoveOnly, 3> y2 = std::to_array(X{{1, 2, 3}}.m);
+ static_assert( y2[0].i == 101 && y2[1].i == 102 && y2[2].i == 103 );
+}
diff --git a/libstdc++-v3/testsuite/23_containers/array/creation/2.cc
b/libstdc++-v3/testsuite/23_containers/array/creation/2.cc
new file mode 100644
index 00000000000..725f95061b2
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/array/creation/2.cc
@@ -0,0 +1,27 @@
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+// Copyright (C) 2019 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/>.
+
+#include <version>
+
+#ifndef __cpp_lib_to_array
+# error "Feature test macro for to_array is missing in <version>"
+#elif __cpp_lib_to_array < 201907L
+# error "Feature test macro for to_array has wrong value in <version>"
+#endif
diff --git a/libstdc++-v3/testsuite/23_containers/array/creation/3_neg.cc
b/libstdc++-v3/testsuite/23_containers/array/creation/3_neg.cc
new file mode 100644
index 00000000000..72f389918e0
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/array/creation/3_neg.cc
@@ -0,0 +1,56 @@
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+// Copyright (C) 2019 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/>.
+
+#include <array>
+
+void
+test01()
+{
+ int two_dee[3][4];
+ std::to_array(two_dee); // { dg-error "here" }
+}
+
+void
+test02()
+{
+ struct X
+ {
+ int two_dee[3][4];
+ };
+ std::to_array(X{}.two_dee); // { dg-error "here" }
+}
+
+void
+test03()
+{
+ struct MoveOnly
+ {
+ MoveOnly() = default;
+ MoveOnly(MoveOnly&&) = default;
+ };
+
+ MoveOnly mo[2];
+ std::to_array(mo); // { dg-error "here" }
+
+ const MoveOnly cmo[3];
+ std::to_array(std::move(cmo)); // { dg-error "here" }
+}
+
+// { dg-prune-output "static assertion failed" }
diff --git
a/libstdc++-v3/testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc
b/libstdc++-v3/testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc
index 5de55fc3194..393f29de5a7 100644
---
a/libstdc++-v3/testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc
+++
b/libstdc++-v3/testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc
@@ -22,4 +22,4 @@
typedef std::tuple_element<1, std::array<int, 1>>::type type;
-// { dg-error "static assertion failed" "" { target *-*-* } 372 }
+// { dg-error "static assertion failed" "" { target *-*-* } 0 }
