* [committed 1/3] libstdc++: Add noexcept to std::optional initialization (PR 96036)
@ 2020-07-06 21:05 Jonathan Wakely
2020-07-06 21:06 ` [committed 2/3] libstdc++: Constrain std::make_optional Jonathan Wakely
0 siblings, 1 reply; 4+ messages in thread
From: Jonathan Wakely @ 2020-07-06 21:05 UTC (permalink / raw)
To: libstdc++, gcc-patches
[-- Attachment #1: Type: text/plain, Size: 363 bytes --]
libstdc++-v3/ChangeLog:
PR libstdc++/96036
* include/std/optional (optional): Add noexcept-specifier to
every constructor, assignment operator, emplace function and
dereference operator.
* testsuite/20_util/optional/assignment/noexcept.cc: New test.
* testsuite/20_util/optional/cons/noexcept.cc: New test.
Tested powerpc64le-linux, committed to trunk.
[-- Attachment #2: patch.txt --]
[-- Type: text/plain, Size: 11376 bytes --]
commit 8992cd1892df1adb352cf5d5b279a00686d1e88a
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Mon Jul 6 21:54:12 2020 +0100
libstdc++: Add noexcept to std::optional initialization (PR 96036)
libstdc++-v3/ChangeLog:
PR libstdc++/96036
* include/std/optional (optional): Add noexcept-specifier to
every constructor, assignment operator, emplace function and
dereference operator.
* testsuite/20_util/optional/assignment/noexcept.cc: New test.
* testsuite/20_util/optional/cons/noexcept.cc: New test.
diff --git a/libstdc++-v3/include/std/optional b/libstdc++-v3/include/std/optional
index 923d45ae0e8..785c434412d 100644
--- a/libstdc++-v3/include/std/optional
+++ b/libstdc++-v3/include/std/optional
@@ -698,6 +698,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
is_convertible<_Up&&, _Tp>> = true>
constexpr
optional(_Up&& __t)
+ noexcept(is_nothrow_constructible_v<_Tp, _Up>)
: _Base(std::in_place, std::forward<_Up>(__t)) { }
template<typename _Up = _Tp,
@@ -706,6 +707,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__not_<is_convertible<_Up&&, _Tp>>> = false>
explicit constexpr
optional(_Up&& __t)
+ noexcept(is_nothrow_constructible_v<_Tp, _Up>)
: _Base(std::in_place, std::forward<_Up>(__t)) { }
template<typename _Up,
@@ -715,6 +717,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__not_<__converts_from_optional<_Tp, _Up>>> = true>
constexpr
optional(const optional<_Up>& __t)
+ noexcept(is_nothrow_constructible_v<_Tp, const _Up&>)
{
if (__t)
emplace(*__t);
@@ -727,6 +730,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__not_<__converts_from_optional<_Tp, _Up>>> = false>
explicit constexpr
optional(const optional<_Up>& __t)
+ noexcept(is_nothrow_constructible_v<_Tp, const _Up&>)
{
if (__t)
emplace(*__t);
@@ -739,6 +743,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__not_<__converts_from_optional<_Tp, _Up>>> = true>
constexpr
optional(optional<_Up>&& __t)
+ noexcept(is_nothrow_constructible_v<_Tp, _Up>)
{
if (__t)
emplace(std::move(*__t));
@@ -751,6 +756,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__not_<__converts_from_optional<_Tp, _Up>>> = false>
explicit constexpr
optional(optional<_Up>&& __t)
+ noexcept(is_nothrow_constructible_v<_Tp, _Up>)
{
if (__t)
emplace(std::move(*__t));
@@ -760,6 +766,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Requires<is_constructible<_Tp, _Args&&...>> = false>
explicit constexpr
optional(in_place_t, _Args&&... __args)
+ noexcept(is_nothrow_constructible_v<_Tp, _Args...>)
: _Base(std::in_place, std::forward<_Args>(__args)...) { }
template<typename _Up, typename... _Args,
@@ -768,8 +775,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Args&&...>> = false>
explicit constexpr
optional(in_place_t, initializer_list<_Up> __il, _Args&&... __args)
+ noexcept(is_nothrow_constructible_v<_Tp, initializer_list<_Up>&,
+ _Args...>)
: _Base(std::in_place, __il, std::forward<_Args>(__args)...) { }
+
// Assignment operators.
optional&
operator=(nullopt_t) noexcept
@@ -786,6 +796,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
is_assignable<_Tp&, _Up>>,
optional&>
operator=(_Up&& __u)
+ noexcept(__and_v<is_nothrow_constructible<_Tp, _Up>,
+ is_nothrow_assignable<_Tp&, _Up>>)
{
if (this->_M_is_engaged())
this->_M_get() = std::forward<_Up>(__u);
@@ -803,6 +815,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__not_<__assigns_from_optional<_Tp, _Up>>>,
optional&>
operator=(const optional<_Up>& __u)
+ noexcept(__and_v<is_nothrow_constructible<_Tp, const _Up&>,
+ is_nothrow_assignable<_Tp&, const _Up&>>)
{
if (__u)
{
@@ -826,6 +840,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__not_<__assigns_from_optional<_Tp, _Up>>>,
optional&>
operator=(optional<_Up>&& __u)
+ noexcept(__and_v<is_nothrow_constructible<_Tp, _Up>,
+ is_nothrow_assignable<_Tp&, _Up>>)
{
if (__u)
{
@@ -845,6 +861,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename... _Args>
enable_if_t<is_constructible_v<_Tp, _Args&&...>, _Tp&>
emplace(_Args&&... __args)
+ noexcept(is_nothrow_constructible_v<_Tp, _Args...>)
{
this->_M_reset();
this->_M_construct(std::forward<_Args>(__args)...);
@@ -855,6 +872,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&,
_Args&&...>, _Tp&>
emplace(initializer_list<_Up> __il, _Args&&... __args)
+ noexcept(is_nothrow_constructible_v<_Tp, initializer_list<_Up>&,
+ _Args...>)
{
this->_M_reset();
this->_M_construct(__il, std::forward<_Args>(__args)...);
@@ -887,27 +906,27 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Observers.
constexpr const _Tp*
- operator->() const
+ operator->() const noexcept
{ return std::__addressof(this->_M_get()); }
constexpr _Tp*
- operator->()
+ operator->() noexcept
{ return std::__addressof(this->_M_get()); }
constexpr const _Tp&
- operator*() const&
+ operator*() const& noexcept
{ return this->_M_get(); }
constexpr _Tp&
- operator*()&
+ operator*()& noexcept
{ return this->_M_get(); }
constexpr _Tp&&
- operator*()&&
+ operator*()&& noexcept
{ return std::move(this->_M_get()); }
constexpr const _Tp&&
- operator*() const&&
+ operator*() const&& noexcept
{ return std::move(this->_M_get()); }
constexpr explicit operator bool() const noexcept
diff --git a/libstdc++-v3/testsuite/20_util/optional/assignment/noexcept.cc b/libstdc++-v3/testsuite/20_util/optional/assignment/noexcept.cc
new file mode 100644
index 00000000000..45592b2a18c
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/optional/assignment/noexcept.cc
@@ -0,0 +1,81 @@
+// 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-do compile { target c++17 } }
+
+#include <optional>
+
+template<bool B>
+struct X
+{
+ X() noexcept(B);
+
+ X(const X&) noexcept(B);
+ X& operator=(const X&) noexcept(B);
+
+ X(int) noexcept(B);
+ X& operator=(int) noexcept(false);
+
+ X(void*) noexcept(true);
+ X& operator=(void*) noexcept(B);
+
+ X(const X<!B>&) noexcept(B);
+ X& operator=(const X<!B>&) noexcept(B);
+
+ X(std::initializer_list<int>, int) noexcept(B);
+};
+
+using std::is_nothrow_assignable_v;
+
+using Xyes = X<true>;
+using Xno = X<false>;
+using Oyes = std::optional<Xyes>;
+using Ono = std::optional<Xno>;
+
+static_assert( is_nothrow_assignable_v<Oyes, std::nullopt_t> );
+static_assert( is_nothrow_assignable_v<Oyes, const Xyes&> );
+static_assert( is_nothrow_assignable_v<Oyes, Xyes> );
+static_assert( ! is_nothrow_assignable_v<Oyes, int> );
+static_assert( is_nothrow_assignable_v<Oyes, void*> );
+static_assert( is_nothrow_assignable_v<Oyes, const Ono&> );
+static_assert( is_nothrow_assignable_v<Oyes, Ono> );
+
+static_assert( is_nothrow_assignable_v<Ono, std::nullopt_t> );
+static_assert( ! is_nothrow_assignable_v<Ono, const Xno&> );
+static_assert( ! is_nothrow_assignable_v<Ono, Xno> );
+static_assert( ! is_nothrow_assignable_v<Ono, int> );
+static_assert( ! is_nothrow_assignable_v<Ono, void*> );
+static_assert( ! is_nothrow_assignable_v<Ono, const Xyes&> );
+static_assert( ! is_nothrow_assignable_v<Ono, Xyes> );
+
+Xyes xyes;
+Xno xno;
+Oyes oyes;
+Ono ono;
+static_assert( noexcept(oyes.emplace()) );
+static_assert( noexcept(oyes.emplace(xyes)) );
+static_assert( noexcept(oyes.emplace(1)) );
+static_assert( noexcept(oyes.emplace(nullptr)) );
+static_assert( noexcept(oyes.emplace(xno)) );
+static_assert( noexcept(oyes.emplace({1,2,3}, 1)) );
+
+static_assert( ! noexcept(ono.emplace()) );
+static_assert( ! noexcept(ono.emplace(xno)) );
+static_assert( ! noexcept(ono.emplace(1)) );
+static_assert( noexcept(ono.emplace(nullptr)) );
+static_assert( ! noexcept(ono.emplace(xyes)) );
+static_assert( ! noexcept(ono.emplace({1,2,3}, 1)) );
diff --git a/libstdc++-v3/testsuite/20_util/optional/cons/noexcept.cc b/libstdc++-v3/testsuite/20_util/optional/cons/noexcept.cc
new file mode 100644
index 00000000000..a529f5d39ad
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/optional/cons/noexcept.cc
@@ -0,0 +1,64 @@
+// 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-do compile { target c++17 } }
+
+#include <optional>
+
+template<bool B>
+struct X
+{
+ X() noexcept(B);
+ X(const X&) noexcept(B);
+
+ X(int) noexcept(B);
+ X(std::initializer_list<int>, int) noexcept(B);
+
+ X(const X<!B>&) noexcept(B);
+
+ X& operator=(const X&) noexcept(false);
+};
+
+using std::is_nothrow_constructible_v;
+using std::in_place_t;
+
+using Xyes = X<true>;
+using Xno = X<false>;
+using Oyes = std::optional<Xyes>;
+using Ono = std::optional<Xno>;
+
+static_assert( is_nothrow_constructible_v<Oyes> );
+static_assert( is_nothrow_constructible_v<Oyes, std::nullopt_t> );
+static_assert( is_nothrow_constructible_v<Oyes, const Xyes&> );
+static_assert( is_nothrow_constructible_v<Oyes, Xyes> );
+static_assert( is_nothrow_constructible_v<Oyes, in_place_t, short> );
+static_assert( is_nothrow_constructible_v<Oyes, in_place_t,
+ std::initializer_list<int>,
+ long> );
+static_assert( is_nothrow_constructible_v<Oyes, const Ono&> );
+static_assert( is_nothrow_constructible_v<Oyes, Ono> );
+
+static_assert( is_nothrow_constructible_v<Ono> );
+static_assert( is_nothrow_constructible_v<Ono, std::nullopt_t> );
+static_assert( ! is_nothrow_constructible_v<Ono, const Xno&> );
+static_assert( ! is_nothrow_constructible_v<Ono, Xno> );
+static_assert( ! is_nothrow_constructible_v<Ono, in_place_t, short> );
+static_assert( ! is_nothrow_constructible_v<Ono, in_place_t,
+ std::initializer_list<int>,
+ long> );
+static_assert( ! is_nothrow_constructible_v<Ono, const Xyes&> );
+static_assert( ! is_nothrow_constructible_v<Ono, Xyes> );
^ permalink raw reply [flat|nested] 4+ messages in thread
* [committed 2/3] libstdc++: Constrain std::make_optional
2020-07-06 21:05 [committed 1/3] libstdc++: Add noexcept to std::optional initialization (PR 96036) Jonathan Wakely
@ 2020-07-06 21:06 ` Jonathan Wakely
2020-07-06 21:07 ` [committed 3/3] libstdc++: Cleanup whitespace and type trait usage in <optional> Jonathan Wakely
2020-07-06 21:08 ` [committed 2/3] libstdc++: Constrain std::make_optional Jonathan Wakely
0 siblings, 2 replies; 4+ messages in thread
From: Jonathan Wakely @ 2020-07-06 21:06 UTC (permalink / raw)
To: libstdc++, gcc-patches
The standard rquires that std::make_optional is constrained similarly to
the std::optional constructors, which our implementation fails to do.
As a conforming extension this also adds a noexcept-specifier to each
std::make_optional overload.
libstdc++-v3/ChangeLog:
* include/std/optional (make_optional): Add enable_if
constraints and noexcept-specifier to each overload.
* testsuite/20_util/optional/make_optional-2.cc: New test.
Tested powerpc64le-linux, committed to trunk.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [committed 3/3] libstdc++: Cleanup whitespace and type trait usage in <optional>
2020-07-06 21:06 ` [committed 2/3] libstdc++: Constrain std::make_optional Jonathan Wakely
@ 2020-07-06 21:07 ` Jonathan Wakely
2020-07-06 21:08 ` [committed 2/3] libstdc++: Constrain std::make_optional Jonathan Wakely
1 sibling, 0 replies; 4+ messages in thread
From: Jonathan Wakely @ 2020-07-06 21:07 UTC (permalink / raw)
To: libstdc++, gcc-patches
[-- Attachment #1: Type: text/plain, Size: 486 bytes --]
This makes the formatting in <optional> consistent and also removes
redundant && tokens from template arguments for traits like
is_constructible and is_convertible.
libstdc++-v3/ChangeLog:
* include/std/optional (_Optional_payload_base, _Optional_base)
(optional, __optional_hash_call_base): Adjust whitespace and
other formatting. Remove redundant && tokens on template
arguments to type traits.
Tested powerpc64le-linux, committed to trunk.
[-- Attachment #2: patch.txt --]
[-- Type: text/x-patch, Size: 15368 bytes --]
commit 6e1c9715b3142bc09e313c0d4b196694ab7ae153
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Mon Jul 6 21:54:12 2020 +0100
libstdc++: Cleanup whitespace and type trait usage in <optional>
This makes the formatting in <optional> consistent and also removes
redundant && tokens from template arguments for traits like
is_constructible and is_convertible.
libstdc++-v3/ChangeLog:
* include/std/optional (_Optional_payload_base, _Optional_base)
(optional, __optional_hash_call_base): Adjust whitespace and
other formatting. Remove redundant && tokens on template
arguments to type traits.
diff --git a/libstdc++-v3/include/std/optional b/libstdc++-v3/include/std/optional
index 24821f81d0f..f9f42efe09c 100644
--- a/libstdc++-v3/include/std/optional
+++ b/libstdc++-v3/include/std/optional
@@ -163,9 +163,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
constexpr void
_M_copy_assign(const _Optional_payload_base& __other)
{
- if (this->_M_engaged && __other._M_engaged)
- this->_M_get() = __other._M_get();
- else
+ if (this->_M_engaged && __other._M_engaged)
+ this->_M_get() = __other._M_get();
+ else
{
if (__other._M_engaged)
this->_M_construct(__other._M_get());
@@ -211,7 +211,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{ }
_Empty_byte _M_empty;
- _Up _M_value;
+ _Up _M_value;
};
template<typename _Up>
@@ -235,7 +235,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
~_Storage() { }
_Empty_byte _M_empty;
- _Up _M_value;
+ _Up _M_value;
};
_Storage<_Stored_type> _M_payload;
@@ -243,14 +243,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
bool _M_engaged = false;
template<typename... _Args>
- void
- _M_construct(_Args&&... __args)
- noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
- {
- ::new ((void *) std::__addressof(this->_M_payload))
- _Stored_type(std::forward<_Args>(__args)...);
- this->_M_engaged = true;
- }
+ void
+ _M_construct(_Args&&... __args)
+ noexcept(is_nothrow_constructible_v<_Stored_type, _Args...>)
+ {
+ ::new ((void *) std::__addressof(this->_M_payload))
+ _Stored_type(std::forward<_Args>(__args)...);
+ this->_M_engaged = true;
+ }
constexpr void
_M_destroy() noexcept
@@ -471,39 +471,41 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
bool = is_trivially_copy_constructible_v<_Tp>,
bool = is_trivially_move_constructible_v<_Tp>>
struct _Optional_base
- : _Optional_base_impl<_Tp, _Optional_base<_Tp>>
+ : _Optional_base_impl<_Tp, _Optional_base<_Tp>>
{
// Constructors for disengaged optionals.
constexpr _Optional_base() = default;
// Constructors for engaged optionals.
template<typename... _Args,
- enable_if_t<is_constructible_v<_Tp, _Args&&...>, bool> = false>
- constexpr explicit _Optional_base(in_place_t, _Args&&... __args)
- : _M_payload(in_place,
- std::forward<_Args>(__args)...) { }
+ enable_if_t<is_constructible_v<_Tp, _Args...>, bool> = false>
+ constexpr explicit
+ _Optional_base(in_place_t, _Args&&... __args)
+ : _M_payload(in_place, std::forward<_Args>(__args)...)
+ { }
template<typename _Up, typename... _Args,
- enable_if_t<is_constructible_v<_Tp,
+ enable_if_t<is_constructible_v<_Tp,
initializer_list<_Up>&,
- _Args&&...>, bool> = false>
- constexpr explicit _Optional_base(in_place_t,
- initializer_list<_Up> __il,
- _Args&&... __args)
- : _M_payload(in_place,
- __il, std::forward<_Args>(__args)...)
- { }
+ _Args...>, bool> = false>
+ constexpr explicit
+ _Optional_base(in_place_t,
+ initializer_list<_Up> __il,
+ _Args&&... __args)
+ : _M_payload(in_place, __il, std::forward<_Args>(__args)...)
+ { }
// Copy and move constructors.
- constexpr _Optional_base(const _Optional_base& __other)
- : _M_payload(__other._M_payload._M_engaged,
- __other._M_payload)
+ constexpr
+ _Optional_base(const _Optional_base& __other)
+ : _M_payload(__other._M_payload._M_engaged, __other._M_payload)
{ }
- constexpr _Optional_base(_Optional_base&& __other)
+ constexpr
+ _Optional_base(_Optional_base&& __other)
noexcept(is_nothrow_move_constructible_v<_Tp>)
- : _M_payload(__other._M_payload._M_engaged,
- std::move(__other._M_payload))
+ : _M_payload(__other._M_payload._M_engaged,
+ std::move(__other._M_payload))
{ }
// Assignment operators.
@@ -515,33 +517,33 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp>
struct _Optional_base<_Tp, false, true>
- : _Optional_base_impl<_Tp, _Optional_base<_Tp>>
+ : _Optional_base_impl<_Tp, _Optional_base<_Tp>>
{
// Constructors for disengaged optionals.
constexpr _Optional_base() = default;
// Constructors for engaged optionals.
template<typename... _Args,
- enable_if_t<is_constructible_v<_Tp, _Args&&...>, bool> = false>
- constexpr explicit _Optional_base(in_place_t, _Args&&... __args)
- : _M_payload(in_place,
- std::forward<_Args>(__args)...) { }
+ enable_if_t<is_constructible_v<_Tp, _Args...>, bool> = false>
+ constexpr explicit
+ _Optional_base(in_place_t, _Args&&... __args)
+ : _M_payload(in_place, std::forward<_Args>(__args)...)
+ { }
template<typename _Up, typename... _Args,
- enable_if_t<is_constructible_v<_Tp,
+ enable_if_t<is_constructible_v<_Tp,
initializer_list<_Up>&,
- _Args&&...>, bool> = false>
- constexpr explicit _Optional_base(in_place_t,
- initializer_list<_Up> __il,
- _Args&&... __args)
- : _M_payload(in_place,
- __il, std::forward<_Args>(__args)...)
- { }
+ _Args...>, bool> = false>
+ constexpr explicit
+ _Optional_base(in_place_t,
+ initializer_list<_Up> __il,
+ _Args... __args)
+ : _M_payload(in_place, __il, std::forward<_Args>(__args)...)
+ { }
// Copy and move constructors.
constexpr _Optional_base(const _Optional_base& __other)
- : _M_payload(__other._M_payload._M_engaged,
- __other._M_payload)
+ : _M_payload(__other._M_payload._M_engaged, __other._M_payload)
{ }
constexpr _Optional_base(_Optional_base&& __other) = default;
@@ -555,36 +557,38 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp>
struct _Optional_base<_Tp, true, false>
- : _Optional_base_impl<_Tp, _Optional_base<_Tp>>
+ : _Optional_base_impl<_Tp, _Optional_base<_Tp>>
{
// Constructors for disengaged optionals.
constexpr _Optional_base() = default;
// Constructors for engaged optionals.
template<typename... _Args,
- enable_if_t<is_constructible_v<_Tp, _Args&&...>, bool> = false>
- constexpr explicit _Optional_base(in_place_t, _Args&&... __args)
- : _M_payload(in_place,
- std::forward<_Args>(__args)...) { }
+ enable_if_t<is_constructible_v<_Tp, _Args...>, bool> = false>
+ constexpr explicit
+ _Optional_base(in_place_t, _Args&&... __args)
+ : _M_payload(in_place, std::forward<_Args>(__args)...)
+ { }
template<typename _Up, typename... _Args,
- enable_if_t<is_constructible_v<_Tp,
+ enable_if_t<is_constructible_v<_Tp,
initializer_list<_Up>&,
- _Args&&...>, bool> = false>
- constexpr explicit _Optional_base(in_place_t,
- initializer_list<_Up> __il,
- _Args&&... __args)
- : _M_payload(in_place,
- __il, std::forward<_Args>(__args)...)
- { }
+ _Args...>, bool> = false>
+ constexpr explicit
+ _Optional_base(in_place_t,
+ initializer_list<_Up> __il,
+ _Args&&... __args)
+ : _M_payload(in_place, __il, std::forward<_Args>(__args)...)
+ { }
// Copy and move constructors.
constexpr _Optional_base(const _Optional_base& __other) = default;
- constexpr _Optional_base(_Optional_base&& __other)
+ constexpr
+ _Optional_base(_Optional_base&& __other)
noexcept(is_nothrow_move_constructible_v<_Tp>)
- : _M_payload(__other._M_payload._M_engaged,
- std::move(__other._M_payload))
+ : _M_payload(__other._M_payload._M_engaged,
+ std::move(__other._M_payload))
{ }
// Assignment operators.
@@ -596,28 +600,29 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp>
struct _Optional_base<_Tp, true, true>
- : _Optional_base_impl<_Tp, _Optional_base<_Tp>>
+ : _Optional_base_impl<_Tp, _Optional_base<_Tp>>
{
// Constructors for disengaged optionals.
constexpr _Optional_base() = default;
// Constructors for engaged optionals.
template<typename... _Args,
- enable_if_t<is_constructible_v<_Tp, _Args&&...>, bool> = false>
- constexpr explicit _Optional_base(in_place_t, _Args&&... __args)
- : _M_payload(in_place,
- std::forward<_Args>(__args)...) { }
+ enable_if_t<is_constructible_v<_Tp, _Args...>, bool> = false>
+ constexpr explicit
+ _Optional_base(in_place_t, _Args&&... __args)
+ : _M_payload(in_place, std::forward<_Args>(__args)...)
+ { }
template<typename _Up, typename... _Args,
- enable_if_t<is_constructible_v<_Tp,
+ enable_if_t<is_constructible_v<_Tp,
initializer_list<_Up>&,
- _Args&&...>, bool> = false>
- constexpr explicit _Optional_base(in_place_t,
- initializer_list<_Up> __il,
- _Args&&... __args)
- : _M_payload(in_place,
- __il, std::forward<_Args>(__args)...)
- { }
+ _Args...>, bool> = false>
+ constexpr explicit
+ _Optional_base(in_place_t,
+ initializer_list<_Up> __il,
+ _Args&&... __args)
+ : _M_payload(in_place, __il, std::forward<_Args>(__args)...)
+ { }
// Copy and move constructors.
constexpr _Optional_base(const _Optional_base& __other) = default;
@@ -694,8 +699,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Converting constructors for engaged optionals.
template<typename _Up = _Tp,
_Requires<__not_self<_Up>, __not_tag<_Up>,
- is_constructible<_Tp, _Up&&>,
- is_convertible<_Up&&, _Tp>> = true>
+ is_constructible<_Tp, _Up>,
+ is_convertible<_Up, _Tp>> = true>
constexpr
optional(_Up&& __t)
noexcept(is_nothrow_constructible_v<_Tp, _Up>)
@@ -703,12 +708,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Up = _Tp,
_Requires<__not_self<_Up>, __not_tag<_Up>,
- is_constructible<_Tp, _Up&&>,
- __not_<is_convertible<_Up&&, _Tp>>> = false>
+ is_constructible<_Tp, _Up>,
+ __not_<is_convertible<_Up, _Tp>>> = false>
explicit constexpr
optional(_Up&& __t)
noexcept(is_nothrow_constructible_v<_Tp, _Up>)
- : _Base(std::in_place, std::forward<_Up>(__t)) { }
+ : _Base(std::in_place, std::forward<_Up>(__t)) { }
template<typename _Up,
_Requires<__not_<is_same<_Tp, _Up>>,
@@ -736,11 +741,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
emplace(*__t);
}
- template <typename _Up,
- _Requires<__not_<is_same<_Tp, _Up>>,
- is_constructible<_Tp, _Up&&>,
- is_convertible<_Up&&, _Tp>,
- __not_<__converts_from_optional<_Tp, _Up>>> = true>
+ template<typename _Up,
+ _Requires<__not_<is_same<_Tp, _Up>>,
+ is_constructible<_Tp, _Up>,
+ is_convertible<_Up, _Tp>,
+ __not_<__converts_from_optional<_Tp, _Up>>> = true>
constexpr
optional(optional<_Up>&& __t)
noexcept(is_nothrow_constructible_v<_Tp, _Up>)
@@ -749,11 +754,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
emplace(std::move(*__t));
}
- template <typename _Up,
- _Requires<__not_<is_same<_Tp, _Up>>,
- is_constructible<_Tp, _Up&&>,
- __not_<is_convertible<_Up&&, _Tp>>,
- __not_<__converts_from_optional<_Tp, _Up>>> = false>
+ template<typename _Up,
+ _Requires<__not_<is_same<_Tp, _Up>>,
+ is_constructible<_Tp, _Up>,
+ __not_<is_convertible<_Up, _Tp>>,
+ __not_<__converts_from_optional<_Tp, _Up>>> = false>
explicit constexpr
optional(optional<_Up>&& __t)
noexcept(is_nothrow_constructible_v<_Tp, _Up>)
@@ -763,7 +768,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename... _Args,
- _Requires<is_constructible<_Tp, _Args&&...>> = false>
+ _Requires<is_constructible<_Tp, _Args...>> = false>
explicit constexpr
optional(in_place_t, _Args&&... __args)
noexcept(is_nothrow_constructible_v<_Tp, _Args...>)
@@ -772,7 +777,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Up, typename... _Args,
_Requires<is_constructible<_Tp,
initializer_list<_Up>&,
- _Args&&...>> = false>
+ _Args...>> = false>
explicit constexpr
optional(in_place_t, initializer_list<_Up> __il, _Args&&... __args)
noexcept(is_nothrow_constructible_v<_Tp, initializer_list<_Up>&,
@@ -833,7 +838,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename _Up>
- enable_if_t<__and_v<__not_<is_same<_Tp, _Up>>,
+ enable_if_t<__and_v<__not_<is_same<_Tp, _Up>>,
is_constructible<_Tp, _Up>,
is_assignable<_Tp&, _Up>,
__not_<__converts_from_optional<_Tp, _Up>>,
@@ -859,7 +864,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename... _Args>
- enable_if_t<is_constructible_v<_Tp, _Args&&...>, _Tp&>
+ enable_if_t<is_constructible_v<_Tp, _Args...>, _Tp&>
emplace(_Args&&... __args)
noexcept(is_nothrow_constructible_v<_Tp, _Args...>)
{
@@ -869,8 +874,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
template<typename _Up, typename... _Args>
- enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&,
- _Args&&...>, _Tp&>
+ enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>,
+ _Tp&>
emplace(initializer_list<_Up> __il, _Args&&... __args)
noexcept(is_nothrow_constructible_v<_Tp, initializer_list<_Up>&,
_Args...>)
@@ -1246,17 +1251,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Hash.
template<typename _Tp, typename _Up = remove_const_t<_Tp>,
- bool = __poison_hash<_Up>::__enable_hash_call>
+ bool = __poison_hash<_Up>::__enable_hash_call>
struct __optional_hash_call_base
{
size_t
operator()(const optional<_Tp>& __t) const
noexcept(noexcept(hash<_Up>{}(*__t)))
{
- // We pick an arbitrary hash for disengaged optionals which hopefully
- // usual values of _Tp won't typically hash to.
- constexpr size_t __magic_disengaged_hash = static_cast<size_t>(-3333);
- return __t ? hash<_Up>{}(*__t) : __magic_disengaged_hash;
+ // We pick an arbitrary hash for disengaged optionals which hopefully
+ // usual values of _Tp won't typically hash to.
+ constexpr size_t __magic_disengaged_hash = static_cast<size_t>(-3333);
+ return __t ? hash<_Up>{}(*__t) : __magic_disengaged_hash;
}
};
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [committed 2/3] libstdc++: Constrain std::make_optional
2020-07-06 21:06 ` [committed 2/3] libstdc++: Constrain std::make_optional Jonathan Wakely
2020-07-06 21:07 ` [committed 3/3] libstdc++: Cleanup whitespace and type trait usage in <optional> Jonathan Wakely
@ 2020-07-06 21:08 ` Jonathan Wakely
1 sibling, 0 replies; 4+ messages in thread
From: Jonathan Wakely @ 2020-07-06 21:08 UTC (permalink / raw)
To: libstdc++, gcc-patches
[-- Attachment #1: Type: text/plain, Size: 614 bytes --]
On 06/07/20 22:06 +0100, Jonathan Wakely wrote:
>The standard rquires that std::make_optional is constrained similarly to
>the std::optional constructors, which our implementation fails to do.
>
>As a conforming extension this also adds a noexcept-specifier to each
>std::make_optional overload.
>
>libstdc++-v3/ChangeLog:
>
> * include/std/optional (make_optional): Add enable_if
> constraints and noexcept-specifier to each overload.
> * testsuite/20_util/optional/make_optional-2.cc: New test.
>
>
>Tested powerpc64le-linux, committed to trunk.
And with the patch attached this time ...
[-- Attachment #2: patch.txt --]
[-- Type: text/x-patch, Size: 6020 bytes --]
commit bcfe4681f9be68f96f0610f30356510ff518806b
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Mon Jul 6 21:54:12 2020 +0100
libstdc++: Constrain std::make_optional
The standard rquires that std::make_optional is constrained similarly to
the std::optional constructors, which our implementation fails to do.
As a conforming extension this also adds a noexcept-specifier to each
std::make_optional overload.
libstdc++-v3/ChangeLog:
* include/std/optional (make_optional): Add enable_if
constraints and noexcept-specifier to each overload.
* testsuite/20_util/optional/make_optional-2.cc: New test.
diff --git a/libstdc++-v3/include/std/optional b/libstdc++-v3/include/std/optional
index 785c434412d..24821f81d0f 100644
--- a/libstdc++-v3/include/std/optional
+++ b/libstdc++-v3/include/std/optional
@@ -1220,19 +1220,28 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
swap(optional<_Tp>&, optional<_Tp>&) = delete;
template<typename _Tp>
- constexpr optional<decay_t<_Tp>>
+ constexpr
+ enable_if_t<is_constructible_v<decay_t<_Tp>, _Tp>,
+ optional<decay_t<_Tp>>>
make_optional(_Tp&& __t)
- { return optional<decay_t<_Tp>> { std::forward<_Tp>(__t) }; }
+ noexcept(is_nothrow_constructible_v<optional<decay_t<_Tp>>, _Tp>)
+ { return optional<decay_t<_Tp>>{ std::forward<_Tp>(__t) }; }
- template<typename _Tp, typename ..._Args>
- constexpr optional<_Tp>
+ template<typename _Tp, typename... _Args>
+ constexpr
+ enable_if_t<is_constructible_v<_Tp, _Args...>,
+ optional<_Tp>>
make_optional(_Args&&... __args)
- { return optional<_Tp> { in_place, std::forward<_Args>(__args)... }; }
+ noexcept(is_nothrow_constructible_v<_Tp, _Args...>)
+ { return optional<_Tp>{ in_place, std::forward<_Args>(__args)... }; }
- template<typename _Tp, typename _Up, typename ..._Args>
- constexpr optional<_Tp>
+ template<typename _Tp, typename _Up, typename... _Args>
+ constexpr
+ enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>,
+ optional<_Tp>>
make_optional(initializer_list<_Up> __il, _Args&&... __args)
- { return optional<_Tp> { in_place, __il, std::forward<_Args>(__args)... }; }
+ noexcept(is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, _Args...>)
+ { return optional<_Tp>{ in_place, __il, std::forward<_Args>(__args)... }; }
// Hash.
diff --git a/libstdc++-v3/testsuite/20_util/optional/make_optional-2.cc b/libstdc++-v3/testsuite/20_util/optional/make_optional-2.cc
new file mode 100644
index 00000000000..65a1fc78d80
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/optional/make_optional-2.cc
@@ -0,0 +1,94 @@
+// { dg-do compile { target c++17 } }
+
+// 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/>.
+
+#include <optional>
+
+int i;
+
+struct Cont
+{
+ Cont() noexcept;
+ Cont(Cont&&) noexcept;
+ Cont(const Cont&);
+ Cont(int);
+ Cont(std::initializer_list<int>, int) noexcept;
+ Cont(std::initializer_list<int>, const char*);
+};
+const Cont c{};
+
+template<typename T, typename = void>
+ struct can_make_optional1
+ : std::false_type
+ { };
+
+template<typename T>
+ struct can_make_optional1<T,
+ std::void_t<decltype(std::make_optional(std::declval<T>()))>>
+ : std::true_type
+ { };
+
+static_assert( can_make_optional1<int>::value );
+static_assert( noexcept(std::make_optional(1)) );
+static_assert( can_make_optional1<int&>::value );
+static_assert( noexcept(std::make_optional(i)) );
+static_assert( ! can_make_optional1<void>::value );
+static_assert( can_make_optional1<Cont>::value );
+static_assert( noexcept(std::make_optional(Cont{})) );
+static_assert( can_make_optional1<Cont>::value );
+static_assert( ! noexcept(std::make_optional(c)) );
+
+template<typename T, typename Arg, typename = void>
+ struct can_make_optional2
+ : std::false_type
+ { };
+
+template<typename T, typename Arg>
+ struct can_make_optional2<T, Arg,
+ std::void_t<decltype(std::make_optional<T>(std::declval<Arg>()))>>
+ : std::true_type
+ { };
+
+static_assert( can_make_optional2<int, int>::value );
+static_assert( noexcept(std::make_optional<int>(1)) );
+static_assert( can_make_optional2<int, int&>::value );
+static_assert( noexcept(std::make_optional(i)) );
+static_assert( ! can_make_optional2<void, void>::value );
+static_assert( can_make_optional2<Cont, Cont>::value );
+static_assert( noexcept(std::make_optional<Cont>({})) );
+static_assert( can_make_optional2<Cont, const Cont&>::value );
+static_assert( ! noexcept(std::make_optional(c)) );
+static_assert( can_make_optional2<Cont, int>::value );
+static_assert( ! noexcept(std::make_optional<Cont>(1)) );
+
+template<typename T, typename Arg, typename = void>
+ struct can_make_optional3
+ : std::false_type
+ { };
+
+template<typename T, typename Arg>
+ struct can_make_optional3<T, Arg,
+ std::void_t<decltype(std::make_optional<T>({1,2}, std::declval<Arg>()))>>
+ : std::true_type
+ { };
+
+static_assert( can_make_optional3<Cont, int>::value );
+static_assert( noexcept(std::make_optional<Cont>({1,2}, 1)) );
+static_assert( can_make_optional3<Cont, char*>::value );
+static_assert( ! noexcept(std::make_optional<Cont>({1,2}, "")) );
+static_assert( !can_make_optional3<Cont, int*>::value );
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-07-06 21:08 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-07-06 21:05 [committed 1/3] libstdc++: Add noexcept to std::optional initialization (PR 96036) Jonathan Wakely
2020-07-06 21:06 ` [committed 2/3] libstdc++: Constrain std::make_optional Jonathan Wakely
2020-07-06 21:07 ` [committed 3/3] libstdc++: Cleanup whitespace and type trait usage in <optional> Jonathan Wakely
2020-07-06 21:08 ` [committed 2/3] libstdc++: Constrain std::make_optional Jonathan Wakely
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