[libcxx-commits] [libcxx] r372778 - [libc++] Implement LWG 3158
Louis Dionne via libcxx-commits
libcxx-commits at lists.llvm.org
Tue Sep 24 13:22:34 PDT 2019
Author: ldionne
Date: Tue Sep 24 13:22:34 2019
New Revision: 372778
URL: http://llvm.org/viewvc/llvm-project?rev=372778&view=rev
Log:
[libc++] Implement LWG 3158
Summary:
LWG 3158 marks the allocator_arg_t constructor of std::tuple as
conditionnally explicit based on whether the default constructors
of the tuple's members are explicitly default constructible.
Reviewers: EricWF, mclow.lists
Subscribers: christof, jkorous, dexonsmith, libcxx-commits
Tags: #libc
Differential Revision: https://reviews.llvm.org/D65232
Added:
libcxx/trunk/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/alloc.fail.cpp
Modified:
libcxx/trunk/include/tuple
libcxx/trunk/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/alloc.pass.cpp
libcxx/trunk/www/cxx2a_status.html
libcxx/trunk/www/upcoming_meeting.html
Modified: libcxx/trunk/include/tuple
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/tuple?rev=372778&r1=372777&r2=372778&view=diff
==============================================================================
--- libcxx/trunk/include/tuple (original)
+++ libcxx/trunk/include/tuple Tue Sep 24 13:22:34 2019
@@ -500,20 +500,22 @@ class _LIBCPP_TEMPLATE_VIS tuple
struct _CheckArgsConstructor<true, _Dummy>
{
template <class ..._Args>
- static constexpr bool __enable_implicit_default() {
+ struct __enable_implicit_default
// In C++03, there's no way to implement the resolution of LWG2510.
#ifdef _LIBCPP_CXX03_LANG
- return true;
+ : true_type
#else
- return __all<__is_implicitly_default_constructible<_Args>::value...>::value;
+ : __all<__is_implicitly_default_constructible<_Args>::value...>
#endif
- }
+ { };
template <class ..._Args>
- static constexpr bool __enable_explicit_default() {
- return __all<is_default_constructible<_Args>::value...>::value
- && !__enable_implicit_default<_Args...>();
- }
+ struct __enable_explicit_default
+ : integral_constant<bool,
+ __all<is_default_constructible<_Args>::value...>::value &&
+ !__enable_implicit_default<_Args...>::value
+ >
+ { };
template <class ..._Args>
static constexpr bool __enable_explicit() {
@@ -653,14 +655,14 @@ class _LIBCPP_TEMPLATE_VIS tuple
public:
template <bool _Dummy = true, _EnableIf<
- _CheckArgsConstructor<_Dummy>::template __enable_implicit_default<_Tp...>()
+ _CheckArgsConstructor<_Dummy>::template __enable_implicit_default<_Tp...>::value
, void*> = nullptr>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
tuple()
_NOEXCEPT_(__all<is_nothrow_default_constructible<_Tp>::value...>::value) {}
template <bool _Dummy = true, _EnableIf<
- _CheckArgsConstructor<_Dummy>::template __enable_explicit_default<_Tp...>()
+ _CheckArgsConstructor<_Dummy>::template __enable_explicit_default<_Tp...>::value
, void*> = nullptr>
explicit _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
tuple()
@@ -669,17 +671,31 @@ public:
tuple(tuple const&) = default;
tuple(tuple&&) = default;
- template <class _AllocArgT, class _Alloc, bool _Dummy = true, class = _EnableIf<
+ template <class _AllocArgT, class _Alloc, bool _Dummy = true, _EnableIf<
_And<
_IsSame<allocator_arg_t, _AllocArgT>,
- __dependent_type<is_default_constructible<_Tp>, _Dummy>...
+ typename _CheckArgsConstructor<_Dummy>::template __enable_implicit_default<_Tp...>
>::value
- >
+ , void*> = nullptr
>
_LIBCPP_INLINE_VISIBILITY
tuple(_AllocArgT, _Alloc const& __a)
: __base_(allocator_arg_t(), __a,
__tuple_indices<>(), __tuple_types<>(),
+ typename __make_tuple_indices<sizeof...(_Tp), 0>::type(),
+ __tuple_types<_Tp...>()) {}
+
+ template <class _AllocArgT, class _Alloc, bool _Dummy = true, _EnableIf<
+ _And<
+ _IsSame<allocator_arg_t, _AllocArgT>,
+ typename _CheckArgsConstructor<_Dummy>::template __enable_explicit_default<_Tp...>
+ >::value
+ , void*> = nullptr
+ >
+ explicit _LIBCPP_INLINE_VISIBILITY
+ tuple(_AllocArgT, _Alloc const& __a)
+ : __base_(allocator_arg_t(), __a,
+ __tuple_indices<>(), __tuple_types<>(),
typename __make_tuple_indices<sizeof...(_Tp), 0>::type(),
__tuple_types<_Tp...>()) {}
Added: libcxx/trunk/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/alloc.fail.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/alloc.fail.cpp?rev=372778&view=auto
==============================================================================
--- libcxx/trunk/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/alloc.fail.cpp (added)
+++ libcxx/trunk/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/alloc.fail.cpp Tue Sep 24 13:22:34 2019
@@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03
+
+// <tuple>
+
+// template <class... Types> class tuple;
+
+// template <class Alloc>
+// explicit(see-below) tuple(allocator_arg_t, const Alloc& a);
+
+// Make sure we get the explicit-ness of the constructor right.
+// This is LWG 3158.
+
+#include <tuple>
+#include <memory>
+
+
+struct ExplicitDefault { explicit ExplicitDefault() { } };
+
+std::tuple<ExplicitDefault> explicit_default_test() {
+ return {std::allocator_arg, std::allocator<int>()}; // expected-error {{chosen constructor is explicit in copy-initialization}}
+}
+
+int main(int, char**) {
+ return 0;
+}
Modified: libcxx/trunk/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/alloc.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/alloc.pass.cpp?rev=372778&r1=372777&r2=372778&view=diff
==============================================================================
--- libcxx/trunk/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/alloc.pass.cpp (original)
+++ libcxx/trunk/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/alloc.pass.cpp Tue Sep 24 13:22:34 2019
@@ -13,7 +13,7 @@
// template <class... Types> class tuple;
// template <class Alloc>
-// tuple(allocator_arg_t, const Alloc& a);
+// explicit(see-below) tuple(allocator_arg_t, const Alloc& a);
// NOTE: this constructor does not currently support tags derived from
// allocator_arg_t because libc++ has to deduce the parameter as a template
Modified: libcxx/trunk/www/cxx2a_status.html
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/www/cxx2a_status.html?rev=372778&r1=372777&r2=372778&view=diff
==============================================================================
--- libcxx/trunk/www/cxx2a_status.html (original)
+++ libcxx/trunk/www/cxx2a_status.html Tue Sep 24 13:22:34 2019
@@ -358,7 +358,7 @@
<tr><td><a href="https://wg21.link/LWG3182">3182</a></td><td>Specification of <tt>Same</tt> could be clearer</td><td>Kona</td><td></td></tr>
<tr><td></td><td></td><td></td><td></td></tr>
- <tr><td><a href="https://wg21.link/LWG2899">2899</a></td><td><tt>is_(nothrow_)move_constructible</tt> and <tt>tuple</tt>, <tt>optional</tt> and <tt>unique_ptr</tt></td><td>Cologne</td><td></td></tr>
+ <tr><td><a href="https://wg21.link/LWG2899">2899</a></td><td><tt>is_(nothrow_)move_constructible</tt> and <tt>tuple</tt>, <tt>optional</tt> and <tt>unique_ptr</tt></td><td>Cologne</td><td>Complete</td></tr>
<tr><td><a href="https://wg21.link/LWG3055">3055</a></td><td><tt>path::operator+=(<i>single-character</i>)</tt> misspecified</td><td>Cologne</td><td></td></tr>
<tr><td><a href="https://wg21.link/LWG3158">3158</a></td><td><tt>tuple(allocator_arg_t, const Alloc&)</tt> should be conditionally explicit</td><td>Cologne</td><td></td></tr>
<tr><td><a href="https://wg21.link/LWG3169">3169</a></td><td><tt>ranges</tt> permutation generators discard useful information</td><td>Cologne</td><td></td></tr>
Modified: libcxx/trunk/www/upcoming_meeting.html
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/www/upcoming_meeting.html?rev=372778&r1=372777&r2=372778&view=diff
==============================================================================
--- libcxx/trunk/www/upcoming_meeting.html (original)
+++ libcxx/trunk/www/upcoming_meeting.html Tue Sep 24 13:22:34 2019
@@ -61,7 +61,7 @@
<tr><th>Issue #</th><th>Has P/R</th><th>Issue Name</th><th>Meeting</th><th>Status</th></tr>
<tr><td><a href="https://wg21.link/LWG2899">2899</a></td><td>Yes</td><td><tt>is_(nothrow_)move_constructible</tt> and <tt>tuple</tt>, <tt>optional</tt> and <tt>unique_ptr</tt></td><td>Cologne</td><td></td></tr>
<tr><td><a href="https://wg21.link/LWG3055">3055</a></td><td>Yes</td><td><tt>path::operator+=(<i>single-character</i>)</tt> misspecified</td><td>Cologne</td><td></td></tr>
-<tr><td><a href="https://wg21.link/LWG3158">3158</a></td><td>Yes</td><td><tt>tuple(allocator_arg_t, const Alloc&)</tt> should be conditionally explicit</td><td>Cologne</td><td></td></tr>
+<tr><td><a href="https://wg21.link/LWG3158">3158</a></td><td>Yes</td><td><tt>tuple(allocator_arg_t, const Alloc&)</tt> should be conditionally explicit</td><td>Cologne</td><td>Complete</td></tr>
<tr><td><a href="https://wg21.link/LWG3169">3169</a></td><td>Yes</td><td><tt>ranges</tt> permutation generators discard useful information</td><td>Cologne</td><td></td></tr>
<tr><td><a href="https://wg21.link/LWG3183">3183</a></td><td>Yes</td><td>Normative permission to specialize Ranges variable templates</td><td>Cologne</td><td></td></tr>
<tr><td><a href="https://wg21.link/LWG3184">3184</a></td><td>Yes</td><td>Inconsistencies in <tt>bind_front</tt> wording</td><td>Cologne</td><td></td></tr>
@@ -95,7 +95,6 @@
<ul>
<li>2899 - Louis</li>
<li>3055 - Eric?</li>
-<li>3158 - Louis</li>
<li>3169 - We don't do ranges yet</li>
<li>3183 - We don't do ranges yet</li>
<li>3184 - We don't do bind_front yet</li>
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