From: Jonathan Wakely <jwakely@redhat.com>
To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org
Subject: [committed] libstdc++: Remove unnecessary variant member in std::expected
Date: Wed, 2 Nov 2022 12:56:38 +0000 [thread overview]
Message-ID: <20221102125638.634917-1-jwakely@redhat.com> (raw)
Tested powerpc64le-linux. Pushed to trunk.
-- >8 --
Hui Xie pointed out that we don't need a dummy member in the union,
because all constructors always initialize either _M_val or _M_unex.
We still need the _M_void member of the expected<void, E>
specialization, because the constructor has to initialize something when
not using the _M_unex member.
libstdc++-v3/ChangeLog:
* include/std/expected (expected::_M_invalid): Remove.
---
libstdc++-v3/include/std/expected | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/libstdc++-v3/include/std/expected b/libstdc++-v3/include/std/expected
index 3ee13aa95f6..e491ce41591 100644
--- a/libstdc++-v3/include/std/expected
+++ b/libstdc++-v3/include/std/expected
@@ -359,7 +359,7 @@ namespace __expected
requires is_copy_constructible_v<_Tp> && is_copy_constructible_v<_Er>
&& (!is_trivially_copy_constructible_v<_Tp>
|| !is_trivially_copy_constructible_v<_Er>)
- : _M_invalid(), _M_has_value(__x._M_has_value)
+ : _M_has_value(__x._M_has_value)
{
if (_M_has_value)
std::construct_at(__builtin_addressof(_M_val), __x._M_val);
@@ -376,7 +376,7 @@ namespace __expected
requires is_move_constructible_v<_Tp> && is_move_constructible_v<_Er>
&& (!is_trivially_move_constructible_v<_Tp>
|| !is_trivially_move_constructible_v<_Er>)
- : _M_invalid(), _M_has_value(__x._M_has_value)
+ : _M_has_value(__x._M_has_value)
{
if (_M_has_value)
std::construct_at(__builtin_addressof(_M_val),
@@ -394,7 +394,7 @@ namespace __expected
expected(const expected<_Up, _Gr>& __x)
noexcept(__and_v<is_nothrow_constructible<_Tp, const _Up&>,
is_nothrow_constructible<_Er, const _Gr&>>)
- : _M_invalid(), _M_has_value(__x._M_has_value)
+ : _M_has_value(__x._M_has_value)
{
if (_M_has_value)
std::construct_at(__builtin_addressof(_M_val), __x._M_val);
@@ -410,7 +410,7 @@ namespace __expected
expected(expected<_Up, _Gr>&& __x)
noexcept(__and_v<is_nothrow_constructible<_Tp, _Up>,
is_nothrow_constructible<_Er, _Gr>>)
- : _M_invalid(), _M_has_value(__x._M_has_value)
+ : _M_has_value(__x._M_has_value)
{
if (_M_has_value)
std::construct_at(__builtin_addressof(_M_val),
@@ -890,7 +890,6 @@ namespace __expected
}
union {
- struct { } _M_invalid;
_Tp _M_val;
_Er _M_unex;
};
--
2.38.1
reply other threads:[~2022-11-02 12:56 UTC|newest]
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